Tektronix TCP400, TCP300, TCPA400, TCPA300 Service manual

Instruction Manual

TCPA300/400 Amplifiers &
TCP300/400 Series AC/DC Current Probes

071-1183-03

This document applies for firmware version 1.0
and above.

Warning

The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.

www.tektronix.com

Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or
suppliers, and are protected by national copyright laws and international treaty provisions.

Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.

TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

Contacting Tektronix

Tektronix, Inc.
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA

For product information, sales, service, and technical support:

H In North America, call 1-800-833-9200.

H Worldwide, visit www.tektronix.com to find contacts in your area.

Warranty 2

Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1)
year from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its
option, either will repair the defective product without charge for parts and labor, or will provide a replacement in
exchange for the defective product. Parts, modules and replacement products used by Tektronix for warranty work
may be new or reconditioned to like new performance. All replaced parts, modules and products become the
property of Tektronix.

In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration
of the warranty period and make suitable arrangements for the performance of service. Customer shall be
responsible for packaging and shipping the defective product to the service center designated by Tektronix, with
shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a
location within the country in which the Tektronix service center is located. Customer shall be responsible for
paying all shipping charges, duties, taxes, and any other charges for products returned to any other locations.

This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage
resulting from attempts by personnel other than Tektronix representatives to install, repair or service the product;
b) to repair damage resulting from improper use or connection to incompatible equipment; c) to repair any
damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been
modified or integrated with other products when the effect of such modification or integration increases the time
or difficulty of servicing the product.

THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY
OTHER WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A P ARTICULAR PURPOSE.
TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY.
TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

Table of Contents

Getting Started

Operating Basics

Preface xv........................................................

System Configuration 1--1.............................................

Options 1--3........................................................

Standard Accessories 1--4.............................................

Optional Accessories 1--5.............................................

Probe Covers 1--6....................................................

Travel Case 1--7.....................................................

Connecting the Amplifier to an Oscilloscope 1--8..........................

Power on the Amplifier 1--8...........................................

Connecting a Current Probe to the Amplifier 1-- 9..........................

Operating the Current Probe Slide 1--10...................................

Degaussing and Autobalancing the Current Probe 1--11......................

DC Measurements 1--12...............................................

AC Measurements 1--14...............................................

Control Summary 2--1.........................................

TCPA300 and TCPA400 Controls 2--2...................................

PROBE DEGAUSS AUTOBALANCE Button and Indicator 2--2..........

MANUAL BALANCE Buttons and Indicator 2--3......................

PROBE OPEN Indicator 2--3.......................................

OVERLOAD Indicator 2--3........................................

NOT TERMINATED INTO 50 Ω Indicator 2--4........................

NONCOMPATIBLE PROBE TYPE Indicator 2--4......................

ON/STANDBY Button 2--4........................................

RANGE Button (TCPA300 only) 2--4................................

COUPLING Button and Indicators 2--4...............................

PROBE INPUT Connector 2--5.....................................

OUTPUT Connector 2--5..........................................

Probe DC Gain Adjust (located on probes) 2--5.........................

GPIB Operation 2--6..............................................

Reference

Reference Notes 3--1...........................................

Degaussing a Probe with an Unpowered Conductor in the Jaws 3--1............

Measuring Differential Current 3--2.....................................

AC and DC Coupling 3--3.............................................

Maximum Current Limits 3--4..........................................

Measuring Noncontinuous Current with the TCP404XL Probe 3--6............

Extending Current Range 3--8..........................................

Increasing Sensitivity 3--10.............................................

Application Notes 3--11..........................................

Automobile Charging Systems 3--11......................................

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

i

Table of Contents

Inductance Measurements 3--13.........................................

Continuity Test of Multiple-Conductor Cable 3--15..........................

Measuring Inductor Turns Count 3--16....................................

Power Measurement and Analysis Software 3--17...........................

Troubleshooting and Error Codes 3--19............................

Displaying Error Codes with the Probe Degauss Autobalance Button 3--22.......

Correcting the Cause of an Error Code 3--24...............................

Shutdown Error 3--24..................................................

Specifications

Warranted Specifications 4 --1..........................................

Nominal and Typical Characteristics 4--2.................................

Mechanical Characteristics 4--3........................................

Environmental Characteristics 4--5......................................

TCP404XL Maximum Measurement Times 4--12...........................

Performance Verification

Performance V erification Overview 5--1...........................

Performance Verification and Functional Checks 5--1.......................

Test Procedure Conditions 5--2.........................................

Equipment Preparation 5--2............................................

TCPA300 and TCPA400 Performance Verification 5--3..............

Equipment Required 5--3..............................................

Making DC Current Loops 5--4.........................................

Front-Panel Display 5--5..............................................

DC Gain Accuracy 5--6...............................................

Bandwidth 5--9......................................................

AC Coupling 5--12....................................................

Degauss 5--13........................................................

Current Overload Test 5--14............................................

TCPA300 Amplifier Test Record 5--16....................................

TCPA400 Amplifier Test Record 5--17....................................

TCP305 and TCP312 Performance Verification 5--19.................

Required Test Equipment 5--20..........................................

DC Gain Accuracy 5--21...............................................

Rise Time 5--24......................................................

Bandwidth 5--26......................................................

TCP305 Current Probe Test Record 5--29..................................

TCP312 Current Probe Test Record 5--30..................................

TCP303 and TCP404XL Performance Verification 5--31..............

Equipment Required 5--32..............................................

DC Gain Accuracy 5--33...............................................

Rise Time 5--36......................................................

Bandwidth (TCP303) 5--39.............................................

Bandwidth (TCP404XL) 5--41..........................................

TCP303 Current Probe Test Record 5--42..................................

TCP404XL Current Probe Test Record 5--43...............................

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TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Adjustment Procedures

Maintenance

Table of Contents

Adjustment Procedures Overview 6--1............................

TCPA300 and TCPA400 Amplifier Adjustments 6--3................

Required Test Equipment 6--3..........................................

Accessing the Adjustments 6--3.........................................

TCPA300 Amplifier 6--4..............................................

TCPA400 Amplifier 6--5..............................................

TCP305 and TCP312 Adjustments 6--7...........................

Required Test Equipment 6--7..........................................

Accessing the Adjustments 6--7.........................................

TCP305 and TCP312 DC Gain Adjustment 6--8............................

TCP303 and TCP404XL Adjustments 6--11........................

Required Test Equipment 6--11..........................................

Adjustment Locations 6--12.............................................

TCP303 and TCP404XL Transient Response and Coarse Gain Adjustment 6--13..

DC Gain Adjustment 6--18.............................................

Replaceable Parts

Customer Maintenance 7--1.....................................

Service Strategy 7--1.................................................

Preventive Maintenance 7--1...........................................

Disassembly 7--3..............................................

Amplifiers 7--3......................................................

Equipment Required 7--3..............................................

Removing the Outer Case and Internal Covers 7--4.........................

Replacing the Front Panel Assembly 7--7.................................

Replacing the Amplifier Board 7 --8.....................................

Replacing the Power Supply 7--10.......................................

Replacing the Fan 7--11................................................

Probes 7--13.........................................................

Equipment Required 7--13..............................................

TCP305 and TCP312 7--14.............................................

TCP303 and TCP404XL 7--18..........................................

Isolating Hardware Faults 7--21..................................

Determining the Amplifier Firmware Version Number 7--22...................

Replaceable Parts 8--1..........................................

Parts Ordering Information 8--1.........................................

Using the Replaceable Parts List 8--1....................................

Amplifier Replaceable Parts 8--3.................................

Current Probes Replaceable Parts 8--9............................

Glossary and Index

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

iii

Table of Contents

iv

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

List of Figures

Table of Contents

Figure 1--1: Typical TCPA300/400 current measurement system 1--1...

Figure 1--2: Using the probe holders 1--6..........................

Figure 1--3: Equipment locations in the travel case 1--7..............

Figure 1--4: Connecting and disconnecting a current probe

to the amplifier 1--9........................................

Figure 1--5: TCP312 and TCP305 slide operation 1--10...............

Figure 1--6: TCP303 and TCP404XL slide operation 1--11............

Figure 1--7: Current probe polarity 1--13...........................

Figure 2--1: The TCPA300 front panel 2--1........................

Figure 3--1: Measuring differential current and nulls 3--3............

Figure 3--2: Effect of AC or DC coupling on low-frequency signals 3--3.

Figure 3--3: Applying the amp-second product rule 3--5..............

Figure 3--4: Duty cycle calculation 3--6............................

Figure 3--5: Increasing the DC measurement range 3--9..............

Figure 3--6: Increasing probe sensitivity 3--10.......................

Figure 3--7: Setup for measuring charging current 3--12..............

Figure 3--8: Charge Current Waveforms 3--12.......................

Figure 3--9: Measuring inductance with a low-impedance source 3--13..

Figure 3--10: Linear current vs. time ramp 3--14.....................

Figure 3--11: Measuring inductance with a high-impedance source 3--15.

Figure 3--12: High-impedance source current ramp 3--15.............

Figure 3--13: Measuring the number of turns in a coil 3--16...........

Figure 3--14: Turns measurement using reference coil 3--17............

Figure 3--15: Error code display 3--22..............................

Figure 3--16: Interpreting the error code display 3--23................

Figure 4--1: Probe jaw dimensions (nominal) 4--4...................

Figure 4--2: Frequency derating--TCP312 4--8......................

Figure 4--3: Frequency derating--TCP305 4--8......................

Figure 4--4: Frequency derating--TCP303 4--9......................

Figure 4--5: Frequency derating--TCP404XL 4--9...................

Figure 4--6: Insertion impedance graphs for the current probes 4--10...

Figure 4--7: Specified operating area of the probes 4--11..............

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

v

Table of Contents

Figure 4--8: Measuring 750A noncontinuous at 50 °C

ambient temperature 4--12....................................

Figure 4--9: Measuring 600A noncontinuous at 50 °C

ambient temperature 4--12....................................

Figure 4--10: Measuring 750A noncontinuous at 23 °C

ambient temperature 4--13....................................

Figure 5--1: Check LED functionality 5--5.........................

Figure 5--2: Equipment setup for DC gain accuracy test 5--6..........

Figure 5--3: Bandwidth test setup 5--9.............................

Figure 5--4: AC coupling test setup 5--12...........................

Figure 5--5: Setup for degaussing the current probe 5 -- 13.............

Figure 5--6: Overload test setup 5--14..............................

Figure 5--7: DC gain accuracy test setup for TCP305 and TCP312 5--21.

Figure 5--8: Rise time test setup for the TCP305 and TCP312 5--24.....

Figure 5--9: Bandwidth test setup for TCP305 and TCP312 5--26.......

Figure 5--10: DC gain accuracy test setup for the

TCP303 and TCP404XL 5--33.................................

Figure 5--11: Rise time test setup for the TCP303 and TCP404XL 5--36.

Figure 5--12: Bandwidth test setup for TCP303 5--39.................

Figure 6--1: Amplifier adjustments 6--4...........................

Figure 6--2: Gain adjustment locations 6--5........................

Figure 6--3: TCP305 and TCP312 DC gain adjustment location 6--7...

Figure 6--4: DC gain adjustment setup for TCP305 and TCP312 6--9..

Figure 6--5: TCP303 and TCP404XL adjustment locations 6--12.......

Figure 6--6: TCP303 and TCP404XL transient response and

coarse gain adjustment setup 6--14.............................

Figure 6--7: DC gain accuracy adjustment setup 6--18................

Figure 7--1: Removing the case from the amplifier 7--4...............

Figure 7--2: Removing the right-side inner panel 7--5................

Figure 7--3: Removing the left-side inner panel 7--6.................

Figure 7--4: Disconnecting the front panel assembly 7--7.............

Figure 7--5: Removing the three heat sink clips 7--8.................

Figure 7--6: Removing the amplifier board 7--9.....................

Figure 7--7: Replacing the power supply 7--10.......................

Figure 7--8: Removing the AC power connector 7--11.................

Figure 7--9: Removing the fan 7--12...............................

vi

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Table of Contents

Figure 7--10: Removing the strain relief boot 7--14...................

Figure 7--11: Removing the top half of the probe 7--15................

Figure 7--12: Removing the probe slide 7--15........................

Figure 7--13: Removing the current transformer 7--16................

Figure 7--14: Removing the circuit board and cable assembly 7--17.....

Figure 7--15: Removing the handle 7--18...........................

Figure 7--16: Removing the current transformer 7--19................

Figure 7--17: Removing the circuit board and cable 7--20.............

Figure 7--18: Displaying the amplifier firmware version number 7--22..

Figure 8--1: TCPA300 and TCPA400 replaceable parts 8--3...........

Figure 8--2: TCPA300 and TCPA400 standard accessories 8--6........

Figure 8--3: TCPA300 and TCPA400 optional accessories 8--7........

Figure 8--4: TCP305 and TCP312 replaceable parts 8--9.............

Figure 8--5: TCP303 replaceable parts 8--11........................

Figure 8--5: TCP404XL replaceable parts 8--13......................

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

vii

Table of Contents

viii

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

List of Tables

Table of Contents

Table 1--1: Amplifier options 1--3................................

Table 1--2: Service options 1--3..................................

Table 3--1: Unpowered circuit degauss limits 3--1...................

T able 3--2: Automobile charging systems test setup 3--11.............

Table 3--3: Troubleshooting 3--19.................................

Table 3--4: Amplifier error codes 3--23.............................

Table 4--1: Warranted TCPA300 and TCPA400 specifications 4--1....

Table 4--2: Nominal and typical amplifier characteristics 4--2........

Table 4--3: TCPA300 and TCPA400 mechanical characteristics 4--3...

Table 4--4: Probe mechanical characteristics 4--4...................

Table 4--5: Shipping weights and dimensions 4--4...................

T able 4--6: Environmental characteristics 4--5.....................

Table 4--7: Certifications and compliances 4--6.....................

Table 5--1: Amplifier checks 5--1.................................

T able 5--2: Probe performance verification checks 5--1..............

Table 5--3: Required test equipment 5--3.........................

Table 5--4: Equipment settings 5--7..............................

Table 5--5: DC gain accuracy test for the TCPA300 and TCPA400 5--7.

Table 5--6: Equipment settings for bandwidth check 5--9............

Table 5--7: TCPA300 bandwidth measurements 5 -- 11................

Table 5--8: TCPA400 bandwidth measurements 5 -- 11................

Table 5--9: TCPA300 AC coupling measurements 5--13...............

Table 5--10: Maximum current ratings for

TCPA300-compatible probes 5--15............................

Table 5--11: Required test equipment 5--20.........................

T able 5--12: Equipment settings for DC gain accuracy 5--21...........

Table 5--13: DC gain accuracy test for the TCP305 and TCP312 5--23..

Table 5--14: Equipment settings for rise time 5--25..................

Table 5--15: Equipment settings for bandwidth 5--27.................

Table 5--16: Bandwidth test for the TCP305 and TCP312 5--28........

Table 5--17: Required test equipment 5 -- 32.........................

T able 5--18: Equipment settings for DC gain accuracy 5--33...........

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

ix

Table of Contents

T able 5--19: DC gain accuracy test worksheet for the TCP303 and

TCP404XL 5--35...........................................

Table 5--20: Equipment settings for rise time 5--37..................

Table 5--21: Equipment settings for bandwidth 5--40.................

Table 5--22: Bandwidth test for the TCP303 5--41...................

Table 6--1: Amplifier and probe adjustments 6--1...................

Table 6--2: Required test equipment 6--3..........................

Table 6--3: TCPA300 gain adjustments 6--4........................

Table 6--4: TCPA400 gain adjustments 6--5........................

Table 6--5: Required test equipment 6--7..........................

Table 6--6: Settings for DC gain adjustment 6--8...................

Table 6--7: DC gain accuracy adjustments for the

TCP305 and TCP312 6--9...................................

Table 6--8: Required test equipment 6--11..........................

Table 6--9: Settings for transient response and

preliminary gain adjustments 6--14............................

T able 6--10: Equipment settings for DC gain accuracy 6--19...........

Table 6--11: DC gain accuracy adjustments for the

TCP303 and TCP404XL 6--19................................

Table 7--1: Equipment required 7--3.............................

Table 7--2: Equipment required 7--13.............................

Table 7--3: Amplifier hardware faults 7--21.........................

Table 7--4: Probe hardware faults 7--22............................

Table 8--1: Power cord identification 8--5.........................

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TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

General Safety Summary

Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.

Only qualified personnel should perform service procedures.

While using this product, you may need to access other parts of the system. Read
the General Safety Summary in other system manuals for warnings and cautions
related to operating the system.

ToAvoidFireor

Personal Injury

Use Proper Power Cord. Use only the power cord specified for this product and
certified for the country of use.

Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.

Connect and Disconnect Properly. Connect the probe output to the measurement
instrument before connecting the probe to the circuit under test. Disconnect the
probe input and the probe ground from the circuit under test before disconnecting
the probe from the measurement instrument.

Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.

Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.

Connect the ground lead of the probe to earth ground only.

Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.

Use Proper Fuse. Use only the fuse type and rating specified for this product.

Avoid Exposed Circuitry. Do not touch exposed connections and components

when power is present.

Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.

Do Not Operate in Wet/Damp Conditions.

Do Not Operate in an Explosive Atmosphere.

Keep Product Surfaces Clean and Dry.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

xi

General Safety Summary

Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.

Symbols and Terms

Terms in this Manual. These terms may appear in this manual:

WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.

CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.

Terms on the Product. These terms may appear on the product:

DANGER indicates an injury hazard immediately accessible as you read the
marking.

WARNING indicates an injury hazard not immediately accessible as you read the
marking.

CAUTION indicates a hazard to property including the product.

Symbols on the Product. The following symbols may appear on the product:

CAUTION

Refer to Manual

Do not connect to or

remove from an

uninsulated conductor that

is HAZARDOUS LIVE.

Protective Ground

(Earth) Terminal

Breakable.

Do not drop.

Do not connect

to or discon-

nect from unin-

sulated Haz-

ardous Live
conductors.

WARNING

Hot Surface

Use only on an

insulated wire.

xii

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Service Safety Summary

Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service

procedures.

Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.

Disconnect Power. To avoid electric shock, switch off the instrument power, then
disconnect the power cord from the mains power.

Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.

To avoid electric shock, do not touch exposed connections.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

xiii

Service Safety Summary

xiv

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Preface

This Instruction Manual supports the operation and basic maintenance of the
TCPA300 and TCPA400 Current Probe Amplifiers, and the TCP300/400 Series
AC/DC current probes that mate with the amplifiers. The current probes covered
in this manual are listed below:

H TCP312 (30 amps, 100 MHz, compatible with TCPA300)

H TCP305 (50 amps, 50 MHz, compatible with TCPA300)

H TCP303 (150 amps, 15 MHz, compatible with TCPA300)

H TCP404XL (500 amps*, 2 MHz, compatible with TCPA400)

*750 amps DC derated with duty cycle

If you are not familiar with these products, please refer to the Getting Started and
Operating Basics chapters of this manual for basic operating information.

If you are an advanced user, the Reference section contains information on
advanced applications as well as user diagnostic and troubleshooting informa­tion.

The Performance Verification and Adjustment Procedure sections support the
qualification and calibration of the probes when used with either amplifier.

Manual Conventions

The Maintenance section supports the routine maintenance and repair of
mechanical parts associated with the amplifiers.

The Glossary and Index are provided as quick reference locators for important
information.

The term “amplifier” is used to refer to either the TCPA300 or TCPA400 when
referring to common attributes. If a subject is unique to either amplifier, the
amplifier will be referred to directly by model.

The terms “current probe” and “probe” are used to refer to any of the
TCP300/400 Series current probes when referring to common attributes. If a
subject is unique to a particular probe, the probe will be referred to directly by
model.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

xv

Preface

xvi

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Getting Started

Getting Started

The TCPA300 and TCPA400 current probe amplifiers let you use one probe to
simultaneously measure AC and DC current. The amplifiers convert the sensed
current into a proportional voltage signal that you can measure directly with an
oscilloscope.

The TCPA300 and TCPA400 current probe amplifiers provide better linearity
than other current measurement systems because of a current feedback process
used with the probe. DC measurement capability and high bandwidth allow the
amplifiers to accurately represent square waves and fast-rise signals.

The TCPA300 and TCPA400 and associated probes provide these features:

H Simultaneous DC and AC current measurements up to 750 A peak

H High sensitivity

H One-button autobalancing and probe degaussing

H No adjustments needed to match a current probe to an individual amplifier

H AC or DC coupling of signal

System Configuration

H Direct scaling and unit readout on compatible TEKPROBE level II

oscilloscopes

A complete current measurement system consists of a current probe amplifier, a
compatible current probe, and an appropriate oscilloscope. Refer to Figure 1--1.

AmplifierTest oscilloscope

Current probe

Input

Output

50 Ω oscilloscope input -- use the
TEKPROBE Interface Cable or use a 50 Ω
cable. (Add 50 Ω termination here if
oscilloscope has only high-impedance input.)

Figure 1- 1: Typical TCPA300/400 current measurement system

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 1

Getting Started

TCPA300 and TCPA400

Current Probe Amplifiers

Current Probes

The amplifier amplifies the current sensed by the probe and converts the current
to a proportional voltage that is displayed on an oscilloscope or other similar
measuring device.

The following Tektronix current probes are compatible with the TCPA300
Amplifier:

H TCP312 (30 amps, 100 MHz)

H TCP305 (50 amps, 50 MHz)

H TCP303 (150 amps, 15 MHz)

The following Tektronix current probes are compatible with the TCPA400
Amplifier:

H TCP404XL (750 amps*, 2 MHz)

* 500 amps continuous, 750 amps DC derated with duty cycle

You can also use the CT-4 High-Current Transformer with the TCP305 and
TCP312 current probes to extend the AC current measurement range to
20,000 peak amps.

Oscilloscope

An oscilloscope displays the output from the current measuring system. A 50 Ω
cable is included to connect the amplifier to the oscilloscope input channel. A
TEKPROBE-to-TEKPROBE interface cable is also included for connecting to
TEKPROBE level II oscilloscopes.

If the oscilloscope does not have an input that can be set to 50 Ω impedance, you
need a feedthrough 50 Ω termination. This termination is included as a standard
accessory with your TCPA300 and TCPA400 Current Probe Amplifiers.

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TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Options

Getting Started

Table 1--1 lists options that are available for the TCPA300 and TCPA400
amplifiers.

Table 1- 1: Amplifier options

Option Description

A1 Universal Euro power cord

A2 United Kingdom power cord

A3 Australia power cord

A5 Switzerland power cord

A6 Japan power cord

AC China power cord

A99 No power cord

L5 Japanese Instruction Manual

Table 1--2 lists the Tektronix service options you can order for your amplifiers
and probes. Designed to support tracking of calibration to requirements of
ISO9000 and to provide for extended repair coverage, these options help fix your
long-term maintenance costs and eliminate unplanned expenditures. Tektronix
Service Options are available at the time you order your instrument. Contact
your local Tektronix Sales Office for more information.

Table 1- 2: Service options

Option Description

D1 Provides the initial Test Data Report from the factory on delivery.

C3 Provides factory calibration certification on delivery, plus two more years of

calibration coverage. Throughout the coverage period, the instrument will be
calibrated according to its Recommended Calibration Interval.

D3 Provides test data on delivery plus a Test Data Report for every calibration

performed during three years of coverage (requires Option C3).

R3 Extends product repair warranty to a total of three years.

C5 Provides factory calibration certification on delivery, plus four more years of

calibration coverage. Throughout the coverage period, the instrument will be
calibrated according to its Recommended Calibration Interval.

D5 Provides test data on delivery plus a Test Data Report for every calibration

performed during five years of coverage (requires Option C5).

R5 Extends product repair warranty to a total of five years.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 3

Getting Started

Standard Accessories

The following accessories are shipped with the amplifiers and probes. Refer to
the Replaceable Parts List beginning on page 8--1 for Tektronix part numbers to
use in ordering accessories.

Amplifiers

Probes

The following accessories are shipped with the TCPA300 and TCPA400
amplifiers.

H Power Cord (customer-chosen option)

H BNC Cable

H Termination, 50 Ω, 2W

H TEKPROBE Interconnect Cable

H Instruction Manual (English or Japanese; customer-chosen language option)

H Certificate of Traceable Calibration

When you order a current probe, you will receive these accessories:

H Probe cover

H Probe ground lead, 6 inch length (TCP305 and TCP312 only)

H Instruction Sheet

H Certificate of Traceable Calibration

1- 4

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Optional Accessories

Getting Started

You can order the following optional accessories for the amplifiers and probes.
Refer to the Replaceable Parts List beginning on page 8--1 for Tektronix part
numbers to use in ordering accessories.

H One-turn 50 Ω current loop. The current loop is used in the performance

verification procedure for checking the performance of the TCPA300
Amplifier and the compatible probes.

H CT-4 High-Current Transformer. If you need to measure high-amplitude AC

currents, consider using the CT-4 with the TCP303 and TCP312 probes. The
CT-4 provides step-down ratios of 20:1 or 1000:1. For more information
about the CT-4, consult your Tektronix sales representative.

H TCPA Calibration Adapter. Use the TCPA Calibration Adapter to verify the

amplifier(s) performance independent of the current probes.

H Travel Case. The travel case includes room to store one amplifier and two

current probes, along with related cables and adapters.

H Deskew Fixture. This fixture converts the PROBE COMPENSATION output

or TRIGGER OUTPUT of the TDS5000 or TDS7000 into a set of test point
connections that allow you a convenient way to compensate for timing
differences between voltage and current probes.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 5

Getting Started

Probe Covers

The TCP300/400 Series Current Probes come with a probe cover that stores the
probe when not in use. Use the probe cover to hold your probe in a convenient
place at your bench or workstation when you are not using it. You can attach the
probe cover to the side of the bench to keep the probe off of your work surface.
See Figure 1--2.

TCP305/312

TCP303/TCP404XL

Figure 1- 2: Using the probe covers

1- 6

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Travel Case

Getting Started

The travel case is a recommended accessory for the TCP A300/400 Amplifiers.
The travel case includes room to store one amplifier and two TCP300/400 Series
Current Probes, one of each size. (For example, you can store a TCP305 and a
TCP303 probe.) A compartment is included to store associated cables and
terminations. See Figure 1--3 for the proper location of the equipment.

Instruction

manual

Large current

probe

Probe holders

Small current

probe

Figure 1- 3: Equipment locations in the travel case

Cables &
terminations

Amplifier

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 7

Getting Started

Connecting the Amplifier to an Oscilloscope

You will need an oscilloscope to display the TCPA300 and TCPA400 measure­ment output. To use the full dynamic range of the probe/amplifier combination,
the oscilloscope must be capable of displaying a vertical scale factor of 1 mV/div
to 1V/div.

If you are using a TEKPROBE II-compatible oscilloscope, use the TEKPROBE­to-TEKPROBE interface cable. Otherwise, use the supplied 50 Ω BNC cable to
connect the amplifier OUTPUT connector to your oscilloscope (see Figure 1--1
on page 1--1).

The input impedance of the oscilloscope channel must be 50 Ω, or you will
encounter slowed pulse response, increased aberrations, or incorrect DC
measurement amplitudes. If your oscilloscope provides only 1 MΩ inputs, you
need to attach a 50 Ω feed-through termination between the oscilloscope input
and the BNC cable. Do not install this termination at the amplifier end of the
BNC cable.

To utilize the full bandwidth capability of the TCPA300 and TCPA400 and
attached current probe, the oscilloscope bandwidth must be approximately five
times that of the current probe. For example, when using a TCP312 Current
Probe, the oscilloscope bandwidth must be at least 500 MHz. When using a
TCP305 Current Probe, the oscilloscope bandwidth must be at least 250 MHz.

Power on the Amplifier

After you have connected the amplifier to the oscilloscope, allow the equipment
to warm up to a stable temperature; usually 20 minutes is required.

Connect the power cord to the power input connector on the rear of the amplifier,
and then connect the power cord to your local mains supply (100 VAC to 240
VAC, 50 Hz to 400 Hz). To allow for proper ventilation, place the rear panel of
the amplifier at least 2 inches away from any obstructions. Set the amplifier on
the bottom rubber feet, and keep papers and other items away from the bottom of
the amplifier which could restrict airflow and cause overheating.

Power on the amplifier by pressing the ON/STANDBY button at the lower-left
corner of the front panel. The amplifier goes through a self-test and cycles the
front-panel LEDs.

NOTE. The amplifier stores the power state it is in when the power cord is
unplugged. If you do not put the amplifier into STANDBY mode before unplug­ging it, the amplifier will power on immediately when you plug it in again.

When you connect a probe to the amplifier, the amplifier uses detection circuitry
to indicate probe conditions such as noncompatible probe type and probe open.

1- 8

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Connecting a Current Probe to the Amplifier

To connect a current probe to the amplifier input connector, align the red dot on
the probe connector with the red dot on the amplifier front panel, as shown in
Figure 1--4. Push the probe connector in to lock the connector. Do not twist the
connector. The connector locks into place when you push it all the way into the
front panel.

If you connect a probe to the wrong amplifier, (for example, a TCP312 to a
TCPA400), the NONCOMPATIBLE PROBE TYPE LED illuminates. Discon­nect the probe and use the correct amplifier. The TCPA400 amplifier accepts
TCP3XX probes, but will only operate properly with TCP4XX probes.

To disconnect the probe from the amplifier, pull back on the connector housing
and pull the connector straight off the front panel.

CAUTION. Handle current probes with care. Do not drop a probe or subject it to
impact, or the core may crack.

Getting Started

Do not connect or disconnect a current probe while the probe is clamped around
a live conductor, or the probe may suffer electrical damage.

Align the red dots

Pull back collar,

then pull out connector

Connecting Disconnecting

Figure 1- 4: Connecting and disconnecting a current probe to the am plifier

Each current probe is calibrated before it is shipped, and should not require
further adjustment. If a probe requires adjustment, refer to the Adjustment
Procedure Overview on page 6--1 or contact your nearest Tektronix Service
Center. The adjustment procedure must be performed only by qualified service
personnel.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 9

Getting Started

Operating the Current Probe Slide

The current probes each have a slide mechanism that opens and closes the probe
jaw. This allows you to clamp the probe around a conductor under test. The slide
must be locked closed to accurately measure current or to degauss the probe. If a
probe is unlocked, the PROBE OPEN indicator on the amplifier will light.

WARNING. Do not clamp the TCP305 or TCP312 current probes around
uninsulated wires. Damage to the probe or personal injury may result. Only use
the TCP305 or TCP312 current probes on INSULATED wires.

The TCP303 and TCP404XL current probes can be used to measure current on
uninsulated wires. However , the circuit must be de-energized when connecting or
removing the current probe.

Figure 1--5 illustrates the slide operation of the TCP305 and TCP312 current
probes. To open the probe, pull the slide back until the jaw is open. To lock the
probe, push the slide forward until the detent snaps into place.

Probe open Probe locked

Figure 1- 5: TCP312 and TCP305 slide operation

Figure 1--6 on page 1--11 illustrates the slide operation of the TCP303 and
TCP404XL current probes. To open the probe, press the bottom of the lock
button and squeeze the handle until the core is open. To lock the probe, release
the squeeze handle and press the top of the lock button.

1- 10

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

(1) Unlock the probe

(2) Squeeze

the handle

(a) Opening the probe

Getting Started

(2) Lock the probe

(1) Release the handle

(b) Closing and locking the probe

Figure 1- 6: TCP303 and TCP404XL slide operation

Degaussing and Autobalancing the Current Probe

Degaussing the probe removes any residual magnetization from the probe core.
Such residual magnetization can induce measurement error. Autobalancing
removes unwanted DC offsets in the amplifier circuitry. Failure to degauss the
probe is a leading cause of measurement errors. The DEGAUSS LED flashes
until you degauss the probe.

To degauss the probe, disconnect the probe from the test circuit, or ensure that
the conductor under test has no power, close and lock the slide, and then press
the amplifier PROBE DEGAUSS AUTOBALANCE button on the front panel of
the amplifier. To maintain measurement accuracy, degauss your probe in each of
these cases:

H After you turn on the amplifier and allow a 20-minute warm-up period.

H Before you connect the probe to a conductor.

H Whenever a current or thermal overload condition occurs.

H Whenever you connect a new probe.

H Whenever you subject the probe to a strong external magnetic field.

H Periodically during normal use.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 11

Getting Started

To degauss and autobalance a current probe, perform these steps:

1. Verify that the current probe is connected to the amplifier.

2. Remove the current probe from the conductor under test.

3. Lock the probe slide closed (see Figures 1--5 and 1--6).

4. Press the amplifier PROBE DEGAUSS AUTOBALANCE button.

5. Wait about five seconds for the degauss procedure to complete.

The PROBE DEGAUSS AUTOBALANCE LED glows green when the
operation has successfully completed. If the LED is blinking orange, the degauss
operation is still in progress. If the LED is red, the operation failed, and the
cause of the failure needs to be found and fixed. For more information, refer to
the PROBE DEGAUSS AUTOBALANCE button discussion on page 2--2.

NOTE. The degauss procedure will fail if the amplifier is not properly connected
to an oscilloscope having 50 Ω input impedance. If this occurs, the NOT
TERMINATED INTO 50 Ω LED lights on the amplifier front panel.

DC Measurements

After you have completed the oscilloscope adjustments and the amplifier
degauss/autobalance procedure, your system is ready to measure current.

To measure DC current, perform these steps:

1. Verify that the amplifier and the oscilloscope input coupling are set to DC,

and the input impedance is set to 50 Ω.

2. Lock the probe closed without a conductor passing through it.

3. Adjust the ground reference of the oscilloscope to move the trace to the

desired graticule line.

4. Press the amplifier PROBE DEGAUSS AUTOBALANCE button.

The NOT TERMINATED INTO 50 Ω LED is lighted if impedance is not 50 Ω.
If this is the case, make necessary changes. (For example, use a 50 Ω termina­tion.)

5. After the degauss/autobalance routine completes, adjust the ground reference
(if necessary) using the amplifier MANUAL BALANCE controls.

1- 12

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Getting Started

WARNING. Do not clamp the TCP305 or TCP312 current probes around
uninsulated wires. Damage to the probe or personal injury may result. Only use
the TCP305 or TCP312 current probes on INSULATED wires.

The TCP303 and TCP404XL current probes can be used to measure current on
uninsulated wires. However , the circuit must be de-energized when connecting or
removing the current probe.

6. Open the probe slide, place the probe around the conductor under test, and
then lock the slide. For correct measurement polarity, make sure the probe
arrow is pointing in the direction of conventional (positive to negative)
current flow. Reversing the flow will display the current waveform upside­down on the oscilloscope.

7. Adjust the oscilloscope time base, trigger, and gain as needed.

Figure 1--7 shows a current probe connected to a power supply line. Notice that
the probe arrow points toward the negative terminal of the power supply to
conform to the conventional current flow of positive (+) to negative (--).

Current probe

Conventional current arrow

Figure 1- 7: Current probe polarity

Power supply

Load

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

1- 13

Getting Started

AC Measurements

To measure AC current only, and remove the DC component of the current being
measured, follow the instructions below. These are identical to the instructions
for DC current measurements except that the amplifier coupling in step 2 is set to
AC.

1. Verify that the oscilloscope input coupling is set to DC.

2. Verify that the amplifier input coupling is AC, and the input impedance is set

to 50 Ω. (The NOT TERMINATED INTO 50 Ω LED is on if impedance is
not 50 Ω.)

3. Adjust the ground reference of the oscilloscope to move the trace to the
desired graticule line.

4. Lock the probe closed without a conductor passing through it, and then press
the amplifier PROBE DEGAUSS AUTOBALANCE button.

WARNING. Do not clamp the TCP305 or TCP312 current probes around
uninsulated wires. Damage to the probe or personal injury may result. Only use
the TCP305 or TCP312 current probes on INSULATED wires.

The TCP303 and TCP404XL current probes can be used to measure current on
uninsulated wires. However , the circuit must be de-energized when connecting or
removing the current probe.

5. Open the probe slide, place the probe around the conductor under test, and
then lock the slide. For correct measurement polarity, make sure the probe
arrow is pointing in the direction of conventional (positive to negative)
current flow. Reversing the flow will invert the displayed current waveform
on the oscilloscope.

NOTE. Even when making AC current measurements, leave the oscilloscope
coupling on DC. Change only the amplifier coupling to AC. Using the oscillo­scope AC coupling may cause the amplifier to exceed its output dynamic range.

6. Adjust the oscilloscope time base and trigger as needed.

1- 14

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Operating Basics

Control Summary

This section describes the function of each TCP A300 and TCPA400 front panel
control and connector. The overview in Figure 2--1 is followed by a detailed
description.

Some seldom-used functions do not appear in Figure 2--1. These functions are
completely discussed in the detailed descriptions that follow Figure 2--1.

The PROBE DEGAUSS AUTOBALANCE button
removes residual magnetism from the attached
current probe. A multi-color LED indicates the
status of the degauss circuit.

The MANUAL BALANCE buttons allow you to
fine-adjust DC offset from the amplifier. The
adjacent LED lights when one of the buttons
has been pressed.

The four probe error lights indicate the following
faults: PROBE OPEN, OVERLOAD (current or
temperature), NOT TERMINATED INTO 50 Ω
and NONCOMPATIBLE PROBE TYPE.

The ON/STANDBY button turns on power to
the amplifier.

Figure 2- 1: The TCPA300 front panel

The RANGE button toggles between the two
scale factors that are available for the attached
probe (TCPA300 only). LEDs indicate the
selected range.

The COUPLING button selects AC or DC probe
coupling, as indicated by the LEDs.

The current probes connect to the TCPA300 and
TCPA400 at the PROBE INPUT connector.

The TCPA300 and TCPA400 output appears at
the OUTPUT connector. Connect this to a 50 Ω
input of your oscilloscope.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

2- 1

Control Summary

TCPA300 and TCPA400 Controls

These front panel controls and indicators are common to both the TCPA300 and
TCPA400 current probe amplifiers, unless otherwise indicated.

PROBE DEGAUSS

AUTOBALANCE Button

and Indicator

When pressed, this button performs two functions that maximize measurement
accuracy. First, the amplifier generates a degauss signal to remove any residual
magnetism from the attached current probe. Second, the amplifier initiates an
operation to remove any undesired DC offsets from the circuitry. During the
degauss process, the amplifier is busy and cannot be used to measure current.

The indicator light next to the PROBE DEGAUSS AUTOBALANCE button
blinks red whenever the amplifier detects that the current probe needs degaus­sing. The amplifier cannot detect all circumstances that require probe degaus­sing, so you may need to degauss the probe at times when the PROBE
DEGAUSS AUTOBALANCE light is not blinking red. The red blinking light
serves as a reminder to degauss the current probe when one of the following
conditions occurs:

H The amplifier has just been turned on with a current probe connected.

H The current probe has been changed.

H An overload was detected.

To perform the probe degauss/autobalance function, remove the probe from all
conductors (or ensure that the conductor under test has no power), make sure the
probe is locked closed, and then press the PROBE DEGAUSS AUTOBA­LANCE button. The probe degauss/autobalance routine will not pass if the
current probe is disconnected from the amplifier input, or if it is unlocked (the
PROBE OPEN LED is on).

2- 2

The indicator blinks orange during the time the amplifier is busy performing the
probe degauss functions. When the degauss and autobalance procedure is
complete, the indicator light turns green.

The PROBE DEGAUSS AUTOBALANCE indicator light will be orange if the
MANUAL BALANCE buttons have been pressed after a degauss has been
successfully completed. This indicates that the DC offset value has been
manually changed from the original value set during the degauss routine.
Depending on the amount of offset (balance) you have entered with the
MANUAL BALANCE buttons, another degauss operation may be necessary to
ensure accurate measurements. Generally, if you change the DC offset by more
than 5 divisions, you should de-energize the circuit under test and perform
another degauss routine. Then, re-energize the circuit and take your measure­ments.

If the degauss operation has failed, and the AC and DC COUPLING LEDs are
alternately flashing, this indicates the amplifier is displaying an error code with
the four status LEDs on the lower-left front panel. If this occurs, refer to

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Control Summary

Displaying Error Codes with the Probe Degauss Autobalance Button on
page 3--22.

NOTE. The NOT TERMINATED INTO 50 Ω LED is on when the amplifier output
is not properly terminated into a 50 Ω load. Make sure your amplifier OUTPUT
is connected to an oscilloscope input using a 50 Ω BNC cable, and that the
oscilloscope input is set to 50 Ω impedance. See Figure 1--1 on page 1--1 for
proper cabling.

If your oscilloscope does not have 50 Ω impedance settings for inputs, you can
place a 50 Ω feed-through termination on the oscilloscope input and connect the
amplifier output cable to the termination. Do not place the feed-through
termination at the amplifier end of the BNC connecting cable.

MANUAL BALANCE

Buttons and Indicator

PROBE OPEN Indicator

OVERLOAD Indicator

The MANUAL BALANCE buttons allow you to fine-adjust the DC offset that
appears at the amplifier OUTPUT connector. The manual balance adjustment
only functions when the amplifier is set to DC coupling, and the MANUAL
BALANCE indicator is only lighted after you press one of the MANUAL
BALANCE buttons in DC coupling mode.

When lit, this indicator informs you that the current probe is unlocked. You must
have the probe slide locked to degauss the probe or to accurately measure
current.

When this LED is red, it informs you that the measurement you are taking
exceeds the continuous amplitude limit of the TCPA300 and TCPA400. The
detection circuits detect only low frequency and DC overloads. Since overloads
can magnetize the probe, always degauss the probe after an overload. When the
OVERLOAD indicator flashes red, it indicates the pulsed waveform is exceeding
the amplitude limit of the amplifier.

When this LED is orange, it indicates that the safe operating temperature of the
probe, and possibly the amplifier, has been exceeded. Disconnect the probe from
the current source and allow time for the probe head and amplifier to cool.

When this LED blinks red and orange, it indicates that both the safe operating
temperature of the probe and the current limit have been exceeded.

WARNING. To avoid personal injury or equipment damage, do not exceed the
specified electrical limits of the TCPA300 and TCPA400 or any applicable
accessories.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

2- 3

Control Summary

NOT TERMINATED

INTO 50 Ω Indicator

NONCOMPATIBLE

PROBE TYPE Indicator

ON/STANDBY Button

RANGE Button

(TCPA300 only)

When lit, this indicator informs you that the TEKPROBE interface cable or BNC
cable from the OUTPUT of the amplifier is not connected to a 50 ohm input on
the oscilloscope. You need to switch the termination setting on the oscilloscope
to 50 Ω,orusea50Ω termination on the oscilloscope input.

NOTE. NOT TERMINATED INTO 50 Ω is only detected during the DEGAUSS
AUTOBALANCE operation.

When lit, this indicator informs you that the probe that is connected to the
amplifier is not designed to work with the amplifier. TCP3XX probes only work
with the TCPA300 Amplifier, and the TCP404XL probe only works with the
TCPA400 Amplifier.

Use this button to power on the amplifier. When the amplifier is in STANDBY
mode, the amplifier is in a limited-power mode. Most of the secondary circuitry
is disabled, but the line voltage remains connected to the amplifier power supply.

Press the RANGE button to toggle between the scale factors (sensitivity settings)
of the probe attached to the TCPA300. If no RANGE LEDs are lit, this indicates
a probe is not connected to the amplifier.

COUPLING Button and

Indicators

The COUPLING button determines the coupling between the
TCPA300/TCPA400 and the oscilloscope. Press the COUPLING button to
toggle between AC and DC coupling. To couple the amplifier for DC plus AC
measurements, use DC coupling. For AC measurements only, use AC coupling.
When the amplifier is set to AC coupling, the Manual Balance adjustment is
disabled since the DC offset component is not visible on the output waveform.

NOTE. Even when making AC current measurements, leave the oscilloscope
coupling on DC. Change only the amplifier coupling to AC. Using the oscillo­scope AC coupling may cause the amplifier to exceed its output dynamic range.

Under normal operation, the AC and DC COUPLING LEDs indicate the
coupling mode of the amplifier. If they alternately flash after a degauss opera­tion, this indicates the amplifier is displaying an error code with the four status
LEDs on the lower-left front panel. If this occurs, refer to Displaying Error
Codes with the Probe Degauss Autobalance Button on page 3--22.

2- 4

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Control Summary

PROBE INPUT Connector

OUTPUT Connector

All current probes compatible with the TCPA300 and TCPA400 attach at the
PROBE INPUT connector, which is a multi-pin female connector. For informa­tion about connecting a probe, see Connecting a Current Probe to the Amplifier
on page 1--9.

The amplifier current measurement output is accessed at the OUTPUT connector,
which should be connected to the oscilloscope input. Attach one end of a 50 Ω
BNC cable to this connector and the other end to a 50 Ω vertical input of your
oscilloscope. The output impedance of the amplifier is 50 Ω.

To get a direct readout of current on your Tektronix oscilloscope, use the
TEKPROBE interface cable to connect the amplifier to your oscilloscope.

NOTE. To obtain accurate measurements, the input impedance of your oscillo­scope must be 50 Ω. Make sure your amplifier OUTPUT is connected to an
oscilloscope input using a 50 Ω BNC cable, and that the oscilloscope input is set
to 50 Ω impedance. See Figure 1--1 on page 1--1 for proper cabling.

If your oscilloscope does not have 50 Ω impedance settings for inputs, you can
place a 50 Ω feedthrough termination on the oscilloscope input and connect the
amplifier output cable to the termination. Do not place the feedthrough
termination at the amplifier end of the BNC connecting cable.

Probe DC Gain Adjust

(located on probes)

After the PROBE DEGAUSS AUTOBALANCE routine has been run, the probe
and amplifier system will meet all published specifications. However, if you
want to improve the tolerance of the system accuracy, or to intentionally offset
the accuracy to make up for total system errors, you can manually adjust the gain
of the probe. Refer to Figures 6--3 and 6--5 on pages 6--7 and 6--12 for the
adjustment locations.

NOTE. You should be careful to note the existing position of the DC Gain
Adjustment before you alter it, so that you may return it to the initial, calibrated
position. By altering the DC Gain Adjustment, you may cause the probe to not
meet the warranted DC Accuracy specification.

For example, the typical accuracy of the TCP312 probe on the 1A/V range is
1%. If you want to measure a 3A p-p, 1kHz square wave and need increased
accuracy (better than 0.25% is attainable), first adjust the TCP312 on the 1A/V
range setting using a calibrated 3A p-p, 1kHz square wave source. Then, attach
the probe to your circuit and take your measurement. Remember, altering the DC
Gain Adjustment may cause the probe to not meet the warranted DC Accuracy
specification.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

2- 5

Control Summary

GPIB Operation

The TCPA300 and TCPA400 Current Probe Amplifiers do not have direct GPIB
connections. However, you can use a computer to control the oscilloscope that
the amplifier is connected to, enabling you to change the time and scale factors
of your current measurements over the oscilloscope GPIB bus.

Refer to your oscilloscope manual for instructions on using the GPIB bus.

2- 6

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Reference

Reference Notes

These notes are provided to help you utilize the full potential of the TCPA300
and TCPA400 current probe systems.

Degaussing a Probe with an Unpowered Conductor in the Jaws

Under almost all conditions, you can degauss your current probe while a
conductor of an unpowered circuit is clamped in the jaws. The advantage of
degaussing with an unpowered circuit is that any offset from stray DC magnetic
fields are compensated. In an automated environment, degaussing with the
conductor in the probe jaws eliminates the need to manually remove the probe.

NOTE. Be certain that the conductor in the probe jaws is completely unpowered.
Any current flowing through the conductor will cause a residual offset in the
current probe, and the amplifier may report an inaccurate result.

If the impedance of your circuit is higher than that shown in Table 3--1, the
degauss procedure will succeed because the amplifier will be able to saturate the
probe core. While degauss occurs, the probe will induce a voltage in the
unpowered circuit. This also appears in Table 3--1. Your circuit must be able to
absorb this induced voltage. With low impedance circuits, several amperes may
be induced in the circuit being measured. This may be of concern when you are
using very small conductors.

Table 3- 1: Unpowered circuit degauss limits

Probe type Minimum circuit resistance Maximum induced voltage

TCP312 10 mΩ 40 mV at 200 Hz

TCP305 5mΩ 40 mV at 200 Hz

TCP303 5mΩ 30 mV at 200 Hz

TCP404XL 1mΩ 15 mV at 100 Hz

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 1

Reference Notes

Measuring Differential Current

You can place two conductors in a current probe to provide differential or null
current measurement. This avoids the necessity of using two current measure­ment systems with a differential oscilloscope.

WARNING. Do not put more than one uninsulated conductor at a time in the
TCP303 or TCP404XL probes. Do not put any uninsulated conductors in the
TCP305 or TCP312 probes. An uninsulated conductor is defined as any
conductor without insulation or without insulation rated for the voltage present
on the conductor under test.

An insulated conductor is defined as any conductor that is surrounded by an
insulating material that is capable of isolating the voltage present on the
conductor. Note that lacquer coatings like those typically found on transformer
windings do not provide sufficient, reliable insulation for use with current
probes. The lacquer coating can be easily nicked or damaged, compromising the
insulating capabilities of the lacquer coating.

Do not force the slide closed. Damage to the probe may result. If you cannot
close the slide around the conductor(s), either reduce the number of conductors
you are measuring, or, if possible, take your measurement on a smaller
conductor.

1. Orient the two conductors under test so that the polarities oppose each other.
Clamp the current probe around the two conductors as shown in Figure 3--1.
Be careful not to pinch a conductor in the probe jaws.

2. Measure the current. A waveform above the baseline indicates the conductor
with the conventional current flow in the direction of the probe arrow is
carrying the greater current. Conventional current flows from positive to
negative.

3. To adjust for a current null, adjust the current in one of the conductors until
the displayed measurement is zero.

3- 2

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

AC and DC Coupling

Reference Notes

Conductor #2

Conductor #1

Current

Current

Current probe

Figure 3- 1: Measuring differential current and nulls

You can couple the signal input to the TCPA300 and TCPA400 with either DC or
AC coupling. DC coupling shows the DC and AC measurement components
while AC coupling removes the DC component from the displayed signal. When
you use AC coupling, make sure that the input DC current does not exceed the
probe specifications.

AC coupling will affect waveforms at frequencies higher than the AC Coupling
Low-Frequency Bandwidth. For example, pulsed currents may exhibit rolloff or
decreased amplitude. Figure 3--2(a) shows a low-frequency square wave using
AC coupling. The signal exhibits low-frequency rolloff. By changing the
amplifier coupling to DC, the pulse is displayed as truly square, as shown in
Figure 3--2(b).

(a) AC-Coupled signal

(b) DC-Coupled signal

Figure 3- 2: Effect of AC or DC coupling on low-fr equency signals

If you are trying to examine a low-frequency signal that is superimposed on a
comparatively large DC component, you can resolve the signal by performing
these steps:

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 3

Reference Notes

1. Select the range setting that will display the maximum detail without

2. Adjust the oscilloscope V/div sensitivity (A/div if using the TEKPROBE

Maximum Current Limits

Current probes have three maximum current ratings: continuous, pulsed, and
Ampere-second product. Exceeding any of these ratings can saturate the probe
core, magnetizing the core and causing measurement errors. See Specifications
beginning on page 4--1 for the maximum current ratings of compatible probes.

H Maximum Continuous Current refers to the maximum current that can be

H Maximum Pulsed Current refers to the maximum peak value of pulsed

exceeding the dynamic range of the signal.

interface), to display maximum signal detail.

continuously measured at DC or at a specified AC frequency. The maximum
continuous current value is derated with frequency; as the frequency
increases, the maximum continuous current rating decreases.

current the probe can accurately measure, regardless of how short (within
bandwidth limitations) the pulse duration is.

Procedure A

H Ampere-Second Product defines the maximum width of pulsed current that

you can measure when the pulse amplitude is between the maximum
continuous and maximum pulsed current specifications. The maximum
continuous specification itself varies by frequency.

NOTE. Always degauss the probe after measuring a current that exceeds the
maximum continuous current, maximum pulsed current, or Ampere-second
product rating of the probe. Exceeding these ratings can magnetize the probe
and cause measurement errors.

To determine if your measurement exceeds the Ampere-second product, perform
either Procedure A or Procedure B.

To determine the maximum allowable pulse width, measure the peak current of
the pulse (see Figure 3--3a). Divide the Ampere-second (or Ampere-microse­cond) specification of your probe by the measured peak current of the pulse. The
quotient is the maximum allowable pulse width; the pulse width at the 50% point
of the measured signal must be less than this value.

For example, the TCP312 Current Probe has a maximum Ampere-second
product of 500 A⋅s in the 10 A/V range setting. If a pulse measured with a
TCP312 has a peak current of 40 A, the maximum allowable pulse width would
be 500 A⋅s divided by 40 A, or 12.5 s.

3- 4

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Reference Notes

I

max

p

Pulse width
at 50%

50%

I

max

c

0A

(a) Maximum allowable pulse width (b) Maximum allowable pulse amplitude

Figure 3- 3: Applying the amp-second product rule

Do Not Exceed

Pulse width
at 50%

50%

Maximum
pulsed
current

Maximum
continuous
current

Procedure B

To determine the maximum allowable pulse amplitude, measure the pulse width
at the 50% points (see Figure 3--3b). Divide the Ampere-second (or Ampere­microsecond) specification of your probe by the pulse width. The quotient is the
maximum allowable current; the peak amplitude of the measured pulse must be
less than this value.

For example, the TCP312 Current Probe has a maximum Ampere-second
product of 500 A⋅s in the 10 A/V range setting. If a pulse measured with a
TCP312 probe has a width of 15 s, the maximum allowable peak current would
be 500 A⋅s divided by 15 s, or 33.3 A.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 5

Reference Notes

Measuring Noncontinuous Current with the TCP404XL Probe

When you measure a noncontinuous current with the TCP404XL probe, you
need to take into consideration several factors to ensure that you make accurate
measurements and do not trip the thermal overload circuit. The amplitude and
duty cycle of the continuous and noncontinuous current, and the ambient
temperature, all affect the maximum amount of time allowed for the measure­ment, which defines the safe operating area of the probe.

You can calculate the duty cycle of the continuous and noncontinuous current
when you know the duration of the noncontinuous current (defined in Figure 3--4
as measurement time) and the measurement period. Figure 3--4 illustrates a
continuous and noncontinuous current and how to calculate the duty cycle.

Measured

current (A)

Noncontinuous

current level (A)

Continuous

current level (A)

Measurement

time (min)

Measurement

period (min)

Duty cycle (%) = 100x

Measurement time

Measurement period

Time (min)

Figure 3- 4: Duty cycle calculation

After you calculate the duty cycle of the noncontinuous current you are
measuring, you can use the other factors (continuous and noncontinuous current
amplitude, etc.) to compare your measurement to those shown in Figures 4--8
through 4--10 in the Specifications section.

You can see how duty cycle affects the measurement time by looking at any of
the three graphs in Figures 4--8 through 4--10. As the duty cycle increases on the
x-axis, the measurement time (of the noncontinuous current) on the y-axis
decreases.

Figures 4--8 and 4--9 on page 4--12 illustrate the effect of measuring two different
noncontinuous current amplitudes, 750 amps and 600 amps respectively, with

3- 6

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Reference Notes

varying duty cycles and levels of continuous current. The ambient temperature in
these two examples is kept constant at 50 °C.

WARNING. When using the probe near the upper current limit and maximum
ambient temperature for extended lengths of time, the probe head surface can
become hot to the touch. To prevent injury, keep your hands away from the probe
head until it has had time to cool after disconnecting the probe from the circuit.

To see how noncontinuous current amplitude affects measurement time, look at
the curves for measurements of 200 amps continuous between the two graphs in
Figures 4--8 and 4--9 on page 4--12. Compare the maximum measurement time
allowed for a duty cycle of 20%: At 750 amps, you have 3 minutes of safe
measurement time, versus 17 minutes for a smaller noncontinuous-current
amplitude of 600 amps.

By looking at any of the three graphs, you can also see that when you measure a
noncontinuous current having the same amplitude and duty cycle, the measure­ment time decreases as the continuous-current amplitude increases.

Finally, compare the two graphs in Figures 4--8 and 4--10 on pages 4--12 and
4--13. Here, the effect of ambient temperature on measurement time is illustrated.
Given a continuous current of 200 A with a noncontinuous current of 750 A, and
having a 20% duty cycle, a 27 °C increase in temperature yields a 12 minute
decrease in maximum measurement time.

Keep these factors into account when taking measurements to ensure accuracy
and to protect both yourself from injury and the equipment from damage.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 7

Reference Notes

Extending Current Range

You may encounter situations where your measurement exceeds the maximum
current rating of the connected probe. This section discusses methods for
extending AC and DC current ranges without exceeding specified limits.

WARNING. To avoid personal injury or equipment damage, do not exceed the
specified electrical limits of the TCPA300 and TCPA400 or any applicable
accessories. When using multiple conductors, do not exceed current limits on
either conductor.

Extending DC Range

If you want to measure a low-amplitude AC component that is superimposed on
an extremely large steady state DC component (such as in a power supply), or if
you want to extend the DC current range of your probe, you can add offset
(bucking) current with a second conductor.

WARNING. Do not put more than one uninsulated conductor at a time in the
probe jaws. An uninsulated conductor is defined as any conductor without
insulation or without insulation rated for the voltage present on the conductor
under test.

To supply additional bucking current, place a second conductor that has a pure
DC component of known value in the probe jaw with the conductor under test, as
shown in Figure 3--5(a). Orient the second conductor so that the bucking current
flows in the opposite direction of the DC flow in the conductor under test.

You can increase the value of the bucking current by winding multiple turns of
the second conductor around the probe, as shown in Figure 3--5(b). The bucking
current is equal to the current flowing in the conductor, multiplied by the number
of turns wound around the probe. For example, if the second conductor has a
current of 100 mA DC and is wrapped around the probe five times, the DC
bucking current is 100 mA multiplied by 5, or 500 mA DC.

3- 8

To determine measurement values, add the value of the bucking current to the
displayed measurement.

NOTE. Adding a second conductor to the probe increases the insertion imped­ance and reduces the upper bandwidth limit of the probe. Winding multiple turns
further increases the insertion impedance, further reducing the upper bandwidth
limit.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Reference Notes

Current

Current

Conductor

under test

Bucking current

supplied by

second conductor

Current probe

(a) Adding a second conductor (b) Adding multiple turns

Figure 3- 5: Increasing the DC measurement range

Extending AC Range

You can extend the AC amplitude limit of the TCPA300 by using the Tektronix
CT-4 High-Current Transformer. The CT-4, designed for use with the TCP305
and TCP312 current probes, extends the current probe range by a factor of 20:1
or 1000:1. The CT-4 can provide external steady-state DC bucking current up to
300 A. For more information about the CT-4, consult your Tektronix sales
representative.

Current

Current

Current probe

Conductor

under test

Extra turns added

to increase

bucking current

Because the CT-4 has a lower AC bandwidth limit than the TCP305 and TCP312
current probes, set the amplifier coupling to DC when using the CT-4.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 9

Reference Notes

Increasing Sensitivity

If you are measuring DC or low-frequency AC signals of very small amplitudes,
you can increase measurement sensitivity of your Current Probe by winding
several turns of the conductor under test around the probe as shown in
Figure 3--6. The signal is multiplied by the number of turns around the probe.

WARNING. Do not put more than one uninsulated conductor at a time in the
probe jaws. An uninsulated conductor is defined as any conductor without
insulation or without insulation rated for the voltage present on the conductor
under test.

When viewing the signal on the oscilloscope screen, divide the displayed
amplitude by the number of turns to obtain the actual current value. For example,
if a conductor is wrapped around the probe five times and the oscilloscope shows
a reading of 5 mA DC, the actual current flow is 5 mA divided by 5, or
1mADC.

NOTE. Winding multiple turns around the probe increases insertion impedance
and reduces the upper bandwidth limit of the probe.

Conductor

under test

Extra turns for

increased sensitivity

Current probe

Figure 3- 6: Increasing probe sensitivity

3- 10

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Application Notes

This section describes some of the typical measurement applications of the
TCPA300 and TCPA400 Current Probe Amplifiers:

H Automobile Charging Systems

H Inductance Measurements

H Continuity Test of Multiple-Conductor Cable

H Measuring Inductor Turns Count

H Power Measurement and Analysis Software Applications

Automobile Charging Systems

Most automotive charging systems are three-phase alternators with a diode
rectifier network. A meter averages current from all three phases, and cannot
detect a single-phase diode problem. Observing the charge current waveform can
quickly reveal if one diode is shorted or open.

The diagram in Figure 3--7 shows the equipment setup. Refer to Table 3--2 for
the test equipment setup. A TCP303 Current Probe was used for this high-cur­rent, low-voltage application. The TCP303 is degaussed and clamped around the
positive battery lead from the alternator. The probe arrow is pointed away from
the alternator and toward the battery side of the circuit, to reflect conventional
current. The automobile is started and the lights are turned on to add a significant
load to the circuit.

Table 3- 2: Automobile charging systems test setup

Instrument Control Setting

TCPA300 COUPLING DC

RANGE 50 A/V

Oscilloscope Coupling DC

Amps/Division
(Volts/Division if not using TEK­PROBE interface cable)

Zero-Current Reference Center graticule line

Time Base 200 s/division

10 A/Div
(200 mV/Div)

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 11

Application Notes

TCP303/404XL

+

---

Battery Alternator

To

ground

To current probe amplifier

Figure 3- 7: Setup for measuring charging current

The waveform in Figure 3--8(a) shows the three-phase ripple frequency. The
average charge current is approximately 27 A with a minimum peak of approxi­mately 23 A and a maximum peak of approximately 31 A. The waveform shows
a continuous cycle with no dropouts, so the alternator circuit appears to be
functioning properly. A single-phase diode failure normally appears as an
extreme drop in charge current every third cycle, as shown in Figure 3--8(b).

+

---

To ground

(a) Normal waveform (b) Waveform with one bad phase

Figure 3- 8: Charge current waveforms

3- 12

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

40A

0A

Inductance Measurements

You can use the TCPA300 and TCPA400 to measure inductance of coils. Two
different methods can be used: one for low-impedance pulse sources and another
for high-impedance pulse sources of known value.

Application Notes

Low-Impedance Pulse

Sources

Figure 3--9 shows a measurement setup using a constant-voltage pulse generator
of extremely low output impedance. The inductor is connected across the output
terminals of the pulse source. The current probe is attached to one of the source
leads and the current ramp is measured.

The inductance is effectively defined by the slope of the current ramp, shown in
Figure 3--10, and is mathematically expressed by the following formula:

− E

L =

di
dt

where L is the inductance in henries, E is the voltage of the pulse generator, dt is
the change in time, and di is the change in current.

Current

Pulse

generator

flow (i)

Inductor

Current

probe

Figure 3- 9: Measuring inductance with a low-impedance source

NOTE. If the probe impedance is a significant part of the total circuit inductance,
measurement accuracy will be affected. Refer to the probe specifications for
probe insertion impedance.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 13

Application Notes

Current

flow (i)

d

i

Time (t)

d

t

Figure 3- 10: Linear current vs. time ramp

High-Impedance Pulse

Sources

If the pulse source has a higher impedance of known resistance, such that the
output voltage drops as the current increases, the inductance of a coil can be
calculated by the time constant of the charge curve. Figure 3--11 shows the setup
diagram, which is similar to the previous example. The current ramp represented
in Figure 3--12 shows how the values for the inductance formula are obtained.

Use this formula to calculate the inductance based on the current measurement:

L = τ R

where L is the inductance in henries, τ is the time required for the current to rise
or fall 63.2% of the total current value, and R is the source resistance of the pulse
generator.

3- 14

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Application Notes

Resistance

Pulse

generator

Current

probe

L

Current

flow (i)

Inductance

Figure 3- 11: Measuring inductance with a high-impedance source

Current

flow (i)

100%

63.2%

36.8%

0

Figure 3- 12: High-impedance source current ramp

Continuity Test of Multiple-Conductor Cable

Single conductors in a multiconductor cable can be tested with the TCPA300 and
TCPA400. To check a conductor, clamp the current probe around the cable
bundle and check for a specific, known current signal. If there is no current or
the current is abnormally low, then the conductor has a continuity problem. If the
current is abnormally high, then the conductor may have a short to ground.

ττ

Time (t)

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 15

Application Notes

Measuring Inductor Turns Count

To obtain an approximate turns count of an inductor, connect the inductor to a
current limited source, as shown in Figure 3--13. Measure the input current on
one of the inductor leads, then clamp the current probe around the inductor and
note the current value. The number of turns is equal to the ratio of coil current to
input current. The accuracy of this method is limited by the current measurement
accuracy. The following method allows more precise turns measurement.

For a more precise turns count, you need a coil with a known number of turns to
use as a reference. The measurement setup is similar to the previously described
one, except the reference coil and the test coil are inserted into the current probe
so that the currents oppose each other (see Figure 3--14). You must observe the
polarity of coil current to determine whether the test coil has more or fewer turns
than the reference coil. The turns are calculated by using the formula:

N2= N1×

where N2is the number of turns in the test coil, N1is the number of turns in the
reference coil, I

I
I

m

1

is the measured coil current, and I1is the input current.

m

Measure input current here

Current flow (i)

Coil

Figure 3- 13: Measuring the number of turns in a coil

Clamp probe
around coil to
measure
current from
coil turns

3- 16

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

TCP303 Current probe

Current flow

in coil #1

Input current

Current flow

in coil #2

Figure 3- 14: Turns measurement using reference coil

Application Notes

Power Measurement and Analysis Software

Power measurement software that is available for some Tektronix oscilloscopes
transform your current measurement system into a sophisticated analysis tool
that quickly measures and analyzes many different applications, such as:

H Power dissipation at switching devices and magnetic components in

switching power supplies

H Precompliance test for EN61000--3--2 standard

H Power quality

H Modulation analysis

After making the measurements, the software generates detailed test reports in
customizable formats. When the software is used with a Tektronix TDS5000
Series or TDS7054/TDS7104 digital phosphor oscilloscope and differential
voltage and current probes, it forms a complete measurement system for power
supply design and test.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 17

Application Notes

3- 18

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Troubleshooting and Error Codes

Table 3--3 lists possible problems that you may encounter when measuring
current with the TCPA300 and TCPA400. Use this as a quick troubleshooting
reference.

Table 3- 3: Troubleshooting

Problem Remedy

Amplifier will not power on Check that the amplifier is plugged into a working AC outlet.

Defective amplifier. See HW Troubleshooting on page 7--21 to help determine which
module is defective, or refer the instrument to qualified service personnel for repair.

Front panel displays an error status. Error
Status LEDs are on the lower-left section of
the amplifier front panel

Note the error status and correct the condition. The error status is labeled on the front
panel. For example, if the PROBE OPEN LED is lit, close and lock the probe jaws.

The AC and DC COUPLING LEDs are
flashing alternately

All LEDs are flashing All LEDs flashing indicates a thermal shutdown. Power-cycle the system and let it

OVERLOAD LED remains lit red after
removing probe from circuit.

OVERLOAD LED remains lit orange Degauss the probe. If the OVERLOAD LED remains lit orange, disconnect the probe

Probe does not degauss successfully and
LEDs are lighted in an unfamiliar pattern

Cannot degauss the probe Current Probe is not locked. Lock the current probe.

The Error Status LEDs are displaying an error code. Error codes are described on
page 3--22. Note the error code and turn the instrument off, then on. If the error
condition persists, refer the instrument to qualified service personnel for repair.

If the RANGE and DEGAUSS LED are both off, and one of the COUPLING LEDs is
lit, this indicates the amplifier is not detecti ng a probe. Reconnect the probe.

All LEDs flashing indicate a thermal shutdown. Power-cycle the system and let it cool
for 15 minutes before taking measurements. In most cases, 15 minutes is sufficient.

cool before taking measurements. In most cases, 15 minutes is sufficient.

Probe transformer or amplifier main board is defective.

from the circuit and let it cool for 15 minutes before degaussing again. If this does not
clear the LED, the probe transformer or probe Hall device may be defective. Connect
another probe to the amplifier, or connect the probe in question to another amplifier.

Amplifier is displaying an error code or is out of calibration or defective. Refer to
Interpreting the Error Code display on page 3--23. If another amplifier is available, try
to degauss the probe on the other amplifier, to help isolate the cause.

Component failure on probe circuit board: broken adjustment/wire/etc. Disassemble
probe, repair/replace component or refer the instrument to qualified service personnel
for repair.

Current Probe is improperly connected to the amplifier input connector.

Amplifier output is not terminated into 50 Ω load. Set input impedance of oscilloscope
to 50 Ω or connect a 50 Ω feed-through termination at the oscilloscope input, not at
the amplifier output.

Current Probe is defective or not compatible with the amplifier type.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 19

Troubleshooting and Error Codes

Table 3- 3: Troubleshooting (Cont.)

Problem Remedy

Degauss takes longer than 10 seconds Probe is attached to an energized circuit. Disconnect probe from ci rcuit and retry.

Probe is faulty -- Probe transformer (defective Hall device with excessive noise or drift)
may cause this symptom. May also be caused by a shorted or open wire in the probe
cable assembly.

Defective main board -- If the probe is not the cause, then it is most likely a defective
main board in the amplifier.

Cannot make a current measurement -- no
measurement output from amplifier

MANUAL BALANCE will not adjust Oscilloscope or amplifier input coupling not set to DC. MANUAL BALANCE buttons

Current Probe is not locked. Lock the current probe.

Current Probe is improperly connected to the amplifier input connector.

Amplifier COUPLING is set to AC. Set the COUPLING to DC.

A Degauss/Autobalance routine has not been completed successfully on the system.
Degauss the probe.

Oscilloscope/Amplifier is not set to an appropriate sensitivity setting.

Defective interface cable (between oscilloscope and amplifier).

only function when the amplifier is in the DC coupling mode.

Oscilloscope/Amplifier is not set to an appropriate sensitivity setting.

Stray DC component in measurement Degauss the probe using the PROBE DEGAUSS AUTOBALANCE button. (The

Current Probe has been overloaded, dropped, or exposed to magnetic field.)

You can use the MANUAL BALANCE buttons to null out any residual DC offset after per­forming a Probe Degauss Autobalance routine.

Measurements are inaccurate Degauss the probe.

The amplifier output is not terminated into 50 Ω load. Set the input impedance of
oscilloscope to 50 Ω or connect a 50 Ω feedthrough termination at the oscilloscope
input. Do not attach the termination at the amplifier output.

The measurement exceeds the maximum continuous current or Ampere-second
product ratings of the Current Probe. If possible, upgrade to a probe with a higher
current rating or use a CT-4 transformer.

Amplifier or current probe out of calibration. Refer to Performance Verification on
page 5--1.

The jaw mechanism is dirty -- disassemble probe, clean and lubricate. Refer to the
probe disassembly procedures on page 7--13.

Defective current probe transformer.

Measurements roll off at high frequencies The oscilloscope bandwidth limit is turned on. Verify that the bandwidth limit switch on

the oscilloscope is set to the desired bandwidth position.

(Be careful not to exceed the frequency limit of the probe used. Frequencies above
the probe design may cause overheating and damage to the probe.)

3- 20

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Troubleshooting and Error Codes

Table 3- 3: Troubleshooting (Cont.)

Problem Remedy

Measurements exhibit excessive noise Current Probe is not locked. Lock the current probe.

Current Probe is improperly connected to the amplifier input.

Amplifier output is not terminated into 50 Ω load. Set input impedance of oscilloscope
to 50 Ω or connect a 50 Ω feed-through termination at the oscilloscope input, not at
the amplifier output.

Defective current probe transformer.

Measurement aberrations exceed the specified
limit

Excessive low frequency droop in pulse
response or low DC gain accuracy

Measurements exhibit excessive delay or
slowed pulse response

Probe jaw not opening and closing freely The jaw mechanism is dirty -- disassemble probe, clean and lubricate. Refer to the

The amplifier output is not terminated into 50 Ω load. Set the input impedance of the
oscilloscope to 50 Ω or connect a 50 Ω feedthrough termination (see the replaceable
parts list on page 8--6) at the oscilloscope input. Do not attach the termination to
amplifier output.

The measurement exceeds the maximum continuous current or Ampere-second
product ratings of the Current Probe. (For more informat ion, see Current Limits on
page 3--4.) If possible, upgrade to a probe with a higher current rating or use a CT-4
transformer.

Check that the probe slider is fully closed and locked.

Check and clean the probe transformer and lid.

Degauss the probe.

The amplifier or the oscilloscope may be AC coupled. Set the COUPLING to DC.

The amplifier output is not terminated into 50 Ω load. Set the input impedance of the
oscilloscope to 50 Ω or connect a 50 Ω feedthrough termination (see the replaceable
parts list on page 8--6) at the oscilloscope input. Do not attach the termination to the
amplifier output.

The measurement exceeds the Ampere-second product of the Current Probe. If
possible, upgrade to a probe with a higher current rating or use a CT-4 transformer.

The oscilloscope bandwidth limit is turned on. Verify that the bandwidth limit switch on
the oscilloscope is set to the desired bandwidth position.

probe disassembly procedures on page 7--13.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

3- 21

Troubleshooting and Error Codes

Displaying Error Codes with the Probe Degauss Autobalance Button

This section describes the error codes that the amplifiers display using the
function indicator LEDs.

When an internal error condition exists, the amplifiers may generate error codes
when you press the PROBE DEGAUSS AUTOBALANCE button. The AC and
DC Coupling LEDs will flash alternately to indicate that error codes are being
displayed instead of normal conditions.

The four fault indicator LEDs above the ON/STANDBY switch are used to form
a four-bit binary error code. The PROBE OPEN LED indicates the most
significant bit (MSB), and the NONCOMPATIBLE PROBE TYPE LED
indicates the least significant bit (LSB). See Figure 3--15.

To continue past an error code, press any button except ON/STANDBY.
However, the degauss will fail until the internal error condition is corrected and
the degauss operation is run again.

Press the PROBE
DEGAUSS AUTO

BALANCE button

AC and DC LEDs flash
alternately to indicate

Four--bit error code

is displayed here

MSB

LSB

error codes are being
displayed

Figure 3- 15: Error code display

For example, after you press the PROBE DEGAUSS AUTOBALANCE button,
if the AC and DC Coupling LEDs are flashing, and the NOT TERMINATED
INTO 50 Ω LED is illuminated, this indicates an Error Code 2 -- a null error in
the DC offset circuit occurred. See Figure 3--16 for an illustrated example.

3- 22

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Four--bit error code

hei

alD

Cof

f

lif

i

I

fth

c

c

lif

i

vic

p

p

plylev

)

thepowersupplylevelsforth

e

1)Removetheprobefromthecircui

t

asadj

O

verloa

dtri

I

fth

c

c

c

ircui

89Unuse

d

hei

alD

Cof

f

lif

i

I

fth

c

c

c

ircui

1

3

w

ireint

h

cab

lea

bly

is displayed here

Figure 3- 16: Interpreting the error code display

Table 3--4 shows the complete list of error codes for the amplifier.

Table 3- 4: Amplifier error codes

Code Description of error Action to take

Troubleshooting and Error Codes

MSB

=

LSB

= binary 0010 = code 2 =

a null error in the DC offset occurred

1 The amplifier detected a probe, but a

valid Hall device was not detected.

2 An error occurred while nulling out

t

3

ntern

er.

set oftheamp

4 TCPA300 ONLY -- An error occurred

while the the amplifier was adjusting
the

ower su

5

different Range settings.

els for the

6 An error occurred while the amplifier

w

7

points.

usting the

p

8 Unused

10 An error occurred while nulling out

11

12

ntern

er.

The amplifier cannot null out the

set oftheamp

t

probe DC offset voltage.

14

Disconnect and reattach the probe to the amplifier.
Power cycle the amplifier.
Check probe transformer (defective Hall device).
If these steps do not resolve the error, the amplifier needs service.
May also be caused by a shorted or open wire in the probe cable assembly.

Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.

-

e error reo

urs, then theamp

er needsser

e.

Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.
If the error reoccurs, then perform the following steps:
1

Removetheprobefrom thecircuit.

.

2) Check probe -- The signal path through the probe transformer may be open or
shorted, which can be caused by defective probe transformer or cable assembly.
If the above steps do not resolve the error, the amplifier needs servi c e.

Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.

e error reo

urs, then removetheprobefrom the

t.

If this does not resolve the error, the amplifier needs service.

Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.

-

e error reo

urs, then removetheprobefrom the

t.

If this does not resolve the error, the amplifier needs service.

Remove the probe from the circuit. Error 12 will most likely occur when the probe is
connected to an energized circuit when a Degauss/Autobalance routine is initiated.
Check probe transformer (defectiveHall device).

This error may also be caused by a Hall device with excessive noise or drift in the
probetransformer, orashortedor open

eprobe

ssem

.
Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.
If these steps do not resolve the error, the amplifier needs service.

15 Unspecified error (internal software

error)

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Power cycle the amplifier and run the Degauss/Autobalance adjustment routine again.
If the error reoccurs, then the amplifier needs service.

3- 23

Troubleshooting and Error Codes

Correcting the Cause of an Error Code

After interpreting the error code, disconnect the probe from the circuit and
degauss the probe again. Take the measurement again. If the error code persists,
contact your Tektronix Service Center.

Shutdown Error

If all LEDs flash at the same time, a shutdown condition exists. If this occurs,
turn off the amplifier and disconnect the probe from the circuit under test.
Turning off the amplifier clears the error register.

A shutdown condition can be caused by exceeding the frequency/current
specifications. Verify that you are not exceeding the specifications and let the
probe and amplifier cool before using them again. In most cases, 15 minutes is
sufficient. If the measurement you were taking was within the probe and
amplifier specifications, degauss the probe and take the measurement again. If
the shutdown error persists, contact your Tektronix Service Center.

3- 24

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Specifications

Specifications

These specifications are valid only under the following conditions:

H The probe and amplifier have been calibrated at an ambient temperature of

23 _±5 _C.

H The probe and amplifier are operating within the environmental limits

described in Table 4--6 on page 4--5 (the operating temperature limits are
0 _Cto+50_C, unless otherwise stated).

H The probe and amplifier have had a warm-up period of at least 20 minutes.

H The probe degauss/autobalance routine has been performed after the

20-minute warm-up period, and thereafter whenever the PROBE
DEGAUSS/AUTOBALANCE light blinks.

H The amplifier output is properly terminated into 50 Ω.

Specifications are separated into two categories: warranted specifications and
nominal or typical characteristics.

Warranted Specifications

Warranted specifications, Table 4--1, are guaranteed performance specifications
unless specifically designated as typical or nominal.

Table 4- 1: Warranted TCPA300 and TCPA400 specifications

Amplifier TCPA300..................... TCPA400

DC Gain Accuracy ≤1% ≤1%

Installed probe TCP312 TCP305 TCP303 TCP404XL

Bandwidth (--3 dB) DC to 100 MHz DC to 50 MHz DC to 15 MHz DC to 2 MHz

Rise Time, 10% to 90% ≤3.5 ns ≤7ns ≤23 ns ≤175 ns

DC Gain Accuracy: Warranted ≤3% ≤3% ≤3%

2

.............. ≤1% ≤1% ≤1% ≤1%

1

Warranted from 10 _Cto50_C. For temperature range of 0 _Cto<10 _C, spec is +3%/- 6%.

2

23 _C ±5 _C

Typical

1

≤3%

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 1

Specifications

(

)

(

)

(

)

Nominal and Typical Characteristics

Nominal and typical characteristics, listed in Table 4--2, are not guaranteed.
They are provided to characterize the configuration, performance, or operation of
typical probe/amplifier combinations.

Table 4- 2: Nominal and typical amplifier characteristics

Installed probe

Parameter

Ranges, nominal 1A/V,

Maximum Amp-Second Product
(See Figures 4--2 through 4--5 for
frequency derating)

Input Coupling, nominal AC, DC AC, DC AC, DC AC, DC

AC Coupling Low­Frequency Bandwidth,
(low-pass --3dB point), typical

Displayed Noise, typical ≤75 A

Signal Delay, typical, (includes
probe, amplifier, and TEKPROBE­to-TEKPROBE interface cable, or
012-0117-00 BNC cable)

Maximum Bare Wire Voltage Use with insulated

Lowest Measurable Current 1mA 5mA 5mA 1A

Insertion Impedance
(see Figure 4--6 for plots)

TCP312

10 A/V

1 A/V -- 50A*s
10 A/V -- 500A*s

<7 Hz <7 Hz <7 Hz <7 Hz

RMS

Limit measurement
bandwidth to 20 MHz.

approximately 17 ns approximately 19 ns approximately 53 ns approximately 103 ns

wires only

1 MHz 0.08Ω
10 MHz 0.15Ω
50 MHz 0.27Ω
100 MHz 0.7Ω

TCP305 TCP303 TCP404XL

5A/V,
10 A/V

5 A/V -- 500A*s
10 A/V -- NA

≤500 A
Limit measurement
bandwidth to 20 MHz.

Use with insulated
wires only

1 MHz 0.035Ω
10 MHz 0.12Ω
50 MHz 0.04Ω

RMS

5A/V,
50 A/V

5 A/V -- 3000A*s
50 A/V -- 15000A*s

≤500 A
Limit measurement
bandwidth to 20 MHz.

600VRMSCATI&II
300 VRMS CAT III

1 MHz 0.01Ω
5 MHz 0.025Ω
15 MHz 0.1Ω

RMS

1A/mV

NA

≤70 mA
Limit measurement
bandwidth to 20 MHz.

600VRMSCATI&II
300 VRMS CAT III

10 kHz 0.1 mΩ
100 kHz 0.6 mΩ
1MHz 8.0mΩ
2MHz 16.0mΩ

RMS

Current Transfer Ratio 1 V/Amp and

100 mV/Amp

Maximum Current Ratings at
Sensitivity Ranges

High Current Sensitivity Range 10 A/V Range 10 A/V Range 50 A/V Range 1 A/ mV Range

DC (continuous).......

DC (noncontinuous).......

RMS (sinusoidal).......

Peak Pulse.......

4- 2

30 A

N/A

21 A

50 A 50 A 500 A 750 A

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

200 mV/Amp and
100 mV/Amp

50 A 150 A 500 A

N/A N/A 750 A

35 A 150 A 500 A

200 mV/Amp and
20 mV/Amp

1 mV/Amp

Table 4- 2: Nominal and typical amplifier characteristics (Cont.)

(

)

(

)

(

)

Specifications

Installed probe

Parameter

Parameter

Low Current Sensitivity Range 1 A/V Range 5 A/V Range 5 A/V Range N/A

DC (continuous).......

DC (noncontinuous).......

RMS (sinusoidal).......

Peak Pulse.......

Input Voltage 100--240 VAC (±10%), 47 Hz to 440 Hz, single phase

Maximum Power 50 Watts maximum

Fuse Rating 3.15 AH, 250 V (Not operator-replaceable.)

5A

N/A

3.5 A

50 A

25 A 25 A -- -- --

N/A N/A -- -- --

17.7 A 17.7 A -- -- --

50 A 500 A -- -- --

Mechanical Characteristics

Mechanical characteristics of the amplifiers are listed in Table 4--3.

Table 4- 3: TCPA300 and TCPA400 mechanical characteristics

Parameter, nominal Characteristic

Length 173 mm (6.8 in)

Width 91.4 mm (3.6 in)

Height 167 mm (6.6 in)

Weight 1.14 kg (2.5 lb)

TCP404XLTCP303TCP305TCP312

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 3

Specifications

Mechanical characteristics of the probes are listed in Table 4--4.

Table 4- 4: Probe mechanical characteristics

TCP305 and TCP312 TCP303 and TCP404XL

Probe dimensions

Length:..............

Width:..............

Height:..............

20 cm (7.77 inches)

1.6 cm (0.625 inches)

3.2 cm (1.25 inches)

268 cm (10.55 inches)

41 cm (1.60 inches)

156 cm (6.13 inches)

Cable length 1.5 m (5 feet) TCP303: 2 m (6.6 feet)

TCP404XL: 8 m (26.25 feet)

Weight 0.15 kg (0.33 lb) TCP303: 0.66 kg (1.45 lb)

TCP404XL: 0.88 kg (1.90 lb)

41 mm
(1.6 in)

11.9 mm

(0.470 in)

18.9 mm

(0.745 in)

Maximum wire size

3.8 mm (0.15 in)

TCP305 and TCP312

67 mm
(2.7 in)

TCP303 and TCP404XL

Maximum wire size

21 mm (0.83 in)

21 mm
(0.83 in)

25 mm
(1.0 in)

Figure 4- 1: Probe jaw dimensions (nominal)

Shipping weights and dimensions are listed in Table 4--5.

Table 4- 5: Shipping weights and dimensions

TCPA300 and TCPA400
Amplifiers

Dimensions

Length:.......

Width:.......

Height:.......

298.5 mm (11.75 inches)

298.5 mm (11.75 inches)

254 mm (10.00 inches)

Weight 2.7 kg (6.00 lb) 0.585 kg (1.29 lb) 1.33 kg (2.93 lb) 1.55 kg (3.42 l b)

4- 4

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

TCP305 and TCP312

Current Probes

330 mm (13.00 inches)

254 mm (10.00 inches)

108 mm (4.25 inches)

TCP303
Current Probe

375 mm (14.75 inches)

318 mm (12.50 inches)

127 mm (5.00 inches)

TCP404XL
Current Probe

375 mm (14.75 inches)

318 mm (12.50 inches)

127 mm (5.00 inches)

Environmental Characteristics

The environmental characteristics in Table 4--6 are warranted performance
specifications. Unlike the warranted characteristics in Table 4--1, the environ­mental characteristics are type tested; therefore there are no performance
verification procedures provided to test these characteristics. Unless otherwise
noted, these characteristics apply to all probes and amplifiers.

Table 4- 6: Environmental characteristics

Parameter Characteristic

Ambient Temperature

Operating 0 _Cto+50_C(32_ F to 122 _F)

Nonoperating -- 4 0 _Cto+75_C(--40_ F to 167 _F)

Humidity

Operating 5 to 95% R.H. to +30 _ C(86_F)

Specifications

5 to 85% R.H. +30 _Cto+50_ C(86_F to 122 _F)

Nonoperating 5 to 95% R. H. t o +30 _C(86_F)

5 to 85% R.H. +30 _Cto+75_ C(86_F to 167 _F)

Altitude

Operating 2000 m (6800 ft) maximum

Nonoperating 12,192 m (40,000 ft) maximum

Random Vibration, Amplifiers

Operating 0.31 g

Nonoperating 2.46 g

Random Vibration, Probes

Operating 2.66 g

Nonoperating 3.48 g

Shock, Amplifiers 50 g, 11 ms duration, hal f-sine pul ses

Electro-Magnetic Compliance Meets FCC Part 15, Subpart B, Class A

, 5 Hz to 500 Hz, 10 minutes each axis

RMS

, 5 Hz to 500 Hz, 10 minutes each axis

RMS

, 5 Hz to 500 Hz, 10 minutes each axis

RMS

, 5 Hz to 500 Hz, 10 minutes each axis

RMS

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 5

Specifications

Declarati

f

Conf

g

y

g

Table 4--7 lists the certifications and compliances for the amplifiers and probes.

Table 4- 7: Certifications and compliances

Category Standards or description

EC Declaration of Conformity -­EMC

Meets intent of Directive 89/336/EEC for Electromagnetic Compatibility. Compliance was
demonstrated to the following specifications as listed in the Official Journal of the European
Communities:

EN 61326 EMC requirements for Class A electrical equipment for

measurement, control and laboratory use.

1

IEC 61000--4--2 Electrostatic discharge immunity (Performance criterion B)
IEC 61000--4--3 RF electromagnetic f ield immunity (Performance criterion A)
IEC 61000--4--4 Electrical fast transient / burst immunity (Performance criterion B)
IEC 61000--4--5 Power line surge immunity (Performance criterion B)
IEC 61000--4--6 Conducted RF immunity (Performance criterion A)
IEC 61000--4--11 Voltage dips and interruptions immunity (Performance criterion B)

EN 61000--3--2 AC power line harmonic emissions

Australia / New Zealand

on o

ormity--

EMC

Complies with EMC provision of Radiocommunications Act per the following standard(s):

AS/NZS 2064.1/2 Industrial, Scientific, and Medical Equipment: 1992

EMC Compliance Meets the intent of Directive 89/336/EEC for Electromagnetic Compatibility when it is used with the

product(s) stated in the specifications table. Refer to the EMC specification published for the stated
products. May not meet the intent of the directive if used with other products.

FCC Compliance Emissions comply with FCC Code of Federal Regulations 47, Part 15, Subpart B, Class A Limits.

EC Declaration of Conformity -­Low Voltage

2

Compliance was demonstrated to the following specification as listed in the Official Journal of the
European Communities:

Low Voltage Directive 73/23/EEC, amended by 93/68/EEC

EN 61010-1/A2:1995 Safety requirements for electrical equipment for measurement

control and laboratory use.

EN 61010-2-032:1995 Particular requirements for hand-held current clamps for electrical

measurement and test equipment.

U.S. Nationally Recognized UL3111-1 Standard for electrical measuring and test equipment.
Testing Laboratory Listing

UL3111--2--032 Standard f or hand-held current clamps for electrical measurement

and test.

Canadian Certification CAN/CSA C22.2 No. 1010.1 Safety requirements for electrical equipment for measurement,

control, and laboratory use.

CAN/CSA C22.2 No. 1010.2.032:1996

Particular requirements for hand-held probe assemblies for
electrical measurement and test equipment.

1

Emissions that exceed the levels required by this standard may occur when this equipment is connected to a test object.

2

The TCP305 and TCP312 Current Probes are exempt from the Low Voltage Directive and are not third-party listed.
However, they have been evaluated to applicable safety standards.

4- 6

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Specifications

gyp

Table 4- 7: Certifications and compliances (cont.)

Category Standards or description

Additional Compliance UL 61010B-1 Safety requirements for electrical equipment for measuring,

controlling and laboratory use.

IEC61010-1/A2:1995 Safety requirements for electrical equipment for measurement,

control, and laboratory use.

IEC 61010-2-032:1995 Particular requirements for hand-held current clamps for electrical

measurement and test.

IEC 61010-1:2001 Safety requirements for electrical equipment for measurement

control and laboratory use.

Installation (Overvoltage)
Category Descriptions

Pollution Degree Descriptions A measure of the contaminates that could occur in the environment around and within a product.

Terminals on this product may have different installation (overvoltage) category designations. The
installation categories are:

CAT III Distribution-level mains (usually permanently connected). Equipment at this level is

typically in a fixed industrial location.

CAT II Local-level mains (wall sockets). Equipment at this level includes appliances, portable

tools, and similar products. Equipment is usually cord-connected.

CAT I Secondary (signal level) or battery operated circuits of electronic equipment.

Typically the internal environment inside a product is considered to be the same as the external.
Products should be used only in the environment for which they are rated.

Pollution Degree 1 No pollution or only dry, nonconductive pollution occurs. Products in

this category are generally encapsulated, hermetically sealed, or
located in clean rooms.

Pollution Degree 2 Normally only dry, nonconductive pollution occurs. Occasionally a

temporary conductivity that is caused by condensation must be
expected. This location is a typical office/home environment.
Temporary condensation occurs only when the product is out of
service.

Pollution Degree 3 Conductive pollution, or dry, nonconductive pollution that becomes

conductive due to condensation. These are sheltered locations
where neither temperature nor humidity is controlled. The area is
protected from direct sunshine, rain, or direct wind.

Pollution Degree 4 Pollution that generates persistent conductivity through conductive

dust, rain, or snow. Typical outdoor locations.

Equipment Type Test and measuring

Safety Class Class 1 (as defined in IEC 61010-1, Annex H) -- grounded product

Overvoltage Category Overvoltage Category II (as defined in IEC 61010-1, Annex J)

Pollution Degree Pollution Degree 2 (as defined in IEC 61010-1). Note: Rated for indoor use only.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 7

Specifications

TCP312 derating curve

35

30

25

20

15

Peak current (A)

10

5

0

1k 10k 100k

Frequency (Hz)

Figure 4- 2: Frequency derating- TCP312

60

50

40

TCP305 derating curve

50_C ambient
25_C ambient

1M 10M

50_C ambient
25_C ambient

100M

30

Peak current (A)

20

10

0

1k 10k 100k

Frequency (Hz)

Figure 4- 3: Frequency derating- TCP305

1M 10M

100M

4- 8

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Specifications

250

200

150

100

Peak current (A)

50

0

100

1k 10k 100k

TCP303 derating curve

Frequency (Hz)

Figure 4- 4: Frequency derating- TCP303

800

700

600

500

TCP404XL derating curve

50_C ambient
25_C ambient

1M 10 M

50_C ambient
25_C ambient

100M

400

300

Peak current (A)

200

100

0

0 1k 10k 100k

Frequency (Hz)

Figure 4- 5: Frequency derating- TCP404XL

1M 10M

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 9

Specifications

1.0

TCP312

.1

.01

Insertion Z (ohms)

.001

10k 100k 1M 10M 100M

1.0

Frequency (Hz)

TCP305

.1

.01

Insertion Z (ohms)

.001

10k 100k 1M 10M 100M

Frequency (Hz)

1.0

TCP303

.1

.01

Insertion Z (ohms)

.001

10k 100k 1M 10M 100M

Frequency (Hz)

100m

10m

1m

Insertion Z (ohms)

100µ

10µ

TCP404XL

10 100 1k 10k 100k

Frequency (Hz)

1M

10M

4- 10

Figure 4- 6: Insertion impedance graphs for the curr ent probes

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Specifications

60

TCP312 Max peak pulse vs PW

50

Maximum peak pulse ≤50A

40

500 A*μs

30

Amperes (Peak)

20

50 A*

10

µs

0

0 5 10 15 20

Allowable pulse width (µseconds)

TCP305 Max peak pulse vs PW

60

50

40

Maximum peak pulse ≤50A

Range setting

500 A*

µs

5A/V
10 A/V

Amperes (Peak)

30

20

Range setting

1A/V
10 A/V

≤30 A continuous

Any width

≤5 A continuous

25

Any width

≤25 A continuous

10

0

0

5 10152025

Allowable pulse width (µseconds)

TCP303 Max peak pulse vs PW

600

Maximum peak pulse ≤500A

Range setting

500

400

300

15000 A*µs

Amperes (Peak)

200

3000 A*µs

≤212 A peak (≤150 A RMS continuous)

100

≤25A continuous

0

0 50 100 150

Allowable pulse width (µseconds)

Figure 4- 7: Specified operating area of the probes

5A/V
50 A/V

Any width

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 11

Specifications

TCP404XL Maximum Measurement Times

Figures 4--8 through 4--10 show the maximum measurement time for the
TCP404XL probe, with varying duty cycles and temperatures. For more detail
on the relationship between measurement factors, refer to Measuring Noncontin-
uous Current with the TCP404XL Probe on page 3--6.

12

10

8

6

time (min)

4

Maximum measurement

2

300A Continuous

0

0 5 10 15 20 25 30 35

Measuring 750A at 50 _C ambient

0A Continuous

100A Continuous

200A Continuous

Duty cycle (%)

Figure 4- 8: Measuring 750A noncontinuous at 50 °C ambient temperature

30

25

20

15

time (min)

10

Measuring 600A at 50 _C ambient

0A Continuous

200A Continuous

300A Continuous

4- 12

Maximum measurement

5

400A Continuous

0

0102030405060

Duty cycle (%)

70

Figure 4- 9: Measuring 600A noncontinuous at 50 °C ambient temperature

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Specifications

25

20

time (min)

15

10

5

Maximum measurement

0

010203040 5060

500A Continuous

Measuring 750A at 23 _C ambient

0A Continuous

200A Continuous

300A Continuous

400A Continuous

Duty cycle (%)

Figure 4- 10: Measuring 750A noncontinuous at 23 °C ambient temperature

At 23 degrees ambient temperature, 600 A can be measured continuously with
the TCP404XL probe.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

4- 13

Specifications

4- 14

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

WARNING

The following servicing instructions are for use only by qualified personnel. To
avoid injury, do not perform any servicing other than that stated in the operating
instructions unless you are qualified to do so. Refer to all safety summaries before
performing any service.

Performance Verification

Performance Verification Overview

The Performance Verification tests allow you to demonstrate that the Current
Probe Amplifier and Current Probes meet their specified levels of performance.
Since the TCPA300 and TCPA400 cannot operate without a current probe, a
calibration adapter is used to verify the amplifier(s) separately. The TCPA
Calibration Adapter is an optional accessory--see Replaceable Parts for part
numbers. After you have verified the amplifier performance independent of the
current probe(s), you can check the performance of current probes with
confidence.

Tolerances that are specified in these procedures apply to the amplifiers and
current probes and do not include test equipment error. The recommended
calibration interval is one year.

Performance Verification and Functional Checks

The warranted specifications for the amplifiers that are checked in the perfor­mance verification procedures are listed in Table 5--1. See Table 4--1 in Specifi-
cations for warranted values. Functional checks are included for you to verify
proper amplifier operation.

Table 5- 1: Amplifier checks

Performance verification Functional checks

DC gain

Amplifier

TCPA300      

TCPA400     

1

accuracy

With probe attached

Bandwidth

Front-panel
display

AC coupling

Degauss

1

Overload

The warranted specifications for the probes that are checked in the performance
verification procedures are listed in Table 5--2. See Table 4--1 in Specifications
for warranted values.

Table 5- 2: Probe performance verification checks

Probe DC gain accuracy Bandwidth Risetime

TCP312   

TCP305   

1

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

5- 1

Performance Verification Overview

Table 5- 2: Probe performance verification checks (Cont.)

Probe RisetimeBandwidthDC gain accuracy

TCP303   

TCP404XL  

Test Procedure Conditions

These procedures are valid only under the following conditions:

H The system has been calibrated at an ambient temperature of 23_ ±5 _C.

H The system is operating in an environment whose limits are described in

Table4--6onpage4--5.

H The system, including probe, has had a warm-up period of at least

20 minutes.

Equipment Preparation

H The probe degauss/autobalance routine has been performed after the

20-minute warm-up period.

Before performing the verification tests, turn all equipment on and allow the
entire system to warm up for a minimum of 20 minutes.

NOTE. Before performing any verification procedure, properly degauss the
probe. Remove the probe from any current-carrying conductor, lock the probe,
and press the amplifier PROBE DEGAUSS AUTOBALANCE button. The
degauss/autobalance routine is complete when the indicator light turns green.

The amplifier front panel will light the NOT TERMINATED INTO 50 Ω LED
during the degauss/ autobalance routine if the amplifier is not properly
terminated into 50 Ω. Verify that the oscilloscope input is 50 Ω and set to DC
coupling. Use a 50 Ω feedthrough termination, attached at the oscilloscope
input, if necessary.

5- 2

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

TCPA300 and TCPA400 Performance Verification

This section covers the performance verification for the TCPA300 and TCPA400
Current Probe Amplifiers. Refer to the list of equipment required in Table 5--3.
Power on the amplifier and test equipment and let them warm up for 20 minutes.

Before starting these procedures, photocopy the appropriate test record beginning
on page 5--16 to record the performance test results. The recommended
calibration interval is one year.

Equipment Required

The performance verification procedures require the test equipment listed in
Table 5--3. The test equipment must meet or exceed the specifications listed. You
may need to modify the test procedures if you do not use the recommended
equipment.

Table 5- 3: Required test equipment

Recommended

Qty Item Description

equipment

1 Oscilloscope 500 MHz bandwidth Tektronix TDS5000

1 Leveled Sine Wave Generator 3 MHz to 100 MHz Wavetek 9100 with >250 MHz Oscilloscope

Calibration Option

1 Digital Multimeter DCV: 0.1% Accuracy, 51/2digit resolution Keithley 2700

1 Current Source DCA: 0.1% Accuracy, 0 to ±100 mA,

floating outputs

1 Current Source DCA: 0.1% accuracy, 0 to ±15 A Wavetek 9100

1 Square Wave Generator ACV 1.5 Vp-p, 28 Hz square wave Wavetek 9100

1 HF Current Loop 50 Ω, BNC Connector Tektronix part number 015-0601-50

1 Precision Termination 50 Ω, ±0.1%, 0.5 W Tektronix part number 011-0129-00

2 BNC Cables 50 Ω, 0.76 m (30 in) long Tektronix part number 012-0117-00

1 Cable TEKPROBE Interface Cable Tektronix part number 012-1605-00

2 BNC to Dual Banana Adapters Tektronix part number 103-0090-00

1 DC Current Loop 5 turns 18 AWG coated wire Refer to page 5--4

1 DC Current Loop 50 turns 13 AWG coated wire Refer to page 5--4

1 Calibration Adapter TCPA Calibration Adapter Tektronix part number 174-4765-00

1 Current Probe

1

Required for functional test only.

1

TCPA300/400-compatible probe Tektronix TCP303, 305, or 312 (TCPA300) or

Fluke 5100 or HP 6612C

TCP404XL (TCPA400)

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

5- 3

TCPA300 and TCPA400 Performance Verification

Making DC Current Loops

You need to construct simple current loops to complete some tests for the
amplifiers. The current loops are also used in the DC gain accuracy tests for the
probes.

5-Turn DC Current Loop

50-Turn DC Current Loop

Construct the loop using a cylindrical form approximately 3 inches in diameter:

1. Wind exactly 5 turns of #18 coated wire around the form.

2. Scrape about a half-inch of coating off of the ends of the wire.

NOTE. Ensure that the current loop has exactly 5 turns. A significant error will
result for each turn variance from 5 turns.

The 5-turn DC current loop is also used in the current probe performance
verification and adjustment procedures.

Construct the loop using a cylindrical form approximately 3 inches in diameter:

1. Wind exactly 50 turns of #13 coated wire around the form.

2. Scrape about a half-inch of coating off of the ends of the wire.

NOTE. Ensure that the current loop has exactly 50 turns. A significant error will
result for each turn variance from 50 turns.

5- 4

The 50-turn DC current loop is also used in the current probe performance
verification procedures.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Front-Panel Display

TCPA300 and TCPA400 Performance Verification

The status and error LEDs on the front panel are illuminated briefly during the
amplifier power-on sequence. Verify that all LEDs are functional by doing the
following procedure:

1. Power-cycle the amplifier and check that the LEDs shown in Figure 5--1
light briefly. Note that the PROBE DEGAUSS AUTOBALANCE and
OVERLOAD LEDs are multi-color:

a. The PROBE DEGAUSS AUTOBALANCE LED lights in an

orange→red→green sequence.

b. The OVERLOAD LED lights in an orange→red→green sequence.

c. The MANUAL BALANCE LED is orange, and lights briefly.

d. The RANGE and COUPLING LEDs are green, and light briefly.

2. Record the results (pass/fail) on the test record.

Multi--color LED

Verify LEDs light

Multi--color LED

Figure 5- 1: Check LED functionality

Verify LEDs light

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

5- 5

TCPA300 and TCPA400 Performance Verification

DC Gain Accuracy

Use the following procedure to verify the DC gain accuracy of the amplifier.

Test Equipment Setup

Refer to Figure 5--2 and set up the test equipment as follows:

1. Connect the output of the amplifier to the DMM:

a. Connect a BNC Cable from the amplifier OUTPUT to the 50 Ω

precision feedthrough termination.

b. Attach the termination to a BNC-to-dual banana adapter.

c. Observe polarity and insert the dual banana adapter into the digital

multimeter DC voltage input.

2. Connect the probe input to the current source:

a. Connect the BNC end of the Calibration Adapter to a BNC-to-dual

banana adapter.

b. Observe polarity and insert the dual banana adapter into the current

source DC output. Do not connect the Calibration Adapter to the
amplifier at this time.

Amplifier

DMM

Current source

5- 6

BNC-to-dual

banana adapter

50 Ω Precision

termination

+--

50 Ω Coaxial cable

Calibration
adapter

BNC-to-dual

banana adapter

+--

Figure 5- 2: Equipment setup for DC gain accuracy test

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

TCPA300 and TCPA400 Performance Verification

3. Make or verify the equipment settings in Table 5--4:

Table 5- 4: Equipment settings

Digital multimeter

Measurement Type DC volts
Range Autoranging

Current source

Voltage 6V
Current 100 mA
Output Off

TCPA300 and TCPA400 amplifier

Coupling DC

Procedure

After the equipment is set up, proceed as follows:

4. Connect the Calibration Adapter to the PROBE INPUT of the amplifier.

5. For each of the Range settings in Table 5--5, perform the following steps:

a. If you are checking a TCPA300, set the amplifier to the desired Range

setting in Table 5--5.

b. Enable the output of the current source.

c. Record the exact measurement of the digital multimeter as M

.

1

Table 5- 5: DC gain accuracy test for the TCPA300 and TCPA400

Current
source out-

Amplifier Range, A/V

TCPA300 1 100 mA 5.0000

5 100 mA 2.5000

10 100 mA 1.2375

50 100 mA 0.4835

50 (COMP)1100 mA 0.4585

put

Expected
output, V
(VDC)

E

Measured
output, M
(VDC)

1

% Error,
calculated

TCPA400 1A/mV 100 mA 2.5000

1

Both 10 A/V and 50 A/V RANGE LEDs light.

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

5- 7

TCPA300 and TCPA400 Performance Verification

d. Calculate the %Error between the measured output, M

expected output (V

M

%Error =

1

)%Errorasfollows:

E

− V

E

V

× 100

E

, and the

1

For example, using an expected output VEof 2.5000 V and a measured
output M

%Error =

of 2.510, the %Error would be:

1

2.5100 − 2.5000

2.5000

× 100 =+0.4%

NOTE. It is important that the correct polarity be used to calculate the %Error.

6. Verify that the measured DC gain accuracy is within the limits specified for
all settings in the test record on page 5--16 for the TCPA300 (page 5--17 for
the TCPA400). Record the %Error in the test record.

NOTE. If the %Error on any of the settings is greater than the specified limit, you
must perform the adjustment procedure that begins on page 6--3.

7. Disconnect the DMM cable from the amplifier and the calibration adapter
from the current source.

5- 8

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

Bandwidth

TCPA300 and TCPA400 Performance Verification

This procedure tests the bandwidth of the TCPA300 and TCPA400 amplifiers. In
this test you measure a signal at a relatively low frequency and again at the upper
test frequency. The two measurements are compared to verify that the signal
amplitude does not fall below a certain limit. Refer to Figure 5--3 when making
equipment connections.

Amplifier

Test oscilloscope

TekProbe interface cable or

50 Ω coaxial cable

50 Ω oscilloscope input -- use the TekProbe
InterfaceCableorusea50Ω cable. (Add
50 Ω termination here if oscilloscope has
only high-impedance input.)

Calibration
adapter

Note: If using a Wavetek 9100, use the Signal Out

BNC connector on the rear of the instrument.

Leveled

sine wave

generator

Output

Figure 5- 3: Bandwidth test setup

1. If you are using a Tektronix oscilloscope that supports the TekProbe Level 2
Interface, use the TekProbe interface cable to connect the amplifier OUT-
PUT to the oscilloscope input. If you are not using a Tektronix oscilloscope
that supports the TekProbe Level 2 Interface, use a 50 Ω BNC cable. If the
input impedance of your oscilloscope is 1 MΩ, connect a 50 Ω feedthrough
termination at the oscilloscope input. Do not connect the termination at the
amplifier output.

2. Connect the Calibration Adapter to the amplifier PROBE INPUT.

3. Make or verify the equipment settings in Table 5--6:

Table 5- 6: Equipment settings for bandwidth check

Oscilloscope

Vertical input impedance 50 Ω
Time base TCPA300

TCPA400

40 ns/division

80 ns/division

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual

5- 9

TCPA300 and TCPA400 Performance Verification

Table 5- 6: Equipment settings for bandwidth check (Cont.)

Oscilloscope

Record length 500
Coupling DC
Offset 0 V (mid-scale)
Trigger type Edge
Trigger mode Auto
Trigger position 50%
Acquisition mode Average
Number of waveforms to average 16
Measurement type Peak-to-Peak

Leveled sine wave generator

Frequency 3MHz
Amplitude TCPA300

TCPA300 and TCPA400

Coupling DC

TCPA400

~3.0 V

1.0 V

p-p

p-p

4. Connect the Calibration Adapter to the output of the leveled sine wave
generator.

5. Enable the output of the leveled sinewave generator.

6. Verify the amplifier output is what is listed for the TCPA300 amplifier in

Table 5--7 on page 5--11. If you are checking a TCPA400 amplifier, use
Table5--8onpage5--11.

7. Using the peak-peak measurement capability of the oscilloscope, measure
and record the peak-peak reading as M

in Table 5--7 or Table 5--8 on

1

page 5--11.

8. If you are checking a TCPA300, for each range setting and bandwidth filter
in Table 5--7 on page 5--11, perform the following steps. If you are checking
a TCPA400, use Table 5--8 on page 5--11.

a. Set the oscilloscope time base to 4 or 5 ns/division. Increase the signal

generator frequency to 50 or 100 MHz, depending on the range setting
and bandwidth.

b. When you check the 100 MHz frequency, press either MANUAL

BALANCE button until the orange MANUAL BALANCE LED lights.
This engages a higher-frequency filter in the amplifier. After you check
the bandwidth at 100 MHz, press either MANUAL BALANCE button
again to turn off the filter (the LED goes off.)

5- 10

TCPA300/400 Amplifiers and TCP300/400 Series Current Probes Instruction Manual