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Page 1

ARMY

NAVY EE010-BJ-MMA-010/E154 DCDUAL

TM 11-6130-416-14

AIR FORCE

TECHNICAL MANUAL

T.O. 35C1-2-847-1

OPERATOR’S, ORGANIZATIONAL,

DIRECT SUPPORT AND GENERAL SUPPORT

MAINTENANCE MANUAL

FOR

POWER SUPPLY, DUAL DC

(H-P MODEL 6255A)

(NSN 6130-00-065-6811)

DEPARTMENTS OF THE ARMY, NAVY, AND AIR FORCE

31 JANUARY 1983

Page 2

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

SAFETY STEPS TO FOLLOW IF SOMEONE IS THE VICTIM OF ELECTRICAL SHOCK

DO NOT TRY TO PULL OR GRAB THE lNDl-

VIDUAL

IF POSSIBLE, TURN OFF THE ELECTRICAL

POWER

IF YOU CANNOT TURN OFF THE ELECTRICAL POWER, PULL, PUSH, OR LIFT THE PERSON TO SAFETY USING A WOODEN POLE OR A ROPE OR SOME OTHER INSULATING MATERIAL

SEND FOR HELP AS SOON AS POSSIBLE

AFTER THE INJURED PERSON IS FREE OF CONTACT WITH THE SOURCE OF ELECTRICAL

SHOCK, MOVE THE PERSON A SHORT

DISTANCE AWAY AND IMMEDIATELY START

ARTIFICIAL RESUSCITATION

Page 3

TM 11-6130-416-14/EE010-BJ-JMA-010/E154 DCDUAL/T.O. 35C1-2-847-1

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

LIST OF EFFECTIVE PAGES

Dates of issue for original and changed pages are:

Original . . 0 . .

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS

Page

No.

Title. . . . . . . . . .

A. . . . . . . . . . . .

- vii. . . . . . . . .

viii Blank. . . . . . . .

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

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

3-1 - 3-8

4-1 - 4-6..............

5-1 - 5-23 . . . . . . . .

5-24 - Blank . . . . . . . .

A-1 . . . . . . . . . . .

A-2 Blank. . . . . . . .

B-1

- B-4 . . . . . . . .

C-1

- C-2. . . . . . . .

D-1 . . . . . . . . . . .

D-2 Blank. . . . . . . .

E-1 . . . . . . . . . . .

E-2 Blank.... . . . .

Index-1

Report of Errors. . . . .

FO-l

- Index-10. . . .

- FO-2 . . . . . . .

# Change

No. No.

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0

Page

83 CONSISTING OF THE FOLLOWING:

# Change

No.

Page

No.

# Change

No.

# Zero in this column indicates an original page.

Page 4

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35Cl-2-847-1

WARNING

DANGEROUS VOLTAGE

Is Used in the Operation of this Equipment

DEATH ON CONTACT

may result if personnel fail to observe safety precautions

Never work on electronic equipment unless there is another person

nearby who is familiar with the operation and hazards of the equipment and who is competent in administering first aid. is aided by operators, he must warn them about dangerous areas.

When the technician

Whenever possible, the power supply to the equipment must be shut off

before beginning work on the equipment. Take particular care to ground every capacitor likely to hold a dangerous potential. When

working inside the equipment, after the power has been turned off,

always ground every part before touching it.

Be careful not to contact high-voltage connections when installing or operating this equipment.

Whenever the nature of the operation permits, keep one hand away from

the equipment to reduce the hazard of current flowing through vital organs of the body.

Do not be misled by the term “low voltage.” Potentials as low as 50

volts may cause death under adverse conditions.

Page 5

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.0.35Cl-2-847-1

Do not touch heat sinks or power transistors mounted on

heat sinks as they may be very hot after the instrument

has been on and operating.

CAUTION

Do not directly short out any of the large capacitors as

it places too much stress on them. Discharge capacitors

through a load resistor.

C/(D blank)

Page 6

Page 7

This manual contains copyright material reproduced by permission of the Hewlett-Packard Company.

TM 11-6130-416-14

EE010-BJ-MMA-010/E154 DCDUAL

T.O.35C1-2-847-1

TECHNICAL MANUAL NO. 11-6130-416-14 TECHNICAL MANUAL EEO10-BJ-MMA-010/E154 DCDUAL TECHNICAL ORDER NO. 35CI-2-847-I

OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, AND GENERAL SUPPORT

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

DEPARTMENTS OF THE ARMY,

THE NAVY,

AND THE AIR FORCE

Washington, DC, 31 January 1983

MAINTENANCE MANUAL

FOR

POWER SUPPLY, DUAL DC

(H-P Model 6255A)

(NSN 6130-00-065-6811)

You can help improve this manual.

If you find any mistakes or if you know of a way to improve the procedures, please let us know. Publications and Blank of

Communications-Electronics Command and Fort Monmouth, DRSEL-ME-MP, Fort Monmouth,

Mail your letter, DA Form 2028 (Recommended Changes to

this

manual

Forms),

direct to:

or DA Form 2028-2 located in back

Commander, US

Army

ATTN:

NJ 07703.

For Air Force, submit AFTO Form 22 (Technical Order System Publication Improvement Report and Reply) in accordance with paragraph 6-5, Section VI, T.O. 00-5-1. Forward direct to prime ALC/MST.

For Navy, mail comments to the Commander, Naval Electronics Systems Command, ATTN:

ELEX 8122, Washington, DC 20360.

In either case, a reply will be furnished direct to you.

This manual is an authentication of the manufacturer’s commercial literature which,

through usage, has been found to cover the data required to operate and maintain this equipment. specifications and AR

Since the manual was not prepared in accordance with military

310-3,

the format has not been structured to consider levels

of maintenance.

Page 8

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O35C1-2-847-1

Section

GENERAL INFORMATION . . . . . . . . . . . .1-1

1-A.1 1-A.3

1-A.4 1-A.6

1-A.8

Page No.

Scope

1-1

Index of Publications 1-1 Army Air Force Maintenance Forms,

1-1 1-1 1-1

Section

3-3 3-5 3-7 3-9 3-11 3-14

Operating Modes Normal Operating Mode Constant Voltage Constant Current Connecting Load Operation of Supply

Records and Reports

1-A.9

Reports of Maintenance

3-16

Optional Operational

and Unsatisfactory

1-A.11

1-A.13

1-A.15

Equipment

1-1

Report of Packaging

and Handling

Deficiencies

1-1

Discrepancy in Shipment

Report (DISREP)

(SF 361)

1-1

Reporting Equipment

3-17

3-24

3-30 3-35

3-39 3-42

Remote Programming,

Remote Programming

Parallel Operation Auto-Tracking

Improvement

1-1 1-1

1-1

1-2 1-2 1-2 1-3

1-3

3-45

3-46 3-48 3-51 3-53

3-55

IV PRINCIPLES OF OPERATION . . . . . . . ...4-1

4-1

4-5 4-8 4-9

1-A.18 l-A.20

1-A.22

1-A.24

1-1 1-6 1-8 1-10

1-13

Recommendations (EIR)

Air Force Navy Administrative

Storage

Destruction Of Army

Electronics Materiel

Description

Specifications

Options

Instrument Identifica-

tion

Ordering Additional

Manuals

4-14

INSTALLATION 2-1 2-3 2-5 2-7 2-9

Initial Inspection

Mechanical Check

Electrical Check Installation Data

Location

2-11 Rack Mounting 2-13 Input Power Requirements 2-1 2-15 Connections for 230 Volt

Operation 2-17 Power Cable 2-20 Repackaging for Shipment 2-2

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

4-16 2-1 2-1

4-20

2-1 2-1

2-1

4-25 4-28

2-1

4-31

4-34

2-1 2-2

V MAINTENANCE . . . . . . . . . . . . . . . . . . . . .5-1

5-1

5-3

III OPERATING INSTRUCTIONS . . . . . . . . . . .3-1

3-1

Operating Controls and

Indicators

3-1

5-8

Page No.

3-1 3-1 3-1 3-2

3-2

Beyond Rated Output

Modes

Constant Voltage

Constant Current Remote Sensing Series Operation

3-2

3-3 3-4 3-4 3-5

Operation

3-6 Special Operating Considerations Pulse Loading

Output Capacitance Reverse Voltage Loading Reverse Current Loading

3-6

3-7

3-7 Overvoltage Protection

Crowbar

3-7

Overall Block Diagram

Discussion 4-1

Simplified Schematic

4-2

Detailed Circuit Analysis 4-3

Feedback Loop

Series Regulator

4-3

4-3 Constant Voltage Input

Circuit

4-3 Constant Current Input

Circuit 4-4

Voltage Clamp Circuit

4-4

Mixer and Error

Amplifiers Reference Circuit Meter Circuit

Introduction

4-4 4-5 4-5

5-1

General Measurement

Techniques

5-1

Test Equipment

Required

5-2

Page 9

TM 11-6130-416-14/EE010-BJ-NMA-010/E154 DCDUAL/T.O.35Cl-2-847-1

TABLE OF CONTENTS (CONTINUED)

Section

5-10 5-12

5-34

5-39

5-41

5-46

5-47A.1

5-47A.3 5-47A.5

5-47A.7

5-47A.9

5-47A.11

5-47A.13

5-47A.15

5-47A.17

5-47A.19

5-47A.21

5-47A.23

5-47A.25

5-47A.27

Page No.

Performance Test Constant Voltage

Tests

Constant Current

(CC) Tests

Troubleshooting Trouble Analysis Repair and Replace-

ment Fuse Replacement Cover Removal

Power Cable

Replacement

Switch S1

Replacement

Transformer T1

Replacement

Overvoltage

Protection Crowbar

P.C. Board Replace-

ment

Main Left P.C.

Board Replacement

(Viewed from Front

of Power Supply)

Main Right P.C.

Board Replacement

(Viewed from Front

of Power Supply)

Capacitator C14

Replacement

Capacitors C5, C6

Replacement

Power Transistor Q4,

Q6, Replacement

Power Transistor Q7,

Replacement

Transistor Q3

Replacement

Voltage/Current

Programming Control Replacement

5-2

5-8

5-9

5-14

5-15 5-15

5-17

5-18

5-19

5-20

Section

Page No.

5-47A.29 Silicon Rectifier

CR19 Replacement

5-47A.31

Meter Switch S2

Replacement

5-47A.33 Meter Replacement

5-20

5-21 5-21

5-47A.35 Shunt Resistor

(R81, R82, or R83)

Replacement

5-21

5-47A.37 Fuse Holder Assembly

Replacement

5-21

5-47A.39 Neon Lamp DS1

Replacement

5-21

5-47A.41 Crowbar Adjust

Potentiometer R5 Replacement

5-22

5-48 Adjustment and

Calibration

5-50 Meter Zero.

5-52 Voltmeter Tracking

5-54 Ammeter Tracking

5-22

5-22 5-22

5-56 Constant Voltage

Programming Current

5-22

5-59 Constant Current

Programming Current

5-23

5-62 Reference Circuit

Adjustments

5-23

5-64 Constant Voltage

Transient Response

5-23

VI REPLACEABLE PARTS . . . . . . . . . . . . . . .6-1

6-1 6-4

Introduction Ordering Information

6-1 6-1

APPENDIX A . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

APPENDIX B . . . . . . . . . . . . . . . . . . . . . . . . B-1

APPENDIX C . . . . . . . . . . . . . . . . . . . . . . . . C-1

APPENDIX D . . . . . . . . . . . . . . . . . . . . . . . D-1

APPENDIX E . . . . . . . . . . . . . . . . . . . . . . . E-1

INDEX

Index 1

iii

Page 10

Figure

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

LIST OF ILLUSTRATIONS

Page No.

Figure

Page No.

1-1

2-1 3-1

3-2 3-3

3-4

3-5

3-6

3-7 3-8

3-9

3-10

3-11

3-12

3-13

4-1

4-2

DC Power Supply Primary Connections

Front Panel Control and

Indicators Normal Strapping Pattern Remote Resistance

Programming(Constant

Voltage)

Remote Voltage

Programming (Constant

Voltage) Remote Resistance

Programming (Constant Current)

Remote Voltage

Programming (Constant

Current) Remote Sensing Normal Series Connections Auto-Series, Two and

Three Units

Normal Parallel ,

Connections

Auto-Parallel, Two and

Three Units

Auto-Tracking, Two and

Three Units

Model 6255A and 6289A

Overvoltage Protection

Crowbar Overall Block Diagram Simplified Schematic

2-1

3-1 3-1

3-2

3-3

3-3 3-4

3-4

3-5

3-6

3-8

4-1 4-2

4-3

4-4

5-1

5-2

5-3

5-4

5-5

5-6

5-7 5-8

5-9

5-10

5-11

5-12

5-13

5-14

FO-1 FO-2

Voltmeter Connections,

Simplified Schematic

Ammeter Connections,

Simplified Schematic

Front Panel Terminal

Connections

Output Current

Measurement Technique

Differential Voltmeter Substitute Test Setup Output Current, Test

Setup

Load Regulation, Constant

Voltage Test Setup

CV Ripple and Noise Test

Setup CV Noise Spike Test Setup 5-6 Transient Response Test Setup Transient Response,

Waveforms

CV Programming, Speed,

Test Setup Output Impedance,

Test Setup CC Ripple and Noise Test

Setup Servicing Printed Wiring

Boards

Model 6255A Modular

Cabinet

6255A Schematic

Parts Location/Intercon-

nection Diagram

4-5

5-1

5-2

5-4

5-6

5-7

5-8

5-13

5-16

Table

5-1 5-2

5-4

5-5

1-1

5-3

LIST OF TABLES

Page No.

Specifications Test Equipment Required 5-3

Common Troubles

Reference, Bias, and

Filtered DC Troubleshooting

Low Output Voltage

Troubleshooting

High Output Voltage

Troubleshooting

1-4

5-9

5-11

5-12

Table

5-6

5-7

5-8

Selected Semiconductor

Characteristics

Checks and Adjustments

After Replacement of Semiconductor Devices

Calibration and

Adjustment Summary

Page No.

5-14

5-15

Page 11

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.0.35C1-2-847-1

Figure 1-1.

Typical DPR Series DC Power Supply

v/(vi blank)

Page 12

Page 13

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.0.35C1-2-847-1

SECTION I

GENERAL INFORMATION

1-A.1

1-A.2

6255A Dual DC Power Supply with Option

11 Overvoltage Protection Crowbar Circuit (power supply serial numbers 2012A-4996 and up). Responsibilities for all levels of maintenance are specified by the Maintenance Allocation Chart (MAC) contained in

1-A.3

1-A.4

1-A.5

PAM 310-1 to determine whether there

are new editions, changes or additional publications pertaining to the equip-

ment.

1-A.6

1-A.7

cal Index and Requirements Table

(NIRT).

1-A.8

REPORTS

1-A.9

UNSATISFACTORY EQUIPMENT

1-A.10

and procedures used for equipment main-

tenance will be those prescribed by

38-750,

System (Army).

will use AFM 66-1 for maintenance re-

porting and T.O. 00-35D54 for unsatis-

factory equipment reporting. Navy personnel will report maintenance performed utilizing the Maintenance Data

Collection Subsystem (MDCS) IAW

OPNAVINST 4790.2, Vol 3, and unsatis-

factory material/conditions (UR submissions) IAW OPNAVINST 4790.2, Vol 2,

chapter 17.

SCOPE

This manual describes the Model

Appendix B.

INDEX OF PUBLICATIONS

ARMY

Refer to the latest issue of DA

AIR

FORCE

Use T.O. 0.1-31 Series Numeri-

MAINTENANCE FORMS, RECORDS AND

REPORTS

Department of the Army forms

The Army Maintenance Management

MAINTENANCE AND

Air

Force personnel

1-A.12

(Report of Discrepancy (ROD) as pre-

scribed in AR 735-11-2/DLAR 4140.55/

NAVMATINST 4355.73/AFR 400-54/MCO

4430.3E.

1-A.13

(DISREP) (SF

1-A.14

ancy in Shipment Report (DISREP) (SF

361) as prescribed in AR 55-38/

NAVSUPINST 4610.33B/AFR 75-18/MCO

P4610.19C/DLAR 4500.15.1-4.

1-A.15

IMPROVEMENT RECOMMENDATIONS) (EIR)

1-A.16

1-A.17

needs improvement, let us know. us an EIR. only one who can tell us what is not

liked about your equipment. Let us know why you do not like the design.

Tell us why a procedure is hard to per-

form.

Deficiency Report).

der, US Army Communications-Electronics Command and Fort Monmouth, ATTN:

DRSEL-ME-MP, Fort Monmouth, We will send you a

1-A.18

1-A.19

encouraged to submit EIRs in accordance

with AFM 900-4.

1-A.20

1-A.21

to submit EIRs through their local Beneficial Suggestion Program.

1-A.22

Fill out and forward SD 364

DISCREPANCY IN SHIPMENT REPORT

361)

Fill out and forward Discrep-

REPORTING EQUIPMENT

ARMY

If the Power Supply, Dual DC

Send

You, the user, are the

Put it on an SF 368 (Quality

Mail it to Comman-

07003.

AIR FORCE

Air Force personnel are

NAVY

Navy personnel are encouraged

ADMINISTRATIVE STORAGE

1-A.11

HANDLING

REPORT OF PACKAGING AND DEFICIENCIES

1-1

1-A.23

Refer to

TM 11-5805-683-12

Page 14

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

TM 11-5805-681-12,

Administrative storage of equip-

age. ment issued to and used by Army activi-

ties will have preventive maintenance

performed in accordance with the Pre-

ventive Maintenance Checks and Services

(PMCS) procedure listed before storing.

When removing the equipment from administrative storage,the PMCS should be performed to assure operational readi-

ness.

equipment for shipment or limited stor-

age are also covered.

90-1 if

charts.

1-A.24

ELETRONICS

1-A.25

ics materiel to prevent enemy use shall

be in accordance with

Disassembly and repacking of

there are no published PM

DESTRUCTION OF ARMY

MATERIEL

Destruction of Army electron-

Administrative Stor-

Refer to

TM 750-244-2.

TM 749-

1-3

Each supply has both Either the positive or negative output terminal may be grounded or the power supply can be operated floating

at up to a

1-4

and operating controls. tiple range type and can measure output voltage or current. The voltage or current by the applicable METER switch

1-5 TWO

the rear of the unit allow ease in adapting to the many operational capabilities of the power supply. A below:

from a remote location by means of an external

voltage source or resistance.

Each section has its own front panel meter

sets of programming terminals located at

brief description

Remote The power supply maybe programmed

b. Remote Sensing

front

maximum

Programming

and rear

300 volts off

The meters are of the mul-

ranges

of these capabilities

terminals.

are selected

the front panel.

ground.

given

1-1

DESCRIPTION

1-2

completely transistorized and suitable

for either rack or bench operation. It is a dual supply consisting of two independently controlled sections; both identical to each other.

will be referred to as the left and right side power supplies as viewed from front of unit. regulated,Constant Voltage/Constant Current source that will furnish full rated output rated output current or can be continuously adjusted throughout either output

range. can be used to establish the output cur-

rent limit when the supply is used as a constant voltage source and the VOLTAGE control(s) voltage limit is used as a constant current source. Each section will automatically crossover from constant voltage to constant

current operation and vice versa if the output current or voltage exceeds these preset limits.

This power supply,

Each section is a well-

voltage at

The front panel CURRENT controls

(overload or

can be

used to establish the

(ceiling) when

Figure 1-1,

These sections

the maximum

short circuit)

the supply

The degradation in regulation which would occur in

the

supply in the remote sensing mode of operation.

when a higher output voltage is required in the voltage mode of operation or compliance

of operation. Auto-Series operation permits one knob control of the total output voltage

“master"

parallel rent capability permits one knob control from

“master” supply, having control “slave” supplies that furnish various voltages for

a system.

1-6 1-7

supply.

d. Parallel and Auto-Parallel Operation

SPECIFICATIONS

Detailed specifications

at the

load leads can be reduced by using the power

Series and Auto-Series Operation

Power supplies maybe used in series

required in

The power supply may be operated

with a

required. Auto-Parallel

“master” supply. Auto-Tracking The power supply maybe used

load because of the voltage drop

when

the

similar unit when greater output cur-

the total output current

for

greater voltage

constant current mode

from a

operation

over

one (or more)

the power supply

1-2

Page 15

TM 11-6130-416-14/EE010-BJ-MM-010/E154 DCDUAL/T.O.35C1-2-847-1

are given in

1-8

1-9

ard instrument that are requested by the customer. The following options are available for the instru-

ment covered by this manual. Where necessary,

detailed coverage of the options is included through-

out the manual. Option No.

Table 1-1.

NOTE Since both sections of this supply are identical, only one section will be discussed throughout the remain-

ing portions of this manual. All descriptions, illustrations, and adjustments apply equally to both sections of the supply.

OPTIONS

Options are factory modifications

Description

Voltage 10-Turn Pot: A single control that replaces both coarse and fine voltage controls and improves output

settability. 6258A power supplies.

Standard item on Model

tests,

of a

stand-

Trip Voltage Margin: The minimum crowbar trip setting above the desired operating output voltage to false crowbar tripping is 4% of the output voltage setting +2V.

Refer to of operation and schematic diagram.

14 Three Digit Graduated Decadial Cur-

Paragraph 3-55

Figure 3-13

Three Digit Graduated Decadial Volt-

age Control: Control that replaces

coarse and fine voltage controls permitting accurate resettability.

rent Control: Control that replaces coarse and fine current controls permitting accurate resettability.

Rewire for 230V AC Input: Supply as normally shipped is wired for 115VAC input. Option 28 consists of reconnecting the input transformer for 230V AC operation.

prevent

for details

for the

Current 10-Turn Pot: A single control that replaces both coarse and fine current controls and improves out put

settability.

Voltage and Current 10-Turn Pot: Consists of Options 07 and 08 on the

same instrument.

Chassis Slides: Enables convenient access to power supply interior for maintenance purposes.

Internal Overvoltage Protection “Crowbars”: This option includes two crowbar circuits, one for each power supply within the 6253A or or 6255A. Each crowbar protects

delicate loads by monitoring the output voltage and firing an SCR that shorts the output when the preset trip voltage is exceeded. The circuit boards are factory installed within the supply. The “Crowbar Adjust”

controls are mounted on the front

panel to permit convenient adjust-

ment.

Trip Voltage Range:

6253A

2.5 to 23V 2.5 to 44V

6255A

1-10

1-11

by a three-part serial number tag. The first part is the power supply model number. The second part is the serial number prefix, which consists of a number-letter combination that denotes the date of a

significant design change. The number designates

the year, and the letter A through L designates the

month, January through December, respective y. The

third part is the power supply serial number.

1-12 If

ply does not agree with the prefix on the title page

of this manual, change sheets are included to up-

date the manual.

information is given in an appendix at the rear of

the manual.

power supply.

INSTRUMENT IDENTIFICATION Hewlett-Packard power supplies are identified

the serial number prefix on your power sup-

Where applicable, backdating

1-13

be obtained from regular publication distribution channels.

ORDERING ADDITIONAL MANUALS

1-14

One manual is shipped with each

Additional manuals may

1-3

Page 16

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.0035C1-2-847-1

Table 1-1. Specifications

INPUT:

105-125/210-250

50-400

OUTPUT:

Two independent outputs each of which can

be set at 0-40 volts @ 0-1.5 amps.

LOAD REGULATION:

Constant Voltage

2mv for a full load to no load change in output

current.

Constant Current

250µa for a zero to maximum change in output

voltage.

LINE REGULATION:

Constant Voltage 2mv for any line voltage change within the input rating.

Constant Current -250µa for any line voltage change within the input rating.

RIPPLE AND NOISE:

Constant Voltage

Constant Current --

cps.

VAC, single phase,

-- Less than 0.01% plus

Less than 0.01% plus

-- Less than 200µv rms. Less than 500µa rms.

OVERLOAD PROTECTION:

A continuously acting constant current circuit protects the power supply for all overloads including a direct short placed across the terminals in constant voltage operation. The constant voltage circuit limits the output voltage in the constant current mode of operation.

METERS:

Each front panel meter can be used as either a 0-50V or 0-5 volt voltmeter or as a 0-1.8A or 0-0.18 amp ammeter.

OUTPUT CONTROLS:

Coarse and fine voltage controls and coarse and fine current controls set desired output voltage or current.

OUTPUT TERMINALS:

Six output posts (three per section) are provided on the front panel and output terminal strips are located on the rear of the chassis. All power supply output terminals are isolated from the chassis and either the positive or negative terminals may be connected to the chassis through a separate ground terminal located on the output terminal strip.

TEMPERATURE RANGES:

Operating:

TEMPERATURE COEFFICIENT:

Constant Voltage

500µv per degree Centigrade.

Constant Current

0.8ma per degree Centigrade.

STABILITY:

Constant Voltage

2.5mv total drift for 8 hours after an initial warmup time of 30 minutes at constant ambient, constant line voltage, and constant load.

Constant Current -4ma total drift for 8 hours after an initial warm-up time of 30 minutes at constant ambient, constant line voltage, and constant load.

OUTPUT

Approximated by a

resistance in series with a

microhenry inductance.

TRANSIENT RECOVERY TIME:

Less than 50µsec 15 mv following a full load current change in the

output.

0 to

50°C.

Storage: -20 to +85°C.

-- Less than 0.02% plus

-- Less than 0.10% plus

Less than 0.10% plus

IMPEDANCE

for output recovery to within

(TYPICAL):

milliohm

ERROR SENSING:

Error sensing is normally accomplished at the front terminals if the load is attached to the front or at the rear terminals if the load is attached to the rear terminals. on the rear terminal strip for remote sensing.

REMOTE PROGRAMMING:

Remote programming of the supply output at ap-

proximately 200 ohms per volt is made available at the rear terminals. In con-

stant current mode of operation, the current can be remotely programmed at approximately 500 ohms per ampere.

COOLING:

Convection cooling is employed. The supply

has no moving parts.

SIZE:

3- 1/2" H x 14- 1/2"

mounted in a standard 19” relay rack.

WEIGHT:

28 lbs. net, 35 lbs. shipping.

FINISH:

Light gray front panel with dark gray case.

POWER CORD:

A three-wire, five-foot power cord is provided

with each unit.

Also, provision is included

constant voltage

D x

19” W. Easily rack

1-4

Page 17

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

SECTION II

INSTALLATION

2-1

INITIAL INSPECTION

2-2

Before shipment, this instrument was inspected and found to be free of mechanical and electrical defects. As soon as the instrument is un-

packed, inspect for any damage that may have oc-

curred in transit. Save all packing materials until

the inspection is completed.

2-3

MECHANICAL CHECK

2-4

This check should confirm that there are no

broken knobs or connectors, that the cabinet and

panel surfaces are free of dents and scratches,

and that the meter is not scratched or cracked.

either power tory, is wired for 115 volt operation. The input power required when operated from a 115 volt 60

cycle power source at full load is 235 watts and

2.6 amperes.

2-15

a nominal 115 volt or 230 volt 50-400 cycle source. The unit, as shipped from the fac-

CONNECTIONS FOR 230 VOLT OPERATION

(Figure 2-1)

2-5

ELECTRICAL CHECK

2-6

The instrument should be

electrical

“in-cabinet” performance check to verify proper instrument operation.

2-7 2-8

operation. It is necessary only to connect the

instrument to a source of power and it is ready for

operation.

2-9 2-10

space should be allotted so that a free flow of cooling air can reach the sides and rear of the instrument when it is in operation. It should be used in an area where the ambient temperature does not exceed 50°C.

2-11 2-12

easily rack mounted in a conventional 19 inch rack panel using standard mounting screws.

2-13 2-14

specifications.

INSTALLATION DATA

The instrument is shipped ready for bench

LOCATION

This instrument is air cooled. Sufficient

RACK MOUNTING

This instrument is full rack size and can be

INPUT POWER REQUIREMENTS

This power supply may be operated from

checked

Section V includes an

against its

Figure 2-1.

2-16

put transformer are connected in parallel for operation from 115 volt source. To convert the power

power transformer windings are connected in series as follows:

Normally, the two primary windings of the in-

supply to operation from a 230 volt source, the

Primary Connections

2-1

Page 18

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Unplug the line cord and remove the

unit covers.

Break the copper between 54 and 55 and also between 50 and 51 on the printed circuit board. These are shown in

Figure 2-1,

and are

labeled on copper side of printed circuit board.

Add strap between 50 and 55.

Replace existing fuse with 2 ampere, 230 volt fuse. Return unit to case and operate

cable three-prong connector is the ground connection.

2-19 To

operating the instrument from a two-contact outlet,

use a three-prong to two-prong adapter and connect the green lead on the adapter to ground.

2-20

REPACKAGING FOR SHIPMENT

normally.

2-21 To

2-17

POWER CABLE

it is recommended that the package designed for the instrument be used. The original packaging

2-18 To

protect

operating

personnel,the

National

material is reusable.

Electrical Manufacturers Association(NEMA)recommends that the instrument panel and cabinet be grounded.

This instrument is equipped with a

three conductor power cable. The third conductor

is the ground conductor and when the cable is plugged into an appropriate receptacle, the instrument is grounded. The offset pin on the power

preserve the protection feature when

insure safe shipment of the instrument,

2-2

Page 19

TM ll-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

OPERATING INSTRUCTIONS

3-1

OPERATING CONTROLS

3-2

The front panel controls and indicators, together with the normal turn-on sequence, are shown in

Figure 3-1.

AND

INDICATORS

SECTION III

graphs describe the procedures for uti-

lizing the various operational capabilities of the power supply. oretical description concerning the operational features of this supply is contained in Application Note 90, DC

Power Supply Handbook.

3-5

NORMAL

3-6

The power supply rear terminal strapping connections arranged for Constant local programming, single unit mode of operation.

This strapping pattern The operator selects either constant current output using the front panel controls (local programming, no strapping changes are necessary).

OPERATING MODE

normally shipped with

Voltage/Constant

illustrated

constant voltage or

A more the-

its

Current,

local sensing,

in Figure 3-2.

Figure 3-1.

3-3

3-4

that its mode of operation can be se-

lected by making strapping connections

between particular terminals on the terminal strip at the rear of the power

supply. The terminal designations are stenciled in white on the power supply above their respective terminals.

Although the strapping patterns illus-

trated in this section show the positive terminal grounded, the operator

can ground either terminal or operate the power supply up to 300vdc off ground(floating).

OPERATING MODES

The power supply is designed so

Dangerous voltages exist in this equipment. when working with the power supplies and their circuits.

Front Panel Controls and Indicators

Be careful

The following

para-

Figure 3-2.

3-7

for

3-8

as follows: controls for desired output voltage (output terminals

open).

RENT controls for maximum output current allowable

(current

If a load change causes the current limit to be exceeded, the power supply will automatically crossover to constant current output at the preset current limit and the output voltage will drop proportionately.

made for high peak current which can cause un-

wanted cross-over.

CONSTANT VOLTAGE (See

controls and indicators.)

To select a constant voltage output, proceed a. Turn-on power supply and adjust VOLTAGE

b. Short output terminals and adjust CUR-

limit),

In setting the current limit, allowance must be

Normal Strapping Pattern

Figure 3-1

determined by

(Refer to

Paragraph 3-46.)

load conditions.

3-1

Page 20

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.351-2-847-1

3-9

for controls and indicators.)

3-10

as follows: RENT controls for desired output current. controls for maximum output voltage allowable (volt-

age limit), as determined by load conditions. If a load change causes the voltage limit to be exceeded,

the power supply will automatically constant voltage output at the preset voltage limit and the output current will drop proportionately.

setting the voltage limit, allowance must be made for high peak voltages which can cause unwanted crossover.

3-11

for output terminals.)

3-12

supply output terminals using separate pairs of connecting wires. This will minimize mutual coupling effects between loads and will retain full advantage of the low output impedance of the power supply.

Each pair of connecting wires should be as short as

possible and twisted or shielded to reduce noise pickup. (If shield is used, connect one end to power supply ground terminal and leave the other

end unconnected.)

CONSTANT CURRENT (See

To select a

a. Short output terminals and adjust CUR-

b. Open output terminals and adjust VOLTAGE

(Refer to

CONNECTING LOAD (See

Each load should be connected to the power

constant

Paragraph 3-46.)

Figure 3-1

current output, proceed

crossover to

Figure 3-1

source can be used for the programming device. The wires connecting the programming terminals of the supply to the remote programming device should be twisted or shielded to reduce noise pick-up. The VOLTAGE controls on the front panel are disabled according to the following procedures.

3-19

Resistance Programming mode, the output voltage will vary at a rate determined by the programming coefficient (200 ohms per Volt for Models 6253A, 6255A, 6281A, 6284A, and

6289A or 300 ohms per Volt for Models 6294A and 6299A). The output voltage will increase 1 Volt for each 200 ohms (or 300 ohms) added in series with the programming terminals. The programming coefficient is determined by the programming current. This current is factory adjusted

Models 6253A, 6255A, 6281A, 6284A, and 6289A or

2% of 3.3mA for Models 6294A and 6299A. If greater programming accuracy by changing resistor-R 13.

(Figure 3-3). In

within 2% of 5mA for

required, it maybe achieved

this

3-13 If

power distribution

from the power supply, then the power supply out-

put terminals should be connected to the remote distribution shielded wires and each load separately connected to the remote distribution

remote sensing should be used

3-14

3-15

indicates the amount of output voltage or current that is available in excess of the normal rated output. Although the supply can be operated in this

shaded region without being damaged, it cannot be guaranteed to meet all of its performance specifications. tained above 115 Vac, the supply will probably operate

3-16

3-17

3-18

ply can be programmed (controlled) location if required. Either a resistance or voltage

load considerations

terminals be remotely located

terminals via a pair of twisted or

OPERATION OF SUPPLY BEYOND RATED OUTPUT

The shaded area on

However, if the line voltage is main-

within its specifications.

OPTIONAL OPERATING REMOTE PROGRAMMING, CONSTANT VOLTAGE The constant voltage output of the power sup-

require that the output

terminals. For this case,

(Paragraph 3-20).

the

front panel meter face

MODES

from

remote

Figure 3-3.

3-20

The output voltage of the power supply should be zero Volts ±2O millivolts when zero ohms is connetted acress the programming terminals. If a zero ohm voltage closer than this is required, it may be achieved by changing resistor R6 or R8 as described in

Paragraph 5-59.

3-21 To

efficient of the power supply, use programming resistors that have stable, low noise, and low temperature (less than 30 ppm per degree Centigrade)characteristics. conjunction to obtain discrete output voltages. The switch should have make-before-break momentarily opening the programming terminals during the switching interval.

3-22

Voltage Programming

the strapping pattern shown on

Remote Resistance Programming

(Constant Voltage)

maintain the stability and temperature co-

A switch can be used in

with various resistance

(Figure 3-4). Employ

values in

contacts to avoid

Figure 3-4

for

order

3-2

Page 21

‘m 11-6130-416-14/EEOI O-BJ-M.MA-0113/E154 DCDUAL/T.0.35Cl -2-847-l

3-27 Use stable, low noise, low temperature coefficient (less than 3 to maintain the power supply temperature coefficient

and stability specifications. A switch may be used to set discrete values of output current. before-break type of switch should be used since the output current will exceed the maximum rating of the power supply if the switch contacts open during the switching interval.

Oppm/oC) programming resistors

make-

Figure 3-4.

Remote Voltage Programming

(Constant Voltage)

voltage programming. In this mode, the output

volt-

age will vary in a 1 to 1 ratio with the programming voltage (reference voltage) and the load on the programming voltage source will not exceed

25mA.

3-23 The impedance matching resistor (Rx) for the programming voltage source should be approximately 500 ohms to maintain the temperature and stability

SUPP1

specifications of the power

REMOl’E

3-24

CURRENl! (Ses

PROGRAMMING, CONSTANT

Figure 3-1 for controls and

indicators. )

3-25 Either a resistance or a voltage source can be used to control the constant current output of the

supply. The CURRENT controls on the front panel

are disabled according to the following procedures.

3-26 Resistance Programming (Figure 3-5). In this

outpdt

mode, the by the programming coefficient — 200 ohms per Amp for Model 628

6253A, 6255A, 6284A,

Ampere for Models ming coefficient is determined by the Constant Cur-

rent programming current

6255A, 6284A,

for Model current is adjusted to within 10% at the factory. If greater programming accuracy is required, it maybe

a thieved by changing resistor R 19 as outlined in

Section V.

current varies at a rate determined

1A,

500 ohms per Ampere for Models

and

6289A,

and 1000 ohms per

6294A

and

6299A.

The program-

(2mA

for Models

and

6294A

6289A, 5mA

and

1.33mA

for Model’

for Model

6253A,

6281A lmA

6299A).

This

If the programming terminals

should open at any time during this mode, the output current will rise to a value that may damage the power supply and/or the load. To avoid this possibility, connect a resistor across the programming terminals having the value listed below. Like the programming resistor, this resistor should be of the low noise, low temperature coefficient type.

Model

Resistance

Model

Resistance

3-28 Voltage Programming (Figure 3-6). In this

mode, the output current will vary linearly with changes in the programming voltage. The programming voltage should not exceed 1.2 Volts. Voltage in excess of 1.2 Volts will result in excessive power

dissipation in the instrument and possible damage.

Al A2 A3 A4 AS A6 A? A8 A9 -S – GNO + +S

6253

A,6284A 6255

5Kn

6281A, 6294A

lKA

(Al and AS)

A,6289A,6299A

750n

AIO

AI A2A3A4A5A6A7A8A9

OlOlOIQ1~lQ1

-----

PROGRAMMING

RESISTOR

Figure 3-5.

Remote Resistance Programming

(Constant Current)

VOLTAGE

-S-

GM++ SAIO

1%’lddq@..j&l

3-3

Figure 3-6.

3-29 The output current will be the programming voltage divided by 1 ohm. The current required

from the voltage source will be ampere. The impedance matching resistor (Rx)

should be approximately 500 ohms if the temperature coefficient and stability specifications of the power supply are to be maintained.

Remote Volta ge Programming

(Constant Current)

less

than 25

micro-

Page 22

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

3-30 REMOTE SENSING (See Figure 3-7) 3-31 Remote sensing is used to maintain good regu-

lation at the load and reduce the degradation of regulation which would occur due to the voltage drop

in the leads between the power supply and the load.

Remote sensing is accomplished by utilizing the strapping pattern shown in Figure 3-7. The pwer supply should be turned off before changing strap-

ping patterns. The leads from the +S terminals to

the load will carry less than 10mA of current, and

it is not required that these leads be as heavy as

the load leads. However, they must be twisted or

shielded to minimize noise pick-up.

Observe polarity when connecting the

sensing leads to the load.

that it is possible to operate a power supply simultaneously in the remote sensing and Constant Voltage/Constant Current remote programming modes.

3-35 SERIES OPERATION 3-36 Normal Series Connections (Figure 3-8). Two

or more power supplies can be operated in series to obtain a higher voltage than that available from a

single supply. When this connection is used, the output voltage is the sum of the voltages of the individual supplies. Each of the individual supplies

must be adjusted in order to obtain the total output voltage. The power supply contains a protective

diode connected internally across the output which

protects the supply if one power supply is turned off while its series partner(s) is on.

Figure 3-7.

Remote Sensing

3-32 Note that it is desirable to minimize the drop in the load leads and it is recommended that the

drop not exceed 1 Volt per lead if the power supply

is to meet its dc specifications. If a larger drop must be tolerated, please consult a Hewlett-Packard field representative.

NOTE

Due to the voltage drop in the load leads, it may be necessary to readjust the current limit in the remote sensing mode.

3-33 The procedure just described will result in a low dc output impedance at the load. If a low ac impedance is required, it is recommended that the following precautions be taken:

a. Disconnect output capacitor C20 by dis-

connecting the strap between A9 and -S.

b. Connect a capacitor having similar char-

acteristics (approximately same capacitance, same

voltage rating or greater, and having good high frequency characteristics) across the load using short leads.

3-34 Although the strapping patterns shown in Figures 3-3 through 3-6 employ local sensing, note

Figure 3-8.

Normal Series Connections

3-37 Auto-Series Connections (Figure 3-9). The

Auto-Series configuration is used when it is desir-

able to have the output voltage of each of the series connected supplies vary in accordance with the

setting of a control unit. The control unit is called the master; the controlled units are called slaves. At maximum output voltage, the voltage of the

slaves is determined by the setting of the front

panel VOLTAGE control on the master. The master

supply must be the most positive supply of the

series. The output CURRENT controls of all series

units are operative and the current limit i

S equal to

the lowest control setting. If any output CURRENT

controls are set too low, automatic crossover to

constant current operation will occur and the out-

put voltage will drop. Remote sensing and pro-

gramming can be used; however, the strapping ar-

rangements shown in the applicable figures show

local sensing and programming.

3-38 In order to maintain the temperature coefficient and stability specifications of the power supply, the external resistors (Rx) shown in Figure 3-9 should be stable, low noise, low temperature coefficient (less than 30 ppm per degree Centigrade) resistors. The value of each resistor is dependant

3-4

Page 23

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35Cl-2-847-1

on the maximum voltage rating of the “master” sup-

ply. The value of Rx is this voltage divided by the

voltage programming current of the slave supply

(1/Kp where K

P is the voltage programming coef-

ficient). The voltage contribution of the slave is determined by its voltage control setting.

controls of each power supply can be separately set. The output voltage controls of one power supply should be set to the desired output voltage; the other power supply should be set for a slightly larger output volts ge.

The supply set to the lower

output voltage will act as a constant voltage

source; the supply set to the higher output will act

as a constant current source, dropping its output

Figure 3-10.

Normal Parallel Connections

Figure 3-9.

Auto-Series, Two and Three Units

3-39 PARALLEL OPERATION (See Figure 3-1 for controls and indicators.)

3-40 Normal Parallel Connections (Figure 3-10). Two or more power supplies can be connected in parallel to obtain a total output current greater than

that available from one power supply. The total

output current is the sum of the output currents of the individual power supplies. The output CURRENT

3-5

Figure 3-11.

Auto-Parallel, Two and Three Units

Page 24

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

voltage until it equals that of the other supply. The constant voltage source will deliver only that frac-

tion of its total rated output current which is neces-

sary to fulfill the total current demand,

3-41

Auto-Parallel

shown in permits equal current sharing under all load conditions, and allows complete control of output cur-

rent from one master power supply. The output current of each slave will be approximately equal to the master’s regardless of the load conditions.

Because the output current controls of each slave

are operative, the y should be set to maximum to avoid having the slave revert to constant current

operation; this would occur if the master output

Auto-Parallel.

Figure 3-11.

current setting exceeded the slave’s.

The strapping patterns for

operation of two power supplies are

Auto-Parallel

operation

3-42

AUTO-TRACKING OPERATION (See

3-43

it is necessary that several different voltages referred to a common bus, vary in proportion to the setting of a particular instrument (the control or

master). A fraction of the master’s output voltage is fed to the comparison amplifier of the slave supply, thus controlling the slave’s output. The master must have the largest output voltage of any power supply in the group (must be the most positive supply in the example shown on

3-44

age of the master's mined by the voltage divider consisting of Rx (or Rx

and Ry)

Rp.

of the power supplies is controlled by the master. Remote sensing and programming can be used; although the strapping patterns for these modes show only local sensing and programming. In order to maintain the temperature coefficient and stability

specifications

sistors should be stable, low noise, low temperature

(less than 30ppm per °C) resistors.

The Auto-Tracking configuration

Figure 3-12).

The output voltage of the slave is a percent-

output voltage, and is deter-

and

where:

the voltage control of the slave supply,

ES=EMRp/Rx+Rp.

Turn-on and turn-off

the power supply, the external re-

Figure 3-12)

used when

3-45 3-46 3-47

over from constant voltage to constant current operation, or the reverse, in response to an increase

(over the preset limit) in the output current or volt-

age, respective y. Although the preset limit may be

set higher than the average output current or voltage, high peak currents or voltages (as occur in pulse loading) may exceed the preset limit and cause

crossever desired, set the preset limit for the peak requirement and not the average.

3-48

3-49 An

output terminals of the power supply, helps to supply high-current pulses of short duration during

constant voltage operation. Any capacitance added

externally will improve the pulse current capability, but will decrease the safety provided by the con-

stant current circuit. A high-current pulse may damage load components before the average output current is large enough to cause the constant current

circuit to operate.

SPECIAL OPERATING CONSIDERATIONS PULSE LOADING The power supply will automatically

occur.

OUTPUT CAPACITANCE

internal capacitor, connected acress the

If this crossover limiting is not

cross-

Figure 3-12.

Auto-Tracking,

Two and Three Units

3-50

constant current operation are as follows:

3-6

The effects of the output capacitor during

The output impedance of the power supply

Page 25

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

decreases with increasing frequency.

b. The recovery time of the output voltage is

longer for load resistance changes.

c.A

large surge current causing a high power dissipation in the load occurs when the load resistance is reduced rapidly.

3-51 3-52

nals. Under norms 1 operating conditions, the diode is reverse biased (anode connected to negative terminal). If a reverse voltage is applied to the output terminals (positive voltage applied to negative terminal), the diode will conduct, shunting current across the output terminals and limiting the voltage to the forward voltage drop of the diode. This diode protects the series transistors and the output electrolytic capacitor.

3-53 3-54

may actually deliver a reverse current to the power supply during a portion of its operating cycle. An external source cannot be allowed to pump current into the supply without loss of regulation and pos-

sible damage to the output capacitor. To avoid

these effects, it is necessary to preload the sup-

ply with a dummy load resistor so that the power

supply delivers current through the entire operating

cycle of the load device.

REVERSE VOLTAGE LOADING

A diode is connected across the output termi-

REVERSE CURRENT LOADING

Active loads connected to the power supply

3-55

OVERVOLTAGE PROTECTION CROWBAR

(See

Figure 3-1

indicators and schematic diagram.)

3-56

Use the following steps to adjust

the crowbar circuit.

a. Turn CROWBAR ADJUST fully clockwise to set trip voltage to maximum.

b. control for desired crowbar trip

voltage. tripping, trip voltage should exceed

desired output voltage by the following amount:4% of 2V.

ccw until crowbar trips, output goes to

OV or a small positive voltage.

and output shorted until supply is

turned off.

supply off, then on.

disabled, remove lead attached to CROWBAR ADJUST potentiometer R5.

for controls and

Figure 3-13

Set power supply VOLTAGE

To prevent false crowbar

the output voltage plus

Slowly turn CROWBAR ADJUST

Crowbar will remain activated

To reset crowbar, turn

If CROWBAR must be completely

for the

3-7

Page 26

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Figure 3-13.

Model 6255A and 6289A Overvoltage Protection Crowbar

3-8

Page 27

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

SECTION IV

PRINCIPLES OF OPERATION

Figure 4-1.

4-1

OVERALL BLOCK DIAGRAM DISCUSSION

4-2

The power supply, as shown on the overall block diagram on transformer,

Figure 4-1,

rectifier and filter, a series regu-

consists of a power

lator, the mixer and error amplifiers, an “OR” gate, a constant voltage input circuit, a constant current input circuit, a reference regulator circuit, a bias supply, and a metering circuit.

4-3

The input line voltage passes through the power transformer to the rectifier and filter. The rectifier-filter DC

which is fed to the positive terminal via the

converts the AC input to raw

regulator and current sampling resister network. The regulator, part of the feedback loop,

made to alter its conduction to maintain a constant output voltage or current. The voltage developed

across the current sampling resistor network is the

input to the constant current input circuit. The

constant voltage input circuit obtains its input by

sampling the output voltage of the supply.

4-4

Any changes in output voltage/current

detected in the constant voltage/constant

are

current input circuit, amplified by the mixer and error amplifiers, and applied to the series regulator in the

correct phase and amplitude to counteract the change in output voltage/output current. The reference circuit provides stable reference voltages which are used by the constant voltage/current

in-

put circuits for comparison purposes. The bias

supply furnishes voltages which are used through-

out the instrument for biasing purposes. The meter

circuit provides an indication of output voltage or

current for both operating modes.

4-1

Page 28

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Figure 4-2.

4-5

SIMPLIFIED SCHEMATIC (See Figure

3-1 for controls and indicators.)

4-6 A simplified schematic of the power supply

is shown in Figure 4-2. It shows the operating controls; the ON-off switch, the voltage and current programming controls R10 and R16. Figure 4-2 also shows the internal sources of bias and reference voltages and their nominal magnitudes

with an input of 115 VAC.

4-7

Diode CR34, connected across the output

terminals of the power supply, is a protective de-

vice which prevents internal damage that might

occur if a reverse voltage were applied across the output terminals. connected across the output terminals when the normal strapping pattern shown on Figure 4-2 is employed.

Note that this capacitor can be removed if an increase in the programming speed is desired. Under these conditions, insure loop stability.

4-2

Output capacitor, C20, is also

capacitor C19 serves to

Page 29

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

4-8 DETAILED CIRCUIT ANALYSIS [Refer

to overall schematic diagram (FO-1) at rear of manual.] 4-9

controls and indicators.)

4-10 The feedback loop functions continuously to keep the output voltage constant, during constant voltage operation, and the output current constant, during constant current operation. For purposes of this discussion, assume that the unit is in con-

stant voltage operation and that the programming resistors R10 A and B have been adjusted so that the supply is yielding the desired output voltage. Further assume that the output voltage instantaneously rises (goes positive) due to a variation in the external load circuit.

4-11 Note that the change maybe in the form of a

slow rise in the output voltage or a positive going AC signal.

point A6 through capacitor C1 and a DC voltage is coupled to A6 through R10.

4-12 The rise in output voltage causes the voltage at A6 and thus the base of Q1A to decrease (go negative). Q1A now decreases its conduction and its collector voltage rises. The positive going error voltage is amplified and inverted by Q3 and fed to the bases of series transistors Q6 and Q7 via

emitter followers Q5 and Q4. The negative going

input causes Q6 and Q7 to decrease their conduction so that they drop more of the line voltage, and reduce the output voltage to its original level.

FEEDBACK LOOP (See Figure 3-1 for

An AC signal is coupled to summing

dissipated in series transistor Q6. The bias voltage

for Q7 is developed across zener diode VR5, The

The conduction of Q7 will decrease as the collector-

to-emitter voltage of Q6 approaches the voltage

developed across the biasing diodes, At low output voltages Q7 is completely cutoff and all of the load current flows through the shunt resistors. The

voltage that is dropped acress Q7 and the shunt

resistors reduces the voltage dropped across Q6, thus diminishing its power dissipation. The reliability of the regulator is further increased by

mounting the shunt resistors outside the rear of the cabinet so that the internal components are operated under lower temperature conditions.

Diode CR11, connected across Q6, protects it from

reverse voltages that could develop across it dur-

ing parallel or auto-parallel operation if one supply is turned on before the other. Diodes CR18

and CR19 perform a similar function for Q7.

4-16 CONSTANT VOLTAGE INPUT CIRCUIT

(See Figure 3-1 for controls and in-

dicators.)

4-17 The circuit consists of programming resistor

R10A and B, and a differential amplifier stage (Q1

and associated components). Transistor Q1 con-

sists of two transistors housed in a single package.

The transistors have matched characteristics min-

imizing differential voltages due to mismatched

stages.

tials is minimized, since both transistors operate

at essentially the same temperature.

Moreover, drift due to thermal differen-

4-13 If the external load resistance is decreased to a certain crossover point, the output current in-

creases until transistor Q2A begins to conduct.

During this time, the output voltage has also decreased to a level so that the base of Q1A is at a high positive potential. tion, its collector voltage decreases by the amount necessary to back bias OR gate diode CR3 and the

supply is now in the constant current mode of operation. current operation commences is determined by the

setting of CURRENT control R16. The operation of

the feedback loop during the constant current operating mode is similar to that occuring during constant voltage operation except that the input to the differential amplifier comparison circuit is obtained from the current sampling resistor network.

4-14 SERIES REGULATOR

4-15 The series regulator consists of transistor

stages Q6 and Q7 (see schematic at rear of manual). Transistor Q6 is the series element, or pass transis-

tor, which controls the output. Transistor Q7, together with shunt resistors R81, R82, and R83, are connected in a manner which minimizes the power

The crossover point at which constant

With Q1A in full conduc-

4-18 The constant voltage input circuit continuously compares a fixed reference voltage with a portion of the output voltage and, if a difference exists, produces an error voltage whose amplitude and phase is proportional to the difference. error output is fed back to the series regulator, through an OR gate and the mixer/error amplifiers. The error voltage changes the conduction of the

series regulator which, in turn, alters the output voltage so that the difference between the two input voltages applied to the differential amplifier is reduced to zero. output voltage constant.

4-19 Stage Q1B of the differential amplifier is connected to a common (+S) potential through impedance equalizing resistor R5. Resistors R6 and R8 are used to zero bias the input stage, offsetting minor base-to-emitter voltage differences in Q1. The base of Q1A is connected to a summing point at

the junction of the programming resistor and the current pullout resistor, R12. Instantaneous changes in output voltage result in an increase or

decrease in the summing point potential. Q1A is then made to conduct more or less, in accordance with the summing point voltage change.

The above action maintains the

The

The re-

4-3

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sultant output error voltage is fed back to the series regulator via OR-gate diode CR3 and the

remaining components of the feedback loop, Resistor R1, in series with the base of Q1A, limits

the current through the programming resistor during rapid voltage turn-down. form a limiting network which prevent excessive voltage excursions from over driving stage Q1A. Capacitors C1 and C2, shunting the programming resistors, increase the high frequency gain of the input amplifier. resistor R12, serves as a trimming adjustment for the programming current.

4-20

CONSTANT CURRENT INPUT CIRCUIT

(See

Figure 3-1

dicators.)

4-21

eration to the constant voltage input circuit. It consists basically of the current programming resistors R16A and B, and a differential stage (Q2 and associated components). Like transistor Q1 in the voltage input circuit, Q2 consists of two transistors, teristics,

4-22

cuit continuously compares a fixed reference voltage with the voltage drop

across the current sampling resistor R54. ferential amplifier produces an error voltage which is proportional to this

difference. in the feedback loop (amplifiers and

series regulator) function to maintain

4-23

tential through impedance equalizing resistor R26. Resistors R25 and R28 are used to zero bias the input stage, offsetting minor base-to-emitter

differences in Q2. put current on the positive line are felt at the current summing point and, hence, the base of Q2A.

Stage Q2A varies its conduction in accordance

with the polarity of the change at the summing

point. The change in Q2A’s conduction also varies

the conduction of Q2B due to the coupling effects of the common emitter resister, R22. The error voltage is taken from the collector of Q2B and fed

back to the series regulator through OR-gate diode

CR4 and the remaining components of the feedback

loop. The error voltage then varies the conduction

of the regulator so that the output current is main-

tained at the proper level.

This circuit is similar in appearance and op-

that are housed in a single package.

The constant current input cir-

If a difference exists, the dif-

the drop across the current sampling resistors, and consequently the output

current, at a constant value.

Stage Q2B is connected to a common (+S) po-

Resistor R13, shunting pullout

for controls and in-

The remaining components

Instantaneous changes in out-

Diodes CR1 and CR2

amplifier

having matched charac-

voltage

4-24

Resistor R20, in conjunction with R21 and C3 helps stabilize the feedback loop, Diode CR5 limits voltage excursions on the base of Q2A. Resister R19, shunting the pullout resistor, serves as a

trimming adjustment for the programming current flowing through R16.

4-25 4-26

stant voltage programming resisters are a shunt

load acress the output terminals of the power supply. If the output voltage changed, the current through these resistors would tend to change re-

sulting in an output current change. The clamp circuit is a return path for the voltage programming current, the current that normally flows through the programming resistors. current into the constant voltage summing point

(A6) constant, thus eliminating the error due to

shunting effects of the constant voltage programming resistors.

4-27

back biases CR30 and Q1O during constant voltage operation. When the power supply goes into con-

stant current operation, CR30 becomes forward biased by the collector voltage of Q1A. This re-

sults in conduction of Q1O and the clamping of the

summing point at a potential only slightly more negative than the normal constant voltage potential. Clamping this voltage at approximately the same potential that exists in constant voltage operation, results in a constant voltage across, and consequently a constant current through the pullout re-

sistor (R12).

4-28

4-29

error signal from the constant voltage or constant current input circuit to a level sufficient to drive the series regulator transistors. potential for mixer amplifier Q3 is established by the emitter follower.

error voltage input from either the constant voltage or constant current circuit via the OR-gate diode

(CR3 or CR4) that is conducting at that time. Diode CR3 is forward biased, and CR4 reversed

biased, during constant voltage operation. The reverse is true during constant current operation.

4-30

an equalizing network which provides for high frequency roll off in the loop gain response in order to

stabilize the feedback loop. Emitter follower transistors Q4 and Q5 are the error amplifiers serving

as the driver and predriver elements, respectively, for the series regulator. Transistor Q4, together

VOLTAGE CLAMP CIRCUIT

During constant current operation the con-

The circuit maintains the

The voltage divider, R51, R52, and VR3,

MIXER AND ERROR AMPLIFIERS The mixer and error amplifiers amplify the

The emitter bias

Transistor Q3 receives the

The RC network, composed of C5 and R30, is

4-4

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with diode CR17, provides a low resistance dis-

charge path for the output capacitance of the power

supply during rapid down programming.

4-31 4-32

supply similar to the main supply. It provides

stable reference voltages which are used throughout the unit. rived from smoothed

wave rectifier (CR22 and CR23) and filter capacitor

C10. The +6.2 and -6.2 voltages, which are used in the constant voltage and current input circuits for comparison purposes, are developed across temperature compensated Zener diodes VR1 and VR2. Resister R43 limits the current through the Zener diodes to establish an optimum bias level.

4-33

ulating transistor Q9 and error amplifier Q8. Output voltage changes are detected by Q8 whose base is connected to the junction of a voltage divider

(R41, R42) connected directly across the supply. Any

error signals are amplified and inverted by Q8 and applied to the base of series transistor Q9. The

series element then alters its conduction in the direction and by the amount necessary to maintain the voltage across VR1 and VR2 constant. Resistor R46, the emitter resistor for Q8, is connected in a manner which minimizes changes in the reference

voltage caused by variations in the input line. Output capacitor C9 stabilizes the regulator loop.

4-34

controls and indicators.)

REFERENCE CIRCUIT

The reference circuit is a feedback power

The reference voltages are all de-

obtained from the full

The regulating circuit consists of series reg-

METER CIRCUIT (See

Figure 3-1

for

this divider is connected across the sampling re-

sistor network. The amplified output of the differ-

ential amplifier is used to deflect the meter.

4-38

having a fixed gain of ten, Stage Q11B of the am-

plifier receives a negative voltage from the appli-

cable voltage divider when S2 is in one of the

voltage positions while stage Q11A is connected to the +S (common) terminal. With S2 in a current position, stage Q11A receives a positive voltage

from the applicable voltage divider while stage

Q11B is connected to the +S terminal. The differential output of the amplifier is taken from the collectors of Q12 and Q14. Transistor Q15 is a constant current source which sets up the proper bias current for the amplifier. Potentiometer R63 permits zeroing of the meter.

current limiting feature which protects the meter movement against overloads. For example, if METER switch S2 is placed in the low current range when the power supply is actually delivering a higher ampere fiers are quickly driven into saturation limiting the current through the meter to a safe value.

The differential

4-39

The meter amplifier contains an inherent

amplifier is a stable device

output,

the differential

ampli-

4-35

The meter circuit provides continuous indica-

tions of output voltage or current on a single multi-

ple range meter. The meter can be used either as a voltmeter or an ammeter depending upon the position of the METER switch S2 on the front panel of the supply. This switch also selects one of two meter

ranges on each scale. The meter circuit consists basically of a selection circuit (switch S2 and asso-

ciated voltage dividers), stable differential stages (Q11, Q12, and Q14), and the meter movement.

4-36

age divider is connected to the differential fier Input. When the METER section of S2 is in

one of the voltage positions,

divider R59, R60, and R61 (connected across the

output of the supply is the input to the differen-

tial amplifier.

4-37

the voltage acress divider R56, R57, and R58 is

the input to the differential

The selection circuit determines which volt-

the voltage across

When S2 is in one of the current positions

amplifier. Note that

amplifier

ampli-

4-5

Figure 4-3.

Figure 4-4.

Voltmeter Connections,

Simplified Schematic

Ammeter Connections,

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

4-40 Figures 4-3

tions when the METER section of S2 is in the

and

4-4

show the meter connec-

output voltage (drop acress R59 and R60) to the

meter higher voltage and current range positions, respectively. For the sake of simplicity, some of the actual circuit components are not shown on these drawings,

With the METER switch in the higher voltage range, position 2, the voltage drop acress R59 is the input to the meter amplifier and the meter indicates the output voltage acress the +S and -S terminals.

be switched to the low voltage position (1)

For low output voltages, S2 can

result-

ing in the application of a larger percentage of the

4-41 As

switch in the high current position (3) the voltage

drop across R58 is applied to the meter amplifier and the meter indicates the output current which flows through the sampling resistor network. For

low values of output current, the METER switch can be set to position 4 and the voltage drop across R57 and R58 is applied to the meter amplifier.

amplifier.

illustrated

Figure 4-4 with the METER

4-6

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SECTION V

MAINTENANCE

5-1 INTRODUCTION

CAUTION

Do not directly short out

any of the large capacitors as it places too much stress

on them.

tors through a load

resistor.

5-2

Upon receipt of the power supply, the performance check This check is suitable for incoming inspection. If a fault is detected in the power supply while making the performance check or during normal operation, proceed to the troubleshooting

graph 5-41). graph 5-46),

and calibrations the power supply to normal operation, repeat the performance check to ensure that the fault has been properly corrected and that no other faults exist. Before doing any maintenance checks, turn on power supply, allow a half-hour warm-up, and read the general information regarding measurement techniques

(Paragraph 5-3).

5-3 GENERAL MEASUREMENT TECHNIQUES

(Paragraph 5-10)

Discharge

After trouble shooting

perform any necessary adjustments

(Paragraph 5-48).

capaci-

should be made.

procedures

and repair

(Para-

Before returning

(Para-

shown tics should never if the load is connected across the rear terminals. Note terminals, the monitoring leads are connected at A, not B, as shown in the measuring ment that includes the resistance of the leads be-

tween the output terminals and the point of connection.

5-6

sampling resistor should be a four-terminal tor. The four terminals are connected as shown in

Figure 5-2. In

the low noise, low temperature coefficient (less than 30ppm/°C) type and should be used at no more than 5% of its rated power so that its temperature rise will be minimized.

in Figure 5-1.

measured

that when

Figure 5-1.

device at A

Figure 5-1.

For output current measurements, the current

Front Panel Terminal Connections

addition, the resister should be of

The performance

on the

measurements

front

are made at

Failure to connect

will result in

characteris-

terminals

the

front

a measure-

resis-

DO not touch heat sinks or

power transistors mounted

on heat sinks as they are very hot after instrument has been on and operating.

5-4

The measuring device must be connected across the sensing leads of the supply or as close to the output terminals as possible when measuring the output impedance, transient response, regulation, or ripple of the power supply in order to achieve valid measurements. A measurement made across the load includes the impedance of the leads to the load and such lead lengths can easily have an impedance several orders of magnitude greater than the supply impedance, thus invalidating the measurement.

5-5

The monitoring device should be connected

to the +S and -S terminals (see

Figure 3-2) or

Figure 5-2.

5-7

When using an oscilloscope, minal of the power supply and then ground the case of the oscilloscope to this same point. Make certain that the case is not also grounded by some other means (Power line). Connect both oscilloscope input leads to the power supply ground terminal and check that the oscilloscope is not exhibiting a ripple or transient due to ground loops, pickup, or other means.

5-1

Output Current Measurement

Technique

ground one ter-

Page 34

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

5-8

TEST EQUIPMENT REQUIRED

5-9 Table 5-1

perform the various procedures described in this

Section.

Care must be exercised when using an electronic null detector in which one input terminal is grounded to avoid ground loops and circulating currents.

lists the test equipment required to

CAUTION

Set METER switch to highest voltage

range and turn on supply.

d. Adjust VOLTAGE control(s) until front panel meter indicates exactly the maximum rated output voltage.

Differential

maximum rated output voltage within ±2%.

5-15 5-4

range and turn on supply.

panel meter indicates exactly the maximum rated

output current.

0.02 Vdc.

Current.

a. Connect test setup as shown in Figure

leaving switch S1 open.

b. Turn CURRENT controls fully clockwise.

Set METER switch to highest current

d. Adjust VOLTAGE control(s)

e. Differential

voltmeter should indicate

Proceed as follows:

until front

voltmeter should read 1.0

Figure 5-3.

5-10 5-11

ing inspection check and appropriate test can be repeated either to check the operation of the instrument after repairs or for periodic maintenance tests. The tests are performed using a 115Vac

rect result is not obtained for a particular check,

Figure 3-1

5-13 5-14

terminals of supply. lows:

Model Resistance 6

and -S terminals of supply observing correct polarity.

PERFORMANCE TEST

The following test can be used as an incom-

60Hz, single phase input power source. If the cordo not adjust any controls; proceed to trouble-

shooting

(Paragraph 5-41).

5-12

CONSTANT VOLTAGE (CV) TESTS (See

Rated Output and Meter Accuracy.

Voltage.

a. Connect load resistor across rear output

b. Connect differential

Differential

for controls and indicators.)

Proceed as follows:

6253A 6255A 6281A 6284A 6289A 6294A

Voltmeter Substitute,

Test Setup

portions of the

Resistor value to be as fol-

1.5

voltmeter across +S

Figure 5-4.

5-16.

load regulation, proceed as follows:

range and turn on supply.

panel meter indicates exactly the maximum rated

output voltage. ferential voltmeter.

not vary from reading recorded in step than the following:

Load Regulation.

a. Connect test setup as shown in b. Turn CURRENT controls fully clockwise. c.

Set METER switch to highest current

d. Adjust VOLTAGE control(s) until front

Read and record voltage indicated on dif-

Disconnect load resistors. Reading on differential

Output Current Test Setup

To check constant voltage

Figure 5-5.

voltmeter should

e by

5-2

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

TYPE

Differential

Voltmeter Variable

Voltage Transformer

AC Voltmeter

Oscilloscope

Oscillator

DC Voltmeter

Repetitive Load Switch

Resistive Loads

Table 5-1.

REQUIRED

CHARACTERISTICS

Sensitivity: 1mV full scale (min.). Input impedance: 10 megohms (min.).

Range: 90-130 volts. voltmeter accurate within 1 volt.

Accuracy: 2%. Sensitivity: 1mV full

scale deflection (min.). Sensitivity: 10OµV/cm. Differential

input.

Range: 5 Hz to 600 kHz. Accuracy: 2%. Output: 1OV rms.

Accuracy: 1%.

20, 000 ohms/volt (min.). Rate: 60-400 Hz, 2µsec rise and

fall

time.

Values: See

Figure 5-4.

Input resistance:

Paragraph 5-14

±5%, 75 watts.

Equipped with

Test Equipment Required

and

USE

Measure calibration procedures

Vary AC input

Measure AC voltages and ripple

Display transient response 140A plus 1400A

waveforms

Impedance checks

Measure

Measure transient response

Power supply load resistors

voltages;

voltages

RECOMMENDED

MODEL

3420 (See Note)

---

403B

plug-in. 1402A plug-in for spike

measurements

only,

200 CD

412A

See Figure 5-8,

---

Current Sampling Resistor

Resistor

Resistor Resistor

Resistor

Capacitor

Decade Resistance Box

A satisfactory

source and null detector as shown in justed so that the voltage difference between the supply being measured and the refer-

ence voltage will have the required resolution for the measurement being made. The voltage difference will be a function of the null detector that is used. Examples of satisfactory null detectors are: 419A null detector, a dc coupled oscilloscope utilizing differential a 2mV change in voltage will result in a meter deflection of four divisions.

6253A, 6284A: O.33

6255A, 6289A: O.66 6281A: 6294A:

±1%, 2 watt non-inductive.

100

ohms,

Value: See

1/2 watt.

Value: See

1/2 watt. 500µf, 50

Range: 0-500K. Accuracy: 0.1% plus 1 ohm. contacts.

substitute for a differential

input, or a 50mV meter movement with a 100 division scale. For the latter,

0.2

±5%, 10 watt.

Paragraph 5-59.

Paragraph 5-62.

wVdc.

Make-before-break

±0.1%,

±0.1%

Figure 5-3.

NOTE

voltmeter is to arrange a reference voltage

Measure current; cal-

ibrate meter; constant current ripple and noise

Measure impedance Measure impedance Calibrate programming

current Calibrate programming

current

Measure impedance

Measure programming coefficients

The reference voltage source is ad-

(CC)

See Parts List R54

---

5-3

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Model No. Variation (mVdc)

5-17 Line Regulation: To check the line regulation,

proceed as follows:

a. Connect variable auto transformer between

input power source and power supply power input.

b. Turn CURRENT controls fully clockwise. c. Connect test setup shown in Figure 5-5. d. Adjust variable auto transformer for 105Vac

input.

Set METER switch to highest voltage

range and turn on supply.

f. Adjust VOLTAGE control(s) until front panel meter indicates exactly the maximum rated output voltage.

Read and record voltage indicated on dif-

g. ferential voltmeter.

h. Adjust variable auto transformer for 125Vac input.

Reading on differential voltmeter should not vary from reading recorded in step g by more than the following:

Model No. Variation (mVdc)

Model No. 6281A 6294A Variation (mVdc)

6253A, 6284A 6255A, 6269A

±6

6281A

±5

6253A, 6284A 6255A, 6289A

±4

±2.75

±6

6294A

±8

±6

±8

5-19 The amount of ripple and noise that is present on the power supply output is measured either in terms of the RMS or (preferably) peak-to-peak value. The peak-to-peak measurement is particularly im-

portant for applications where noise spikes could be detrimental to a sensitive load, such as logic circuitry. The RMS measurement is not an ideal

representation of the noise, since fairly high out-

put noise spikes of short duration could be present

in the ripple and not appreciably increase the RMS

value.

5-20 The technique used to measure high frequency

noise or "spikes" on the output of a power supply

is more critical than the low frequency ripple and

noise measurement technique; therefore the former

is discussed separately in Paragraph 5-28.

Figure 5-5.

5-18 Ripple and Noise. Ripple and noise measurement can be made at any input AC line voltage combined with any DC output voltage and load current within rating.

Load Regulation, Constant Voltage

Test Setup

Figure 5-6. CV (Constant Voltage)

Ripple and Noise Test Setup

5-4

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5-21

Ripple and Noise Measurements. shows an incorrect method of measuring p-p ripple. Note that a continuous ground loop exists from the

third wire of the input power cord of the supply to the third wire of the input power cord of the oscil-

loscope via the grounded power supply case, the

wire between the negative output terminal of the

power supply and the vertical input of the scope, and the grounded scope case. Any ground current

circulating in this loop as a result

in potential EG between the two ground points

causes an IR drop which is in series with the scope

input. This IR drop, normally having a 60Hz line

frequency fundamental, plus any pickup on the un-

shielded leads interconnecting scope, appears on the face of the CRT. The magnitude of this resulting noise signal can easily be much greater than the true ripple developed between the plus and minus output terminals of the power

supply, and can completely invalidate the measure-

ment.

5-22

The same ground current and pickup problems can exist if an RMS voltmeter is substituted in place of the oscilloscope the oscilloscope display, unlike the true RMS

meter reading, tells the observer immediately

whether the fundamental period of the signal dis -

played is 8.3 milliseconds (1/120 Hz) or 16.7 milliseconds (1/60 Hz). Since the fundamental ripple frequency present on the output of is 120

(due to full-wave rectification),

cilloscope display showing a 120 Hz fundamental

component is indicative of a “clean” measurement

setup, while the presence of a 60 Hz fundamental usually means that an improved setup will result in a more accurate (and lower) value of measured ripple.

in Figure 5-6.

Figure 5-6A

the difference

the power supply and

However,

supply

os-

will flow through this shield, thus inducing a

noise signal in the shielded leads.

5-25 To

playing ripple that is induced in the leads or picked up from the grounds, the (+) scope lead should be shorted to the (-) scope lead at the power supply terminals. The ripple value obtained when the leads are shorted should be subtracted from the actual ripple measurement.

5-26 In

method of nate non-real components of ripple and noise so that a satisfactory measurement may be obtained. However, in more stubborn cases it may be necessary to use a differential put as shown in

single conductor shielded cables may be substituted in place of the shielded two-wire cable with equal success. jection, a differential the difference in signal between its two vertical input terminals, thus ignoring the effects of any common mode signal introduced because of the difference in the AC potential between the power supply case and scope case. ferential input scope in this manner, however, it is imperative that the common mode rejection capability of the scope be verified by shorting together its two input leads at the power supply and observing the trace on the CRT. If this trace is a

straight line, the scope is properly ignoring any common mode signal present. If this trace is not a straight line, then the scope is not rejecting the ground signal and must be realigned in accordance with the manufacturer’s common mode rejection is attained.

verify that the oscilloscope is not dis-

most cases, the single-ended scope

Figure 5-6B

Figure 5-6C. If

Because of its common mode re-

will be adequate to elimi-

scope with floating in-

desired, two

oscilloscope displays only

Before using a dif-

instructions until proper

5-23 Figure 5-6B

suring the output ripple of a constant voltage pow-

er supply using a single-ended scope. The ground

loop path is broken by floating the supply output.

Note that to ensure that no potential difference exists between the supply and the oscilloscope, it is recommended that whenever possible they both be plugged into the same AC power buss. If the

same buss cannot be used, both AC grounds must be at earth ground potential.

5-24

ed two-wire cable should be used to connect the output terminals of the power supply to the vertical

input terminals of the scope. When using a twisted pair, care must be taken that one of the two

wires is connected to the grounded input terminal

of the oscilloscope. wire, it is essential for the shield to be connected to ground at one end only so that no ground current

Either a twisted pair or (preferably)

shows a correct method of mea-

shield-

When using shielded two-

5-5

5-27 To

ceed as follows: meter as shown in

and adjust VOLTAGE control until front panel meter

indicates maximum rated output voltage. less than 200µV RMS and 1mV p-p.

5-28

quency spike measurement is being made, an in-

strument of sufficient bandwidth must be used; an

oscilloscope with a bandwidth of 20 MHz or more is adequate. Measuring noise with an instrument that

has insufficient quency spikes detrimental to the load.

5-29

check the ripple and noise output, proConnect the oscilloscope or RMS volt-

Figures 5-6B or 5-6C.

b. Turn the CURRENT control fully clockwise

The observed ripple and noise should be

Noise Spike Measurement. When a high fre-

bandwidth may conceal high fre-

The test setups illustrated

in Figures 5-6A

Page 38

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

and

5-6B

are generally ing spikes; a differential oscilloscope is necessary. Furthermore,

5-6C

must be modified if accurate spike measure-

ment is to be achieved:

1. As shown in

must be substituted

2. Impedance matching resistors must be included to eliminate standing waves and cable ringing, and the capacitors must be connected to

block the

not

the measurement concept of

Figure 5-7,

for the shielded two-wire cable.

current path.

acceptable for

two coax cables,

measur-

Figure

range and turn on supply.

panel meter indicates exactly the maximum rated output voltage.

switch setup.

display is obtained on oscilloscope. Waveform should be within the tolerances shown in

5-9

value in less than 50 microseconds).

a. Connect test setup shown in b. Turn CURRENT controls fully clockwise. c.

Set METER switch to highest current

d. Adjust VOLTAGE control(s) until front

e. Close line switch on repetitive load f. Adjust 25K potentiometer until a stable

(output should return to

within

Figure 5-8.

Figure

15mV of original

Figure 5-7.CV

3. The length of the test leads outside the coax is critical and must be kept as short as possible; the blocking capacitor and the impedance

matching resister should be connected directly from the inner conductor of the cable to the power supply terminals.

4. Notice that the shields of the power supply end of the two coax cables are not connected to the power supply ground, since such a connection

would give rise to a ground current path through the coax shield, resulting in an erroneous measurement.

5. The measured noise spike values must be doubled, since the impedance matching resisters,

constitute

scope should be less than O.5mV

5-30

the normal measurement of low frequency ripple and noise; simply remove the four terminating resisters and the blocking capacitors and substitute a higher

gain vertical plug-in in place of the wide-band plug-

in required for spike measurements. Notice that with these changes, cable version of

2-to-1 attenuator.

6. The noise spikes observed on the oscillo-

The circuit of

Figure 5-6C.

Noise Spike Test Setup

p-p.

Figure 5-7

can also be used for

becomes a two-

Figure 5-8.

Transient Response, Test Setup

5-31

transient recovery time proceed as follows:

Transient Recovery Time. To check the

5-6

Figure 5-9.

Transient Response, Waveforms

Page 39

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

5-32

made by monitoring the output voltage with an oscilloscope while rapidly changing the remote programming resistance. mote resistance is varied from zero ohms to the value that will produce maximum output voltage; and for down-programming, ied from the value that will produce maximum output voltage to zero ohms. To check the up-programming

speed, make the connections indicated in

5-10;

Proqramming Speed. This measurement is

For up-programming, the re-

the remote resistance is var-

Figure

for down-programming,

simply remove RL.

will produce maximum output voltage of the supply.

This value is obtained by multiplying the program-

ming coefficient (200 ohms/volt, 300 ohms/volt for Model 6294A) by the maximum rated output voltage of the supply.

3. A mercury-wetted relay is employed to rapidly switch the programming resistance from zero to maximum at a 60 Hz rate. Other automatic

switching devices can be used; however, a handoperated switch connected acress the programming resistor is not adequate, because the resulting one-

shot displays are difficult to observe on most oscilloscopes.

4. The time (T) required for the output volt-

age to change from zero volts to maximum rated out-

put or from maximum rated output to zero should be

less than 10 milliseconds.

5-33

pedance, proceed as follows:

Output Impedance. To check the output im-

Connect test setup as shown in

Figure 5-11.

Figure 5-10.

The load resistance is included for up-programming and removed for down-programming to present the worst possible conditions for the supply to reach the programmed voltage. Refer to Application Note

90, Power Supply Handbook for” further details on remote programming speed. To check the programming speed, proceed as follows:

1. Restrap the rear barrier strip as indicated

Figure 5-10.

and A10 is removed. capacitor C20 to increase the programming speed. A minimum amount of output capacitance (C19) is

permanently wired to the output and should not be

removed, because the supply could oscillate under certain load conditions. The programming speed increases by a factor of from 10 to 100 when the out-

put capacitor C20 is removed.

2. Connect the relay, oscilloscope, and programming resistor Rp as illustrated Select the value of the programming resister that

CV Programming Speed, Test

Setup

Note that the jumper between +S

This disconnects the output

in Figure 5-10.

5-7

Figure 5-11.

Set METER switch to highest voltage range and turn CURRENT controls fully clockwise, and turn on supply.

Adjust VOLTAGE control(s) until front

panel meter reads 20 volts.

d. Set AMPLITUDE control on Oscillator to

10 volts (Ein) , and FREQUENCY control to 1 kHz.

Record voltage across output terminals of

the power supply (Eo) as indicated on AC voltmeter.

Calculate the output impedance by the following formula: Zout = (EoR)/(Ein Eo=

rms voltage across power supply output terminals.

= 1000.

R Ein = 10 volts.

Output Impedance, Test Setup

Eo)

Page 40

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

The output impedance (Zout) should be

less than 0.01 ohm.

h. Using formula of step f, calculate output impedance at frequencies of 10kHz, 100kHz, and lMHz. Values should be less than O. 05 ohm, O. 5 ohm, and 5 ohms, respectively.

5-34

Figure 3-1 for controls and indicators.)

5-35

rent load regulation, proceed as follows:

and turn on supply.

Variation (mVdc)

CONSTANT CURRENT (CC ) TESTS (See

Load Regulation.

a. Connect test setup as shown in b. Turn VOLTAGE control(s) fully clockwise. c.

Set METER switch to highest current range

d. Adjust CURRENT control until front panel meter reads exactly the maximum rated output current.

Read and record voltage indicated on

differential

switch S1.

not vary from reading recorded in step e by more than the following: Model No.

Model No.

5-36

proceed as follows: leaving switch S 1 open throughout test. tween input power source and power supply power

input.

and turn on supply.

meter reads exactly the maximum rated output cur-

rent, ferential voltmeter. Vac input.

not vary from reading recorded in step g by more than the follow ing: Model No.

Variation (mVdc)

Model No.

Variation (mVdc)

5-37

pertaining to the ground

voltmeter.

f, Short out load resistor (Ry) by closing

Reading on differential

9. $

Line Recmlation. a. Utilize test setup shown in b. Connect variable auto transformer be-

C. Adjust auto transformer for 105Vac input.

d. Turn VOLTAGE control(s) fully clockwise. e.

Set METER switch to highest current range

f. Adjust CURRENT controls until front panel

g, Read and record voltage indicated on difh, Adjust variable auto transformer for 125 i,

Reading on differential

Ritmle and Noise.

To check the constant cur-

Figure 5-4.

voltmeter should

6253A, 6284A

*O. 183

6281A

*o. 5

To check the line regulation

6253A, 6284A

+0. 183

6281A 6294A

+0. 15

Most of the instructions

loop and pickup problems

6255A, 6289A

+~265

6294A

*o. 35

Figure 5-4

voltmeter should

6255A, 6289A

*O. 265

+0. 35

Figure 5-12.

associated with constant voltage ripple and noise measurement also apply to the measurement of con-

stant current ripple and noise. trates the most important precautions to be observed when measuring the ripple and noise of a constant current supply. The presence of a 120 cycle waveform on the oscilloscope is normally indicative of a correct measurement method. 60 Hz as its fundamental component is typically associated with an incorrect measurement setup.

Ripple and Noise Test Setup

Figure 5-12

A wave shape having

illus-

5-8

Page 41

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

5-38

ripple and noise, proceed as follows:

meter as shown in

and turn on supply. meter reads exactly the maximum rated output current. less than the following:

Model 6253A,6284A 6255A,6289A 6281A 6294A

ITA rms

Ripple and Noise Measurement. To check the

Connect the oscilloscope or RMS volt-

Figures 5-12B or 5-12C.

b. Rotate the VOLTAGE control fully CW.

Set METER switch to highest current range d. Adjust CURRENT control until front panel e. The ripple and noise indication should be

5-39 5-40

supplies are conservatively operated to provide maximum reliability a supply may fail. Usually the instrument must be

immediately repaired with a minimum of “ down time” and a systematic approach as outlined in succeeding paragraphs can repair.

5-41

5-42

this instrument, ensure that the fault is with the

instrument and not with an associated circuit. The

performance

determined without having to remove the instrument from the cabinet.

5-43

at fault, check for obvious troubles such as open

fuse, a defective power cable, or an input power

failure.

open connections, charred components, etc.

trouble source cannot be detected by visual inspec-

has been located (by means of visual inspection or

TROUBLESHOOTING Components within Hewlett-Packard power

y. In

greatly simplify and speed up the

TROUBLE General.

Once it is determined that the power supply is

(each held by four retaining screws) and inspect for

tion, follow the detailed procedure outlined in suc ceeding paragraphs. Once the defective component

ANALYSIS

Before attempting to troubleshoot

test

(Paragraph 5-10)

Next, remove the top and bottom covers

0.5

spite of this, parts within

0.5

enables this to be

If the

Table 5-2.

Common Troubles

trouble anal ys is) correct it and re-conduct the performance test. If a component is replaced, refer to the repair and replacement and adjustment and calibration paragraphs in this section.

5-44 A

eration is a helpful aid in troubleshooting,

is recommended that the reader review Section IV of the manual before attempting to troubleshoot the unit in detail. Once the principles of operation are understood, logical application of this knowledge used in conjunction with the normal voltage read-

ings shown on the schematic and the additional procedures given in the following paragraphs should

suffice to isolate a fault to a component or small group of components. on the schematic are positioned adjacent to the applicable test points (identified bers on the schematic and printed wiring boards).

5-45 Table 5-2

able causes of many possible troubles.If high or low output voltage is a symptom, there are

two methods of isolating the fault. The first is a

simplified procedure that involves only measuring voltages; the second is a more thorough approach

requiring that transistor stages be opened or shor-

ted.

voltages as given in

Then the voltage levels at critical points (base and

collector) in the feedback loop should be measured

and compared to the normal voltages given on the

overall schematic diagram at the rear of the manual.

This method of troubleshooting

not aiways conclusive; a better method is described

in (2).

filtered dc voltages as given in

drive each stage in the feedback loop into conduc tion or cutoff by either shorting or opening the pre -

vious stage as indicated in

good understanding

includes the symptoms and prob-

Both methods are described as follows:

First, the reference, bias, and filtered dc

Table 5-3

2. First, measure the reference, bias, and

the principles of op-

and it

The normal voltages shown

encircled num-

either

should be checked.

feedback loop is

Table 5-3.

Tables 5-4 or 5-5.

Then,

Symptom

Low output or no output voltage

High output voltage

High ripple

Probable Cause Refer to Refer to

a. b. If output floating, connect lpf capacitor between output

c. d. Ensure that supply is not in constant-current

Table 5-3, Table 5-3,

Check operating setup for ground-refer

and ground. Check for excessive internal ripple; refer to

under loaded conditions.To CURRENT control fully clockwise. *

Check for low voltage across C14, C12, or C1O.

5-9

then

5-4.

then

5-5.

to Paragraph 5-18.

Table 5-3.

operation

prevent this condition turn

Page 42

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Symptom

Poor line regulation

Poor load regulation

(Constant Voltage)

Poor load regulation

(Constant Current)

Table 5-2.

Common Troubles (Continued)

Probable Cause

Improper measuring technique; refer to

b. Check reference circuit voltages,

Check reference circuit adjustment,

Improper measuring technique; refer to

b. Check the regulation characteristics

follows:

(1) Connect differential (2) Connect appropriate

across (+) and (-) output terminals (3) Perform steps b through f of (4) If the differential

0.5mV, replace VRl.

Ensure that supply is not in constant-current loaded conditions. To prevent this condition turn CURRENT control fully clockwise. *

Improper measuring technique; refer to

b. Check the regulation characteristics

follows :

(1) Connect differential (2) Connect appropriate

across (+) and (-) output terminals

(3) Perform steps b through f of (4) If the differential

O .5mV, replace VR2.

C19, C20, and CR34 leaky.

d. Check clamp circuit, Q1O, CR30, VR3, and CR32.

Ensure that supply is not crossing over into constant voltage operation. To prevent this condition, load the supply and turn the VOLTAGE control fully clockwise. *

voltmeter acress VR1

load resistor (Ry), given in

voltmeter reading varies by more than

voltmeter across VR2

load resistor (Ry), given in

voltmeter reading varies by more than

Paragraph 5-3.

Table 5-3.

Paragraph 5-62.

Paragraph 5-3. of

Paragraph 5-16

Paragraph 5-3.

Paragraph 5-35

Zener diode VRl as

Figure 5-4,

operation under

Zener diode VR2 as

Figure 5-4,

Oscillates

Poor stability (Constant Voltage)

Poor stability (Constant Current)

Poor transient recovery

* See

Figure 3-1

for controls and indicators.

Check C5 open. Adjustment of R30; refer to

a. b. Check R21 and C3 in current input circuit.

Check +6 .2Vdc reference voltage

b. Noisy programming resistor R1O.

CR1, CR2 leaky.

d. Check Rl, R12, R13, and C2 for noise or drift.

Stage Q 1 defective.

Check -6 ,2Vdc reference voltage

b. Noisy programming resistor R16. c.

CR5, CR34, C19, C3 leaky.

d. Check R18, R19, R20, R21, and R54 for noise or drift.

Stage Q2 defective.

Check R30 and C5, Refer to adjustment procedure

Paragraph 5-64.

5-10

(Table 5-3).

Paragraph 5-64.

Page 43

TM 11-6130-416-14/EE0110-BJ-MMA-010/E154° DCDUAL/T.0.35C1-2-847-1

Meter

Common

31 +s +s

- out

Table 5-3.

Meter

Positive

+s 33

37 37

23 38

Reference, Bias, and filtered DC Troubleshooting

Normal Normal

Vdc

6.2

12.4 24

4.4

28V(6253A)

53V(6255A) 12V(6281A) 28V(6284A) 53V(6289A) 80V(6294A)

38V(6253A) 62V(62S5A) 21 V(6281A) 38V(6284A) 62V(6289A) 90V(6294A)

Ripple (P-P)

0. 5mV

1. 4V.

o. 4V O. 6V o. 2V o. 4V o. 5V

O. 8V

5 mV

20mV

3V lV 2V 3V

lV lV

Probable

VR2 VR1

Q8, Q9

C1O, CR22, CR23, T1

VR4

C12, CR24, CR25, T1

C14, C16, CR26, CR27, R49, T1

Cause

Step

Table 5-4.

Action

Turn the VOLTAGE control fully clockw ise*and disconnect the load

TO eliminate the constant current circuit as a cause of the

malfunction, ode or anode lead

Check conduction of Q6 and Q7 by connecting a jumper between Q4 emitter (22) and base (18)

Check turnoff of Q4 by short-

ing Q5 emitter to base

Check turnoff of Q5 by short-

ing Q3 emitter to collector

remove C R4 cath-

Low Output Voltage Trouble shooting

Response

Output increases

s. b. Output remains low

a. Output remains low

b. Output increases

s. Output remains low

b. Output increases

s. Output remains low

b. Output increases

Probable Cause

Stage Q2 defective

b, Reconnect CR4 and proceed

to step 3

a. Q6, Q7, CR1l or associated

parts defective

b. Remove jumper and proceed

to step 4 a. Q4, CR17, R38 defective b, Remove jumper and proceed

to step 5 a. Q5, R31 or associated com-

ponents defective b. Remove short acress Q3

and proceed to step 6

5-11

Page 44

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Step

* See

Figure 3-1

steD I

Table 5-4.

Action

Check conduction of Q3 by shorting QIA emitter to collector

Remove CR32 anode or cathode lead

for controls and indicators.

Table 5-5.

Action

Turn the VOLTAGE control-to approximately mid-range and disconnect the load, If the output voltage should rise to an excessive value with the VOLTAGE control turned ccw, the control could be damaged.

Low Output Voltage Troubleshooting

(Continued)

Response

a. Output remains low

b. Output increases

Output increases

b. Output remains low

High Output Voltage Troubleshooting

Response

Probable Cause

Stage Q3 or Q16 defective

b. Remove short and proceed

to step 7

a. Voltage clamp circuit is de-

fective

b. Reconnect CR32. Stage

Q1 defective, Check R1O,

Cl for short and R12, R13

for open.

Probable Cause

Check turnoff of Q6 and Q7

by shorting collector of Q5

to emitter of Q4

Check conduction of Q4 by

shorting Q5 emitter to col-

lector

Open Q3 collector lead

Check conduction of Q5 by

shorting R33

Check turnoff of Q3 by

shorting Q3 base to emitter

Remove CR32 anode or cathode

On rear terminal board, short

A6 to (-)

a. Output remains high

b. Output decreases

a. Output remains high b. Output decreases

a. Output remains high

b. Output decreases

Output remains high

b. Output decreases

Output decreases

b. Output remains high

Output remains high

b. Output decreases

Q6, Q7, CR1l, R23, R27, R34

defective

Remove short across Q4

and proceed to step 3 Q4, CR17, R38 defective

Remove short across Q5 and

proceed to step 4 Q5, R31 or associated com-

ponents defective Remove short and proceed

to step 5 Stage Q3 or Q17 defective

Remove short and proceed

to step 6 Voltage clamp circuit is de-

fective Reconnect CR32 and pro-

ceed to step 7

Stage Q1 defective

a. b.

Remove short across terminals A6 and (-). Check R1O for open and R12, R13 for short,

* See

Figure 3-1

for controls and indicators.

5-12

Page 45

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Figure 5-13.

Servicing Printed Wiring Boards

5-13

Page 46

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

REPAIR AND REPLACEMENT

5-46

5-47

board, refer to

for this manual contains a list of re-

placeable parts.

semiconductor device, refer to

5-6

Before servicing a printed wiring

Figure 5-13.

Before replacing a

which lists the special character-

Table 5-6.

Reference

Designator

Matched differential fier.

Q1,2

Q11 Q6,7(16)

CR1-5,19,

20,30,32 VR3 VR4 ,5

7(I (min.) hFE ic = 1 ma. VCE. 5V. Ico O. Olp.a@ Vcbo= 5V.

NPN Power. @It=

Si. rectifier, 200ma, 200prv

Diode, zener, 4.22V, 400mW

Diode, zener, 4.3V, lW

The RPSTL

Table

Selected Semiconductor Characteristics

Characteristics

NPN Si Planar.

hFE= 35 (min.)

4A, VCE= 4V.

ampli-

i.stlcs of selected semiconductors. If the device to be replaced is not listed in

Table 5-6,

er’s part number listed in the RPSTL is applicable. After replacing a semiconductor device, refer to checks and adjustments that may be

necessary.

@ Stock No.

1854-0229

1854-0221 1854-0228

1901-0033

1902-3070 1902-0797

the standard manufactur-

Table 5-7

Suggested

Replacement

2N2917 G.E.

2N4045

2N3055 R.C.A.

1N485B Sylvania

1N749 Motorola 1N3824 Motorola

for

Table 5-7.

Reference

Q3, Q16 Q4, Q5

Q6, Q7

Q8, Q9

Q1O

Q1l-Q15

CR1, CR2 CR3, CR4, CR5 OR-gate diodes and limiting diode

Checks and Adjustments After Replacement of Semiconductor Devices

Function

Constant voltage differential

Constant current differential

Mixer amplifier

Error amplifiers and driver Series regulator

Reference regulator

Clamp circuit

M,~ter circuit

Limiting diodes

amplifier

Check

Constant voltage (CV)

line and load regulation.

Zero volt output.

Constant current (CC) line and Ioad regulation.

Zero current output.

CV/CC load regulation. CV transient response.

CV/CC load regulation. CV/CC load regulation. Reference circuit line

regulation. CC

load regulation.

Meter zero. ammeter tracking.

CV load regulation. CV/CC load regulation.

Voltmeter/

Adjust

R6 orR8

R25 orR28

R30.

R46

R63, R72

R56

5-14

Page 47

11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Table 5-7.

Checks and Adjustments After Replacement of Semiconductor Devices (Continued)

Reference

CR8-CR1O

CR22-CR27

CR34

VR1

VR2

VR4

Adjustment or

Calibration *

Meter Zero Voltmeter Tracking

Ammeter Tracking

“Zero” Volt Output

Function

Forward bias regulator

Rectifier diodes

Protection diode

Positive reference voltage

Negative reference voltage

Bias voltage

Table 5-8.

Paragraph

5-50 5-52

5-54 5-57

Calibration and Adjustment Summary

Control

Device

Pointer R63 and R72

R56 R6 or R8

Check

Voltage across each

diode O. 6 to O. 9 volts. Voltage across appro-

priate filter capacitor. Output voltage

Positive reference voltage (+6. 2v).

Negative reference

voltage (-6. 2V).

4. 4V

Adjustment or

Calibration

“Current” Program-

ming Current

Reference Circuit

Line Voltage Adjustment

Paragraph

5-61

5-63

Adjust

Control

Device

R19

R46

“Voltage” Program-

ming Current

5-58

R13

“Zero” Current

output

5-60

R25 or R28

* See

Figure 3-1

5-47A.1

FUSE REPLACEMENT

for controls and indicators.

(Figures

1-1,3-1)

5-47A.2

Replace fuses by using the

following procedure:

Turn off instrument power.

a. b.

Remove fuse holder by inserting screwdriver blade into fuse holder slot on front panel and turning Ccw.

Remove defective fuse from

holder, and replace fuse.

Replace fuse holder.

Restore power.

5-47A.3

COVER REMOVAL

Negative Reference

Load Adjustment

5-64

Replace VR2

Positive Reference

Load Adjustment

Transient Response

5-47A.4

When it is necessary to repair

5-65 5-66

Replace VR1 R30

.—

or ad] us t the power supply, one or more covers will have to be removed.

Figure 5-14

and the following steps

Refer

for cover removal procedure.

Top Cover Remove four top cover screws,

and lift cover to remove.

Bottom Cover

Remove four bottom cover screws along with rubber feet, and lift cover to remove.

Front Panel

Remove six sets of knobs

(METER, VOLTAGE and CURRENT controls)

for both

switches

power supplies.

Remove nut attaching meter

to front panel.

5-15

Page 48

11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Figure 5-14.

Model 6255A Modular Cabinet

5-16

Page 49

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

CAUTION

Exercise care when pulling

front panel forward to avoid damaging any of the compon-

ents or connecting wiring.

Carefully pull front panel

forward, freeing it from shafts on the

METER, VOLTAGE and CURRENT programming

controls.

Top Red Rear Cover

Remove two screws from ends of back of unit, and slide cover to rear for removal.

5-47A.5 POWER CABLE REPLACEMENT (FO-1)

5-47A.6

the power cable, turn instrument pewer

off, unplug power cord, and remove top cover. following procedure.

leads

minal

power

solder leads to terminal and ground.

5-47A.7 1-1,

3-1 F0-1, F0-2)

5-47A.8

LINE ON switch S1, off, unplug power cord, and remove top cover. following procedure.

terminals on switch, and tag leads.

front panel.

and resolder leads.

5-47A.9

(Figures 4-2, FO-1, FO-2)

5-47A.10 When it is

When it is necessary to replace

Replace power cable by using the

Unsolder three power cable

(white, black and green) from ter-

and ground.

Remove cable from rear of

supply l

Install new power cable, and

Replace top cover.

SWITCH S1 REPLACEMENT

—.

When it is necessary to replace

turn instrument power

Replace switch S1 by using the

Unsolder four leads from

Remove nut securing switch to

Install new switch in panel,

Replace top cover.

TRANSFORMER T1 REPLACEMENT

necessary to

(Figures

replace transformer Tl, use the following procedure.

Turn instrument power off, un-

plug power cord, and remove top and bot-

tom covers for access to transformer T1.

Use following steps for replacement of transformer on left P.C. board:

Remove hardware and

bracket from transformer on left side of case.

Remove two I’NItS from upper

right side of transformer.

Remove four screws frOm bottom of P.C. board, securing transformer to board.

Unsolder and tag transformer leads from P.C. board, and carefully remove transformer.

Place new transformer on

P.C. board with spacer nuts and screws.

Solder leads onto P.C.

board.

Install nuts on top, right

of transformer and bracket to left side of case.

Use following steps for re-

placement of transformer on right P.C.

board.

Remove six top

ing transformer to horizontal braces.

Remove upper screw in vertical bracket securing it to horizontal brace.

Remove two screws securing

Overvoltage Protection Crowbar P.C.

board to horizontal brace on left of transformer. (Carefully place this P.C.

board back towards rear of power

supply).

Remove two screws and nuts securing horizontal braces to right side of case.

Remove horizontal braces.

Remove screws and spacer nuts securing transformer to P.C. board.

-7.

Unsolder and tag transformer leads from P.C. board, and carefully remove transformer.

Place new transformer on

P.C. board with spacer nuts and screws.

Solder leads onto P.C.

board.

nuts secur-

5-17

Page 50

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

10.

Mount horizontal braces over transformer and secure top with six mounting nuts.

11*

Replace screws and nuts at

right side of case.

12.

Re-install Crowbar P.C.

board on horizontal brace.

13.

Re-install screw in verti-

cal bracket securing bracket to horizontal brace.

5-47A.11

OVERVOLTAGE PROTECTION CROWBAR P.C. BOARD REPLACEMENT (FO-1, FO-2, 3-13)

5-47A.12

When it is necessary to re-

place the Overvoltage Protection Crowbar

P.C. boards, turn instrument power off, unplug power cord, and remove top cover.

Use caution when removing the P.C.

boards to avoid damaging mounted components.

Remove two screws securing

P.C. board.

Unsolder and tag leads from P.C. board.

Remove P.C. board from

chassis.

c. Solder leads to replacement

P.C. board.

Mount left P.C. board on horizontal brace at top of case.

Mount right P.C. board on

right side of case.

5-47A.13

REPLACEMENT (VIEWED FROM FRONT

SUPPLY) (FO-1,

MAIN LEFT P.C. BOARD

~-2)

POWER

Power supply output

terminals

Fuse cartridge F1.

Neon lamp DS1.

Remove the left Overvoltage Protection Crowbar P.C. board from the case by removing two screws.

Remove bottom plate in center

of power supply that is attached to both main P.C. boards by four screws accessible from the top.

CAUTION

Note and mark locations of power transistors before removing them.

Remove seven nuts and screws

securing heat sink and power transistors to P.C. board.

Unsolder leads attaching three

power transistors to P.C. board.

Remove single screw attaching

left side of P.C. board to case of power

Supply

●

Remove two top nuts securing

transformer to side of case.

Remove two nuts securing

transformer to horizontal braces.

Remove four nuts from top of

transformer on right side of power

Supply .

Remove two screws and nuts

j. securing horizontal braces to right side of case.

CAUTION

5-47A.14

When it is necessary to re-

place the main left P.C. board assembly,

turn instrument power off, unplug power cord, and remove top and bottom covers

and front panel.

Use caution when removing the P.C. board to avoid damaging mounted components.

Replace the P.C.

board by using the following procedure.

Unsolder and tag leads from

the following components mounted on left

half of front panel.

Crowbar adjust. Meter.

P.C. board assembly damaging P.C. board

to avoid

or its

components.

Carefully slide

P.C. board as-

sembly to right and downward, holding it

by the transformer.

Reverse steps k through a for

reassembly.

5-47A.15

MAIN RIGHT P.C. BOARD REPLACE-

MENT (VIEWED FROM FRONT OF powm SUPPLY)

(m-l,

m-2)

5-18

Page 51

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

5-47A.16

place the main right P.C. board assembly, turn instrument power off, unplug power cord, and remove top and bottom covers and front panel. Use

caution when removing the P.C. board to avoid damaging mounted components.

Replace the P.C. board by using the following procedure:

the following components mounted on

right half of front panel.

terminals.

Protection Crowbar P.C. board from the

case by removing two screws.

of power supply that is attached to both

main P.C. boards by four screws accessi-

ble from the top.

When it is necessary to re-

Unsolder and tag leads from

Crowbar adjust.

Meter.

Power supply output

Fuse Cartridge F1.

Neon lamp DS1 .

Remove the right Overvoltage

Remove bottom plate in center

CAUTION

Exercise care when removing P.C. board assembly to avoid

damaging P.C. board or its components.

Carefully slide P.C. board as-

J. sembly to left and downward, holding it by the transformer.

Reverse steps ] through a for

reassembly.

5-47A.17

(Figures 4-2, FO-1 FO-2)

5-47A.18

place capacitor C14, turn instrument

power off, unplug power cord, and remove

top and bottom covers. capacitor in either half of the power

supply by using the following procedure.

board securing capacitor to board.

P.C. board.

install new capacitor.

CAPACITOR C14 REPLACEMENT

When it is necessary to re-

Replace

Remove two screws under P.C.

Remove capacitor from top of

Reverse steps b and c to

CAUTION

Note and mark locations of

power transistors before removing them.

Remove seven nuts and screws securing heat sink and power transistors to P.C. board.

Unsolder leads attaching three

power

right

power

transformer to horizontal braces.

transformer on left side of power supply securing braces.

securing

of case.

transistors to P.C. board. f.

Remove single screw attaching

side of P.C. board to case of Supply .

Remove four top nuts securing

Remove two nuts from top of

transformer to horizontal

Remove two screws and nuts

horizontal braces to right side

5-47A.19

(FO-1, FO-2)

5-47A.20

place capacitors C5 or C6, turn instru-

ment power off,

remove top and bottom covers.

capacitors in either half of the power

supply by using the following procedure.

Overvoltage Protection Crowbar P.C. board to allow access to capacitors.

capacitor.

tion Crowbar P.C. board, and top and

bottom covers.

5-47A.21

REPLACEMENT (??0-1, FO-2)

CAPACITORS C5, C6 REPLACEMENT

When it is necessary to re-

unplug power cord, and

Remove two screws securing

Unsolder and remove defective

Install replacement capacitor.

Re-install Overvoltage Protec-

POWER TRANSISTOR Q4, Q6

Replace

5-19

Page 52

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

5-47A.22

When it is necessary to re-

place a power transistor, turn instru-

ment power off, unplug power cord, and

remove top and bottom covers.

Replace

transistor by using the following proce-

dure.

Remove hardware securing crow-

bar P.C. board, and re-position board without unsoldering to provide access to

‘Q4

orQ6.

Remove hardware attaching

transistor to heat sink.

Unsolder transistor leads from

P.C. board.

d. Carefully remove transistor,

complete with mica insulator.

Install new transistor, using

new mica insulator.

Solder transistor leads to

P.C. board.

Re-install crowbar P.C. board.

9* h.

5-35,

Refer to

and check cv/cc load regulation.

Re-install top and bottom

paragraph 5-16

and

cove rs.

5-47A.23

POWER TRANSISTOR Q7 REPLACE-

MENT (FO-1, FO-2)

5-47A.24

When it is necessary to re-

place power transistor Q7, turn instru-

ment pgwer off,

remove top and bottom covers.

unplug power cord, and

Replace

Q7 by using the following procedure.

Remove hardware attaching

transistor to heat sink.

Unsolder transistor leads from

P.C. board.

Carefully remove transistor,

complete with mica insulator.

Install new transistor, using

new mica insulator.

Solder transistor leads to

P.C. board.

5-35,

Refer to

and check cv/cc regulation.

Re-install top and bottom

paragraphs 5-16

and

covers.

5-47A.25

(FO-1,FO-2)

TRANSISTOR Q3 REPLACEMENT

5-47A.26

When it is necessary to

replace Q3, turn instrument power off, unplug power cord, and remove top and

bottom covers.

Replace Q3 by using the

following procedure.

Remove hardware securing crowbar P.C. board, and re-position to provide access to Q3.

Unsolder Q3 from P.C. board.

Install new transistor, and

solder in

5-35,

place.

Re-install crowbar P.C. board.

Refer to check cv/cc load regulation.

and

Refer to

paragraph 5-16

paragraph 5-31,

and

check cv transient response.

Re-install top and bottom

covers.

5-47A.27

CONTROL REPLACEMENT

VOLTAGE/CURRENT PROGMMMING

(Figures 4-2, FO-1,

FO-2)

5-47A.28

When it is necessary to re-

place either a Voltage or Current Pro-

gramming Control, turn instrument power off, unplug power cord, and remove top

and bottom covers.

To replace programming controls, use the following procedure.

Remove front panel knobs from

all four programming control shafts.

Remove front panel, leaving all leads attached to front panel controls/indicators.

Unsolder potentiometers from

P.C. board.

Carefully install new program-

ming control potentiometer.

Re-install knobs on shaft.

e. f.

Re-install top and bottom

covers.

5-47A.29

SILICON RECTIFIER CR19 RE-

PLACEMENT (FO-1, FO-2)

5-47A.30

When it is necessary to replace rectifier CR19, turn instrument power off,

top and bottom covers.

unplug power cord, and remove

Replace recti-

fier in either half of power supply by

5-20

Page 53

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

using the following procedure.

Remove hardware securing

crowbar P.C. board, and reposition

without unsoldering to provide access

to CR19.

Unsolder and remove defective

rectifier.

Install replacement rectifier.

Re-install Overvoltage Protection Crowbar P.C. board, and top and bottom covers.

5-47A.31

METER SWITCH S2 REPLACEMENT

(Figures 1-1, 3-1, FO-1, FO-2)

5-47A.32

When it is necessary to re-

place switch S2, turn instrument power

off ,

unplug power cord, and remove top cover to provide access to switch terminals.

Replace switch S2 by using the

following procedure.

Remove knob from meter shaft

on front panel.

Remove nut securing METER

switch to front panel.

Remove METER switch from front panel and position switch unsoldering of leads from

to facilitate switch ter-

minals.

Reverse steps c

through a to

install new METER switch.

5-47A.33

METER REPLACEMENT

(Figures

1-1, 3-1, FO-1, FO-2)

5-47A.34

When it is necessary to replace a meter, turn instrument power off ,

unplug power cord, and remove top

cover to provide access to the two plastic brackets (bezels) securing each meter to front panel.

Replace meters

by using the following procedure.

Unsolder and tag two leads

attached to back of meter.

CAUTION

Exercise extreme care when removing or replacing a meter to

avoid damage.

Avoid cracking or breaking

plastic bezel by carefully prying it open sufficiently to unsnap it from meter case.

Carefully install new meter,

and solder two leads.

5-47A.35

5HUNT RES15T0R (R81, R82, OR

R83) REPLACEMENT (FO-I )

5-47A.36

When it is necessary to replace a shunt resistor, turn instrument power off, unplug power cord, and remove red rear cover to provide access to re-

sistors.

Unsolder resistor leads and

a. remove two screws securing set of shunt resistors to be replaced.

Remove defective resistor(s);

b. re-install replacement resistors with

screws, and solder.

Replace red rear cover.

5-47A.37

MENT

(Figures 1-1, 3-1, FO-1, FO-2)

5-47A.38

FUSE HOLDER ASSEMBLY REPLACE-

When it is necessary to re-

place a defective fuse holder assembly,

turn instrument power off, unplug power

cord,

and remove top cover.

To replace

fuse holder assembly, use the following

procedure.

Remove fuse from front panel.

Loosen plastic nut attaching

fuse assembly to front panel.

Unsolder two leads from fuse

holder terminals.

Install new fuse holder, and

d. reverse above steps c through a for reassembly.

Replace top cover.

5-47A.39

NEON LAMP

DS1

REPLACEMENT

(Figures 1-1, 3-1, FO-1, FO-2)

5-47A.40

When it is necessary to re-

place a defective neon lamp, turn in-

strument power off, unplug power cord, and remove top cover.

To replace a neon

lamp, use the following procedure.

Unsolder two leads from lamp

assembly behind front panel.

Remove clip from behind panel,

b. and pull lamp out through front of panel.

5-21

Page 54

TM 11-6130-416-14/EE010-MMA-010/E154

Insert new lamp, install new

clip, and solder leads to terminals.

Replace top cover.

5-47A.41

R5 REPLACEMENT

FO-2) 5-47A.42

place a defective crowbar adjust poten-

tiometer, turn instrument power off, un-

plug power cord, and remove top cover.

TO replace a crowbar adjust potentiome-

ter, use the following procedure.

CROWBAR ADJUST POTENTIO~TER

(Figures 1-1, 3-1, FO-1,

When it is necessary to re-

DCDUAL/T.O.35C1-2-847-1

Turn the adjustment screw clockwise un-

til the pointer is exactly over the zero mark on the

scale.

c and d. clockwise about 15 degrees to break contact be-

tween adjustment screw and pointer mounting yoke,

but not far enough to move the pointer back down-

scale. needle moving, repeat the procedure. now zero-set for best accuracy and mechanical stability.

5-52

for controls and indicators. )

If the screw is turned too far, repeat steps

Turn meter adjustment screw counter-

If screw is turned too far, as shown by the

The meteris

VOLTMETER TRACKING (See

Figure 3-1

Unsolder two leads from pote-

ntiometer terminals behind panel.

Unbolt potentiometer shaft

from back of panel.

Unbolt shaft from potentiome-

ter.

Remove nut supplied with new

potentiometer.

Install shaft on new

potentiometer.

Bolt potentiometer shaft to

back of panel.

Solder leads to potentiometer.

9h.

Replace top cover.

5-48

ADJUSTMENT AND CALIBRATION

5-49

Adjustment and calibration maybe required

after performance testing, troubleshooting,

and replacement. thataffectthe operation ofthefaulty circuit and no others. Table 5-8 summarizes the adjustments and calibrations contained in the following paragraphs.

5-50

controls and indicators.)

5-51

brationmarkonthe meter scale whenthe instrument

is at normal operating temperature, resting in its normal operating position, and the instrument is turned off. Tozero-set the meter proceedas follows:

up to normal operating temperature (about 20 minutes).

for power supply capacitors to dischargecompletely,

METER ZERO (See

The meter pointer mustrest onthe zero cali-

Turnon instrument and allow it to come

b. Turn the instrument off. Waittwo minutes c.

Rotate adjustment screw on front of meter clockwise until the meter pointer is to the left of zero and further clockwise rotation will move the pointer upscale towards zero.

Perform only those adjustments

Figure 3-1

orrepair

for

5-53 To

follows:

switch to highest current position and, with supply on and no load connected, adjust R63 until front panel meter reads zero.

ply, observing correct polarity. range and turn on supply. Adjust VOLTAGE control

until differential

imum rated output voltage. dicates maximum rated output voltage.

5-54

for controls and indicators. )

5-55 To

follows:

leaving switch S1 open.

set METER switch to highest current range.

trols until differential

cates exactly the maximum rated output current.

5-56

RENT (See indicators. )

5-57 To

racy, proceed as follows:

and -S terminals. jumper between terminals A6 and -S. and turn on supply.

resistor R6 with decade resistance box.

calibrate voltmeter tracking, proceedas “ Toelectrically zero meter, set METER

b. Connect differential

Set METER switch to highest voltage

voltmeter reads exactly the max-

d. Adjust R72 until front panel meter also in-

AMMETER TRACKING (See

calibrate ammeter tracking proceed as

Connect test setup shown on

b. Turn VOLTAGE control fully clockwise and

Turn on supply and adjust CURRENT con-

c. d. Adjust R56 until front panel meter indi-

CONSTANT VOLTAGE PROGfWf’4kiING CUR-

Figure 3-1

calibrate the zero volt programming accua. Connect differential b. Short out voltage controls by connecting c.

Rotate CURRENT controls fully clockwise

d, Observe reading on differential

If it is more positive than O volts, shunt

voltmeter across sup-

Figure 3-1

Figure 5-4

voltmeter reads 1. OVdc.

for controls and

voltmeter between +S

voltmeter.

5-22

Page 55

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

f. Adjust decade resistance until differential voltmeter reads zero, then shunt R6 with resistance value equal to that of the decade resistance.

g. If reading of step d is more negative than

O volts, shunt resistor R8 with the decade resist-

ance box.

h. Adjust decade resistance until differential voltmeter reads zero then shunt R8 with resistance value equal to that of the decade box.

5-58 To

current, proceed as follows:

terminals -S and A6 on rear barrier strip. Resistor

value to be as follows:

Model

Resistance

(leaving A6 and A7 jumpered) on rear terminal bar-

rier strip. R13. +S and -S and turn on suPply. ferential voltmeter indicates maximum rated output

voltage within the following tolerances: Model No. Tolerance (Vdc)

Mode Tolerance (Vdc)

of appropriate value in R13 position.

5-59

RBNT ( Sae

5.ndicators. )

5-60 To

curac y, proceed as follows:

and -S terminals.

jumper bemeen terminals Al and A5.

and turn on supply.

resistor R25 with a decade resistance box.

tial voltmeter reads zero, then shunt R25 with re-

sistance value equal to that of decade resistance.

O volts, shunt resister R28 with decade resistance.

voltmeter reads zero, then shunt R28 with resistance

value equal to that of decade box.

calibrate the constant voltage programming

a. Connect a O. 1%, ~ watt resistor between

6253A,6284A 6255A, 6289A 6281A 6294A

4Kn

b. Disconnect jumper between A6 and A8

c. Connect a decade resistance in place of

d. Connect a differential e. Adjust decade resistance box so that dif-

6253A, 6284A

*o. 4

1 No.

Replace decade resistance with resistor

CONSTANT CURRENT PROGRAMMING CUR-

Figure 3-1

calibrate the zero current programming aca. Connect differential b. Short out current controls by connecting c. Rotate VOLTAGE control (s) full y clockwise d. Observe reading on differential

If it is more positive than O volts, shunt

f. Adjust decade resistance until differen-

g. If reading of step d is more negative than h. Adjust decade resistance until differential

6281A

l o. 15

8Kn 1.5Kn 18Kn

voltmeter between

6255A, 6289A

+0. 8

6294A

*1. 2

for controls and

voltmeter between +S

voltmeter.

5-61 To

current, proceed as follows:

5-4.

A4 and A5 jumpered). Al and A5.

Model No. Resistance

of R19. range and turn on supply. differential priate value resistor in R19 position.

5-62 5-63

tion capabilities

lows:

tween +S (common) and 33 (positive).

tween supply and input power source.

trol(s) for maximum rated output voltage. indicated by differential

more than the follow ing as input line voltage is varied from 105 to 125Vac:

Model No.

Variation (mVdc) Model No.

Variation (mVdc)

priate value resistor in R46 position.

5-64 5-65 To

as follows:

5-8. Paragraph 5-31.

is as shown in

calibrate the constant current programming a. Connect power supPly as shown in b. Remove strap between A3 and A4 (leaving

Connect a O. 1%, #watt resistor between

Resistor value to be as follows:

6253A, 6284A

1.5Kn 6281A

lKn lKn

d. Connect decade resistance box in place

Set METER switch to highest current

f. Adjust the decade resistance so that the

voltmeter indicates 1.0 + 0.01 Vdc.

Replace decade resistance with appro-

REFERENCE CIRCUIT ADJUSTMENTS Line Recmlation.

a. Connect the differential b. Connect variable voltage transformer be-

Adjust line to 105 Vat.

d. Connect decade resistance in place of R46.

Turn on supply and adjust VOLTAGE con-

e. f. Adjust decade resistance so that voltage

Replace

CONSTANT VOLTAGE TRANSIENT RESPONSE

adjust the transient response, proceed

Connect test setup as shown in b. Repeat steps a through e as outlined in c. Adjust R30 so that the transient response

Figure 5-9.

To adjust the line regula-

the instrument proceed as fol-

voltmeter does not change

6253A, 6284A

0.95

6281A 6294A

1.24

decade resistance with appro-

6255A, 6289A

voltmeter be-

Figure

750*

6294A

6255A, 6289A

0.81

0.75

Figure

5-23/(5-24 blank)

Page 56

Page 57

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-l

A-1/(A-2 blank)

APPENDIX A

REFERENCES

AR 750-58

DA PAM 310-1

SB 11-573

TB SIG-222

TB 43-0116

TB 43-0118

TB 746-10

TM 38-750

TM 740-90-1

Painting, Camouflage Painting and Marking of Army

Material.

Consolidated Index of Army Publications and Blank Forms.

Painting and Preservation Field Use for Electronics

Supplies Available for

Command Equipment.

Solder and Soldering.

Identification of Radioactive Items in the Army Supply System.

Field Instructions for Painting and Preserving Electronics Command Equipment Including Camouflage

Pattern Painting of Electrical Equipment Shelters.

Field Instructions for Painting

and Preserving

Electronics Command Equipment.

The Army Maintenance Management

System (TAMMS).

Administrative Storage of Equipment.

TM 750-244-2

TM 11-6130-416-24P

EE010-BJ-MMA-010/E154 DCDUAL

T.O. 35C1-2-847-4

TM 11-6625-1541-15

TM 11-6625-654-14

TM 11-6625-2568-14

*T.O. 33A1-13-432-1

Procedures for Destruction of Electronics Materiel

to Prevent Enemy Use (Electronics Command).

Organizational, Direct Support and General Support Repair Parts and Special Tools List (Including Depot Repair Parts and Special Tools List) for Power Supply, Dual DC (Hewlett-Packard Model 6255A) (

NSN

6130-00-065-6811!c

Technical Manual True RMS Meter AN/

To be published.

USM

-224

Operator, Organizational, Direct Support, General Support, and Depot Maintenance Manual Including

Repair Parts and Special Tool Lists for Multimeter

AN/USM-223

Operator, Organizational, Direct Support, and General Support Maintenance Manual for CLscilloscope AN/USM-281C (

NSN

6625-00-106-9622).

To be published. Technical Manual:

Oscilloscope AN/

USM

-338

*Refer to Air Force Index NIRT 0-1-31

Page 58

Page 59

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

APPENDIX B

MAINTENANCE

Section I.

B-1.

Golt8ML This appendix provides a summary of the maintenance operations for the DC Power Supply DPR Series, Model 6255A. It authorizes categories of maintenance for specific maintenance functions on repairable items and components and the tools and equipment required to perform each function.

B-2.

Mdntenanoe Concept Two levels of maintenance shall be utilized for the equipment as follows:

Organizational Depot Level.

a. Orgam”zm”on Maintenance. That maintenance which is the responsibility using organization on its assigned equipment. Its phases normally consist of inspecting, lubricating, parts, minor assemblies and subassemblies. level is designated by an O in the Maintenance Category columns in

b. Depot Maintenance. That maintenance which is the responsibility

maintenance activities, serviceable activities facilities, technical skills than are available at the lower level of maintenance. Its phases normally consist of inspection, test, repair, modification, modernization, conversion, overhaul reclamation, or rebuild of parts, assemblies, subassemblies, components, equipment end items, and weapon systems; and the manufacture of critical nonavailable parts. Depot Maintenance is normally accomplished in fixed shops. This level is designated by a Din the Maintenance Category columns in

B-3.

functions for the DC Power Supply DPR Series, Mcxiel 6255A are defined as follows:

a. Inspect. item by comparing its physical, mechanical, and/or electrical through examination.

b. Test. To verify serviceability incipient failure by measuring the mechanical or electrical those characteristics

equipment and personnel of higher

Section II.

Maintenance Funotlon. Maintenance

characteristics

Level

and performed by a

servicing,

and adjusting, and the replacement of

This

Section II.

and performed by designated

augment stocks of

material, and to support lower level

the use of more extensive shop

alteration,

determine the serviceability

with established standards

and to detect

of an

with prescribed standards.

item and comparing

ALLOCATION

INTRODUCTION

c. Service. Operations required periodically

keep an item in proper operating condition, i.e., to clean (decontaminate), paint, or to replenish fuel, lubricants,

fluids, or compressed air supplies.

d. Adjust. by bringing into proper or exact position, or by setting the operating characteristics parameters.

e. Afign. To adjust specified variable elements of an item to bring about optimum or desired performance.

~ Calibrate. to be made or to be adjusted on instruments or test measuring and diagnostic equipments used in precision measurement. Consists of comparisons of two instruments, standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being compared.

g. ZnstaU. The act of emplacing, seating, or fixing into position an item, part, or module (component or assembly) in a manner to allow the proper functioning of the equipment or system.

h. Replace. The act of substituting

like type part, subassembly, or module (component or assembly) for an unserviceable

i. Repair. The application of maintenance

service (inspect, test, service, adjust, align, calibrate, or replace) or other maintenance actions (welding, grinding, riveting, straightening, remachining, or resurfacing) to an item by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or assembly), end item, or system.

j. OverhauL That maintenance effort (service/ action) necessary to restore an item to a completely serviceable/operational maintenance standards (i.e., DM

technical publications.

highest degree of maintenance performed by the

Army. Overhaul does not normally return an item to like new condition.

k. Rebuild. Consists of those services/actions necessary for the restoration equipment to a like new condition in accordance

with original manufacturing standards. Rebuild is

the highest degree of materiel maintenance applied to Army equipment. The rebuild operation includes

preserve, to drain, to

hydraulic

maintain, within prescribed limits,

the specified

determine and cause corrections

one of which is a certified

counterpart.

facing,

restore serviceability

condition as prescribed by

WR) in

Overhaul is normally the

unserviceable

serviceable

appropriate

B-1

Page 60

11-6130-416-14/EE010-BJ-MMA-010/E154

DCDUAL/T.O.35C1-2-847-1

the act of returning to zero those age measurements (hours, miles, etc.) considered in classifying

B-4.

a. Column 1, Group Number. Column 1 lists

group numbers, the purpose of which is to identify components, assemblies, subassemblies, modules with the next higher assembly.

b. Column 2, ComponentLAssembly. Column 2

contains the noun names of components, assemblies, subassemblies,

maintenance is authorized.

c. Column 3, Maintenance Function. Column 3

lists the functions to be performed on the item

listed in Column 2. maintenance functions, it is solely for the purpose

of having the group numbers in the MAC and

RPSTL

d. Column 4, Maintenance Category. Column 4

specifies by the listing of a worktime figure in the appropriate subcolumn(s), maintenance authorized to perform the function listed in Column .9. This figure represents the active time required to perform that maintenance function at the indicated category of maintenance.

If the number or complexity of the tasks within the listed maintenance function vary at different maintenance categories, figures will be shown for each category. The number of task-hours specified by the worktime figure represents the average time required to restore an item (assembly, subassembly, component, module, end item or system) to a serviceable

condition under typical field operating conditions. This time includes preparation time,

troubleshooting

control time in addition to the time required to

perform the specific tasks identified for the maintenance functions authorized in the maintenance allocation chart. Subcolumns of Column 4 are as follows:

c o

Army equipments/components.

Column Entries.

and modules for which

When

coincide.

time, and quality assurance/quality

Operator/Crew Organizational

items are listed without

the lowest level of

appropriate worktime

and

Direct Support

General Support

Depot.

e. Column 5, Tools and Equipment. Column 5 specifies, individual ~ools), and special tools, test, and support equipment required to perform the designated function.

alphabetic code which leads to the remark in

Section IV,

opposite the particular code,

B-5.

(Section III).

Code. The numbers in this column coincide with

the numbers used in the tools and equipment column of the applicable tool or test equipment for the maintenance functions.

column indicate the maintenance category allocated the tool or test equipment.

name and nomenclature of the tools and test equipment required to perform the maintenance functions.

lists the National/NATO stock number of the specific tool or test equipment.

manufacturer’s the Federal Supply Code for manufacturers (5digit) in parentheses.

B-6.

appropriate explanatory information necessary to clarify items

appearing in

code, those

f Column 6, Remarks. Column 6 contains an

Remarks, which is pertinent to the item

TOOI and Test Equipment Requlremente

a. Tool or Test Equipment Reference

MAC.

b. Maintenance Category. The codes in this

c. Nomenclature. This column lists the noun

d. NationaUNATO Stock Number. This column

e. Tool Number. This column lists the

part number of the tool followed by

Remarks

a. Reference Code. This code refers to the b. Remarks. This column provides the required

(Section IV).

item in

Section II.

common

The numbers indicate the

Section II,

tool sets (not

Column 6.

B-2

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11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.0035C1-2-847-1

Group

Number

SECTION II.

DC POWER SUPPLY DPR SERIES, MODEL 6255A

(2)

Component/Assembly

POWER SUPPLY,

6255A

PRINTED CIRCUIT BOARDS

MAINTENANCE

FOR

(3)

Maintenance

Function

INSPECT TEST REPAIR

TEST

ADJUST CALIBRATE

OVERHAUL

REBUILD

REPAIR

ALLOCATION

Maintenance

APPENDIX C

COMPONENTS

Section I.

C-1

SCOpe. This appendix lists integral

components of and basic issue items for the HP 6255A to help you inventory items required for safe and efficient operation.

C-2

Geneml. This Components of End Item List is

divided into the following sections:

Section II.

Item. These items, when assembled, comprise the

HP 6255A and must accompany it whenever it is transferred or turned in. The illustrations you identify these items.

Section III.

minimum essential items required to place the HP 6255A in operation, to operate it, and to perform

emergency repair. Although shipped separately

packed they must accompany the HP 6255A during operation and whenever it is transferred between accountable officers. The illustrations with hard-to-identify authority to requisition TOE/MTOE authorization

C-3.

Explanation of Columns.

a. Illustration.

number of the illustration shown.

Integral Components of the End

will help

Basic Issue Items. These are the

will assist you

items. This manual is your

replacement B II, based on

the end item.

This column is divided as follows:

(1) Figure Number. Indicates figure

which the item is

END ITEM LIST

INTRODUCTION

(2) Item Number. The number used

to identify item called out in the illustration.

b. National Stock Number. Indicates the

National stock number assigned to the item and which will be used for requisitioning.

c. Part Number. Indicates the primary number used by the manufacturer, which controls the design and characteristics its engineering drawings, specifications, and inspection requirements to identify an item or range of items.

d. Description.

and, if required, a minimum description to identify the item,

e. Location. The physical location of each item listed is given in this column. The lists are designed to inventory all items in one area of the major item before moving on to an adjacent area.

f Quantity Required (Qty Reqd). This column

lists the quantity of each item required for a complete major item.

g. Quantity. This column is left blank for use during an inventory. Under the Rcv’d column, list the quantity you actually receive on your major item. The Date columns are for your use when you inventory the major item at a later date, such as for shipment to another site.

the item by means of

standards,

Indicates the Federal item name

Wge

(1)

Illustration

(a)

c-1

Item

:’

SECTION II.

(2)

National

Stock

Number

(3)

Part No.

6255A

INTEGRAL COMPONENTS

(4)

Description

Power supply (28480)

(5)

Location

C-1

OF END

(6)

Usable

Code

(7)

Qty

Reqd

ITEM

Rcv’d

(8)

Quantity

Date Date Date

Page 64

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Illustration

(a)

. .

(1)

(b)

Itam

I I

(2)

National

Stock

Number

(3)

Part No.

SECTION III.

(4)

Description

No Basic Issue Items

BASIC ISSUE ITEMS

(5)

Location

(6)

Usable

Code

(7)

Qty

Reqd

Rcv’d Date

(8)

Quantity

Date

Figure C-1.

Power Supply HP6255A

C-2

Page 65

TM 11-6130-416-14/EE010-BJ-MMA-010/E154

DCDUAL/T.O.35C1-2-847-1

APPENDIX D

ADDITIONAL AUTHORIZATION LIST

Section I. INTRODUCTION

D-1. SOops. This appendix lists additional items you are authorized for the support of the HP 6255A.

D-2. Gml. This list identified items that do not

have to accompany the HP 6255A and that do not

authorized to you by CTA, MTOE, TDA, or JTA. D-3. Explanation of Listing. National stock

numbers, descriptions, and quantities are provided to help you identify and request the additional items you require to support this equipment.

have to be turned in with it. These items are all

SECTION II. ADDITIONAL AUTHORIZATION LIST

(1)

(2)

Description

National

Stock

Part Number & FSCM

Usable on Code

(3)

U/M

(4)

Additional Authorized Items

D-l/(D-2 blank)

Page 66

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

APPENDIX E

EXPENDABLE

E-1

scope. This appendix lists expendable

supplies and materials you will need to operate and maintain the HP 6255A. These items are authorized-to Items (Except Medical, Class V, Repair Parts, and Heraldic Items).

E-2.

a. Column 1 – Ztem Number. This number is

assigned to the entry in the listing and is referenced in the narrative instructions (e.g., “Use cleaning compound, item 5,

b. Colums 2 – Level. This column identifies

lowest level of maintenance that requires the listed item.

c o

you by CTA 50-970, Expendable

Explanation of Columns.

identify the material

Operator/Crew Organizational Maintenance

Direct Support Maintenance

SUPPLIES

Section I.

App. D").

the

INTRODUCTION

AND MATERIALS

General Support Maintenance

c. Column 3 – National Stock Number. This is the National stock number assigned to the item; use it to request or requisition

d. Column 4 – Description.

Federal item name and, if required, a description to identify the item. The last line for each item indicates the part number followed by the Federal Supply Code for Manufacturer (FSCM) in parentheses, if applicable.

e. Column 5 – Unit of Measure (U/M). Indicates the measure used in performing the actual maintenance function. This measure is expressed by a two-character in, pr). If the unit of measure differs from the unit

of issue, requisition

satisfy your-requirements.

alphabetical

LIST

the item.

Indicates the

abbreviation (e.g., ea,

the lowest unit of issue that will

Item

Number

Level

(3)

National

Stock

Number

8305-267-3015

6810-00-292-9625

(4)

Description

Cloth, cotton, cheesecloth

Trichlorotrifluoroethane

0T620 (81349)

(5)

Unw

Roll

E-1/(E-2 blank)

Page 68

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

INDEX

Subject

Accuracy, Rated Output and Meter

Adjustment and Calibration

Ammeter Tracking

Constant Current Programming Current

Constant Voltage Programming Current

Constant Voltage Transient Response

Crowbar

Meter Zero

Reference Circuit

Voltmeter Tracking

Zero Current Programming

Paragraph

5-13

5-54

5-61

5-58

5-64

Appendix A

5-50

5-62

5-52

5-60

Zero Volt Programming

Ammeter

Connections

Tracking

Amplifiers

Error

Meter

Mixer

5-57

4-40,41

5-54

4-29,30

4-39

4-29

Index-1

Page 70

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Analysis

Detailed Circuit

Trouble

Auto Parallel

Auto-Series

Connections

Operations

Auto-Tracking Operation

Block Diagram Discussion

INDEX

- Continued

Paragraph

4-8

5-41

3-41

3-37

1-5

1-5, 3-42

4-1

Cable, Power

Calibration Adjustment

Capacitance, Output

Check

Electrical

Mechanical

Circuit

Analysis

Constant

Current Input

Voltage Input

Meter

Reference

2-17

5-48

3-48

2-5

2-3

4-8

4-20

4-16

4-34

4-31

Index-2

Page 71

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

INDEX - Continued

Subject

Reference Adjustment

Voltage Clamp

Connecting Load

Connections

Auto-Parallel

Auto-Series

230V Operation

Front Panel Terminal

Meter

Normal Parallel

Normal Series

Paragraph

5-62

4-25

3-11

3-41

3-37

2-15

5-6

4-40, 41

3-40

3-36

Constant Current

Input Circuit

Programing Current

Remote Programming

Tests

Constant Voltage

Input Circuit

Programming Current

Remote Programming

Tests

Transient Response

Controls and Indicators

3-9

4-20

5-59

3-24

5-34

3-7

4-16

5-56

3-17

5-12

5-64

3-1

Index-3

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Crowbar

Description and Operation

Trip Voltage

Current Reverse Loading

Description

Divider Voltage

Electrical Check

INDEX

- Continued

Paragraph

1-9, 3-55

3-53

1-1

4-27

2-5

Error Amplifiers

Equipment, Required Test

Feedback Loop

Front Panel

Operating Controls and Indicators

Terminal Connections

General Measurement Techniques

Indicators, Controls

Information Ordering

Initial Inspection

4-29, 30

5-8

4-9

3-1

5-6

5-3

3-1

RPSTL

2-1

Index-4

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Input Circuit

Constant Current

Constant Voltage Input Power Requirements

Installation Data

Instrument Identification

Introduction

Maintenance

Replaceable Parts

INDEX

- Continued

Paragraph

4-20 4-16

2-13 2-7

1-10

5-1 6-1

Line Regulation

Load Regulation Location

Installation

Pulse Reverse Current Reverse Voltage

Loop, Feedback

Maintenance

Maintenance Allocation Chart

5-17, 36 5-16, 35

2-9

3-46 3-53

3-51

4-9

5-1

Appendix B

Measurement Techniques, General

Mechanical Check

5-3

2-3

Index-5

Page 74

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Meter

Accuracy

Amplifier

Circuit

Zero

Mixer Amplifier

Mode (s)

Normal Operating

Operating

INDEX

- Continued

Paragraph

5-13

4-39

4-34

5-50

4-29

3-5

3-3

Optional Operating

Mounting, Rack

Normal Operating Mode

Ordering

Information

Replacement Parts

Options

Operating

Controls and Indicators

Modes

Normal Mode

3-16

2-11

3-5

RPSTL

1-8

3-1

3-3

3-5

Optional Modes

3-16

Index-6

Page 75

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Operation

Auto-Parallel

Auto-Tracking

Supply Beyond

Rated Output

Parallel

Series

Ordering Information

Output

Capacitance

Impedance

INDEX

- Continued

Paragraph

3-41

3-42

3-14

3-39

3-35

RPSTL

3-48

5-33

Overall Block Diagram Discussion

Parallel Operation

Auto

Performance Test

Power

Cable

Input Requirements

Programming Current

Constant Current

Constant Voltage

Programming, Remote

Constant Current

4-1

3-39

3-41

5-10

2-17

2-13

5-59

5-56

3-24

Constant

Voltage

3-17

Index-7

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Programming Speed

Principles of Operation

Detailed Circuit Analysis

Overall Block Diagram Discussion

Pulse Loading

Rack Mounting

Rated Output and Meter Accuracy

Recovery Time, Transient

Reference Circuit

INDEX

- Continued

Paragraph

5-32

4-8

4-1

3-46

2-11

5-13

5-31

4-31

Adjustments

References

Regulation

Line

Load

Regulator Series

Remote Programming

Constant Current

Constant Voltage

Remote Sensing

Repackaging for Shipment

Repair and Replacement

Required Test Equipment

5-62

Appendix A

5-17, 36

5-16, 35

4-14

3-24

3-17

3-30

2-20

5-46

5-8

Index-8

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

Subject

Resistance Programming

Voltage

Current

Reverse Loading

Current

Voltage

Ripple and Noise

Measurements

Sensing, Remote

INDEX

- Continued Paragraph

3-19

3-26

3-53

3-51

5-18, 19, 37

5-21, 38

3-30

Series

Operation

Regulator

Simplified Schematic

Shipment, Repackaging for

Special Operating Considerations

Specifications

Techniques, General Measurement

Test(s)

Constant Current

Constant Voltage

Equipment Required

3-35

4-14

4-5

2-20

3-45

1-6

5-3

5-34

5-12

5-8

Performance

5-10

Index-9

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

INDEX

Subject

Tool and Test Equipment Requirements

Tracking

Ammeter

Auto

Voltmeter

Transient

Recovery Time

Response

Trouble

Analysis

- Continued

Paragraph

Appendix B

5-54

3-42

5-52

5-31

5-64

5-41

Shooting

Voltage

Clamp Circuit

Constant

Input Circuit Constant

Programming Current, Constant

Remote Programming, Constant

Reverse Loading

Tests Constant

Voltmeter Tracking

5-39

4-25

3-7

4-16

5-56

3-17

3-51

5-12

5-52

Index-10

Page 79

Page 80

Page 81

Page 82

Page 83

Page 84

Page 85

Page 86

Page 87

By Order of the Secretary

of the Army, the Navy, and the Air Force

Official:

ROBERT M. JOYCE

Major General United States Army

The Adjutant General

Official:

JAMES P. MULLINS

General USAF, Commander, Air Force

Logistics Command

E. C. MEYER

General United States Army

Chief of Staff

G. B. SHICK

Rear Admiral, United States Navy

Commander, Naval Electronic

Systems Command

CHARLES A. GABRIEL, General USAF

Chief of Staff

DISTRIBUTION :

To be distributed in accordance with Special List.

Page 88

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TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

FO-1. 6255A Schematic Diagram

Page 90

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

FO-2. Parts Location/Interconnection

Diagram (Sheet 1 of 3)

Page 91

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

FO-2. Parts Location/Interconnection

Diagram (Sheet 2 of 3)

Page 92

TM 11-6130-416-14/EE010-BJ-MMA-010/E154 DCDUAL/T.O.35C1-2-847-1

FO-2. Parts Location/Interconnection

Diagram (Sheet 3 of 3)

Page 93

Page 94

PIN: 052756-000

Page 95

HP 6255a schematic

Specifications and Main Features

Frequently Asked Questions

User Manual

WARNING

TABLE OF CONTENTS

SECTION I

SECTION II

SECTION III

Figure 3-1

SECTION IV

SECTION V

Figure 5-7

Figure 5-12

Table 5-7

APPENDIX A

APPENDIX B

APPENDIX C

APPENDIX D

APPENDIX E

INDEX