Keithley 247 Service manual

Model 247

High Voltage Supply

Instruction Manual

Contains Operating and Servicing Information

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of
shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries,
diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will
be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs
will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the origi­nal warranty period, or at least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of
any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or
problems arising from normal wear or failure to follow instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRAN

TIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE
BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDI-

RECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND
SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF
SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL
AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.

Test Instrumentation Group, Keithley Instruments, Inc. l 28775 Aurora Road l Cleveland, Ohio 44139 l [phone] * Fax: [phone]

CHINA: Keithley Instruments, Inc. * Holiday Inn Lido l Office Building 4&4C l Beijing, China, ICOO l 8610-436-2871/2860 l 8610-436-2871
FRANCE: Keithley Instruments SARL * 3 All&e des Gamys l B.P. 60 l 91122 Palaiseau C&dex * 01-60-11-51-55~ Fax: 01-60-H-77-26
GERMANY. Keithley Instruments GmbH l Landsberge.r Str. 65.82110 Gennering 0 089-849307-O l Fax: [phone]
GREAT BRITAINz Keitbley Instruments, Ltd. l The Minster l 58 Portman Road l Reading, Be&shire RG30 IEA l 01734-575666 l Fax: [phone]
ITALY: Keithley Instruments SRL l Vialc S. Gimignano 38 l 20146 hfilano. 02-48303008 l Fax: [phone]
JAPAN: Keithley Instruments Far East KK l Sumiyoshi 24 Bldg., Room 201 l 2-24-2 Sumiyoshi-cho * Naka-ku, Yokohama 231 l 81-45-201-2246 l Fax: [phone]
NE-S:
SWlTZERUNDz

Keithley Instruments BV. Awlingen West 49 l 4202 MS Gorinchem . Postbus 559 l 4200 AN Gorinchem l 01830-35333 *Fax: [phone]
Keithley Instruments SA* Kriesbachstrasse 4 l 8600 Diibendorf * 01-821-9444 l Fax: [phone]

Model 247 High Voltage Supply

Instruction Manual

Q 1990, Keithley Instruments, Inc.

Test Instrumentation Group

All rights reserved.

Cleveland, Ohio, U.S.A.

December 1992, Sixth Printing

Document Number: 31834 Rev. F

AU KeithIey product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.

SAFETY PRECAUTIONS

The following safety precautions should be observed before using Model 247 High Voltage Supply.

The Model 247 High Voltage Supply is intended for use by qualified personnel who recognize shock hazards and are
familiar with the safety precautions required to avoid possible injury. Read over the instruction manual carefully before
using the instrument.

Exercise extreme caution when a shock hazard is present. Lethal voltages may be present on the test fixture or the supply
output connector. The American National Standards Jnstitute (ANSI) states the a shock hazard exists when voltage lev­els greater than3OV RMS or 42.4V peak are present. A good safety practice is to expect that hazardous voltage is present

in any unknown circuit before measuring.

Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

For maximum safety, do not touch the voltage supply, test fixture, test cables or any other insfnunents while power is
applied to the circuit under test. Turn off all power and discharge any capacitorsbefore connecting or disconnecting
cables or jumpers.

Do not touch any object which could provide a current path to the common side of the circuit under test or power line
(earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of with-

standing the voltage being measured.

Instrumentation and accessories should not be connected to humans.

The
Instruction Manual.

symbol on a Model 247 indicates that 1OOOV or more may be present on the terminals. Refer to the Model 247

L

Model 247

High Voltage Power Supply

OUTPUT:

Voltage: 0 to 3kV DC
Currentz 6mA DC maximum.
Polarity: Positive or negative with respect to chassis.

ACCUI&4CY: (W-28°C): f (0.25% of setting t 1.5V DC) from 1% to 100% of maximum

output voltage.
RESOLUTION: Dial graduations of 200mV.
STABILITY: &O.Ol% of setting/hr.; fo.OZ% of setting/b hrs., at constant temperature after

r+hour warm-up.
TEMPEIUTURE COEFFICIENT (W’-18°C & 28”-50°C): sOppm/“C
LINE REGULATIONz 0.001% voltage change for 10% line variation.
LOAD REGULATION: 0.005% voltage change from no load to full load.
RIPPLEANDNOISE:3.5mVrms,lOmVp-p@3kV,6mA;lmV~,3mVp-p@lkV,lmA,

lOHz-1OOkHz
SE’ITLING TIME: 4 seconds to within 1V with full resistive load.
OVERLOAD PROTECTIONr Short circuit proof, arc protected, self restoring.
METER Monitors voltage output.
ENVIRONMENT:

Operating: 0’ to 50°C, 0 to 80% relative humidity up to 35°C
Storage: -40° to 75°C

CONNECTORz Rear panel, MI-IV Type LJG931/U.
POWER: 90-125V/180-25OV, 50-6OHz,13OVA.
DIMENSIONS,WEIG~:483mmwidex89mmhighx273~deep(l9inx3~/~in.x103/4

in.), excluding handles. Four holes spaced for rack mounting. Net weight 5.9kg (13 Ibs.).
ACCESSORIES SUPPLIEIX Instruction manual, UG932/U mating connector, mounting

feet for bench operation.

Specifications subject to change without notice.

Table of Contents

SECTION 1

1.1

1.2

1.3

1.4

1.5 W~INFoRMATION....................................................l- 2

- General Information

PURPOSEOFEQUIPMENT

DESCRIPTION
SPECIFICATIONS
sAFETYsYMEioLsANDTERMs..

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..I- 1

l-l
l-l
l- 1

SECTION 2 - Operation

2.1

2.2 FRONTl?ANELCONTROLSANDTERMlNALS

2.3 REAR PANEL CONNECTORS AND TERMINALS

2.4

2.5

2.6
27

2.8 APPLICATIONS

2.8.1

2.8.2

2.8.3

INSTALLATION

l?REPAlK!JONFORUSE

INPUTPOWER ...............................................................

CURRENTLIMITING
HIGH VOLTAGE OUTPUT

Application of 247 wit& Photomultipliers
Application of 247 to Resisfivify Measurements
Application of 247 with Ionization Chambers

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2-l

..2- 1

2-2

..2- 3

2-3

..2- 3

2-3

2-4
2-4
2-4

SECTION 3 - Theory of Operation

3.1

3.2

FUNCTIONALDESCRTMTON
CIRCUtTDESCIUI’TION

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SECTION 4 - Maintenance

4.1

4.2

4.3 PREPARATION FORMEAS

4.4

4.5 PERFORMANCETESTS

4.6

INTRODUcTloN .............................................................. 4-l

RECOMMENDED TEST EQUIPMENT

UREMENTS ............................................ 4-2

CALIBRATION ADJUSTMENTS .................................................. 4-2

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TROUJ3LESHOOTlNG PROCEDURE ..

SECTION 5 - Replaceable Parts

5.1 INTRODUCTION

5.2

5.3

ORDERINGINFORMATION

FACTORYSERVICE............................................................5- 1

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f.

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3-l

..3- 1

4-l

4-2
4-3

5-l
5-l

SECTION 4 - Maintenance

List of Tables

Table 41

Recommended Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41