Valleylab Force EZ - C Series Service Manual

Service Manual

Valleylab Force EZ™-C Series
Electrosurgical Generator

with Instant Response™ Technology

Preface

This manual and the equipment it describes are for use only by qualified medical
professionals trained in the particular technique and surgical procedure to be
performed. It is intended as a guide for servicing the Valleylab Force EZ™-C
Series Electrosurgical Generator only.

Caution

Federal (USA) law restricts this device to sale by or on the order of a physician.

Equipment covered in this manual:

Force EZ™-C Series Electrosurgical Generator with Instant Response™ T echnology
100–120 V ~ (110 V ~ nominal), 220–240 V ~ (230 V ~ nominal) –

(user selectable)
The Service Manual, For ce EZ™-C Series Electr osurgical Generator with Instant

Response™ Technology, consists of two parts—the text (part 1 of 2) and a
Schematics Supplement (part 2 of 2), which contains the schematics.

Valleylab Part Number: 1015435 (part 1 of 2)
Effective Date: November 2008
Trademark acknowledgements:

Force FX™. Force EZ™, Force Argon™, Force GSU™, SurgiStat™, REM™,
EDGE™, AccuVac™, PolyHesive™, and Instant Response™ are trademarks of
Valleylab.

Patent Information:

Protected by U.S. Pat. Nos. 5,599,344; and 5,628,745.

Manufactured by

Valleylab
a division of Tyco Healthcare Group LP
Boulder, Colorado 80301-3299 USA

European Representative:

Tyco Healthcare UK Ltd.
Gosport, PO13 0AS, UK

For information call:

1-303-530-2300

Made in USA
Printed in USA
©2008 Valleylab All rights reserved.

ii Force EZ-C Series Service Manual

Conventions Used in this Guide

Warning

Indicates a potentially hazardous situation which, if not avoided, could result in
death or serious injury.

Caution

Indicates a hazardous situation which, if not avoided, may result in minor or
moderate injury.

Important

Indicates an operating tip or
maintenance suggestion.

Notice

Indicates a hazard which may result in product damage.

Force EZ-C Series Service Manual iii

Warranty

Valleylab, a division of Tyco Healthcare Group LP, warrants each product
manufactured by it to be free from defects in material and workmanship under
normal use and service for the period(s) set forth below. Valleylab’s obligation
under this warranty is limited to the repair or replacement, at its sole option, of
any product, or part thereof, which has been returned to it or its Distributor within
the applicable time period shown below after delivery of the product to the
original purchaser, and which examination discloses, to Valleylab’s satisfaction,
that the product is defective. This warranty does not apply to any product, or part
thereof, which has been repaired or altered outside Valleylab’s factory in a way so
as, in Valleylab’s judgment, to affect its stability or reliability, or which has been
subjected to misuse, neglect, or accident.

The warranty periods for Valleylab products are as follows:

ForceTriad™ Energy Platform One year from date of shipment

Electrosurgical Generators One year from date of shipment

RFG-3C

LigaSure™ Vessel Sealing System One year from date of shipment

LigaSure™ Reusable Instruments One year from date of shipment

Mounting Fixtures (all models) One year from date of shipment

Footswitches (all models) One year from date of shipment

Force Argon

OptiMumm

LigaSure
Items

Sterile Single Use Items Sterility only as stated on packaging

Patient Return Electrodes Shelf life only as stated on packaging

™ Plus Lesion Generator One year from date of shipment

™ Units One year from date of shipment

™ Smoke Evacuator Two years from date of shipment

™ Sterile Single Use

Sterility only as stated on packaging

This warranty is in lieu of all other warranties, express or implied, including
without limitation, the warranties of merchantability and fitness for a particular
purpose, and of all other obligations or liabilities on the part of Valleylab.
Valleylab neither assumes nor authorizes any other person to assume for it any
other liability in connection with the sale or use of any of Valleylab’s products.

Notwithstanding any other provision herein or in any other document or
communication, Valleylab’s liability with respect to this agreement and products
sold hereunder shall be limited to the aggregate purchase price for the goods sold
by Valleylab to the customer. There are no warranties which extend beyond the
terms hereof. Valleylab disclaims any liability hereunder or elsewhere in
connection with the sale of this product, for indirect or consequential damages.

iv Force EZ-C Series Service Manual

This warranty and the rights and obligations hereunder shall be construed under
and governed by the laws of the State of Colorado, USA. The sole forum for
resolving disputes arising under or relating in any way to this warranty is the
District Court of the County of Boulder, State of Colorado, USA.

Valleylab, its dealers, and representatives reserve the right to make changes in
equipment built and/or sold by them at any time without incurring any obligation
to make the same or similar changes on equipment previously built and/or sold by
them.

Force EZ-C Series Service Manual v

vi Force EZ-C Series Service Manual

Table of Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Conventions Used in this Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Section 1. Service Personnel Safety

Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Warnings, Cautions, and Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Fire/Explosion Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Electric Shock Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Section 2. Introduction

General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

List of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Instant Response Technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Bipolar Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Monopolar Cut and Coag Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Cut Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Coag Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

REM Contact Quality Monitoring System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

How the REM System Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Electrodes Without the REM Safety Feature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Low (Desiccate) Coag Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

High (Fulgurate) Coag Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Recall of Most Recently Used Modes and Power Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Default Coag Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Original Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Section 3. Controls, Indicators, and Receptacles

Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Rear Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Option Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

Section 4. Technical Specifications

Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Force EZ-C Series Service Manual vii

Dimensions and Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Operating Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Transport and Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Internal Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Audio Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

REM Contact Quality Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

RF Activation Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Input Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Low Frequency (50-60 Hz) Leakage Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

High Frequency (RF) Leakage Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Standards and IEC Classifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Class I Equipment (IEC 60601-1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Liquid Spillage (IEC 60601-2-2 Clause 44.3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Electromagnetic Interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Electromagnetic Compatibility (IEC 60601-1-2 and IEC 60601-2-2). . . . . . . . . . . . . . . . . . . . . . . 4-9

Voltage Transients (Emergency Generator Mains Transfer). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Output Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Available Power Settings in Watts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Maximum Output for Force EZ-C Series Electrosurgical Generator Modes . . . . . . . . . . . . . . . . 4-15

Output Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Output Power vs. Resistance Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Section 5. Principles of Operation

Functional Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Instant Response Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

REM Contact Quality Monitoring System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Control Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Microcontrollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Main Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Feedback Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

Shared RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

Real-Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

I/0 Expansion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

Keyboard Interface and Activation Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

Power Supply Supervisor Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

A/D and D/A Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Waveform Generation (T_ON ASIC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

T_ON Average Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Audio Alarm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Serial Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Dosage Error Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

viii Force EZ-C Series Service Manual

Instant Response Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

Display Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

Bipolar, Cut, and Coag Power Setting Encoders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

RF Indicator Lamps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

LED and Seven-Segment Display Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

Mode Selection Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

REM Switch Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

Front Panel Footswitch Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

Footswitch Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

Power Supply/RF Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

Power Supply/RF Board Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

High Voltage Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

Low Voltage Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

RF Output Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

Spark Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24

RF Leakage Sensing and Reduction Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

REM Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

IsoBloc Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

Audio Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26

Footswitch Decode Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28

Temperature Sense Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28

Section 6. Setup, Tests, and Adjustments

Setting Up the Generator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Connections for Bipolar Surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Setting the Bipolar Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

Connections for Monopolar Surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

Set the Cut and Coag Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Using Two Generators Simultaneously. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Setting Up the Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Changing the Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

Changing the Power Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

Activating the Surgical Instrument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

Periodic Safety Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Recommended Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Inspecting the Generator and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Inspecting the Internal Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Testing the Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

Verifying REM Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16

Confirming Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16

Checking the Monopolar Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18

Checking Low Frequency Leakage Curren t an d Gr ou n d Resistance . . . . . . . . . . . . . . . . . . . . . 6-20

Force EZ-C Series Service Manual ix

Checking High Frequency Leakage Curr en t and Gr ou n d Resistance. . . . . . . . . . . . . . . . . . . . . 6-21

Calibrating the Force EZ-C Series Electrosurgical Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-22

Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24

Entering Calibration Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24

Exiting Calibration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-25

Calibration Step 1 – Verify the Force EZ-C Series Electrosurgical Generator Data . . . . . . . . . . 6-25

Calibration Step 2 – Adjust the Calendar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26

Calibration Step 3 – Adjust the Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-27

Calibration Step 4 – Check the REM Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28

Calibration Step 5 – Check and Adjust the Current Sense Gain. . . . . . . . . . . . . . . . . . . . . . . . . 6-29

Calibration Step 6 – Check and Adjust the Voltage Sense Gain. . . . . . . . . . . . . . . . . . . . . . . . . 6-31

Calibration Step 7 – Check and Adjust the Reactance Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33

Calibration Step 8 – Check and Adjust the ECON Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35

Section 7. Troubleshooting

Inspecting the Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Correcting Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

Responding to System Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

Correcting Integrated Circuit (IC) Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22

Correcting T_ON ASIC Malfunctions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-22

Correcting Battery-Backed RAM Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24

Section 8. Replacement Procedures

Interconnect Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2

Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Control Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Display Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

Remove the Display Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

Install the Display Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

Display Board Seven-Segment LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

Footswitch Board Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

Front Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

Remove the Front Panel Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

Remove and Reinstall the Front Panel Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9

Install the Front Panel Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10

x Force EZ-C Series Service Manual

Front Panel Footswitch Receptacle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10

Front Panel Knob. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11

Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11

Front Panel Power Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12

Front Panel REM Lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

Replacing Fuses in the Fuse Drawer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

Replacing the Fuse on the Low Voltage Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

Replacing the Fuse on the Power Supply/RF Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15

Handle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16

Left Front Heat Sink Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17

Remove the Left Front Heat Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17

Replace the Left Front Heat Sink Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18

Install the Left Front Heat Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18

Left Rear Heat Sink Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19

Remove the Left Rear Heat Sink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19

Replace the Left Rear Heat Sink Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-20

Install the Left Rear Heat Sink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21

Right Heat Sink Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21

Remove the Right Heat Sink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21

Replace the Right Heat Sink Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-22

Install the Right Heat Sink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-23

Low Voltage Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24

Remove the Low Voltage Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24

Install the Low Voltage Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25

Power Entry Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26

Remove the Power Entry Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26

Install the Power Entry Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27

Power Supply/RF Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28

Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28

Remove the Power Supply/RF Board and Heat Sinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28

Install the Power Supply/RF Board and Heat Sinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-29

Section 9. Repair Policy and Procedures

Responsibility of the Manufacturer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

Returning the Generator for Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

Force EZ-C Series Service Manual xi

Returning Circuit Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

Service Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

Section 10. Service Parts

Ordering Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

Force EZ-C Series Electrosurgical Generator Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

Generator Assembly Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

Control Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7

Footswitch Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8

Power Supply/RF Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-9

xii Force EZ-C Series Service Manual

List of Figures

Figure 3-1. The front panel 3-2
Figure 3-2. The front panel - continued 3-4
Figure 3-3. Controls and receptacles on the rear panel 3-6
Figure 3-4. The option panel on the generator rear panel with the plate removed to show the serial and RF activation

ports 3-8
Figure 4-1. Standard Bipolar mode — load resistance vs. output power 4-17
Figure 4-2. Pure mode — load resistance vs. output power 4-18
Figure 4-3. Blend mode — load resistance vs. output power 4-18
Figure 4-4. Low 1 (Desiccate) mode — load resistance vs. output power 4-19
Figure 4-5. Low 2 (Desiccate) mode — load resistance vs. output power 4-19
Figure 4-6. Low 3 (Desiccate) mode — load resistance vs. output power 4-20
Figure 4-7. High 1 (Fulgurate) mode — load resistance vs. output power 4-20
Figure 4-8. High 2 (Fulgurate) mode — load resistance vs. output power 4-21
Figure 4-9. Standard Bipolar mode @ 100 ohms — generator setting vs. output power 4-22
Figure 4-10. Standard Bipolar mode — peak voltage vs. output power 4-22
Figure 4-11. Pure mode @ 300 ohms — generator setting vs. output power 4-23
Figure 4-12. Pure mode — peak voltage vs. output power 4-23
Figure 4-13. Blend mode @ 300 ohms — generator setting vs. output power 4-24
Figure 4-14. Blend mode — peak voltage vs. output power 4-24
Figure 4-15. Low 1 (Desiccate) mode @ 500 ohms — generator setting vs. output power 4-25
Figure 4-16. Low 1 (Desiccate) mode — peak voltage vs. output power 4-25
Figure 4-17. Low 2 (Desiccate) mode @ 300 ohms— generator setting vs. output power 4-26
Figure 4-18. Low 2 (Desiccate) mode — peak voltage vs. output power 4-26
Figure 4-19. Low 3 (Desiccate) mode @ 300 ohms— generator setting vs. output power 4-27
Figure 4-20. Low 3 (Desiccate) mode — peak voltage vs. output power 4-27
Figure 4-21. High 1 (Fulgurate) mode @ 500 ohms— generator setting vs. output power
Figure 4-22. High 1 (Fulgurate) mode — peak voltage vs. output power 4-28
Figure 4-23. High 2 (Fulgurate) mode @ 500 ohms— generator setting vs. output power 4-29
Figure 4-24. High 2 (Fulgurate) mode — peak voltage vs. output power 4-29
Figure 5-1. A block diagram of the Force EZ-C Series generator 5-2
Figure 6-1. Bipolar connections (footswitch activation from the Bipolar Footswitch receptacle on the rear panel) 6-4
Figure 6-2. Bipolar connections (footswitch activation from the Footswitch receptacle on the front panel) 6-4
Figure 6-3. Bipolar connection (handswitching instrument) 6-5
Figure 6-4. Monopolar connections (handswitching instrument) 6-6
Figure 6-5. Monopolar connections (footswitch activation from the Monopolar Footswitch receptacle on the rear

panel) 6-6
Figure 6-6. Monopolar connections (footswitch activation from the Footswitch receptacle on the front panel) 6-7
Figure 6-7. The leakage current test circuit 6-20
Figure 8-1. Electric cable connections 8-2
Figure 8-2. Power switch and cable connections 8-12

4-28

Force EZ-C Series Service Manual xiii

Figure 8-3. Left front heat sink components 8-18
Figure 8-4. Left rear heat sink components 8-20
Figure 8-5. Right heat sink components 8-22
Figure 8-6. Connections to the low voltage power supply 8-25
Figure 8-7. Cable connections to the power entry module 8-27
Figure 10-1. Exploded view of Force EZ-C Series Electrosurgical Generator parts 10-3
Figure 10-2. Top view of Force EZ-C Series Electrosurgical Generator parts, after assembly 10-4

xiv Force EZ-C Seri es Service Manual

1Service Personnel Safety

Valleylab stresses safety in the use and servicing of its
electrosurgical equipment. This section presents the following:

SECTION

1

• Safety information

• Warnings, Cautions, and Notices
Refer to the Preface, Conventions, for further information on

Warnings, Cautions, and Notices.

Force EZ-C Series Service Manual 1-1

Safety Information

Safety Information

The safe and effective servicing of electrosurgical equipment depends to a large
degree on factors solely under the control of the service person. There is no
substitute for a properly trained and vigilant service staff.

Warnings, Cautions, and Notices

Before servicing the generator, it is important that you read, understand, and
follow the instructions supplied with it and with any other equipment used to
install, test, adjust, or repair the generator.

General

Warning

Patient Safety – Use the generator only if it has completed the self-test as
described. Otherwise, inaccurate power outputs may result.

The instrument receptacles on this generator are designed to accept only one
instrument at a time. Do not attempt to connect more than one instrument at a
time into a given receptacle. Doing so will cause simultaneous activation of the
instruments.

Caution

Do not stack equipment on top of the generator or place the generator on top of
electrical equipment (except a Force Argon Unit). These configurations are
unstable and/or do not allow adequate cooling.

Provide as much distance as possible between the electrosurgical generator and
other electronic equipment (such as monitors). An activated electrosurgical
generator may cause interference with them.

Do not turn the activation tone down to an inaudible level. The activation tone
alerts the surgical team when an accessory is active.

Notice

If required by local codes, connect the generator to the hospital equalization
connector with an equipotential cable.

To avoid product damage, connect the power cord to a wall receptacle having the
correct voltage.

1-2 Force EZ-C Service Manual

Warnings, Cautions, and Notices

Active Accessories

Caution

Connect accessories to the proper receptacle type. In particular, connect bipolar
accessories to the Bipolar Instrument receptacle only. Improper connection may
result in inadvertent generator activation or a REM Contact Quality Monitor
alarm.

Patient Return Electrodes

Warning

Using a patient return electrode without the REM safety feature will not activate
the Valleylab REM Contact Quality Monitoring System.

Fire/Explosion Hazards

Warning

Danger: Explosion Hazard –þDo not install the generator in the presence of

flammable anesthetics, gases, liquids, or objects.
Fire Hazard – Do not place active accessories near or in contact with flammable

materials (such as gauze or surgical drapes). Electrosurgical accessories that
are activated or hot from use can cause a fire. Use a holster to hold
electrosurgical accessories safely away from patients, surgical team, and
flammable materials.

Service Personnel Safety

Fire Hazard – Do not use extension cords.
Fire Hazard – For continued protection against fire hazard, replace fuses only

with fuses of the same type and rating as the original fuse.

Force EZ-C Service Manual 1-3

Warnings, Cautions, and Notices

Electric Shock Hazards

Warning

Connect the generator power cord to a properly grounded receptacle. Do not use
power plug adapters.

Do not connect a wet power cord to the generator or to the wall receptacle.
To allow stored energy to dissipate after power is disconnected, wait at least five

minutes before replacing parts.
Always turn off and unplug the generator before cleaning.
Do not touch any exposed wiring or conductive surfaces while the generator is

disassembled and energized. Never wear a grounding strap when working on an
energized generator.

When taking measurements or troubleshooting the generator, take appropriate
precautions, such as using isolated tools and equipment, using the “one hand
rule,” etc.

Potentially lethal AC and DC voltages are present in the AC line circuitry, high
voltage DC circuitry, and associated mounting and heat sink hardware described
in this manual. They are not isolated from the AC line. Take appropriate
precautions when testing and troubleshooting this area of the generator.

High frequency, high voltage signals that can cause severe burns are present in
the RF output stage and in the associated mounting and heat sink hardware
described in this manual. Take appropriate precautions when testing and
troubleshooting this area of the generator.

Servicing

Caution

Read all warnings, cautions, and instructions provided with this generator before
servicing.

The generator contains electrostatic-sensitive components. When repairing the
generator, work at a static-control workstation. Wear a grounding strap when
handling electrostatic-sensitive components, except when working on an
energized generator. Handle circuit boards by their nonconductive edges. Use an
antistatic container for transport of electrostatic-sensitive components and circuit
boards.

Notice

After installing a new low voltage power supply, verify that the voltages are
correct.

1-4 Force EZ-C Service Manual

Warnings, Cautions, and Notices

Calibration

Caution

To avoid inadvertent coupling and/or shunting of RF currents around the resistor
elements, keep the resistors at least 10.2 cm (4 in.) away from any metal surface
including tabletops and other resistors. This is especially true if several resistors
are connected in series or parallel to obtain a specified value. Do not allow the
resistor bodies to touch each other.

Notice

After completing any calibration step, proceed to the next step to save the values
from the completed calibration step.

Do not activate the generator with any load resistor higher than 10 ohms while
calibrating the current sense gain. Otherwise, product damage will result.

Do not activate the generator with any load resistor lower than 750 ohms while
calibrating the voltage sense gain for bipolar output. Otherwise, product damage
will result.

Do not activate the generator with any load resistor lower than 3000 ohms while
calibrating the voltage sense gain for the pure cut mode. Otherwise, product
damage will result.

Service Personnel Safety

Do not activate the generator with any load resistor lower than 2000 ohms while
calibrating the voltage sense gain for the blend mode. Otherwise, product
damage will result.

After calibration, the generator will be ready to use only after you initiate the
internal self-test by turning the generator off, then on.

Calibrate the generator after you install a new battery. All data stored in internal
memory, including calibration constants, is lost when the battery is replaced.

Calibrate the generator after you install a new Control board. Otherwise it uses
default calibration values.

Calibrate the generator after you install a new heat sink or replace components
on the heat sink. Component differences may affect output waveforms.

Calibrate the generator after you install a new Power Supply/RF board.
Component differences may affect output waveforms.

Cleaning

Notice

Do not clean the generator with abrasive cleaning or disinfectant compounds,
solvents, or other materials that could scratch the panels or damage the
generator.

Force EZ-C Service Manual 1-5

1-6 Force EZ-C Service Manual

2Introduction

This manual provides instructions for servicing the Valleylab Force
EZ-C Series Electrosurgical Generator. This section introduces the
features and components of the generator.

SECTION

2

Additional information about using the generator is available in the
Force EZ-C Series Electrosurgical Generator with Instant
Response Technology User’s Guide.

Force EZ-C Series Service Manual 2-1

General Description

General Description

The Valleylab Force EZ-C Series Electrosurgical Generator is an isolated output
electrosurgical generator that provides the power for cutting, desiccating, and
fulgurating tissue during electrosurgery . The generator is s pecifically designed for
use in bipolar or monopolar electrosurgery.

It includes the following features:

• Instant Response Technology

• Standard bipolar mode

• Two monopolar cut modes: pure and blend

• Two monopolar coag modes: low (desiccate) and high (fulgurate)

• The Valleyl ab REM Contact Quality Monitoring System, which protects
patients against burns at the patient return electrode site

• User selectable coag settings

• User selectable default settings

• Adjustable activation tone volume

• Force GSU and Force Argon system compatibility

List of Components

The Valleylab Force EZ-C Series Electrosurgical Generator is a self-contained
unit. It consists of a main enclosure (cover and base) and power cord. It includes
the following components:

• Front panel – the power switch ; controls for setting the modes and output
power; a footswitch receptacle and button for selecting bipolar or accessory
output; receptacles for connecting electrosurgical accessories, and indicators
that alert you to the selected modes and the patient return electrode status.

• Rear panel – the power entry module, volume control, two footswitch
receptacles, equipotential grounding lug, and option panel.

• Internal components – include the Control (microcontroller) board, Display
board, Footswitch board, Power Supply/Radio Frequency (RF) board, low
voltage power supply, and heat sinks.

A handle is located on the underside of the chassis.
For details about the interaction of the main components and circuit board

descriptions, refer to Section 5, Principles of O perati on.

2-2 Force EZ-C Series Service Manual

Instant Response Technology

The Force EZ-C Series Electrosurgical Generator automatically senses resistance
and adjusts the current and output voltage to maintain a consistent effect across
different tissue density. This adjustment is based on the selected mode, the power
setting, and the level of tissue resistance. As tissue resistance increases, the
generator outputs constant current followed by constant power followed by
constant voltage. The system controls maximum output voltage to reduce
capacitive coupling and video interference and to minimize sparking. This
technology applies to the bipolar mode, the cut modes, and the low 2 and low 3
coag settings. It does not apply to the low 1, high 1, and high 2 coag settings.

Bipolar Modes

Instant Response Technology

The Force EZ-C Series Electrosurgical Generator provides a standard bipolar
mode usable for most bipolar applications.

Delicate tissue requires less heat to desiccate quickly . The generator provides low
voltage, continuous current for faster desiccation without sparking.

The possibility of sparking increases as desiccated tissue dries and becomes more
resistant. The generator protects against sparking by limiting the bipolar voltage
at relatively high levels of tissue resistance.

For details about the bipolar output characteristics, refer to Section 4, Technical
Specifications.

Monopolar Cut and Coag Modes

Cut Modes

Two cut modes – pure and blend – allow a wide range of power settings to
perform diverse surgical applications.

• Pure provides an even cut with little or no hemostasis. It offers good cutting
performance over a wide range of tissue resistance.

• Blend provides cutting ability with additional hemostasis.

Introduction

Force EZ-C Series Service Manual 2-3

REM Contact Quality Monitoring System

Coag Modes

Two coagulation modes help control the size of the area and the depth of
penetration during tissue coagulation. The low (desiccate) mode has three
settings; the high (fulgurate) mode, two settings. You can select, as default
settings, one low setting and one high setting. For a description of each setting,
refer to Special Features in this section.

• Low (desiccate) dehydrates and destroys tissue without sparking or cutting.

Because the active electrode directly touches the tissue, more current reaches
the patient. Desiccation places the greatest demand on the patient return
electrode.

• High (fulgurate) coagulates tissue by sparking from the active electrode,

through air, to the patient tissue. In this mode, you have less control over
sparking, thus it is best suited for coagulation of larger areas. Accidental
sparking to adjacent areas can occur as tissue at the surgical site dries and
becomes more resistant to current flow.

For details about the monopolar output characteristics, re fer to
Specifications.

REM Contact Quality Monitoring System

During monopolar electrosurgery, a patient return electrode is always required to
safely recover the current that flows through the patient’s body and return it to the
generator. A reduction in surface area contact or poor conductivity between the
patient and the return electrode can cause the current to become concentrated,
potentially resulting in burns at the return electrode site.

The Force EZ-C Series Electrosurgical Generator uses the Valleylab REM
Contact Quality Monitoring System to monitor the quality of electrical contact
between the patient return electrode and the patient. The REM system is designed
to eliminate the risk of burns at the return electrode site. Use of any return
electrode other than a REM patient return electrode may compromise the REM
safety feature. This could result in a patient burn.

Section 4, Technical

2-4 Force EZ-C Series Service Manual

Special Features

How the REM System Works

The REM system continuously measures the resistance at the return electrode site
and compares it to a standard range of safe resistance (between 5 and 135 ohms),
thus eliminating intermittent false alarms that could result from small changes in
resistance. The REM system also adapts to individual patients by measuring the
initial contact resistance between the patient and the patient return electrode and
lowering the baseline resistance if the contact resistance drops.

A REM alarm sounds and the generator stops producing output power when
either of the following occurs:

• The measured resistance is below 5 ohms or above 135 ohms, the limits of the
standard range of safe resistance.

• An increase in contact resistance is greater than 40% from the initial
measurement (baseline resistance).

Electrodes Without the REM Safety Feature

Warning

Using a patient return electrode without the REM safety feature will not activate
the Valleylab REM Contact Quality Monitoring System.

Introduction

Special Features

When you use a patient return electrode that does not have the REM safety
feature, the REM system does not monitor the patient contact area as previously
described. The REM system monitors only the pin-to-pin resistance at the
connector and can detect broken wires or connectors in the return electrode cord.

Five special features allow customizing the Force EZ-C Series Electrosurgical
Generator. You can access these features only in the setup mode. For details on
selecting these features, refer to Setting Up the Special Features in Chapter 4 of
the User’s Guide.

Low (Desiccate) Coag Settings

The low (desiccate) coag mode provides three settings with subtle differences in
output characteristics:

• Low 1 is appropriate for the majority of surgical procedures. It provides tissue
desiccation with a minimal tendency to cut or spark.

• Low 2 produces tissue desiccation and further reduces the chance of cutting or
sparking by using the lowest possible voltage (ð 200 V

• Low 3 uses a slightly higher voltage (ð 300 V
offers comparable desiccation.

) than the low 2 setting, but

rms

rms

).

Force EZ-C Series Service Manual 2-5

Special Features

Important

The default coag mode featur e
is available only when the
most recently used modes and
power settings feature is
turned off.

High (Fulgurate) Coag Settings

The high (fulgurate) coag mode provides two settings:

• High 1 produces coagulation of smaller areas without touching the electrode

tip to the tissue.

• High 2 produces coagulation of larger areas without touching the electrode to

the tissue.

Recall of Most Recently Used Modes and Power Settings

When you activate this feature, the generator will, when turned on, revert to the
most recently used modes and power settings.

Default Coag Mode

You can select either low (desiccate) or high (fulgurate) as the default coag mode
for the Force EZ-C Series Electrosurgical Generator. Each time you turn on the
generator, it automatically selects the default coag mode.

Original Default Settings

This feature resets the generator to the original default setting for each mode,
power setting, and special feature. The next time you turn on the generator, it
automatically selects the original default settings.

Mode or Feature Original Default Setting

Monopolar Pure

Coag High (fulgurate)

Low (desiccate) coag setting 1 (low 1)

High (fulgurate) coag setting 2 (high 2)

Last used modes and power settings 1 (on)

2-6 Force EZ-C Series Service Manual

3Controls, Indicators,

and Receptacles

This section describes the front and rear panels, including all
controls, indicators, and receptacles.

SECTION

3

Force EZ-C Series Service Manual 3-1

Front Panel

Front Panel

A

B

C

Figure 3-1.

The front panel

E

F

A.

Bipolar Indicator

D

G

H

I

J

K

L

M

When you activate the generator in bipolar mode, this bar illuminates blue and
an activation tone sounds.

N

B. Bipolar Display

Shows the power setting, in watts, for bipolar output.

C. Bipolar Power Control Knob

To increase (+) the power, turn the knob clockwise.
To decrease (–) the power, turn the knob counterclockwise.

D. Cut Indicator

When you activate the generator in cut mode, this bar illuminates yellow and
an activation tone sounds.

E. Cut Display

Shows the power setting, in watts, for cut output.

F. Cut Power Control Knob

To increase (+) the power, turn the knob clockwise.
To decrease (–) the power, turn the knob counterclockwise.

G. Pure Button

Select for an even cut with little or no hemostasis.

H. Blend Button

Select for slower cutting and additional hemostasis.

3-2 Force EZ-C Series Service Manual

Front Panel

I. Coag Indicator

When you activate the generator in coag mode, this bar illuminates blue and
an activation tone sounds.

J. Coag Display

Shows the power setting, in watts, for coag output.

K. Coag Power Control Knob

To increase (+) the power, turn the knob clockwise.
To decrease (–) the power, turn the knob counterclockwise.

L. Low (Desiccate) Button

Select to desiccate the area of tissue that is in direct contact with the active
electrode.

M. High (Fulgurate) Button

Select to fulgurate an area of tissue with a spray of sparks.

N. REM Alarm Indicator

This indicator illuminates red until you properly apply a REM patient return
electrode to the patient and connect it to the generator. Then, the indicator
illuminates green. (When you connect an electrode without the REM safety
feature, the indicator light does not illuminate.)

If the REM system senses an alarm condition, the indicator flashes red until
you correct the alarm condition – then the indicator illuminates green. (If you
are using a return electrode without the REM safety feature, the red indicator
is extinguished when you correct the alarm condition.)

Controls, Indicators,

and Receptacles

Force EZ-C Series Service Manual 3-3

Front Panel

T

Figure 3-2.

The front panel - continued

RS

O.

Patient Return Electrode Receptacle

For monopolar electrosurgery, connect a patient return electrode to this
receptacle.

P. Monopolar Instrument Receptacle

You can connect either a handswitching instrument (three-pin connector) or a
footswitching instrument (single-pin connector) to this receptacle.

T o activate a footswitching instrument, connect a monopolar footswitch to the
rear panel.

Q. Accessory Instrument Receptacle

Connect a monopolar footswitching instrument with a single-pin connector to
this receptacle.

To activate the instrument, connect a monopolar footswitch to the front panel.

OPQ

3-4 Force EZ-C Series Service Manual

Front Panel

R. Footswitch Receptacle, Button, and Indicators

Connect a two-pedal Valleylab monopolar footswitch to this receptacle.
Press the Footswitch Selector button to select bipolar or accessory output.

Use only a Valleylab monopolar footswitch with the Force EZ-C Series
Electrosurgical Generator. Use on an incompatible footswitch may cause
unexpected output.

When the left arrow indicator illuminates green, the footswitch activates the
instrument connected to the Bipolar Instrument receptacle.

When the right arrow indicator illuminates green, the footswitch activates the
instrument connected to the Accessory Instrument receptacle.

The footswitch will not activate an instrument connected to the Monopolar
Instrument receptacle.

S. Bipolar Instrument Receptacle

You can connect either a handswitching instrument (three-pin connector) or a
footswitching instrument (two-pin connector) to this receptacle.

To activate a bipolar footswitching instrument, you can connect a bipolar
footswitch to the rear panel or a monopolar footswitch to the front panel.

T. Power Switch

This switch supplies power to the generator.

To turn on the generator, press ( | ).
To turn off the generator, press ( O ).

Controls, Indicators,

and Receptacles

Force EZ-C Series Service Manual 3-5

Rear Panel

Rear Panel

B

A

Figure 3-3.

Controls and receptacles on the
rear panel

C

D

H

G

A.

Volume Control

F

E

The Force EZ-C Series Electrosurgical Generator includes an audible tone
that sounds in two circumstances:

• When you activate the generator

• When any alarm occurs
You can adjust the volume of the activation tones. However, to ensure that

the surgical team is alerted to inadvertent activation, you cannot turn the
activation tones off.

• To increase volume, turn the knob clockwise.

• To decrease volume, turn the knob counterclockwise.
You cannot adjust the alarm tone volume.

B. Power Entry Module

This module contains the power cord receptacle and the fuse drawer.

3-6 Force EZ-C Series Service Manual

Rear Panel

C. Power Cord Receptacle

The power cord provided with the generator connects to this receptacle.

D. Fuse Drawer

The fuse drawer contains two fuses. Refer to Section 8, Replacement
Procedures, for instructions for changing the fuses.

E. Equipotential Grounding Lug

Use this lug to connect the generator to protective earth ground.

F. Option Panel

Refer to the next page for information about this panel.

G. Bipolar Footswitch Receptacle

Connect a single-pedal bipolar footswitch to this receptacle if you connect an
instrument to the Bipolar Instrument receptacle on the front panel.

The footswitch will not activate instruments connected to the Monopolar
Instrument or Accessory Instrument receptacles on the front panel.

H. Monopolar Footswitch Receptacle

Connect a two-pedal Valleylab monopolar footswitch to this receptacle if you
connect an instrument to the Monopolar Instrument receptacle on the front
panel.

The footswitch will not activate instruments connected to the Bipolar
Instrument or Accessory Instrument receptacles on the front panel.

Controls, Indicators,

and Receptacles

Force EZ-C Series Service Manual 3-7

Option Panel

Option Panel

A removable plate on the rear panel covers a serial port and a radio frequency
(RF) activation port. To review the technical specifications for each port, refer to
Section 4, Technical Specifications.

Serial Port

Allows connection of a computer to the generator.
You can obtain information about the generator
using the RS-232 communications pro tocol.

RF Activation Port

Allows a connected device to receive information
during RF activation of the generator, which can
then generate a response in the device.

Figure 3-4.

The option panel on the
generator rear panel with the
plate removed to show the serial
and RF activation ports

3-8 Force EZ-C Series Service Manual

1Technical Specifications

All specifications are nominal and subject to change without notice.
A specification referred to as “typical” is within ± 20% of a stated
value at room temperature (77° F/25° C) and a nominal input power

SECTION

4

voltage.

Force EZ-C Series Service Manual 4-1

Performance Characteristics

Performance Characteristics

General

Output configuration

Cooling

Display

isolated output
natural convection; side and rear panel vents
eight digital seven-segment displays: 1.9 cm (0.75

in.) each

Mounting

Valleylab Universal Cart (UC8009), Force Argon
Unit, or any stable flat surface

Dimensions and Weight

Width

Depth

Height

Weight

40.6 cm (16 in.)

39.5 cm (15.6 in.)

12.7 cm (5 in.)
< 6.8 kg (< 15 lbs)

Operating Parameters

Ambient temperature
range

10° to 40° C (50° to 104° F)

Relative humidity

Atmospheric pressure

Warm-up time

30% to 75%, noncondensing
700 to 1060 millibars
If you transported or stored the generator at

temperatures outside the operating temperature
range, allow one hour for the generator to reach
room temperature before use.

4-2 Force EZ-C Series Service Manual

T ransport and Storage

Performance Characteristics

Ambient temperature
range

Relative humidity

Atmospheric pressure

Duration of storage

-34° to 65° C (-29° to 149° F)

25% to 85%, noncondensing
500 to 1060 millibars
If you stored the generator longer than one year,

replace the battery for battery-backed RAM and
complete a full test and recalibration before use.
Refer to Section 6, Setup, Tests, and Adjustments
for instructions.

Duty Cycle

Under maximum power settings and rated load conditions (pure cut, 300 watt
setting, 300 ohm load), the Force EZ-C Series Electrosurgical Generator is
suitable for activation times of 10 seconds on, 30 seconds off for one hour. With
lesser settings and loads, you can activate the generator for greater durations
without generating excessive internal temperatures.

If the internal temperature of the generator is too high, an alarm tone sounds and a
number (451) flashes in the Cut display alternately with the power settings. You
can activate the generator and change the power settings while this condition
exists.

Internal Memory

Memory type Nonvolatile, battery-backed RAM
Battery type 3 V lithium button cell
Battery life 5 years
Storage capacity • the last twenty error codes detected by the

generator

• the number of times and length of activation for
each mode

• the average power setting used for each mode

• the total time the generator is on

• calibration constants

• special features settings

• last setup parameters

• other service-related information

Technical Specifications

Force EZ-C Series Service Manual 4-3

Performance Characteristics

Audio Volume

The audio levels stated below are for activation tones (bipolar, cut, and coag) and
alarm tones (REM and system alarms) at a distance of one meter. Alarm tones
meet the requirements for IEC 60601-2-2 and AAMI HF18.

Activation Tone

Volume (adjustable)

Frequency

45 to ≥ 65 dBA
Bipolar: 554 Hz

Cut: 440 Hz
Coag: 554 Hz

Duration

continuous while the generator is activated

Alarm Tone

Volume (not
adjustable)

Frequency

Duration

≥ 65 dBA

440 Hz
250 to 500 ms. The pulse train is repeated for REM

and dosage error alarms at 30 second intervals.

REM Contact Quality Monitor

REM current is measured according to IEC 60601-1, Ed. 1988, Figure 15.

Measurement
frequency

80 kHz ± 10 kHz

Measurement current

< 10 µA

Acceptable Resistance Range

REM resistance measurements are ± 10% during RF activation and ± 5% when
RF output is not activated.

REM patient return electrode: 5 to 135 ohms or up to a 40% increase in the initial
measured contact resistance (whichever is less)

Patient return electrode without the REM safety feature (single section electrode):
0 to 20 ohms

If the measured resistance is outside the acceptable range(s) noted above, a REM
fault condition occurs.

4-4 Force EZ-C Series Service Manual

Performance Characteristics

REM Alarm Activation

REM patient return electrode: When the measured resistance exceeds the
standard range of safe resistance (below 5 ohms or above 135 ohms) or when the
initial measured contact resistance increases by 40% (whichever is less), the REM
Alarm indicator flashes red, a tone sounds twice, and the generator disables RF
output. The indicator remains illuminated red until you correct the condition
causing the alarm. Then, the indicator illuminates green and the generator enables
RF output.

Patient return electrode without the REM safety feature: When the measured
resistance between the patient return electrode pins exceeds 20 ohms, the REM
Alarm indicator flashes red, a tone sounds twice, and the generator disables RF
output. The indicator remains illuminated red until you correct the condition
causing the alarm. Then, the red indicator is extinguished and the generator
enables RF output.

Serial Port

RS-232 compatible; 9600 baud, 8 data bits, 1 stop bit, no parity
This port is a 9-pin connector supporting the following signals:

• pin 2 – isolated transmit (serial data output transmit line)

• pin 3 – isolated receive (serial data input receive line)

• pin 5 – isolated ground (reference for transmit and receive)

RF Activation Port

The RF activation port is a subminiature phone jack attached to the contacts of a
small relay. The contacts close when you activate the generator, but remain open
at all other times. This port provides a means to tell other equipment that the
generator is producing RF. This may be useful when making EEG or ECG
measurements.

Technical Specifications

Force EZ-C Series Service Manual 4-5

Performance Characteristics

Input Power

100–120 Volt 220–240 Volt

Maximum VA input:

Idle: 50 VA
Bipolar: 500 VA
Cut: 850 VA
Coag: 500 VA

Full regulation range: 90–135 Vac Full regulation range: 186–264 Vac

Operating range: 85–140 Vac Operating range: 170–280 Vac

Mains current (maximum):

Idle: 0.4 A
Bipolar: 4.2 A
Cut: 8.0 A
Coag: 4.2 A

Mains line frequency range (nominal):
50 Hz to 60 Hz

Mains fuse: F8.0 A Mains fuse: T4.0 A

Power plug: 3-prong hospital grade
connector

Maximum VA input:

Idle: 50 VA
Bipolar: 500 VA
Cut: 850 VA
Coag: 500 VA

Mains current (maximum):

Idle: 0.2 A
Bipolar: 2.1 A
Cut: 4.0 A
Coag: 2.1 A

Mains line frequency range (nominal):
50 Hz to 60 Hz

Power plug: 3-prong locally approved
connector

Power Cord Specification

This unit was equipped from the factory with either a 110VAC hospital grade NEMA
5-15 power cord or a 220VAC CEE7/7 power cord. Should the AC power cord need
to be replaced to match another plug configuration, the replacement plug/cable/
receptacle configuration must meet or exceed the following specifications:

100-120 VAC

Cable - SJT16/3, IEC color code, maximum length 15 ft (5 m)
Plug - minimum 10 A - 125 VAC
Unit receptacle - IEC female, minimum 10 A - 125 VAC

220-240 VAC

Cable - H05VVF3G1.0 VDE, maximum length 15’ (5 meters)
Plug - minimum 6 A - 250VAC
Unit receptacle - IEC female, minimum 6 A - 250VAC

4-6 Force EZ-C Series Service Manual

Performance Characteristics

Low Frequency (50-60 Hz) Leakage Current

Enclosure source
current, ground open

Source current, patient
leads, all outputs

< 100 µA

Normal polarity, intact ground: < 10 µA
Normal polarity, ground open: < 50 µA
Reverse polarity, ground open: < 50 µA

Sink current at high
line, all inputs

< 20 µA

High Frequency (RF) Leakage Current

Bipolar RF leakage
current

Monopolar RF leakage
current

< 60 mA

< 150 mA

rms

rms

Force EZ-C Series Service Manual 4-7

Technical Specifications

Standards and IEC Classifications

Standards and IEC Classifications

The Force EZ-C Series Electrosurgical Generator meets all pertinent clauses of
the IEC 60601-1 second edition and IEC 60602-2-2 third edition.

ATTENTION

Consult accompanying documents.

F

The generator output is floating (isolated) with respect to
ground.

DANGER

Explosion risk if used with flammable anesthetics.

Rear Panel—To reduce the risk of electric shock, do not
remove the cover. Refer servicing to qualified service
personnel.

Front Panel—Dangerous Voltage Output.

Non-Ionizing Radiation

Classified with respect to electrical shock, fire, and
mechanical hazards only in accordance with UL60601-1 and
CAN/CSA C22.2 No. 601.1.

Class I Equipment (IEC 60601-1)

Accessible conductive parts cannot become live in the event of a basic insulation
failure because of the way in which they are connected to the protective earth
conductor.

Type CF Equipment (IEC 60601-1)/Defibrillator Proof

The Force EZ-C Series Electrosurgical Generator provides a
high degree of protection against electric shock, particularly
regarding allowable leakage currents. It is type CF isolated
(floating) output and may be used for procedures involving the
heart.

The Force EZ-C Series Electrosurgical Generator patient return
electrode terminal is protected from defibrillator discharge
according to ANSI/AAMI HF18 and IEC 60601-2-2.

4-8 Force EZ-C Series Service Manual

Standards and IEC Classifications

Liquid Spillage (IEC 60601-2-2 Clause 44.3)

The Force EZ-C Series Electrosurgical Generator enclosure is constructed so that
liquid spillage in normal use does not wet electrical insulation or other
components which, when wetted, are likely to adversely affect the safety of the
equipment.

Electromagnetic Interference

The Force EZ-C Series Electrosurgical Generator minimizes electromagnetic
interference to video equipment used in the operating room. The generator
complies with the requirements of IEC 61000-4-2.

Electromagnetic Compatibility (IEC 60601-1-2 and
IEC 60601-2-2)

The Force EZ-C Series Electrosurgical Generator meets IEC 60601-1-2 and IEC
60601-2-2 requirements for electromagnetic compatibility.

Notice

The Force EZ should not be used adjacent to or stacked with equipment other
than specified in the Force EZ User Guide and Service Manual. If adjacent or
stacked use is necessary, the Force EZ should be observed to verify normal
operation in the configuration in which it will be used.

The Force EZ intentionally applies RF energy for diagnosis or treatment during
activation. Observe other electronic medical equipment in the vicinity during the
Force EZ activation for any possible adverse electromagnetic effects. Ensure
adequate separation of electronic medical equipment based on observed
reactions.

The use of accessories, other than specified in the Force EZ User Guide and
Service Manual, may result in increased emissions or decreased immunity of the
Force EZ.

Voltage Transients (Emergency Generator Mains
Transfer)

The Force EZ-C Series Electrosurgical Generator operates in a safe manner when
you transfer between line AC and an emergency generator voltage source.

Technical Specifications

Force EZ-C Series Service Manual 4-9

Standards and IEC Classifications

Guidance and manufacturer's declaration - electromagnetic emis sions

The Force EZ-C Series Electrosurgical Generator is intended for use in the electromagnetic environment specified
below. The customer or the user of the Force EZ-C Series Electrosurgical Generator should ensure that it is used in
such an environment.

Emissions test Compliance Electromagnetic environment -

guidance

RF emissions

CISPR 11

RF emissions

CISPR 11

Harmonic emissions

IEC 61000-3-2

Voltage fluc tuations/ flicker

emissions IEC61000-3-3

Group 1 The Force EZ-C Series

Electrosurgical Generator uses RF
energy only for its internal function.
Therefore, its RF emissions are very
low and are not likely to cause any
interference in nearby electronic
equipment.

Class A The Force EZ-C Series

Electrosurgical Generator is suitable
for use in all establishments other

Class A

Complies

than domestic and those directly
connected to the public low-voltage
power supply network that supplies
buildings used for domestic purposes.

4-10 Force EZ-C Series Service Manual

Standards and IEC Classifications

Guidance and manufacturer's declaration - electromagnetic immunity

The Force EZ-C Series Electrosurgical Generator is intended for use in the electromagnetic environment specified
below. The customer or the user of the Force EZ-C Series Electrosurgical Generator should assure that it is used in
such an environment.

Immunity test IEC 60601 test

Electrostatic discharge

(ESD)

IEC 61000-4-2

Electrical fast transient/

burst IEC 61000-4-4

Surge

IEC 61000-4-5

Voltage dips, short

interruptions and voltage

variations on power supply

input lines

IEC 61000-4-11

+/-6 kV contact

+/-2 kV for power

supply lines

+/-1 kV for input/

output lines

+/-1 kV differential

+/-2 kV common

(>95% dip in Ut)

for 0,5 cycle

(>60% dip in Ut)

(>30% dip in Ut)

for 25 cycles

(>95% dip in Ut)

level

+/-8 kV air

mode

mode

<5% Ut

40% Ut

for 5 cycles

70% Ut

<5% Ut

for 5 sec

Compliance level Electromagnetic environment -

guidance

+/-6 kV contact

+/-8 kV air

+/-2 kV for power

supply lines

+/-1 kV for input/

output lines

+/-1 kV differential

mode

+/-2 kV common

mode

<5% Ut

(>95% dip in Ut)

for 0,5 cycle

40% Ut

(>60% dip in Ut)

for 5 cycles

70% Ut

(>30% dip in Ut)

for 25 cycles

<5% Ut

(>95% dip in Ut)

for 5 sec

Floors should be wood, concrete or
ceramic tile. If floors are covered with
synthetic material, the relative humidity
should be at least 30%.

Mains power quality should be that of a
typical commercial or hospital environment.

Mains power quality should be that of a
typical commercial or hospital environment.

Mains power quality should be that of a
typical commercial or hospital environment.
If the user of the Force EZ-C Series
Electrosurgical Generator requires
continued operation during power mains
interruptions, it is recommended that the
Force EZ-C Series Electrosurgical
Generator be powered from an
uninterruptible power supply or a battery.

Power frequency (50/60

Hz) magnetic field

IEC 61000-4-8

NOTE: Ut is the a.c. mains voltage prior to the application of the test level.

3 A/m 3 A/m Power frequency magnetic fields should be

at levels characteristic of a typical location
in a typical commercial or hospital
environment.

Force EZ-C Series Service Manual 4-11

Technical Specifications

Standards and IEC Classifications

Guidance and manufacturer's declaration - electromagnetic immunity

The Force EZ-C Series Electrosurgical Generator is intended for use in the electromagnetic environment specified
below. The customer or the user of the Force EZ-C Series Electrosurgical Generator should assure that it is used in
such an environment.

Immunity test IEC 60601 test level Compliance level Electromagnetic environment -

guidance

Portable and mobile RF
communications equipment should be
used no closer to any part of the Force
EZ-C Series Electrosurgical Generator,
including cables, than the
recommended separation distance
calculated from the equation applicable
to the frequency of the transmitter.

Conducted RF IEC

61000-4-6

Radiated RF

IEC 61000-4-3

NOTE 1 At a 80MHz and 800MHz, the higher frequency range applies.
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and

reflection from structures, objects and people.

3 Vrms

150KHz to 80MHz

3 V/m

80MHz to 2.5GHz

7 V

7 V/m

Recommended separation distance

√P

d=0.5

√P 80MHz to 800MHz

d=0.5

√P 800MHz to 2.5GHz

d=

Where P is the maximum output power
rating of the transmitter in watts (W)
according to the transmitter
manufacturer and d is the
recommended separation distance in
meters (m).

Field strengths from fixed RF
transmitters, as determined by an
electromagnetic site survey, should be
less than the compliance level in each
frequency range

Interference may occur in the vicinity of
equipment marked with the following
symbol:

a. Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land
mobile radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with
accuracy. To assess the electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey
should be considered. If the measured field strength in the location in which the Force EZ-C Series Electrosurgical
Generator is used exceeds the applicable RF compliance level above, the Force EZ-C Series Electrosurgical
Generator should be observed to verify normal operation. If abnormal performance is observed, additional measures
may be necessary, such as reorienting or relocating the Force EZ-C Series Electrosurgical Generator.

b. Over the frequency range 150kHz to 80MHz, field strengths should be less than 7V/m.

4-12 Force EZ-C Series Service Manual

Standards and IEC Classifications

Recommended separation distances between portable and mobile RF communication equipment and the

Force EZ-C Series Electrosurgical Generator

The Force EZ-C Series Electrosurgical Generator is intended for use in an electromagnetic environment in which
radiated RF disturbances are controlled. The Customer or the user of the Force EZ-C Series Electrosurgical
Generator can help prevent electromagnetic interferences by maintaining a minimum distance between portable and
mobile RF communications equipment (transmitters) and the Force EZ-C Series Electrosurgical Generator as
recommended below, according to the maximum output power of the communications equipment.

Separation distance according to frequency of transmitter (m)

Rated maximum output

power of transmitter (W)

0.01 0.05 m 0.05 m 0.1 m

0.1 0.16 m 0.16 m 0.32 m

1 0.5 m 0.5 m 1 m

150 kHz to 80MHz

d=0.5√P

80MHz to 800MHz

d=0.5√P

800MHz to 2.5GHz

d=√P

10 1.6 m 1.6 m 3.2 m

100 5 m 5 m 10 m

For transmitters rated at a maximum output power not listed above, the recommended separation distance d in
meters (m) can be estimated using the equation applicable to the frequency of the transmitter, where P is the
maximum output power rating of the transmitter in watts (W) according to the transmitter manufacturer.

NOTE 1 At a 80MHz and 800MHz, the separation distance for the higher frequency range applies.
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and

reflection from structures, objects and people.

Technical Specifications

Force EZ-C Series Service Manual 4-13

Output Characteristics

Output Characteristics

Available Power Settings in Watts

Bipolar

12345678910
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
45 50 55 60 65 70

Monopolar Cut: Pure

12345678910
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
45 50 55 60 65 70 75 80 85 90
95 100 110 120 130 140 150 160 170 180
190 200 210 220 230 240 250 260 270 280
290 300

Monopolar Cut: Blend

12345678910
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
45 50 55 60 65 70 75 80 85 90
95 100 110 120 130 140 150 160 170 180
190 200

4-14 Force EZ-C Series Service Manual

Output Characteristics

Monopolar Coag

12345678910
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
45 50 55 60 65 70 75 80 85 90
95 100 110 120

Maximum Output for Force EZ-C Series Electrosurgical
Generator Modes

Power readouts agree with actual power into rated load to within 15% or 5 watts,
whichever is greater.

Crest Factor

Open Circuit P-

Mode

Bipolar 300 V 100 Ω 70 W 1.5

Monopolar Cut

Pure
Blend

Monopolar
Coag

Low 1
Low 2
Low 3
High 1
High 2

P Voltage (max) Rated Load

(max)

2000 V
3400 V

3500 V

660 V
1100 V
6000 V
8500 V

Ω

300
300 Ω

Ω

500
300 Ω
300 Ω
500 Ω
500 Ω

Power (max)

300 W
200 W

120 W
120 W
120 W
120 W
120 W

(typical @

Rated Load)

1.5

2.1

5.0

1.5

1.5

4.9

7.0

a. An indication of a waveform’s ability to coagulate bleeders without a cutting effect

a

Technical Specifications

Force EZ-C Series Service Manual 4-15

Output Characteristics

Output Waveforms

Instant Response Technology, an automatic adjustment, applies to the bipolar
mode, the cut modes, and the low 2 and low 3 coag settings. It does not apply to
the low 1, high 1, and high 2 coag settings. As tissue resistance increases, the
generator produces constant current followed by constant power followed by
constant voltage. The generator controls maximum output voltage to reduce
capacitive coupling and video interference, and to minimize sparking.

Bipolar

Standard

Monopolar Cut

Pure

Blend

Monopolar Coag

Desiccation

Low 1

Low 2

Low 3

Fulguration

High 1

470 kHz sinusoid

393 kHz sinusoid
393 kHz bursts of sinusoid recurring at 27.1 kHz

intervals, 50% duty cycle

240 ±40 kHz sinusoid recurring at 39 kHz.
8% duty cycle at open load

393 kHz sinusoid
393 kHz sinusoid

470 kHz damped sinusoidal bursts with a repetition
frequency of 57 kHz at open load

High 2

470 kHz damped sinusoidal bursts with a repetition
frequency of 30 kHz at open load

4-16 Force EZ-C Series Service Manual

Output Power vs. Resistance Graphs

The graphs that follow depict the changes for each mode at specific power
settings.

Bipolar Graph

The insulating surface described in IEC 60601-2-2 and full length leads was used
to obtain the bipolar output measurements.

Figure 4-1.

Standar d Bip o l ar mo de — load
resistance vs. output power

100

90

80

70

60

50

40

Output Power vs. Resistance Graphs

30

Output Power (watts)

20

10

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Load Resistance (ohms)

70 W
30 W

Technical Specifications

Force EZ-C Series Service Manual 4-17

Output Power vs. Resistance Graphs

Monopolar Cut Graphs

Valleylab used the procedures described in IEC 60601-2-2 and full length leads to
obtain the monopolar cut output measurements.

Figure 4-2.

Pure mode — load resistance vs.
output power

350

300

Figure 4-3.

Blend mode — load resistance
vs. output power

250

200

150

100

Output Power (watts)

50

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Load Resistance (ohms)

250

225

200

175

150

300 W

120 W

200 W

125

100

75

Output Power (watts)

50

25

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

80 W

Load Resistance (ohms)

4-18 Force EZ-C Series Service Manual

Figure 4-4.

O

t

t

P

(

tt

)

Low 1 (Desiccate) mode — load
resistance vs. output power

Output Power vs. Resistance Graphs

Monopolar Coag Graphs

The procedures described in IEC 60601-2-2 and full length leads were used to
obtain the monopolar coag output measurements.

Output Power (watts)

Figure 4-5.

Low 2 (Desiccate) mode — load
resistance vs. output power

Load Resistance (ohms)

140

120

100

s

80

wa

60

ower

40

pu
u

20

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Load Resistance (ohms)

60 W

120 W

Technical Specifications

Force EZ-C Series Service Manual 4-19

Output Power vs. Resistance Graphs

Figure 4-6.

Low 3 (Desiccate) mode — load
resistance vs. output power

Figure 4-7.

High 1 (Fulgurate) mode — load
resistance vs. output power

140

120

100

80

60

Output Power (watts)

40

20

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Load Resistance (ohms)

140

120

120 W

60 W

100

80

60

40

Output Power (watts)

20

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Load Resistance

Load Resistance

120 W

60 W

4-20 Force EZ-C Series Service Manual

Figure 4-8.

High 2 (Fulgurate) mode — load
resistance vs. output power

Output Power vs. Resistance Graphs

Output Power (watts)

Load Resistance

Force EZ-C Series Service Manual 4-21

Technical Specifications

Output Power vs. Resistance Graphs

Output Power vs. Generator Settings

Figure 4-9.

Standard Bipolar mode
@ 100 ohms — generator setting
vs. output power

70

60

50

40

30

Figure 4-10.

Standard Bipolar mode — peak
voltage vs. output power

Output Power (watts)

20

10

0

020406070

Generator Setting

503010

140

120

100

80

60

40

20

Open Circuit Peak Voltage (volts)

0

1 10203040506070

Output Power (watts)

4-22 Force EZ-C Series Service Manual

Output Power vs. Resistance Graphs

Figure 4-11.

Pure mode @ 300 ohms —
generator setting vs. output power

Figure 4-12.

Pure mode — peak voltage vs.
output power

300

250

200

150

100

Output Power (watts)

50

0

0 100 200 300

Generator Setting

1000

800

600

400

200

Open Circuit Peak Voltage (volts)

0

1

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

Output Power (watts)

Technical Specifications

Force EZ-C Series Service Manual 4-23

Output Power vs. Resistance Graphs

Figure 4-13.

Blend mode @ 300 ohms —
generator setting vs. output power

200

180

160

140

120

100

80

60

Output Power (watts)

40

20

0

0 50 100 150 200

Generator Setting

Figure 4-14.

Blend mode — peak voltage vs.
output power

Open Circuit Peak Voltage (volts)

1600

1400

1200

1000

800

600

400

200

0

1

20

40

60

80

100

120

140

160

180

200

Output Power (watts)

4-24 Force EZ-C Series Service Manual

Figure 4-15.

Low 1 (Desiccate) mode
@ 500 ohms — generator setting
vs. output power

Output Power vs. Resistance Graphs

Output Power (watts)

Generator Setting

Figure 4-16.

Low 1 (Desiccate) mode — peak
voltage vs. output power

Open Circuit Peak Voltage (volts)

2500

2000

1500

1000

500

0

1 10 20 30 40 50 60 70 80 90 100 110 120

Output Power (watts)

Technical Specifications

Force EZ-C Series Service Manual 4-25

Output Power vs. Resistance Graphs

Figure 4-17.Low 2 (Desiccate)
mode @ 300 ohms— generator
setting vs. output power

120

100

80

60

40

Output Power (watts)

20

0

0 20 100 120

40 60 80

Generator Setting

Figure 4-18.

Low 2 (Desiccate) mode — peak
voltage vs. output power

300

250

200

150

100

Open Circuit Peak Voltage (volts)

50

0

1 10 20 30 40 50 60 70 80 90 100 110 120

Output Power (watts)

4-26 Force EZ-C Series Service Manual

Figure 4-19.

Low 3 (Desiccate) mode
@ 300 ohms— generator setting
vs. output power

Figure 4-20.

Low 3 (Desiccate) mode — peak
voltage vs. output power

500

450

Output Power vs. Resistance Graphs

120

100

80

60

Output Power (watts)

40

20

0

0 20 100 120

40 60 80

Generator Setting

400

350

300

250

200

150

100

Open Circuit Peak Voltage (volts)

50

0

1 10 20 30 40 50 60 70 80 90 100 110 120

Output Power (watts)

Technical Specifications

Force EZ-C Series Service Manual 4-27

Output Power vs. Resistance Graphs

Figure 4-21.

High 1 (Fulgurate) mode
@ 500 ohms— generator setting
vs. output power

Figure 4-22.

High 1 (Fulgurate) mode — peak
voltage vs. output power

Output Power (watts)

3500

3000

120

100

80

60

40

20

0

0 20 100 120

40 60 80

Generator Setting

2500

2000

1500

1000

500

Open Circuit Peak Voltage (volts)

0

1 10 20 30 40 50 60 70 80 90 100 110 120

Output Power (watts)

4-28 Force EZ-C Series Service Manual

Figure 4-23.

High 2 (Fulgurate) mode
@ 500 ohms— generator setting
vs. output power

Figure 4-24.

High 2 (Fulgurate) mode — peak
voltage vs. output power

Output Power vs. Resistance Graphs

120

100

80

60

40

Output Power (watts)

20

0

0 20 100 120

40 60 80

Generator Setting

4500

4000

3500

3000

2500

2000

1500

1000

Open Circuit Peak Voltage (volts)

500

0

1 10 20 30 40 50 60 70 80 90 100 110 120

Output Power (watts)

Force EZ-C Series Service Manual 4-29

Technical Specifications

4-30 Force EZ-C Series Service Manual

1Principles of Operation

This section provides detailed information about how the
Force EZ-C Electrosurgical Generator functions and how the
internal components of the generator interact.

SECTION

5

The Force EZ-C Series Electrosurgical Generator circuitry resides
on four printed circuit boards: the Control board, the Display board,
the Footswitch board, and the power supply/radio frequency (RF)
board.

This section includes the following information:

• a block diagram that illustrates how the generator functions

• an overview that describes, in general terms, the functionality of
the generator

• detailed descriptions of the circuitry for each Printed Circuit board

Force EZ-C Series Service Manual 5-1

Pencil Button Switch Wires

Isolation

Circuit

RMS to DC

Converter

Cut/Coag

Buttons

Current

RMS to DC

Converter

Output

Sense

Voltage

Transformer

Monopolar

Active

Sense

Patient

Bipolar

Output

Amplier

Return

Current

Sense

Output

Resonator

Variable Output

Electrode

High Voltage DC

Power Supply

Voltage

Scaling

VPK+

HV_SEN

RMS to DC

Converter

I_SEN

RMS to DC

Converter

V_SEN

REM

Circuit

R_SEN

Battery

Backed

Time

Clock

Date/Time

RAM

Watchdog

LVDC Monitor

Calibration Values

Footswitch Command

Serial Data

Footswitch

Decode

Serial

Por t

Real-

Calibration Values

Figure 5-1.

A block diagram of the
Force EZ-C Series generator

Digital Pencil Button Commands

Dosage Error

Main

Microcontroller

A to D Converter

Display Data

Control Input

Audio

Display

Keyboard

I2_SEN

Control

Audio

V2_SEN

R_SEN

SYS_ECON

HV_SEN

RF Drive

Output

Dual Port RAM

T_ON AVG

Wavefo rm

Microcontroller

Wavefo rm

Control

SYS_ECON

HVDC Control

Feedback

Microcontroller

Digital to

Analog

Converter

A to D Converter

Output and

Relay

Control

T_ON AVG

Scaling Relays

5-2 Force EZ-C Series Service Manual

Functional Overview

Functional Overview

Principles of Operation

The Valleylab Force EZ-C Series Electrosurgical Generator is specifically
designed for use in bipolar or monopolar electrosurgery to cut and coagulate
(desiccate and fulgurate) tissue. In electrosurgery, radio frequency (RF) current
flows from the generator to an active electrode, which delivers the current to the
patient. The resistance to the current, provided by the patient’s tissue and/or the
air between the active electrode and the tissue, produces the heat that is necessary
for the surgical effect. The RF current flows from the active electrode through the
patient’s body tissue to the return electrode, which recovers the current and
returns it to the generator.

Instant Response Technology

The Force EZ-C Series Electrosurgical Generator automatically senses resistance
and adjusts the current and output voltage to maintain a consistent effect across
different tissue density. It bases this adjustment on the selected mode, the power
setting, and the level of tissue resistance. As tissue resistance increases, the
generator outputs constant current followed by constant power followed by
constant voltage. The generator controls maximum output voltage to reduce
capacitive coupling and video interference and to minimize sparking. It applies
this technology to all generator modes except the
low 1 (desiccate) coag setting and the two high (fulgurate) coag settings. For
details, refer to Instant Response Algorithm in this section.

REM Contact Quality Monitoring System

The Force EZ-C Series Electrosurgical Generator uses the Valleylab REM
Contact Quality Monitoring System to monitor the quality of electrical contact
between the patient return electrode and the patient. The REM system reduces the
risk of burns at the return electrode site during monopolar electrosurgery.

When you connect a REM patient return electrode to the Patient Return Electrode
receptacle, you activate the REM system. When you activate monopolar output,
the generator connects the patient return electrode path. If you activate bipolar
output when a return electrode is applied to the patient, the generator
automatically deactivates the return electrode circuit to eliminate the possibility of
current dispersal.

The REM system continuously measures the resistance at the return electrode site
and compares it to a standard range of safe resistance (between 5 and 135 ohms),
thus eliminating intermittent false alarms that could result from small changes in
resistance. The REM system also adapts to individual patients by measuring the
initial contact resistance (baseline resistance) between the patient and the patient
return electrode. If the tissue impedance at the return electrode decreases during
the surgical procedure, the REM system resets the baseline resistance.

Force EZ-C Series Service Manual 5-3

Control Board

REM Alarm Activation

The REM Alarm indicator flashes red, a tone sounds, and the generator stops
producing output power when either of the following occurs:

• The measured resistance is below 5 ohms or above 135 ohms, the limits of the
standard range of safe resistance.

• An increase in contact resistance is greater than 40% from the initial
measurement (baseline resistance).

The REM alarm indicator remains illuminated red until you correct the condition
causing the alarm. Then, the indicator illuminates green and the generator enables
RF output.

Electrodes Without the REM Safety Feature

When you use a patient return electrode that does not have the REM safety
feature, the REM system does not monitor the patient contact area. It monitors
only the pin-to-pin resistance at the connector and can detect broken wires or
connectors in the return electrode cord.

The REM indicator does not illuminate green when you connect a patient return
electrode without the REM safety feature. Instead, the generator extinguishes the
indicator light. If the generator detects a break in continuity between the electrode
and the generator, the REM alarm indicator illuminates red.

Control Board

When resistance between the patient return electrode receptacle pins exceeds 20
ohms, the REM Alarm indicator flashes red, a tone sounds twice, and the
generator disables RF output. The REM Alarm indicator remains illuminated red
until you correct the condition causing the alarm. Then, the generator
extinguishes the red indicator light and enables RF output.

Refer to Section 10, Service Parts, for components and the Schematics
Supplement for the board drawing and schematic.

The Control board contains the circuitry that controls the generator, including the
indicators and switches on the Display board and the RF output stage on the
Power Supply/RF board. Firmware on the Control board performs many
diagnostic and initialization routines. It also reports errors as alarm numbers on
the front panel. For a complete list of alarm numbers, refer to Section 7,
Responding to System Alarms.

The Control board interfaces with the Power Supply/RF board through a 96-pin
card edge connector. It interfaces with the Display board through a 64-pin ribbon
cable.

5-4 Force EZ-C Series Service Manual

Control Board

Microcontrollers

Two microcontrollers on the Control board (the main microcon troller an d the
feedback microcontroller) work together to control the generator. They
communicate with each other through a shared RAM. The main microcontroller
(U5) performs all system functions, except the time-critical real time feedback
control of generator RF output. The feedback microcontroller (U11), which is a
separate, dedicated microcontroller, handles this. All system analog signals are
available to these microcontrollers.

A third microcontroller (U9) functions as an application-specific integrated
circuit, or ASIC. It generates the RF drive waveforms (T_ON\) for the RF output
stage.

Main Microcontroller

The main microcontroller (U5) is an 80C562 that incorporates an 8-input
multiplexed 8-bit analog-to-digital (A/D) converter. The main microcontroller
performs the following activities:

• monitors all dosage error functions and safety circuits

• implements the user interface, including activation control

• communicates with the feedback microcontroller

Principles of Operation

It is primarily responsible for these functions:

• segment display drivers and LED update

• power control knob, mode buttons, and the activation interface

• serial port interface

• alarm handling

•REM

• audio control

• memory control and storage (system alarms with time stamps, calibration
values)

• real-time clock control and interface

• internal self-tests

• dosage error monitoring

• setup mode (for special features)

Force EZ-C Series Service Manual 5-5

Control Board

Main Microcontroller Memory

An ST microelectronics PSD835G2 programmable systems device (U3) provides
program memory (512K x 8 external flash memory) and data memory (2K x 8
external battery-backed static RAM) for the main microcontroller. Additional
data memory is available from these sources:

• 256 x 8 microcontroller internal RAM

• 4K x 8 external static RAM (U4) shared with the feedback microcontroller

• 128 x 8 external battery-backed static RAM inside the real-time clock (U1)

Battery-Backed RAM

A socket on the Control board contains a 3.0 V lithium button cell battery (BT1)
that provides backup power for the 2K x 8 external RAM on the PSD835G2
device (U3) and the 128 x 8 external RAM on the real-time clock (U1) used by
the main microcontroller. The battery-backed RAM stores statistical data about
generator use, calibration constants, special features settings, and last setup
parameters.

Feedback Microcontroller

The feedback microcontroller (U11) is an 80C562. It receives commands from the
main microcontroller and, when the generator is activated, establishes the
appropriate relay closures and activates RF output. The feedback microcontroller
continually adjusts the output signal of the generator by controlling the high
voltage DC power supply and the RF clock circuitry. The feedback
microcontroller serves the following primary functions:

• scaling relay control and output relay control

• T_ON ASIC waveform control

• leakage control (coag)

• constant voltage, current, and power feedback control

• ECON initialization

• real-time information update (actual voltage, current, power, impedance,
Instant Response System)

• memory tests

Feedback Microcontroller Memory

An ST microelectronics PSD835G2 programmable systems device (U6) provides
program memory (512K x 8 external flash memory) and data memory (2K x 8
external static RAM) for the feedback microcontroller. Additional dat a memory is
available from these sources:

• 256 x 8 microcontroller internal RAM

• 4K x 8 external static RAM (U4) shared with the main microcontro ller

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Control Board

Shared RAM

An IDT 713425A device (U4) with semaphore flags provides the 4K x 8 external
shared static RAM. The shared RAM allows the main microcontroller (U5) and
the feedback microcontroller (U11) to share common variables. It functions as a
communications interface between the main and feedback microcontrollers. It
also provides these microcontrollers with additional general purpose RAM.

Real-Time Clock

The real-time clock (U1), a DS12885, tracks the date and time of day and
provides 128 bytes of battery-backed RAM. Of the 128 bytes, it uses 14 internal
to the chip for the clock and control registers. The main microcontroller uses 114
bytes of general purpose RAM to store calibration constants, special features
settings, and last setup parameters.

I/0 Expansion

Three devices provide I/O expansion capabilities:

• One ST microelectronics PSD835G2 programmable systems device

• One ST microelectronics PSD835G2 programmable systems device

• 82C55 expansion port (U2)

Principles of Operation

The ST Microelectronics PSD835G2 incorporates 52 individually programmable
I/O pins divided into 6 ports of 8-bits each and 1 port of 4-bits. Of the general I/O
pins, 24 can by alternatively utilized for 24 PLD outputs. The PSD835G2 also
contains 512K x 8 main flash memory, 32K x 8 boot flash memory, 2K x 8 of
SRAM, and a power management unit for battery backup. The power
management unit for battery backup is not used by the feedback microcontroller.
The I/O expansion capabilities of the feedback PSD835G2 has a built-in IEEE

1149.1 compliant JTAG serial port to allow full-chip in-system programmability
(ISP). The main PSD835G2 is #1 on the JTAG chain and the feedback
PSD835G2 with the exception that the 512K x 8 flash memory for the main
PSD835G2 is accessed in a bank switching methodology and the I/O expansion
capabilities are configured as outputs for lamp control, keyboard scanning, and
chip selects. The 82C55 is configured as all inputs, and is used to read the
keyboard, keying signals, accessory switches, and system status flags.

Keyboard Interface and Activation Inputs

The keyboard interface is a simple row and column matrix between three bank
select output lines (BANK0–BANK2) on port A of the PSD835G2 (U3) used by
the main microcontroller and eight keyboard (KBD_D0–KBD_D7) input lines on
port A of the 82C55 expansion port (U2).

Port B of the 82C55 expansion port reads activation inputs from the IsoBloc
decoding circuits on the Power Supply/RF board.

Force EZ-C Series Service Manual 5-7

Control Board

Power Supply Supervisor Circuit

The power supply supervisor circuit (U14), a MAX691, generates a Reset signal
and a Reset\ signal for the main microcontroller (U5) if the power supply voltage
to the Control board drops below 4.65 V. Reset\ also places the PSD835G2 (U3)
and the PSD835G2 (U6) in sleep mode and disables the 2K x 8 external static
RAM.

A/D and D/A Conversion

Each 80C562 microcontroller (U5 and U11) contains an 8-channel multiplexed 8­bit A/D converter. Incorporating gain scaling relays in the sense circuits on the
Power Supply/RF board and prescaling based on the expected input voltage or
current values enhances the resolution of voltage and current sense inputs.

The main microcontroller senses redundant RF output current and voltage from
additional sense circuits located on the Power Supply/RF board. The system does
not gain scale this information since it is for dosage monitoring only.

An MP7226 quad digital-to-analog (D/A) converter (U15) provides 4-channel 8­bit D/A capabilities for the feedback microcontroller to output 0 to 5 Vdc analog
voltages.

Waveform Generation (T_ON ASIC)

A dedicated 89C54 microcontroller (U9) generates the RF waveforms (T_ON\)
for the RF output amplifier on the Power Supply/RF board. The microcontroller
functions as an application-specific integrated circuit (ASIC) performing an
endless series of repetitive tasks while enabled.

The feedback microcontroller (U11) holds the T_ON ASIC (U9) in a reset state
until the feedback microcontroller detects a valid activation request. After
validating the request, the feedback microcontroller releases the T_ON ASIC
from reset and communicates a 4-bit code that represents the generator mode to
be activated. Six activation codes are acceptable:

• 0: bipolar

• 2: pure, low 2, and low 3

•3: blend

• 7: low 1

• 8: high 1

• C: high 2

The Force EZ-C Series Electrosurgical Generator does not use Codes 1, 4, 5, 6,
9,A,B, and D-F.

Each code generates a unique waveform pattern to be delivered to the RF output
stage of the generator. The T_ON ASIC reads and evaluates the code and, if the
code value is acceptable, repetitively generates the appropriate waveform until
the activation request ends. After the request ends, the feedback microcontroller
places the T_ON ASIC back into reset.

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Control Board

If the code received by the T_ON ASIC is not valid, the internal program sets an
error flag, deactivates all output signals, and remains in an error state until the
system is reset.

T_ON Average Check

Hardware integrates the T_ON waveform generator output waveform and
returns it to the main microcontroller as an analog value called T_ON average.
The T_ON average is different for each distinct output mode of the T_ON
waveform generator. The main microcontroller continually checks the T_ON
average for compliance with the calibrated value to ensure that the T_ON
waveform generator is operating properly.

The T_ON average signal rests at 5 V when the generator is inactive and drops to
the calibrated value when activation occurs. The main microcontroller checks to
make sure the T_ON average signal is within ± 15 counts of the calibrated value.

During spark control in the cut modes or wak control in the coag modes, the
T_ON average rises an indeterminate amount. Due to this unknown, the system
allows the T_ON average to rise to 253 counts, which guarantees the T_ON
waveform generator is still operating. It still does not allow The T_ON average to
drop below the lower limit of 15 counts mentioned above.

Principles of Operation

Audio Alarm

The audio alarm circuit resides on the Power Supply/RF board. Software and
hardware control the audio alarm:

• The UP_TONE\ and LO_TONE signals generated by the main
microcontroller in response to activation inputs, alarms, and power-up provide
software control.

• The RF_TONE\ signal generated in the RF output stage by RF sensing
circuitry on the Power Supply/RF board provides hardware control.

Serial Interface

The RS-232 serial port is a software-polled interface to the main microcontroller
(U5). It provides diagnostics and calibration to an external device (for example, a
computer) connected to the port. Transmission and receipt of command strings do
not stop real time processing, except as single characters are read from or written
to the serial port. The serial port configuration is the following:

• 9600 baud

• 8 data bits,

• 1 stop bit

• no parity

The system derives this timing from the main microcontroller oscillator frequency
of 11.0592 MHz.

The Control board serial port signals connect to the Power Supply/RF board
through the 96-pin connector. The signals then connect to the 9-pin serial port
connector on the Power Supply/RF board.

Force EZ-C Series Service Manual 5-9

Control Board

Dosage Error Algorithm

The basis for the dosage error algorithm for the closed loop modes (bipolar, cut,
and the low 2 and low 3 settings) is a comparison between two microcontroller/
sensor sets:

• backup current and voltage sensors, read by the main microcontroller (U5)

• primary current and voltage sensors, read by the feedback microcontroller
(U11)

Each microcontroller monitors one set of sensors and calculates real-time output
current, voltage, and power. While the feedback microcontroller operates the
generator, the main microcontroller checks the values to make sure the main and
feedback microcontroller calculations agree.

In a closed loop mode, there is a 500 ms delay before the dosage error algorithm
monitors the rms output of the generator. After the delay, the algorithm first
checks to see that the voltage and current calculated by the backup sensors are
less than 125% of the value calculated by the primary sensors. On passing this
test, the algorithm checks the feedback mode of the generator:

• In current control mode, the current calculated by the backup sensors should
not deviate from the current calculated by the primary sensors by more than
50% of the value calculated by the primary sensors.

• In power control mode, the power calculated by the backup sensors should not
be greater than 125% of the value calculated by the primary sensors.

• In voltage control mode, the voltage calculated by the backup sensors should
not deviate from the voltage calculated by the primary sensors by more than
50% of the value calculated by the primary sensors.

During closed loop activation, the main microcontroller continually checks for
broken backup sensors. It compares the current and voltage sensor analog values
to the previous readings to ensure that the sensor values are not constant or falling
while ECON is rising.

The basis for the dosage error algorithm for the open loop modes (the
low 1, high 1, and high 2 settings) is the ECON calculated for the mode. The main
microcontroller calculates an ECON that represents 125% of the front panel
power setting and verifies that SYS_ECON and HV_SEN do not exceed this
value while the generator is activated.

These tests detect power output while not activated, stuck or aberrant sensors, and
improperly delivered power. The dosage error firmware executes in less than one
second.

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Control Board

Instant Response Algorithm

The Force EZ-C Series Electrosurgical Generator’s Instant Response system is a
closed loop control algorithm implemented in microcontroller firmware. The
system applies it to some settings, but not others:

• Applied to

• bipolar

• monopolar cut modes

• low 2 coag

• low 3 coag

• Not applied to

•low 1

• high 1

• high 2 coag

As tissue impedance increases from short circuit to open circuit, the algorithm
implements first constant current, then constant power, and finally, constant
voltage. Controlling the maximum output voltage reduces capacitive coupling,
reduces video interference, and eliminates sparking. At low impedances, constant
current protects output circuitry. At high impedances, constant voltage control
limits arcing and electromagnetic interference (EMI).

Principles of Operation

Constant Current

The algorithm holds output current constant according to this equation:
I = (P/R) ˆ(1/2)
where I is the output current, P is the power set by the user, and R is the constant

current to constant power impedance switchpoint.

Constant Power

The algorithm maintains the power set by the user.

Constant Voltage

The algorithm controls the output voltage according to the following equation:
V = (P*R) ˆ(1/2)
where V is the output voltage, P is the power set by the user, and R is the constant

power to constant voltage impedance switchpoint.

High Impedance Instant Response Operation

The firmware algorithm clamps the output voltage to specific levels for high
impedance conditions. The clamp level is a function of the active mode. This
helps prevent arcing and electromagnetic interference (EMI).

Force EZ-C Series Service Manual 5-11

Display Board

Display Board

Analog to Digital Saturation

If the analog to digital converter is saturated, the Instant Response feedback loop
reduces the output voltage to allow an unsaturated operating condition. The
feedback loop switches the control function to maintain the analog to digital
converter in the linear operating range.

Refer to the Schematics Supplement for the schematic.
The Display board resides in the fron t panel assem bly. It contains several types of

display:

• LED displays

• seven-segment power setting displays

• RF indicator lamps

The Display board switch circuitry includes the following components:

• mode selection switches

• encoders for changing power settings

• REM switch circuit

• footswitch decoding circuit for the front panel Footswitch receptacle

Bipolar, Cut, and Coag Power Setting Encoders

Three mechanical encoders (S1, S3, and S6) change the current power settings for
bipolar (S1), cut (S3), and coag (S6). The encoders effectively contain two
switches that open and close as the knob turns, either shorting the encoder output
to DGND or allowing pull-up resistors on the Control board to pull the encoder
output high. The switches open and close 90 degrees out of phase. The system
determines the knob’s turning direction by determining which switch is leading
the other. The result seen by the main microcontroller is a 2-bit binary code in
which only one bit changes for each state change. When the knob turns clockwise,
the switches cycle through states 00, 10, 11, 01, 00, etc; counterclockwise, the
cycle reverses (00, 01, 11, 10, 00, etc).

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Display Board

RF Indicator Lamps

The RF indicator lamps illuminate during RF activation to indicate the presence
of RF power. Four incandescent bulbs (LP1–LP12) illuminate each of the three
indicator bars (bipolar, cut, and coag) on the front panel:

• LP1–LP4 illuminate the bipolar bar, changing its color from white to blue to
indicate bipolar activation.

• LP5–LP8 illuminate the yellow bar, indicating cut activation.

• LP9–LP12 illuminate the blue bar, indicating coag activation.

Field effect transistors (FETs) Q1, Q4, and Q5 turn the RF indicator lamps on and
off. Resistors R2, R3, R4, R10, R39, R40, R42, R44, R49, R50, R52, and R54 set
the amount of current flowing through the lamps when they are turned on. The
value of these resistors varies for each indicator bar, depending on the color of the
bar, to make the different colors of the bars illuminate with equal intensities. Pull­down resistors R1, R47, and R48 attach to gates Q1, Q4, and Q5 to reduce the
input impedance of Q1, Q4, and Q5 as seen by the main microcontroller on the
Control board. This rounds off the edges of these digital signals, reducing high
frequency emissions. The lowered impedance also reduces the susceptibility of
the circuit to noise from other circuits.

LED and Seven-Segment Display Drivers

Principles of Operation

This circuit contains two display drivers: the LEDs and the seven-segment
displays The LEDs indicate modes of operation, REM condition, and the selected
footswitch mode. The seven-segment displays indicate bipolar, cut, and coag
power settings.

Each display driver (U5 and U6) can drive up to eight banks of eight LEDs by
multiplexing the time that it turns each bank on. Wiring the banks together
increases the time that a group of LEDs can remain on, effectively increasing the
brightness of that group.

U6 drives the discrete LEDs. These include green indicators for several displays:

• cut modes (pure and blend)

• coag modes (low and high)

• bipolar and accessory footswitch arrow indicators

• eight red/green bicolor LEDs for the REM indicator

The anode of the mode and footswitch selection LEDs (D1–D6) connect to driver
U6, pin 16 (digit 2) and pin 23 (digit 3). Using pairs of the driver digit lines makes
the effective duty ratio for these LEDs 1/4:

• The red anodes of the REM LEDs connect to U6, pins 17 and 20 (digits 4 and

5) for a 1/4 duty cycle.

• The green anodes of the REM LEDs connect to U6, pins 18, 21, and 22 (digits
6-8) for a 3/8 duty cycle.

Force EZ-C Series Service Manual 5-13

Display Board

U5 drives the seven-segment displays that indicate power settings:

• DS1 and DS2 indicate the bipolar power setting

• DS3–DS5 indicate the cut power setting

• DS6–DS8 indicate the coag power setting.
The anodes of these displays each connect to only one digit line of the driver. The

effective duty cycle is 1/8 for each seven-segment display.
Some filtering components are associated with U5 and U6. Bypass capacitors

C19, C20, C21, and C22 connect between + 5V and DGND. C19 and C21 have a
relatively small capacitance value of 0.1 µF to filter higher frequency noise. C20
and C22 have a relatively large capacitance value of 47 µF to supply the large
spikes of current for the LEDs. The multiplexing action of the drivers, which
typically occurs at 250 Hz, generates the large current spikes.

Resistors R18, R20, R22, R24, R26, R28, R30, R32, R34, R36, and R38 reduce
the input impedance of the display driver inputs as seen by the main
microcontroller on the Control board. This rounds off the edges of these digital
signals, reducing high frequency emissions. The lowered impedance also reduces
the susceptibility of the circuit to noise from other circuits.

Mode Selection Switches

The mode selection switch circuitry uses five discrete switches (S2, S4, S5, S7,
and S8). S2 toggles the front panel footswitch control between bipolar output or
single-pin accessory output. S4 and S5 select the pure and blend cut modes. S7
and S8 select the low or high coag modes.

FETs Q2, Q3, and Q6 select a bank of switches for the main mi crocontroller to
read. When one of the digital signals (BANK0–BANK2) is high, the
corresponding FET pulls its output low allowing the main microcontroller to read
any switch closure in that bank as a logic low. If a switch is not pressed, a pull-up
resistor on the Control board pulls the corresponding output (KBD_D6 or
KBD_D7) high and the main microcontroller reads it as a logic high. Resistors
R16, R43, and R53 pull the outputs of Q2, Q3, and Q6 high when they are off.
Pull-up resistors R15, R41, and R51 attach to gates Q2, Q3, and Q6 to reduce the
input impedance as seen by the main microcontroller on the Control board. This
rounds off the edges of these digital signals, reducing high frequency emissions.
The lowered impedance also reduces the susceptibility of the circuit to noise from
other circuits.

Schottky diodes (Z1–Z5) prevent false switch readings if someone presses
multiple switches. For example, when S4, S5, and S7 are all closed and the
BANK2 signal is high, Q6 pulls KBD_D6 low through S7. If Z2 is not placed in
line with S4, the output of Q3 is pulled low through S4, and KBD_D7 is pulled
low through S5. To the main microcontroller, S7 and S8 appear to be pressed;
however, since S8 is not pressed, this reading is false. Schottky diodes are used
because the logic low level placed on KBD_D6 or KBD_D7 must be below 0.8
volts to be read correctly.

5-14 Force EZ-C Series Service Manual

Display Board

REM Switch Circuit

The REM switch circuit detects the presence of a REM patient return electrode
plugged into the Patient Return Electrode receptacle. The center plastic pin on the
REM plug moves a mechanical lever in the receptacle, allowing it to sense the
plug and open S9. This allows R55 to pull REM_SW high, telling the main
microcontroller that a REM patient return electrode is connected to the generator.

When you use an electrode without the REM safety feature, S9 remains closed
and REM_SW is pulled low. Capacitor C23 filters noise on REM_SW. Resistor
R56 limits the amount of current that flows through S9 when it closes and C23
discharges.

Front Panel Footswitch Circuit

The footswitch circuit on the Display board provides a means of activating the
selected receptacle: the Bipolar Instrument receptacle or the single-pin Accessory
Instrument receptacle. This circuit consists of a footswitch receptacle, an isolated
DC/DC converter, two optoisolators, and associated circuitry.

The footswitch connector (P1) provides the connecting point for the footswitch.
The common mode choke (L1) and capacitors (C1–C3, C16–C18, and C24–C26)
provide filtering that blocks high frequency noise from exiting the generator on
the footswitch cable. Note that C16–C18 decouple the footswitch outputs to
DGND and then C1–C3 and C24–C26 decouple DGND to CHGND. This occurs
in two stages in order to use the DGND plane on the board as a low impedance
path from the footswitch circuit to the edge of the board, where it is easier to
connect to chassis ground.

Principles of Operation

• Pressing a footswitch coag pedal allows, +V_ISO_5_FIL, pulling
MON1_COAG\ low through U1, to pull the corresponding signal
(FRONT_FSW_COAG_FIL) high.

• Pressing a footswitch cut pedal allows +V_ISO_5_FIL, pulling MON1_CUT\
low through U2, to pull the corresponding signal (FRONT_FSW_CUT_FIL)
high.

Resistors R5 and R6 set the amount of current flowing through optoisolators U1
and U2. An isolated DC/DC converter (U3) provides the power source for the
footswitch circuit via isolated power (+V_ISO_5) and ground (ISO5). Capacitors
C6, C10, and C15 provide high frequency filtering to reduce emissions. Capacitor
C12 supplies a source for current spikes flowing into the switching input of U3.

Force EZ-C Series Service Manual 5-15

Footswitch Board

Footswitch Board

Refer to Section 10, Service Parts, for components and the Schematics
Supplement for the board drawing and schematic.

The Footswitch board contains circuitry for the footswitch connectors on the rear
panel, a speaker, and the volume control potentiometer for the audio circuit. The
board interfaces to the Power Supply/RF board.

The monopolar footswitch connector (J1) provides footswitching capability for
the multipin Monopolar Instrument receptacle located on the front panel. Use
only a Valleylab footswitch with the Force EZ-C Series Electrosurgical
Generator. Use of an incompatible footswitch may cause unexpected output. The
bipolar footswitch connector (J4) provides footswitching capability for the
Bipolar Instrument receptacle located on the front panel. Capacitors C1–C5
provide filtering that blocks high frequency noise from exiting the generator on
the footswitch cables.

The audio circuit on the Power Supply/RF board uses the speaker (SP1) on the
Footswitch board to enunciate the presence of RF output and to provide an
auditory indication of alarm conditions. The potentiometer (R1) adjusts the
volume of RF output activation tones. You cannot turn the speaker volume
entirely off. You also cannot adjust the volume used during alarm conditions.

Power Supply/RF Board

Refer to Section 10, Service Parts, for components and the Schematics
Supplement for the board drawing and schematics.

The Power Supply/RF board is the main board of the generator. It contains the
high voltage power supply and the RF output stage. Circuitry on this board
performs several functions:

• output voltage monitoring (spark control circuit)

• leakage current sensing (RF leakage sensing and reduction circuits)

• REM impedance monitoring (REM circuit)

• switch closure detection (IsoBloc circuit)

• RS-232 connector detection

• EKG contact closure connector detection

• rear panel footswitch control (footswitch decode circuit)

• audio tone generation (audio circuit)

• thermal monitoring (temperature sense circuit) power

5-16 Force EZ-C Series Service Manual

Power Supply/RF Board

Power Supply/RF Board Interfaces

The Power Supply/RF board interfaces to other boards and generator components:

• Control board

• Footswitch board

• heat sink components (RF damping resistors and the RF MOSFET)

• a series of single wire attachment points for connecting the sense transformers

• low voltage power supply (AC input and output)

A series of fuse clips connect the RF outputs and other front panel interfaces (i.e.,
REM and handswitching signals). The fuse clips mate to lugs located in the output
portion of the front panel assembly.

High Voltage Power Supply

Warning

Potentially lethal AC and DC voltages are present in the AC line circuitry, high
voltage DC circuitry, and associated mounting and heat sink hardware described
in this manual. They are not isolated from the AC line. Take appropriate
precautions when testing and troubleshooting this area of the generator.

Principles of Operation

The high voltage power supply contains several circuits:

• the power entry circuitry

• auto mains switching circuitry

• AC/DC conversion circuitry

• a DC/DC switching regulator

Power Entry Circuit

The power entry circuit consists of several items:

• an integral three-wire power cord receptacle

• a fuse drawer

• an EMI filter

• a separate power switch

The receptacle/filter reside on the rear panel of the generator; the power switch,
on the front panel. AC line fuses are changeable from the rear of the generator.

Force EZ-C Series Service Manual 5-17

Power Supply/RF Board

Auto Mains Switching Circuitry

The auto mains switching circuit detects the AC line voltage level and controls
the triac (D3). This triac controls the topology of the AC/DC converter. For 110 to
120 Vac operation, the triac is on, which connects the AC neutral to the center of
the AC/DC converter capacitor bank (C58–C61). In this configuration, the circuit
acts as a doubler using the right hand half of the bridge rectifier (CR80). For 220
to 240 Vac operation the triac is off and CR80 becomes a full wave rectifier.

The control IC (U10) functions as follows:

• The series circuit (CR6, R59, R64, and C57) provides power for U10.

• Pin 1 (Vss),a shunt regulator, provides a –9 V (nominal) output.

• The divider (R65 and R66) measures the input line voltage. Since the voltage
at pin 8 varies with the line, it can sense the line voltage zero crossing as well
as the peak voltage.

• Pins 2 and 3 are inputs to an oscillator used for triac triggering timing.

• R67 and C50 set the oscillator frequency.

• Pin 7 connects to Vss, which places the circuit in the fail-safe mode. Thus,
once the circuit enters full bridge mode it remains in that mode until input
power recycles. A power dropout cannot cause the circuit to accidentally act
as a doubler when the higher input voltage range is in use.

AC/DC Converter

The AC/DC converter uses CR80 as either a doubler or full wave rectifier,
depending on the input voltage. In either case, it provides an unregulated nominal
300 Vdc to the DC/DC switching regulator. Thermistors R68 and R70 provide
inrush current limiting, and fuse F1 provides protection against faults in the DC/
DC switcher.

Capacitors C58–C61 function as an energy storage reservoir for the
DC/DC switcher. C70 is a high frequency bypass filter. Bleeder resistors R69 and
R71 discharge the capacitors when you disconnect the AC line or turn the power
switch off.

DC/DC Switching Regulator

The DC/DC switching regulator is a buck-derived, pulse width modulated
(PWM) transformer. It is an isolated, fixed frequency, full bridge converter. The
system uses PWM IC (U3) in the voltage mode. The output of the regulator is
adjustable from approximately zero (0) to 180 Vdc.

The full bridge consists of four power MOSFETs (Q2, Q4, Q5, and Q7) that
operate at AC line potential. Transistors Q2 and Q5 are on while Q4 and Q7 are
off, and the reverse, making power signals to the power transformer bidirectional,
or push-pull. This allows full use of the transformer core magnetization
capability. Regulation results from modulating the time that each MOSFET pair is
on. Capacitor C67, in series with the power transformer T3 primary, prevents DC
flux imbalance. A snubber circuit (C66 and R79) absorbs leakage energy spikes.
Another snubber circuit (C91 and R121) reduces spikes due to reverse recovery of
the output bridge rectifier.

5-18 Force EZ-C Series Service Manual

Important

T1 consists of two
transformers electrically and
magnetically isolated from
each other but assembled into
the same package. T1A and
T1B form one transformer;
T1C and T1D form the other.

Power Supply/RF Board

Principles of Operation

Transformer T1 transformer-couples the gate driver circuitry for each MOSFET
to provide AC line isolation. It consists of a dual MOSFET driver (U1) and
various damping resistors. Resistors R40, R58, R63, and R78 minimize turn-off
oscillations. Resistors R17 and R41 damp ringing due to parasitic inductances in
T1. Blocking capacitors C12 and C26 prevent DC flux imbalance in T1.

A high voltage diode bridge (CR17, CR22, CR23, and CR36) provides full wave
rectification for the output of the power transformer. L1, C89, and C108 filter the
rectified power signal. The regulated DC output from this supply is the input to
the RF stage of the generator.

The SYS_ECON signal from the microcontroller controls the output voltage
level. This 0 to 5 Vdc signal sets the reference for the PWM control loop. An
external op-amp (U4A) provides gain and integration, since common mode
voltage limitations in U3’s internal op-amp preclude its use over the full range of
0 to 5 V. The internal op-amp is connected as a follower. SYS_ECON is compared
to the feedback voltage from the output divider (R21 and R22) and an error signal
(ECON) is sent to the PWM microcontroller. In addition to the error signal, U4A
and the associated R-C networks provide lead-lag loop compensation to increase
the bandwidth of the regulator beyond that of the output L-C filter.

The output of U3 is a pair of 180× out-of-phase signals: comparing ECON with
the internal oscillator ramp waveform modulates the signals’ pulse width. At the
start of an oscillator cycle, U3 turns on an output, turning it off when the ramp
voltage crosses the ECON level. The two output signals from U3 (pins 11 and 14)
feed the MOSFET drivers (U1A and U1B).

R42 and C27 set the U3 oscillator frequency. C29 controls the ramp-up of the
pulse width at power on for slow start contro l. Transformer T2 limits the power
transformer primary current, protecting against faults in the DC/DC switcher
power stage and faults in circuitry downstream of the switcher. CR2–CR5 rectify,
and R47 and C30 filter, the secondary current of T2, which then goes to the
current limit pin (pin 9 of U3). Duri ng an overcurrent condition the U3 current
limit function resets the slow start circuit, resulting in the output cycling from on
to off until the current falls. Pin 9 of U3 also allows remote shutdown of the DC/
DC switcher through Q1 and CR1. The shut down signal comes from the main
microcontroller on the Control board.

The resistor divider formed by R88 and R89 provides dosage error sensing.

Force EZ-C Series Service Manual 5-19

Power Supply/RF Board

Low Voltage Power Supply

The low voltage power supply, rated for 40 watts, delivers a regulated +5 Vdc and
±12 Vdc output. This power supply has a universal input and works for both input
voltage ranges. It has internal current limiting, overvoltage, and thermal
shutdown protection. The low voltage power supply connects to the Power
Supply/RF board through four pins:

PIN Voltage

1+5 Vdc

2-12 Vdc

3 +12 Vdc

4 Ground

The significant specifications of the low voltage power supply compared to
estimated loads are the following:

Output
Voltage

+5 Vdc 4000 mA 20.0 W 1000 mA

-12 Vdc 400 mA 4.8 W 160 mA

+12 Vdc 2000 mA 24.0 W 1400 mA

Output
Current

Output Power Estimated

Load

5-20 Force EZ-C Series Service Manual

Power Supply/RF Board

RF Output Stage

Warning

High frequency, high voltage signals that can cause severe burns are present in
the RF output stage and in the associated mounting and heat sink hardware
described in this manual. Take appropriate precautions when testing and
troubleshooting this area of the generator.

The RF stage consists of the following components:

• a single MOSFET power switch with associated gate drive circuitry

• an RF power transformer

• tuning capacitors

• an RF output L-C filter

• output directing relays

• topology selecting relays

• RF voltage and current sense circuits

• a switched damping network for certain operational modes

Principles of Operation

The MOSFET gets its gating signal from the T_ON ASIC (U9) on the Control
board. The T_ON ASIC also provides the gating signal for the switched damping
network.

The topology selecting relays (K1 and K15) set the RF stage in the following
modes:

unenergized energized

RF stage is in the coag mode RF stage is in the cut and bipolar

mode.

Note that cut modes include the low 2 and low 3 settings from the topology
standpoint.

Primary Sense Circuits

The primary voltage and current sense circuits provide feedback information to
the feedback microcontroller in the bipolar and cut modes.

For voltage sensing, the two 10 k ohm resistors in series with the primary of T12
work in concert with the 100 ohm resistor across the secondary to divide the
output voltage down to a manageable level. Depending on the front panel power
setting, one of three relays (K2–K4) switches in to give optimum scaling. The
four op-amps (U18 and U23), along with the associated resistors, capacitors, and
diodes, form a precision full wave rectifier circuit. U23B is a high input
impedance follower to prevent the rectifier circuit from loading down the resistive
divider. U23A is a follower that adds phase delay, which improves balance in the
rectified waveform between positive and negative half cycles of the input signal.
U18A and U18B perform the actual rectification. The R-C filter after the last
op-amp converts the rectified waveform to DC, with the full scale at 5 Vdc.

Force EZ-C Series Service Manual 5-21

Power Supply/RF Board

The current sense circuit, which uses current transformers T5 and T6, works the
same as the voltage sense circuit. T6 senses bipolar current and T5 senses
monopolar current. Relay K9 selects the appropriate current. Note that the current
scaling relays (K5–K7) switch at different power settings than the voltage scaling
relays.

Redundant Sense Circuits

The primary sense circuits are functionally in parallel to redundant sen se circuits
for the dosage error monitoring function performed by the main microcon troller
on the Control board.

For redundant voltage sensing, a current sense transformer (T8) connects in series
with the capacitor ladder. A bridge rectifier (CR24, CR25, CR27, and CR28)
rectifies, divides, and limits this voltage before op-amp circuit U31A filters and
buffers it.

For redundant current sensing, another current sense transformer (T7) senses
current flow in both the bipolar output leads and the monopolar output leads. A
circuit identical to the redundant voltage sensing circuit follows for rectification,
division, limiting, buffering, and filtering.

The signals produced from the redundant sense circuits are scaled for zero to 5
Vdc operation for use by the analog-to-digital channels of the main
microcontroller on the Control board.

Output Relays

In all monopolar modes, K12 is closed and routes patient return current through
the REM receptacle. K10 routes active current through the single-pin (footswitch
activated) Accessory Instrument receptacle. K11 routes the active current through
the multipin (handswitch or footswitch activated) Monopolar Instrument
receptacle.

In bipolar mode, the REM receptacle relay is open. Relays K13 and K14 route
bipolar current to the Bipolar Instrument receptacle.

All output relays are open when the generator is not being activated.

Bipolar Mode

The bipolar mode circuit topology is essentially the same as the cut modes, except
the output voltage flows from C159 and the switching frequency is 470 kHz.
These differences allow the higher currents and lower voltages required in bipolar
surgery while still maintaining the advantages of zero voltage switching in the
MOSFET. The T_ON\ signal is a continuous pulse train.

5-22 Force EZ-C Series Service Manual

Power Supply/RF Board

Cut Modes

In the cut modes, the K1 setting allows the following conditions:

• diode CR7 is in parallel with the MOSFET body drain diode

• C62 and C65 are across the MOSFET

• the transformer primary consists of windings 1-2 and 3-4 in series
K15 is closed so the series capacitor bank (C143, C154, C159, C165, and C166) is

across the output.
In the pure cut mode, the T_ON\ signal is a continuous pulse train with a

frequency of 393 kHz. In this case, essentially two resonant circuits operate in
tandem. The output L-C filter is tuned just slightly higher than the RF switching
frequency, achieving a high degree of filtering. The output is very sinusoidal over
the full range of load impedances. Capacitors C62 and C65 are tuned with the RF
transformer primary so that the flyback voltage appearing across the MOSFET at
turn off is a half sine pulse and returns to zero volts before the next cycle begins.
The T_ON\ pulse width is chosen to support this tuning. This zero voltage
switching improves the efficiency of the RF stage and is effective over a wide
range of load impedances.

The circuit topology of the blend cut mode is the same as the pure cut mode. In
blend mode, however, the T_ON\ signal is an interrupted pulse train with a 50%
duty cycle and a frequency of 27.1 kHz. For a given power setting, blend gives a
higher peak current, providing better hemostasis than pure. To minimize ringing
at the beginning of the off period of the blend waveform envelope, the damping
resistor switches on just before switching ends and stays on for part of the off
period.

Principles of Operation

Coag Modes

In the high 1 (fulgurate) setting, the K1 setting allows these conditions:

• diode CR7 blocks reverse current in the power MOSFET

• C100 as well as C62 and C65 are across the MOSFET

• the transformer primary consists of winding 1-2 only
K15 is open, keeping the series capacitor bank (C143, C154, C159, C165, and

C166) out of the circuit.
The T_ON\ signal is a continuous pulse train with a pulse width of 1.69 µs and a

frequency of 57 kHz. When the MOSFET turns on, some energy goes to the
output and some goes to storage in the T4 core. When the MOSFET turns off, the
energy stored in the core rings out with a nominal frequency of 470 kHz. C62,
C65, C100 and the inductance of winding 1-2 of T4 set the frequency. CR7 blocks
reverse current in the body drain diode of the MOSFET so that the power
waveform can ring negative. This allows high peak voltages at the output. In most
cases, the system delivers all the energy stored in the transformer core during one
switching cycle to the load before the next cycle begins.

To minimize ringing on the output voltage waveform at light loads, transistor Q8
switches in the 50 watt, 50 ohm heat sink mounted resistor in series with the
transformer primary for part of the RF switching cycle.

Force EZ-C Series Service Manual 5-23

Power Supply/RF Board

The high 2 (fulgurate) setting works the same as the high 1 (fulgurate) setting,
except the T_ON\signal is a continuous pulse train with a pulse width of 1.69 µs
and a frequency of 30 kHz.

In the low 1 coag setting, the K1 setting allows these conditions:

• diode CR7 is in parallel with the MOSFET body drain diode (like the cut
modes)

• K15 is open

The T_ON\ signal is a continuous pulse train with a pulse width of 2 µs and a
frequency of 39 kHz. The output resonates with a nominal frequency of 290 Khz.

The microcontroller treats the low 2 and low 3 coag settings as feedback
controlled cut modes. Its operation is the same as pure cut described above,
except the power curve is different.

Spar k C ont rol Ci rcuit

The spark control circuit uses the voltage sense circuit to monitor the output
voltage. It interrupts the delivery of power if the output voltage exceeds a preset
threshold. This greatly reduces sparking when removing an activated accessory
from tissue. The sparking occurs because the RF stage tuning results in a higher
natural gain at light loads than at heavy loads. Thus, during sudden transitions
from heavy to light loads, the output voltage rises faster than the microcontroller
can respond. This analog circuit works outside the microcontroller loop at a much
greater speed.

The rectified but unfiltered waveform from the output voltage sense circuit goes
into a peak detector (U13A, CR8, and C76). This input signal is called
VSEN_SCC. A high impedance buffer (U13B) maintains the integrity of the peak
detected signal. The output of this buffer divides and goes to a comparator. The
other input to the comparator is an analog threshold level (VMAX_CLP) that the
feedback microcontroller on the Control board sets: This input depends on the
mode and power setting.

When the peak detected sample of the output voltage exceeds the threshold, the
condition fires one-shot U15A, which generates a 3 ms pulse (SPARK_CON) that
goes to the T_ON ASIC on the Control board. the T_ON ASIC ignores this pulse
if it occurs during the first 0.2 seconds of activation. Otherwise, SPARK_CON
causes the T_ON\ signal to stop. The feedback microcontroller on the Control
board senses this and realizes that the circuit has suppressed a spark. The
feedback microcontroller waits either 10 ms in low 2 or low 3 coag or 100 ms in
pure cut, then re-initiates T_ON\ with a frequency of 470 kHz. The frequency
returns to 393 kHz after one second of continuous activation or when the
generator is reactivated.

5-24 Force EZ-C Series Service Manual

Power Supply/RF Board

RF Leakage Sensing and Reduction Circuit

For the high (fulgurate) settings, the pulse repetition period for high voltage RF
output varies with changes in spark and patient tissue impedance to limit the RF
leakage current to a desired level. The divider (R90, R94) located on the primary
side of T4 produces the VSENSE signal. VSENSE goes to a negative peak
detector (U20A) that generates the analog signal (VPEAK–). Then U21A
amplifies and inverts the signal.

The averaged signal (now called VPK+) goes to the feedback microcontroller on
the Control board, which adds it to the ECON value at the selected power setting.
The sum of these signals, with the proper gain factors, varies linearly with load
impedance at the patient site. This sum enters into a pulse width modulator (also
part of U11) on the Control board, which sends its output (WAK\) to the NAND
gate (U10) on the Control board. This action inhibits the T_ON\ signal for up to
four consecutive cycles.

REM Circuit

The REM transformer (T10) provides isolated reflected impedance sensing for
tissue impedance across the REM patient return electrode terminals (connected to
J17 and J19). In addition to tuning the REM circuit, capacitors C149–C151 and
C157 provide a return path for high frequency RF signals to the RF output
transformer.

Principles of Operation

The REM transformer (T10) and capacitors C149–C151 and C157 form a
resonant circuit with a nominal operating frequency of 80 kHz. This frequency is
positioned between RF output harmonics to prevent electrosurgical RF noise from
corrupting the impedance measurement. The resonant characteristics of the REM
circuit are similar to those of a band pass filter. This arrangement heavily
attenuates spectral components outside the 80 kHz pass band while allowing the
80 kHz components to pass. When the resonant circuit is perfectly tuned, the
primary voltage and current are exactly in phase.

REM Oscillator

The REM oscillator is a stable adjustable ceramic oscillator. R125, a temperature
dependent resistor, provides temperature compensation. The REM_CLK signal
from driver U29A actually provides the REM current to the REM transformer
(T10). The REM_DRV signal is an inverted version of this signal that correctly
times the REM voltage sensing. The main microcontroller on the Control board
uses digital potentiometer U26 to calibrate the REM circuit during calibration.

IsoBloc Circuit

The IsoBloc circuit provides a means of detecting a switch closure in an output
accessory while maintaining electrical isolation between the generator output and
ground referenced circuitry. The IsoBloc circuit consists of an isolated DC power
supply and an optoisolator link from the output connected circuitry to the ground
referenced low voltage circuitry. Each handswitching output of the generator
(multipin monopolar and bipolar) is associated with its own IsoBloc power source
and isolated signal paths.

Force EZ-C Series Service Manual 5-25

Power Supply/RF Board

Oscillator

The oscillator circuit consists of a 74HCT4060 oscillator/divider (U30) using a 5
MHz ceramic resonator as the frequency determining element. The output of the
oscillator connects internally to the input of a counter/divider chain. The Q6
output of the divider yields a 78.13 kHz square wave, applying it to the input of
two 4081 AND gates (U27A and U34A) for buffering and gating with the
ISO_TST\ signal. The software system uses the ISO_TST\ signal to shut off the
IsoBloc supplies for safety testing.

Power Supply

The two 4081 AND gates drive two VN10KM FETs (Q9 and Q10) that connect
to transformers T9 and T11. The system operates the transformers in a flyback
mode with their associated 6800 pF capacitors (C133 and C139). The voltages at
the secondaries of the two transformers, half-wave rectified and referenced to two
separate isolated grounds, provide –8 V for operating the isolated activation
circuitry.

Optoisolators

The isolated power supply voltages produced by the IsoBloc power supplies
connect to the Active output terminals of the generator (J15, J22, and J24).
Sensing Active-to-Cut or Active-to-Coag switch closure in a handswitching
accessory accomplishes handswitch activation. Current limiting resistors, in
series with LEDs in the optoisolators, cause the LEDs to light to a controlled
degree while not excessively loading the IsoBloc power supply. The photo­transistor in the optoisolator detects this light. The photo-transistor, which
connects to an input to an 82C55 expansion port in the main microcontroller
circuit, turns on, pulling the associated input low. The software interprets this as
an activation request, and activates the generator after using ISO_TST\ to verify
the validity of the activation request.

Audio Circuit

The audio system enunciates the presence of RF output and provides an auditory
indication of alarm conditions. This system consists of the following components:

• an audio oscillator

• tone control signals

• a volume control potentiometer

• an audio amplifier

• a speaker

Pulling UP_TONE\ (from the Control board) or RF_TONE\ (from the Power
Supply/RF board) low enables the audio oscillator. Diodes D1 and D2 provide a
wired-OR function for the two signals. Since UP_TONE\ and RF_TONE\ are +5
V (logic level) signals, resistors R24 and R49 divide the +12 V audio power
supply down to about 4.85 V to prevent D1 and D2 from sourcing current into
their logic level drive signals. R25 and C31 provide filtering for the resultant
wired-OR output.

5-26 Force EZ-C Series Service Manual

Power Supply/RF Board

Enabling either UP_TONE\ or RF_TONE\ low pulls the voltage at the
noninverting input of U5B below the Vref threshold present at U5B’s inverting
input. This condition turns the output transistor of U5B (open collector) on,
grounding R31 and allowing U6A to oscillate. Vref, used throughout the audio
circuit, results from dividing the +12 V power supply down to about 2 volts
through R50 and R54 while C33 provides low pass filtering for Vref.

U6A is a relaxation oscillator: The RC time constants of R29, C11, and C42
determine its frequencies. This design allows the oscillator to produce two distinct
frequencies that the state of the LO_TONE signal can select.

• With LO_TONE asserted (+5 V), the voltage at the inverting input of U5A
exceeds the 2 volt Vref signal at its noninverting input, thus turning on its
output transistor. This effectively connects C11 in parallel with C42 to
produce a higher RC time constant for the oscillator, which results in a lower
audio frequency.

• Conversely, with LO_TONE not asserted, the output transistor of U5A (open
collector) floats, thus removing C11 from the circuit.

The ALARM signal from the Control board selects the user-controlled audio
volume or the fixed alarm level volume. U5C and U5D are configured in an
exclusive OR arrangement in which the state of the output transistor of U5C or
U5D is complementary. In other words, the output transistor of one of these two
devices is always on, but both cannot be on simultaneously. Under normal
operating conditions, the ALARM signal is low, allowing the U5C output to float
while the U5D output transistor is turned on. The output of U5D creates a voltage
divider through R1 (the volume control potentiometer on the Footswitch board),
R27, and R28 to attenuate the audio signal to levels acceptable for input to the
audio amplifier. R27 determines the minimum audio volume. R55 provides an
alternate audio signal path in the event of an open volume potentiometer.

Principles of Operation

When the ALARM signal is high, the U5C output transistor is on while the output
of U5D floats. When the U5C output transistor is on, the system pulls R26 to
ground, creating a fixed voltage divider with R28 to produce the alarm volume
level at the input to audio amplifier U8.

Meanwhile, the output of U5D floats, removing the variable resistor divider from
the circuit. In this case, the volume control potentiometer becomes a small
resistance in series with the high impedance input from the audio amplifier,
negating the effect of the volume setting.

Audio amplifier U8 and speaker SP1 (on the Footswitch board) comprise the final
stage in the audio system. AC coupling the audio signal to the amplifier by C43
eliminates the need for well controlled input biasing. Floating its gain select pins
sets the U8 voltage gain to about 20. Because the U8 output signal is internally
biased to Vcc/2, it is necessary to AC couple the speaker through C51 to prevent
the amplifier from DC biasing the speaker.

The LO_TONE signal drives Q3 to change the gain of U8 to compensate
(equalize) the volume for low frequency operation. This is necessary because the
speaker (SP1) does not have flat frequency response between the cut tone and the
coag tone.

Force EZ-C Series Service Manual 5-27

Power Supply/RF Board

Footswitch Decode Circuit

The Footswitch board resides inside the rear panel of the Force EZ-C Series
Electrosurgical Generator. The 3-pin Bipolar Footswitch receptacle (J4) and the
4-pin Monopolar Footswitch receptacle (J1), mounted on the board, extend
through the rear panel. The footswitch decode circuit resides on the Power
Supply/RF board.

Footswitch activation causes current to flow through the LED section of an
optical isolator (ISO1, ISO2, and ISO3). This current generates an IR beam that
causes the corresponding photo-transistor to conduct. The signals from the
collectors of the transistors go to the microcontroller where they activate the
desired mode of operation.

As required by the IEC, the footswitch circuit is isolated from patient connected
circuits and able to withstand a potential of
500 Vrms (50/60 Hz). To obtain this isolation, the footswitch side of the circuitry
receives power from an isolated power supply (U11). The isolated power supply,
an HPR-107, operates from the ground referenced +12 V supply on the Power
Supply/RF board. Its output is an isolated 12 volts called +V_ISO_4.

The Control board fault tests this circuit using the ISO_TST\ signal. The main
microcontroller asserts ISO_TST\ to shut down U11 and discharge +V_ISO_4.
Using comparators U7A, U7B, and U9A to gate Vref2 allows loopback testing of
the footswitch activation circuits.

Temperature Sense Circuit

Since the Force EZ-C Series Electrosurgical Generator does not use a fan to cool
the internal components, monitoring the internal air temperature is important.
Under worst case conditions, it may be necessary to dissipate as much as 180
watts of heat via the convection cooling slots and surface areas.

A thermistor device (R13) in the temperature sense circuit measures the internal
air temperature at the left rear corner of the Power Supply/RF board. If the
temperature exceeds 65° C, the main microcontroller receives a signal to indicate
an over-temperature condition.

An error code displays in the Cut display. When the air temperature decreases to
60° C, operation returns to normal.

R5, R6, R15, and R16 determine a reference voltage, which is then applied to the
noninverting input of U2B (LM 393). It is designed to be equal to the voltage at
the inverting input of U2B when the thermistor is at 65° C.

At temperatures below 65° C, the output of U2B pin 7 is LOW. When the
thermistor temperature exceeds the threshold, the voltage comparator changes
state causing the output at U2B pin 7 to go HIGH (+5 Vdc). The HIGH goes to
the main microcontroller.

5-28 Force EZ-C Series Service Manual

SECTION

1Setup, Tests, and Adjustments

After unpacking or after servicing the Valleylab Force EZ-C Series
Electrosurgical Generator, set it up and verify that it functions
correctly.

6

If the generator does not satisfactorily complete the self-test,
calibrate the generator to ensure its accuracy.

Force EZ-C Series Service Manual 6-1

Setting Up the Generator

Setting Up the Generator

Warning

Electric Shock Hazard –þConnect the generator power cord to a properly
grounded receptacle. Do not use power plug adapters.

Fire Hazard –þDo not use extension cords.

Caution

Do not stack equipment on top of the generator or place the generator on top of
electrical equipment (except a Force Argon Unit). These configurations are
unstable and/or do not allow for adequate cooling.

Provide as much distance as possible between the electrosurgical generator and
other electronic equipment (such as monitors). An activated electrosurgical
generator may cause interference with them.

Notice

If required by local codes, connect the generator to the hospital equalization
connector with an equipotential cable.

Connect the power cord to a wall receptacle having the correct voltage.
Otherwise, product damage may result.

1. Verify the generator is off by pressing the power switch off ( O ).

2. Place the generator on any stable flat surface, such as a table, platform, or

Valleylab cart. Valleylab recommends carts with conductive wheels. For
details, refer to the procedures for your institution or to local codes.

Ensure that the generator rests securely on the cart or platform. The underside
of the generator contains four rubber feet and additional holes that allow you
to reposition the feet to ensure stability. Use a Phillips screwdriver to remove
the rubber feet from the generator. Then, reinstall the feet in the preferred
locations.

Provide at least four to six inches of space from the sides and top of the
generator for convection cooling. Normally, the top, sides, and rear panel are
warm when the generator is in use continuously for extended periods of time.

3. According to the procedures used by your institution, connect an equipotential

grounding cable to the grounding lug on the rear panel of the generator. Then,
connect the cable to earth ground.

4. Plug the generator power cord into the rear panel receptacle. Secure the cord

to the rear panel using the screw and C clamp provided.

5. Plug the generator power cord into a grounded receptacle.

6-2 Force EZ-C Series Service Manual

Important

Status for the last used mode
and power settings feature
momentarily appears in the
Cut display. The selected low
(desiccate) setting and high
(fulgurate) setting momentarily
appear in the Coag display.

Setting Up the Generator

6. Turn on the generator by pressing the power switch on ( | ). Ve rify the

following:

• All visual indicators and displays on the front panel illuminate.

• Activation tones sound to verify that the speaker is working properly.

If the self-test is successful, a tone sounds. Verify the following:

7.

• Either the Pure button indicator or the Blend button indicator illuminates

green, and either the Low button indicator or the High button indicator
illuminates green.

• The right arrow indicator at the Footswitch Selector button illuminates

green.

• Each display shows a power setting.

• The REM Alarm indicator illuminates red.
If the self-test is not successful, an alarm tone sounds. A number may

momentarily appear in the Cut display and, in most cases, the generator is
disabled. Note the number and refer to Section 7, Responding to System
Alarms.

Setup, Tests, and Adjustments

Force EZ-C Series Service Manual 6-3

Connections for Bipolar Surgery

Connections for Bipolar Surgery

If you plan to use a footswitching bipolar instrument, you must connect a
footswitch. You may also use a footswitch to activate a handswitching
instrument.

Warning

Electric Shock Hazard –

• Do not connect wet accessories to the generator.

• Ensure that all accessories and adapters are correctly connected and that no
metal is exposed.

Caution

Accessories must be connected to the proper receptacle type. In particular,
bipolar accessories must be connected to the Bipolar Instrument receptacle only.
Improper connection of accessories may result in inadvertent generator activation
or a REM Contact Quality Monitor alarm.

Figure 6-1.

Bipolar connections (footswitch
activation from the Bipolar
Footswitch receptacle on the rear
panel)

Figure 6-2.

Bipolar connections (footswitch
activation from the Footswitch
receptacle on the front panel)

footswitching
or
handswitching

handswitching
or footswitching
instrument

Valleylab
monopolar

bipolar footswitc

Press the Footswitch Selector button
until the left arrow indicator illuminates
green.

6-4 Force EZ-C Series Service Manual

Figure 6-3.

Bipolar connection
(handswitching instrument)

Connections for Monopolar Surgery

handswitching
instrument

Setting the Bipolar Output

Caution

Set power levels to the lowest setting before testing an accessory .

Setup, Tests, and Adjustments

1. To increase (+) the power, turn the Bipolar Power Control knob clockwise.

To decrease (-) the power, turn the knob counterclockwise. The maximum
power setting for bipolar output is 70 watts.

2. To display and use the previous power setting, press the Pure and Blend

buttons simultaneously.

Connections for Monopolar Surgery

If you plan to use a footswitching monopolar instrument, you must connect a
Valleylab monopolar footswitch. You may also use a footswitch to activate a
handswitching instrument.

For most procedures, you will connect only one monopolar instrument
(handswitching or footswitching).

Warning

Electric Shock Hazard —

• Do not connect wet accessories to the generator.

• Ensure that all accessories and adapters are correctly connected and that no
metal is exposed.

Use only a Valleylab monopolar footswitch with the Force EZ-C Series
Electrosurgical Generator. Use of an incompatible footswitch may cause
unexpected output.

The instrument receptacles on this generator accept only one instrument at a
time. Do not attempt to connect more than one instrument at a time into a given
receptacle. Doing so will cause simultaneous activation of the instruments.

Force EZ-C Series Service Manual 6-5

Connections for Monopolar Surgery

Figure 6-4.

Monopolar connections
(handswitching instrument)

handswitching
instrument

patient return electrode

Figure 6-5.

Monopolar connections
(footswitch activation from the
Monopolar Footswitch receptacle
on the rear panel)

handswitching
or footswitching
instrument

Valleylab monopolar
footswitch

patient return
electrode

6-6 Force EZ-C Series Service Manual

Figure 6-6.

Monopolar connections
(footswitch activation from the
Footswitch receptacle on the
front panel)

Connections for Monopolar Surgery

Valleylab monopolar
footswitch

Setup, Tests, and Adjustments

footswitching
instrument

patient return electrode

Press the Footswitch
Selector button until the
right arrow indicator
illuminates green.

Set the Cut and Coag Output

Caution

Set power levels to the lowest setting before testing an accessory .

To display and use the previous power settings, press the Pure and Blend buttons
simultaneously.

1. To select a cut mode, press the Pure or Blend button. The indicator in the

button of the selected mode illuminates green.

2. To select a coag mode, press the Low or High button. The indicator in the

button of the selected mode illuminates green.
To verify the selected low (desiccate) or high (fulgurate) coag setting, press

and hold the Low or High button. While you press the Low button, a 1 (low

1), 2 (low 2), or 3 (low 3) appears in the Coag display. While you press the
High button, a 1 (high 1) or 2 (high 2) appears in the Coag display. To change
these settings, refer to Setting Up the Special Features in this section.

3. To increase (+) the power, turn the Cut or Coag Power Control knob

clockwise. To decrease (–) the power, turn the knob counterclockwise.

• The maximum power setting for the pure cut mode is 300 watts.

• The maximum power setting for the blend cut mode is 200 watts.

• The maximum power setting for the low (desiccate) coag mode and the
high (fulgurate) coag mode is 120 watts.

Force EZ-C Series Service Manual 6-7

Connections for Monopolar Surgery

Using Two Generators Simultaneously

Caution

Do not stack equipment on top of the generator or place the generator on top of
electric equipment (except a Force Argon Unit). These configurations are
unstable and/or do not allow adequate cooling.

You can use two generators (and two patient return electrodes) simultaneously on
the same patient, provided the generators are the same type (both are isolated or
both are ground referenced). However, the two generators are not synchronized.
One return electrode frequently acquires a high positive voltage while the other
acquires an opposite negative voltage. When this occurs, the potential voltage
difference between them may cause the current to flow from one patient return
electrode to the other . The current causes no harm if it produces no sparks or high
current densities on the patient.

Place each patient return electrode as close as possible to the site of the surgery to
be performed by the generator to which it is connected. Ensure that the two
patient return electrodes do not touch.

Setting Up the Special Features

Important

During the setup mode,
dashes
(– –) appear in the Bipolar
display and the Bipolar Power
Control knob has no function.

Special
Feature

Low (desiccate)
coag settings

Action

1. Press the Low button.

2. Turn the Coag Power Control

knob to select the desired
setting:

1 = low 1
2 = low 2
3 = low 3

Five special features are available to customize the Force EZ-C Series
Electrosurgical Generator. Refer to the following table for setup information. You
must enter the setup mode to modify the special features.

Entering the Setup Mode

Press the Footswitch Selector button, the Low button, and the High button
simultaneously.

A number (1, 2, or 3) appears in the Coag display, and the indicator in the Low or
High button flashes.

Cut

Display

– – – blank 1, 2, or 3 Low flashes

Cut Button

Indicator

Coag

Display

Coag Button

Indicator

6-8 Force EZ-C Series Service Manual