HP (Hewlett-Packard) 6205B User Manual

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TM 11-6625-2965-14&P

TECHNICAL MANUAL

OPERATOR’S ORGANIZATIONAL

DIRECT SUPPORT AND GENERAL SUPPORT

MAINTENANCE MANUAL

[INCLUDING REPAIR PARTS

AND SPECIAL TOOLS LISTS]

POWER SUPPLY PP-7548/U

(HEWLETT-PACKARD MODEL 6205B]

[NSN 6625-00-437-4861]

HEADQUARTERS, DEPARTMENT OF THE ARMY

25 FEBRUARY 1980

WARNING

HIGH VOLTAGE is used during the performance of maintenance as instructed in this manual. DEATH ON CONTACT may result if personnel fail to observe safety precautions.

DO NOT ATTEMPT to make internal connections or perform adjustments unless another person, capable of performing first aid, is present.

For electric shock protection, use only extension cord and power receptacles with a safety-ground connector, or otherwise connect the chassis to a safety ground.

CERTIFICATION

The Hewlett-Packard Company certifies that this instrument was thoroughly tested and inspected and found to meet its published specifications when it shipped from the factory. The Hewlett-Packard Company further certifies that its calibration measurements are traceable to the U.S. National Bureau of Standards to the extent allowed by the Bureau’s calibration facility.

Was

WARRANTY AND ASSISTANCE

All Hewlett-Packard products are warranted against defects in materials and workmanship. This warranty applies for one year from the date of delivery, or, in the case of certain major components listed in the operating manual, for the specified period. We will repair or replace products which prove to be defective during the warranty period. No other warranty is expressed or implied. We are not liable for consequential damages.

TM 11-6625-2965-14&P

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

TECHNICAL MANUAL

HEADQUARTERS

DEPARTMENT OF THE ARMY

No. 11-6625-2965-14&P

OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT AND

GENERAL SUPPORT MAINTENANCE MANUAL

(INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS)

ASHINGTON, DC, 25 February 1980

POWER SUPPLY PP-7548/U (HEWLETT-PACKARD MODEL)

(NSN 6625-00-437-4861)

REPORTING OF ERRORS

OU can improve this manual by recommending improvements using DA Form 2028-2

located in the back of the manual. Simply tear out the self-addressed form, fill it out as shown on the sample, fold it where shown, and drop it in the mail.

If there are no blank DA Forms 2028-2 in the back of your manual, use the standard DA Form 2028 (Recommended Changes to Publications and Blank Forms) and forward to the Commander, US Army Communications and Electronics Materiel Readiness Command, ATTN: DRSEL-ME-MQ, Fort Monmouth, NJ 07703.

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. Since the manual was not prepared

in accordance with military specifications, the format has not been structured to consider levels of

maintenance.

TABLE OF CONTENTS

TM 11-6625-2965-14&P

Section Page No.

O INSTRUCTIONS . . . . . . . . . . . . . . . . 0-1

0-l Scope

0-1

0-2 Indexes of Publications 0-1 0-3 Maintenance Forms,

Records and Reports

0-1

0-4 Reporting Equipment

Section

3-38

Special Operating Con-

siderations

Pulse Loading

3-39 3-41

Output Capacitance

3-43

Reverse Voltage Loading

3-45

Reverse Current Loading

Improvement Recommen-

dations (EIR)

0-5 Administrative Storage 0-1

0-6 Destruction of Army

Electronics Materiel 0-1

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

1-1 Description 1-6 Specifications 1-8 Options 1-10 Accessories 1-12 Instrument and Service Man-

ual Identification

1-15 Ordering Additional Manuals 1-2

II INSTALLATION

2-1

Initia1 Inspection Mechanical Check

2-3

Electrical Check

2-5

Installation Data

2-7

Location

2-9

Outline Diagram

2-11

Rack Mounting

2-13 2-17

Input Power Requirements

2-19

Connections for 230 Volt

Operation

Power Cable

2-21 2-24

Repackaging for Shipment

I I I OPERATING INSTRUCTIONS . . . . . . . . 3-1

3-1

Turn-on Checkout Procedure

3-3

Operating Modes

3-5

Norma1 Operating Mode

3-7

Constant Voltage

3-9

Changing Current Limit

3-11

Connecting Load

3-14

Operation Beyond Norma 1

Rated Output

3-16

Optional Operating Modes

3-17

Remote Programming, Con-

stant Voltage

3-25

Remote Sensing

3-30

Series Operation

3-35

Auto-Tracking Operation

. . . . . . . . . . . . . . . . . . .

0-1

1-1 1-1 1-1 1-2

1-2

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

2-3 2-3 2-3

3-1 3-1

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

3-2 3-2

3-2 3-3 3-4 3-5

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

4-1

Overall Description 4-8 Detailed Circuit Analysis 4-9 Feedback Loop 4-13 Series Regulator 4-15 Constant Voltage Comparator 4-2 4-19 Error Amplifier and Driver 4-22 Current Limit Circuit 4-26 Reference Circuit

4-29 Meter Circuit

V MAINTENANCE

5-1

Introduction

5-3

General Measurement

Techniques

5-8

Test Equipment Required

Performance Test

5-10 5-12

Constant Voltage Tests

5-38

Output Impedance

Troubleshooting

5-48 5-53

Overa11 Troubleshooting

Procedure

5-58

Repair and Replacement

5-60

Adjustment and Calibration

Meter Zero

5-62 5-64

Ammeter Tracking

5-66

Constant Voltage Programming

Current

5-69

Reference Circuit Adjustments

5-71

Constant Voltage Transient

Recovery Time

5-73

Current Limit Adjustment

VI REPLACEABLE PARTS . . . . . . . . . . .

6-1 Introduction 6-1 6-4 Ordering Information

APPENDIX A

B C

VII CIRCUIT

Page No.

. . . . . . . . . . . . . . . . . . .

References

Components of End

Item

Maintenance

Allocation

Manual

Changes

DIAGRAMS

backdating

........... 7-1

3-6 3-6 3-6 3-6 3-6

4-1 4-2

4-2

4-3 4-3

4-3

5-1 5-1

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

5-9 5-12 5-13 5-13 5-13

5-13

5-15

5-15 5-15

. . . . 6-1

6-1

A-1 B-1

C-1

TM 11-6625-2965-14&P

LIST OF ILLUSTRATIONS

Figure

2-1 2-2 2-3 2-4 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9

3-10

4-1

Page No. Outline Diagram 2-1 Rack Mounting, Two Units 2-2 Rack Mounting, One Unit 2-2 Primary Connections 2-3 Front Panel Controls and Indicators 3-1 Normal Strapping Pattern Current Limit Alteration Remote Resistance Programming 3-3 Remote Voltage Programming Remote Sensing 3-3 Norma I Series Connections 3-4

Auto-Series, Two and Three Units 3-4 Auto-Parallel, Two and Three

Units

Auto-Tracking, Two and Three

Units 3-5

Overa11 Block Diagram 4-1

3-1 3-2

3-3

3-5

LIST OF TABLES

Figure

4-2

5-1 5-2

5-3 5-4

5-5 5-6 5-7 5-8

5-9

5-10 5-11

Page No.

Multiple Range Meter Circuit,

Simplified Schematic Front Panel Terminal Connections 5-1 Output Current Measurement

Technique Differential Voltmeter Substitute,

Test Setup Output Current, Test Setup 5-4 Load Regulation, Test Setup

CV Ripple and Noise, Test Setup 5-5 CV Noise Spike, Test Setup Transient Recovery Time,

Test Setup

Transient Recovery Time,

Waveforms Output Impedance, Test Setup Servicing Printed Wiring Boards

4-4

5-1 5-2

5-4 5-6

5-7

5-7 5-8 5-14

Table

1-1 Specifications 5-1 Test Equipment Required 5-2 Reference Circuit Troubleshooting 5-3 Overall Trouble shooting 5-9 5-4 High Output Voltage Troubleshooting 5-5 Low Output Voltage Troubleshooting 5-6 Selected Semiconductor Characteristics 5-7 Checks and Adjustments After Replacement of Semiconductor Devices 5-12

6-1 Reference Designators 6-2 Description Abbreviations 6-3 Code List of Manufacturers 6-4 Replaceable Parts

Page No.

1-3 5-2 5-9

5-11 5-11 5-12

6-1

6-2

6-5

iii

SECTION O

INSTRUCTIONS

TM 11-6625-2965-14&P

0-1.

Model 6205) having serial prefix number 7L2301 and up. For serial prefixes below 7L2301 refer to Appendix E.

inclusion of change page.

0-2.

whether there are new editions , changes, or additional publications pertain-

ing to the equipment.

modification work orders (MWO

0-3.

the Army forms and procedures used for equipment maintenance will be those

described by TM 38-750, The Army Maintenance Management System,

DD Form 6 (Packaging Improvement Report) as prescribed in AR 700-58/ NAVSUPINST 4030.29/AFR 71-12/MCO P4030.29A, and DLAR 4145.8.

SCOPE

This manual applies directly to Power Supply PP-7548/U (Hewlett-Packard

For serials above 7L4450 check for

INDEXES OF PUBLICATIONS

DA Pam 310-4.

DA Pam 310-7.

MAINTENANCE FORMS, RECORDS AND REPORTS

Reports of Maintenance and Unsatisfactory Equipment.

Report of Packaging and Handling Deficiencies.

Refer to the latest issue of DA Pam 310-4 to determine

Refer to DA Pam 310-7 to determine whether there are

) pertaining to the equipment.

Department of

Fill out and forward

Discrepancy in Shipment Report (DISREP) (SF 361). Fill out and

forward Discrepancy in Shipment Report (DISREP) (SF 361) as prescribed in

AR 55-38/NAVSUPINST 4610.33B/AFR 75-18/MCO P461O.19C and DLAR 4500.15.

0-4.

Send us an EIR. don’t like about your equipment. Tell us why a procedure is hard to perform. Deficiency Report). Electronics Materiel Readiness Command and Fort Monmouth, ATTN: DRSEL-ME-

MQ, Fort Monmouth, New Jersey 07703. We'll send yOu a reply.

0-5.

shall be in accordance with paragraph 2-5.

0-6.

accordance with TM 750-244-2.

REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS(EIR)

If your Power Supply PP-7548/U (HP-6205) needs improvement, let us know.

You, the user,

Mail it to Commander, US Army Communications and

ADMINISTRATIVE STORAGE

Administrative storage of equipment issued to and used by Army activities

DESTRUCTION OF ARMY ELECTRONICS MATERIEL

Destruction of Army electronics materiel to prevent enemy use shall be in

are the only one who can tell us what you

Let us know why you don’t like the design.

Put it on an SF 368 (Quality

0-1

TM 11-6625-2965-14&P

1-1 DESCRIPTION

1-2

This power supply, Figure 1-1, is completely transistorized and suitable for either bench or relay rack operations, The dual supply consists of two independently controlled dual range sections; both identical to the other. Each section can fur-

nish either a 0-40 Volt output at 300mA or a 0-20 Volt output at 600mA. Each section has its own front panel meter and operating controls, The oper-

ating modes (40V or 20V) are selected by means of the front panel RANGE switches, The VOLTAGE controls permit each output voltage to be continuously

adjusted throughout either output range.

may be programmed from a remote location by means of an external voltage source or resistance.

b. Remote Sensing. The degradation in regulation which would occur at the load because of the voltage drop which takes place in the load leads can be reduced by using the power supply in

the remote sensing mode of operation.

c. Series and Auto-Series Operation, Power supplies may be used in series when a higher output voltage is required in the voltage mode of operation or when greater voltage compliance is required in the constant current mode of operation,

Auto-Series operation permits one knob control of the total output voltage from a “master” supply.

d. Parallel and Auto-Parallel Operation, The power supply may be operated in parallel with a

similar unit when greater output current capability is required. knob control of the total output current from a “master” supply.

e. Auto-Tracking.

used as a “master” supply, having control over one

(or more) “slave”

ages for a system.

1-6 SPECIFICATIONS

Auto-Parallel operation permits one

The power supply may be

supplies that furnish various volt-

Figure 1-1. DC Power Supply, Model 6205B

1-3 Both sections of the supply are of the regulated, Constant Voltage/Current Limiting, type. Each section is fully protected from overloads by the fixed current limit which is set by means of an

internal adjustment.

1-4 Both front and rear terminals are available

for each section. Either the positive or negative terminals may be grounded or the supply can be

operated at up to a maximum of 300 Volts off ground.

Each meter can be used to measure either output

voltage or output current in one of two ranges. The

voltage or current ranges are selected by the ap-

plicable METER switch on the front panel.

1-5 Two sets of programming terminals, located at the rear of the unit, allow ease in adapting to the many operational capabilities of the supply. A brief description of these capabilities is given below:

a, Remote Programming,

The power supply

1-7 Detailed specifications for the power supply

are given in Table 1-1.

1-8 OPTIONS

1-9 Options are factory modifications of a standard instrument that are requested by the customer. The following options are available for the instru-

ment covered by this manual, Where necessary, de-

tailed coverage of the options is included through-

out the manual.

Option No.

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

nettability.

Overvoltage_Protection_“Crowbar”: A completely separate circuit for protecting delicate loads against power

supply failure or operator error. This independent device monitors the output voltage and within 10µsec imposes a virtual short-circuit (crowbar) across

the power supply output if the preset

Description

TM 11-6625-2965-14P

trip voltage is exceeded. When Option 11 is requested by the customer the device is connected at the factory.

Trip Voltage Range: 2.5 to 44 Volts, screwdriver adjustable.

Detailed coverage of Option 11 is included in Appendix A at the rear of manuals that support power supplies containing Option 11.

1-10 ACCESSORIES

1-11 The accessories listed in the following chart may be ordered with the power supply or separately from your local Hewlett-Packard field sales office

(refer to list at rear of manual for addresses).

Three Digit Graduated Decadial

Voltage Control: Control that replaces

coarse and fine voltage controls permitting accurate resettability.

230Vac Input: shipped is wired for l15Vac input. Option 28 consists of reconnecting the input transformer for 230Vac operation.

Supply as normally

14523A

1-12 INSTRUMENT AND SERVICE MANUAL

IDENTIFICATION

1-13 Hewlett-Packard power supplies are identified 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 respectively, with “I” omitted. The third part is the power supply serial number.

1-14 If the serial number prefix on your power supply does not agree with the prefix on the title page of this manual, change sheets are included to update the manual. Where applicable, backdating information is given in an appendix at the

rear of the manual.

ORDERING ADDITIONAL MANUALS

1-15

Rack Kit for mounting two 3½” high

supplies. (Refer to Section II for de-

tails.)

C05

14513A

Description

8” Black Handle that can be attach-

ed to side of supply.

Rack Kit for mounting one 3½” high supply. (Refer to Section II for details.)

1-16

One manual is shipped with each power supply, Additional manuals may be purchased from your local Hewlett-Packard field office (see list at rear of this manual for addresses). Specify the model number, serial number prefix, and Part number provided on the title page.

1-2

Table 1-1.

Specifications

TM 11-6625-2965-14&P

INPUT:

l15Vac ±10%, single phase, 48-440 Hz.

OUTPUT:

Two independent outputs, each of which can be set at either 0-40 Volts @ 0.3 Amp or 0-20 Volts @ 0.6 Amp.

LOAD REGULATION:

Less than 0,01% plus 4mV for a full load to no

load change in output current.

LINE REGULATION:

Less than 0.01% plus 4mV for any line voltage

change within the input rating.

RIPPLE AND NOISE:

Less than 200µVrms 1mV p-p,

TEMPERATURE RANGES:

operating: 0 to 50°C. Storage: -40 to + 750C.

TEMPERATURE COEFFICIENT:

Less than 0.02% plus lmV per degree Centi-

grade. STABILITY.

Less than 0.10% plus 5mV total drift for 8 hours after an initial warm-up time of 30 minutes at constant ambient, constant line voltage, and constant load.

INTERNAL IMPEDANCE AS A CONSTANT VOLT-

AGE SOURCE:

Less than 0.02 ohms from dc to lkHz. Less than 0.5 ohms from lkHz to 1OOkHz. Less than 3.0 ohms from 1OOkHz to lMHz.

TRANSIENT RECOVERY TIME:

Less than 50µsec for output recovery to with-

in 10mV following a full load current change in the output.

OVERLOAD PROTECTION:

A fixed current limiting circuit protects the power supply for all overloads including a direct short placed across the terminals in con-

stant voltage operation.

METERS:

Each front panel meter can be used as either a

0-50 or 0-5 Volt voltmeter or as a 0-0.75 or

0.075 Amp ammeter.

OUTPUT CONTROLS:

RANGE switches select desired operating mode

for each section and coarse and fine VOLTAGE

controls set desired output voltages.

OUTPUT TERMINALS:

Six “five-way” output posts (three for each

section of supply) are provided on the front

panel and two output terminal strips (one per

section) are located on the rear of the chassis. A1l power supply output terminals are isolated from the chassis and either the positive or negative terminals may be connected to the chassis through separate ground terminals located on the output termina1 strips.

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 at-

tached to the rear terminals. Also, provisions are included on the rear termina1 strips for remote sensing.

REMOTE RESISTANCE PROGRAMMING:

200 ohms per Volt.

REMOTE VOLTAGE PROGRAM MING:

1 Volt per Volt.

COOLING:

Convection cooling is employed. The supply

has no moving parts. SIZE:

3~½" H x 12-5/8" D x 8½" W. Two of the units

can be mounted side by side in a standard 19” relay rack.

WEIGHT:

10 lbs, net, 13 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.

1-3

TM 11-6625-2965-14&P

SECTION II

INSTALLATION

2-1 INITIAL INSPECTION

2-2 Before shipment, this instrument was in-

spected and found to be free of mechanical and electrical defects. As soon as the instrument is unpacked, occurred in transit. Save all packing materials until the inspection is completed. If damage is found, a claim should be filed with the carrier. Hewlett-Packard Sales and Service office should be notified.

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.

2-5

inspect for any damage that may have

ELECTRICAL CHECK

2-6 The instrument should be checked against its electrical specifications. Section V includes an “ in-cabinet” performance check to verify proper instrument operation,

2-7 INSTALLATION DATA

2-8 The instrument is shipped ready for bench operation. It is necessary only to connect the instrument to a source of power and it is ready for

operation.

2-9 LOCATION

2-10 This instrument is air cooled. Sufficient

space should be allotted so that a free flow of cooling air can reach the sides and rear of the in-

strument when it is in operation. It should be used in an area where the ambient temperature does not exceed 50°C.

2-11 OUTLINE DIAGRAM

2-12 Figure 2-1 is an outline diagram showing the dimensions of the instrument.

2-13 RACK MOUNTING

2-14 This instrument may be rack mounted in a

standard 19 inch rack panel either alongside a

similar unit or by itself. Figures 2-2 and 2-3 show

Figure 2-1. Outline Diagram

how both types of installations are accomplished.

2-15 To mount two units side-by-side, proceed

as follows:

a. Remove the four screws from the front

panels of both units.

b. Slide rack mounting ears between the

front panel and case of each unit.

c. Slide combining strip between the front

panels and cases of the two units.

d. After fastening rear portions of units together using the bolt, nut, and spacer, replace panel screws.

2-16 To mount a single unit in the rack panel, proceed as follows:

a. Bolt rack mounting ears, combining

straps, and angle brackets to each side of center

2-1

TM 11-6625-2965-14&P

Figure 2-2. Rack Mounting, Two Units

Figure 2-3.

Rack Mounting, One Unit

TM 11-6625-2965-14&P

spacing panels. Angle brackets are placed behind

combining straps as shown in Figure 2-3.

b. Remove four screws from front panel of

unit.

Slide combining strips between front

panel and case of unit.

d. Bolt angle brackets to front sides of case

and replace front panel screws.

2-17 INPUT POWER REQUIREMENTS

2-18 This power supply may be operated from either a nominal 115 Volt or 230 Volt 48-440 Hertz power source. The unit, as shipped from the factory, is wired for 115 Volt operation. The input power required when operated from a 115 Volt 60 Hertz power source at full load is 31 Watts and

0.35 Amperes.

2-19 CONNECTIONS FOR 230 VOLT OPERATION

2-20 Normally, the two primary windings of the

input transformer are connected in parallel for operation from 115 Volt source. To convert the power

supply to operation from a 230 Volt source, the

power transformer windings are connected in series

as follows:

Unplug the line cord and remove the unit

from case.

b. Break the copper between 54 and 55 and also between 50 and 51 on the printed circuit board. The se are shown in Figure 2-4, and are labeled on copper side of printed circuit board.

Add strap between 50 and 55.

d. Replace existing fuse with 1 Ampere,

230 Volt fuse.

normally.

Return unit to case and operate

2-21 POWER CABLE

2-22 To protect operating personnel, the National 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 cable three-prong connector is the ground connection.

2-23 To preserve the protection feature when 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.

2-24 REPACKAGING FOR SHIPMENT

2-25 To insure safe shipment of the instrument, it is recommended that the package designed for the

Figure 2-4.

instrument be used. The original packaging material is reusable. If it is not available, contact your local Hewlett-Packard field office to obtain

the materials. This office will also furnish the address of the nearest service office to which the instrument can be shipped. Be sure to attach a tag to the instrument which specifies the owner, model number, full serial number, and service re-

quired, or a brief description of the trouble,

2-3

Primary Connections

SECTION Ill

OPERATING INSTRUCTIONS

TM 11-6625-2965-14&P

3-1 TURN-ON CHECKOUT PROCEDURE

Figure 3-1.

3-2 The front panel controls and indicators are shown in Figure 3-1.

is described below:

A. Push ON/OFF button

that button lights,

B. Set range switch

mode and meter switch to desired voltage range.

C. Adjust coarse and fine voltage controls

Front Panel Controls and Indicators

The normal turn-on sequence,

① and observe

② to desired operating

③ until desired output voltage is indicated on

meter.

Set meter switch to highest current range

and short

meter.

terminals be used for both sections of supply.

circuit output terminals.

Observe short circuit output current on Remove short and connect load to output

(front or rear),

For Model 6205B, this procedure should

erational capabilities of the supply. A more theoretical description concerning these operational features is contained in Application Note 90 and in various Tech Letters. Copies of these can be obtained from your local Hewlett-Packard field office,

3-5 NORMAL OPERATING MODE

3-6 The power supply is normally shipped with its rear terminal strapping connections arranged for Constant Voltage/Current Limiting, local sensing, local programming, single unit mode of operation. This strapping pattern is illustrated in Figure 3-2. The operator selects a constant voltage output using the front panel controls (local programming, no strapping changes are necessary).

Figure 3-2.

Norma 1 Strapping Pattern

3-3 OPERATING MODES

3-4 The power supply is designed so that its mode of operation can be selected 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 illustrated in this section show the positive terminal grounded, the operator can ground either termina1 or operate the power supply up to 300Vdc off ground (floating). The following paragraphs describe the procedures for utilizing the various op-

3-7 CONSTANT VOLTAGE

3-8 To select a constant voltage output turn on the supply and, with no load connected, adjust the VOLTAGE controls for the desired output volt-

age. To check the current limit, connect an ex-

ternal ammeter across the output of the turn the VOLTAGE controls fully clockwise, and observe the reading. adjusted to approximately 100mA above the current rating of the supply. is not compatible with the anticipated load requirements, the limit can be changed as outlined in the following paragraphs.

3-1

The current limit is factory

If the existing current limit

supply,

TM 11-6625-2965-14&P

3-9 CHANGING CURRENT LIMIT

3-10 The current limit can be varied by adjusting resistor R81, located on the printed wiring board. This adjustment procedure is described in Paragraph 5-74. In Models 6204B and 6206B, the current limit may be reduced to a value lower than that attainable by adjusting R81, by adding an external resistor as shown in Figure 3-3. The approximate value of the external resistance (Rx) can be determined by using the following equation

=1.75

where: I = the output current

R = the internal current sampling resist-

ance for the particular operating mode to be used.

1.75 . the approximate voltage drop across the internal sampling resistance at the current limit crossover point.

NOTE

The power supply’s performance will be somewhat degraded if it is operated too close to (within 10OmA) the current limit crossover point.

3-13 If load considerations require that the output

power distribution terminals be remotely located from the power supply, then the power supply output terminals should be connected to the remote distribution terminals via a pair of twisted or

shielded wires and each load separately connected

to the remote distribution termina1s. For this case, remote sensing should be used (Paragraph 3-25).

3-14 OPERATION BEYOND NORMAL RATED OUTPUT

3-15 Although the supply can deliver greater than the rated output on both the lower and higher voltage ranges without being damaged, it can not be

guaranteed to meet all of its performance specifications.

Generally when operating the supply in this manner, the output is unstable when connected to a load.

When greater than the lower rated

voltage is required, the higher voltage range

should be used.

This range will deliver half as much output current and all specifications will apply as listed in Table 1-1. However, if the line voltage is maintained above its nomina1 value, the

supply will probably operate within specifications

above its rated output.

3-16 OPTIONAL OPERATING MODES

3-17 REMOTE PROGRAMMING, CONSTANT VOLTAGE

A1 A2 A6 A7 A8 A9 -S – GND + +S A10

Figure 3-3.

Current Limit Alteration

3-11 CONNECTING LOAD

3-12 Each load should be connected to the power supply output terminals using separate pairs of

connecting wires.

This will minimize mutual cou-

pling 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. )

3-18 The constant voltage output of the power supply can be programmed (controlled) from a remote location if required. Either a resistance or voltage 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 pickup. The VOLTAGE controls on the front panel are disabled according to the following pro-

cedures.

3-19 Resistance Programming (Figure 3-4). In this mode, the output voltage will vary at a rate determined by the programming coefficient (200

ohms per Volt for Model 6204B and 6205B or 300 ohms per Volt for Model 6206 B). The output voltage will increase by 1 Volt for each 200 ohms (or

300 ohms) added in series with the programming terminals. The programming accuracy is 1% of the programmed voltage. If greater programming ac-

curacy is required, it may be achieved by chang-

ing resistor R13 as outlined in Section V.

3-20 The output voltage of the power supply should be zero Volts ± 20 millivolts when zero ohms is connected across 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 Section V.

3-2

A7 A6 A8 A10+S + GND - –S

Figure 3-4.

PROGRAMMING

RESISTOR

Remote Resistance Programming

3-21 To maintain the stability and temperature coefficient of the power supply, u se programming resistors that have stable, low noise, and low temperature (less than 30ppm per degree Centigrade) characteristics. A switch can be used in conjunction with various resistance values in order to obtain discrete output voltages.

The

switch should have make-before-break contacts to avoid momentarily opening the programming terminals during the switching interval.

TM 11-6625-2965-14&P

programming voltage source should be approximately 1000 ohms if the temperature and stability specifications of the power supply are to be maintained. The programming accuracy is 1% of the programmed voltage.

3-24 Methods of voltage programming with gain are discussed in Application Note 90, Power Supply Handbook; available at no charge from your local

Sales Office.

3-25 REMOTE SENSING (See Figure 3-6)

3-26 Remote sensing is used to maintain good regulation 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 uti-

lizing the strapping pattern shown in Figure 3-6. The power supply should be turned off before changing strapping patterns. The leads from the

+S terminals to the load will carry less than 10

milliamperes 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.

CAUTION

3-22 Voltage Programming (Figure 3-5). Employ the strapping pattern shown on Figure 3-5 for voltage programming.

In this mode, the output

voltage will vary in a 1 to 1 ratio with the pro-

gramming voltage (reference voltage) and the load

on the programming voltage source will not exceed 25 microampere.

A7 A6 A8 A10 +S + GND - -S

REFERENCE

VOLTAGE

Figure 3-5. Remote Voltage Programming

3-23 The impedance (Rx) looking into the external

Observe polarity when connecting the sensing leads to the load.

A7 A6 A8 A10+S + AND– –S

Figure 3-6. Remote Sensing

3-27 For reasonable load lead lengths, remote sensing greatly improves the performance of the supply. However, if the load is located a consid-

erable distance from the supply, added precautions

must be observed to obtain satisfactory operation. Notice that the voltage drop in the load leads sub-

3-3

TM 11-6625-2965-14&P

tracts directly from the available output voltage and also reduces the amplitude of the feedback error signals that are developed within the unit. Because of these factors it is recommended that the drop in each load lead not exceed 1 Volt. If a

larger drop must be tolerated, please consuIt a

sales

engineer.

NOTE

Due to the voltage drop in the load

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

3-28

Another factor that must be considered is

the inductance of long load leads which could affect the stability of the feedback loop and cause oscillation. In these cases, it is recommended that the output capacitor (C20) be physically removed from the power supply and placed across the output terminals.

3-29 Although the strapping patterns shown in

Figures 3-4 and 3-5 employ local sensing, notice that it is possible to operate a power supply simultaneously in the remote sensing and the remote programming modes.

ages 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.

3-32 Auto-Series Connections (Figure 3-8). The Auto-Series configuration is used when it is desirable 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 current limit settings of all series

3-30 SERIES OPERATION 3-31 Normal Series Connections (Figure 3-7).

Two or more power supplies can be operated in

series to obtain a higher voltage than that available from a single supply. When this configuration is used, the output voltage is the sum of the volt-

A7 A6 A8 A10-S + GND – –S

A7 A6 A8 A10 - S + GND – –S

Figure 3-7. Normal Series Connections

Figure 3-8, Auto-Series, Two and Three Units

3-4

units are effective and the current limit for the entire configuration is equal to the lowest current

limit setting. If any of the settings are too low, automatic crossover to current limiting operation

will occur and the output voltage will drop. Re-

mote sensing and programming can be used; however, the strapping arrangements shown in the applicable figures show local sensing and programming.

3-33 In order to maintain the temperature coeffi-

cient and stability specifications of the power

supply, the external resistors (Rx) shown in Figure 3-8 should be stable, low noise, low temperature

coefficient (less than 30ppm per degree Centigrade)

resistors. The value of each resistor is dependant

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

(l/Kp where Kp is the voltage programming coeffi-

cient). The voltage contribution of the slave is

determined by its voltage control setting.

TM 11-6625-2965-14&P

3-34 Auto-Parallel. The strapping patterns for Auto-Parallel operation of two and three plies are shown in Figure 3-9. Auto-Parallel operation permits equal current sharing under all load conditions, and allows complete control of the output current 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, they should be set to maximum to avoid having the slave revert to constant current operation; this would occur if the master output current setting exceeded the slave’s. In Model

6205B, it is necessary to make internal connections

in order to operate the supply in this mode. The

internal connections, specified in Figure 3-9, made to the sampling terminals of the current sam-

pling terminals of the current sampling resistor,

R54 (see Figure 5-2).

power sup-

are

3-5

TM 11-6625-2965-14&P

3-35 AUTO-TRACKING OPERATION (See Figure 3-10)

3-36 The Auto-Tracking configuration is used when 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 posi-

tive supply in the example shown on Figure 3-10).

3-37 The output voltage of the slave is a percentage of the master’s output voltage, and is determined by the voltage divider consisting of R Rx and R

supply, R

Y) and the voltage control of the slave

, where:

M RP

E = Rx+Rp

Turn-on and turn-off 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 of the pow-

er supply, the external resistors should be stable, low noise, low temperature (less than 30ppm per

C) resistors.

3-38

SPECIAL OPERATING CONSIDERATIONS

X (or

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

3-41 OUTPUT CAPACITANCE

3-42 An internal capacitor, acress the output terminals of the power supply, helps to supply highcurrent pulses of short duration during constant voltage operation.

Any capacitance added exter-

nally will improve the pulse current capability, but

will decrease the safety provided by the current

limiting circuit.

A high-current pulse may damage

load components before the average output current is large enough to cause the current limiting circuit to operate.

3-43 REVERSE VOLTAGE LOADING

3-44 A diode is connected across the output terminals.

Under normal 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 capacitors.

3-45 REVERSE CURRENT LOADING

3-39 PULSE LOADING

3-40 The power supply will automatically cross over from constant voltage to constant current operation in response to an increase (over the preset

limit) in the output current, Although the

preset

limit may be set higher than the average output

current high peak currents (as occur in pulse loading) may exceed the preset current limit and cause crossover to occur.

If this crossover limiting is

3-46 Active loads connected to the power supply 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 possible damage to the output capacitor.

To avoid these effects, it is necessary to preload the supply with a dummy load resistor so that the power supply delivers current through the entire operating cycle of the load device.

3-6

SECTION IV

PRINCIPLES OF OPERATION

REFERENCE REGULATOR

CIRCUIT

TM 1 I-6625-2965-14&P

INPuT TRANSFORMER

POWER

NOTE

— DENOTES VOLTAGE

— DENOTES CURRENT

FEEOBACK PATH VOLTAGE

LIMIT PATH

RANGE

SWITCH

(s2)

BIAS

SUPPLY

RECTIFIER

AND

FILTER

Figure 4-1.

IAS

VOLTAGES

SERIES

REGULATOR

DRIVER

AMPL

Overall Block Diagram

CURRENT LIMITING CIRCUIT

CURRENT

sAMPLING

RESISTORS

CONSTANT

INPUT

CIRCUIT

P/o

4-1 OVERALL DESCRIPTION

4-2

Figure 4-1 shows one section of the Model

6205B

dual power supply. The supply

consistsof

two dual range sections; each identical to the other. Each section consists ofa rectifier and fil-

ter, a series regulator, an error amplifier and driver,

a constant voltage input circuit, a

cument limiting

circuit, a reference regulator circuit, a bias supply, and a metering circuit.

Since both sections of the

supply are identical, only one section is described

below.

4-3 The ac line voltage is first applied to the

power transformer, The tap for the appropriate voltage range is selected by S2. The input is then rectified and filtered. This raw dc is then fed to the series regulator which alters its conduction to

obtain the proper regulated dc output voltage. 4-4 Any changes in output voltage are felt by

constant voltage comparator which compares a portion of the output with a fixed reference volts ge.

If a difference exists, the comparator circuit sends a n error signal to the series regulator via the error amplifier and driver stages. This error signal

changes the conduction of the series regulator so that a constant output voltage is maintained.

4-5 Changes

in output current are reflected in the

voltage drop across the current sampling resistor network. If this voltage drop exceeds a preset limit, the current limit transistor conducts, sending a turn-down signal to the series regulator via the driver. This signal changes the conduction of the

4-1

the

TM 11-6625-2965-14&P

series regulator so that the output current is limited to the proper value.

4-6 The reference circuit provides stable reference voltages used in the constant voltage comparator and current limit circuits. The bias circuit provides the less critical bias voltages used in the

supply. 4-7 The meter circuit provides a continuous indi-

cation of output voltage or current in both ranges.

4-8 DETAILED CIRCUIT ANALYSIS

4-9 FEEDBACK LOOP 4-10 The feedback loop functions continuously to

keep the output voltage constant during normal op-

eration of the supply. For purposes of this discussion, assume that the output voltage instantane-

ously rises (goes positive) due to a variation in the

external load circuit. Note that the change may be in the form of a slow rise in the output voltage or a positive going ac signal. An ac signal is coupled

to summing point A6 through capacitor Cl and a dc

voltage is coupled to A6 through R 10.

4-11 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 base of the series transistor(s) via emitter fol-

lower Q4. The negative going input causes the

series transistor(s) to decrease its conduction so that it drops more of the line voltage, reducing the

output voltage to its original level.

4-12 If the external load resistance decreases to

a certain crossover point, the supply will operate

in the current limiting mode. In the current limit

mode, Q1O conducts sending a negative going,

turn-down signal to the series regulator via driver

Q4 .

4-13 SERIES REGULATOR

4-14 The series regulator consists of transistor stage Q7 (and Q6 on Model 6206 B). The regulator serves as a series control element by altering its conduction so that the output voltage is kept constant and the current limit is never exceeded, The conduction of the transistor(s) is controlled by the feedback voltage obtained from driver Q4. Diode

CR11, connected across the regulator circuit, protects the series transistor(s) against reverse voltages that could develop across it during parallel or auto-parallel operation if one supply is turned on

before the other.

4-15 CONSTANT VOLTAGE COMPARATOR

4-16 The circuit consists of the coarse and fine programming resistors (Rl0A and R 10 B), and a differential amplifier stage (Ql and associated com-

ponents). Transistor Q1 consists of two transistors housed in a single package. The transistors have matched characteristics minimizing differential voltages due to mismatched stages. Moreover, drift due to thermal differentials is minimized, since both transistors operate at essentially the same temperature.

4-17 The constant voltage comparator continuously compares a fixed reference voltage with a portion of the output voltage and, if a difference ex-

ists, produces an error voltage whose amplitude and phase is proportional to the difference. error output is fed back to the series regulator, through the (mixer) error and driver 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. voltage constant.

4-18 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 resistors and the current pullout resistors, R12 and R13. Instantaneous changes in output voltage result in

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

The resultant output error voltage is fed back to

the series regulator via the remaining components of the feedback loop. the base Q1A, limits the current through the pro-

gramming resistors during rapid voltage turn-down. Diodes CR1 and CR2 form a limiting network which

prevent excessive voltage excursions from over driving stage Q1A. programming resistors, increases the high frequency gain of the input amplifier. Resistor R1 3, shunt-

ing pullout resistor R12, is factory selected so

that all of the + 6.2 Volt reference is dropped across

R12 and R13. Linear constant voltage programming is assured with a constant current flowing through R1O.

removed to avoid current surges and increase the programming speed.

4-19 ERROR AMPLIFIER AND DRIVER

4-20 The error and driver amplifiers amplify the error signal from the constant voltage comparator circuit to a leve1 sufficient to drive the series regulator transistor(s). current limiting input if Q10, the current limiting transistor, conducts.

The above action maintains the output

Resistor Rl, in series with

Capacitor Cl, shunting the

C20 stabilizes the feedback loop and may be

Driver Q4 also receives a

The

4-2

4-21 Stage Q3 contains a feedback equalizer network, C5 and R30, which provides for high frequency roll off in the loop gain in order to stabilize the feedback loop. Q17 establishes a stable emitter bias potential for error amplifier Q3. Emitter follower transistor(s) Q4 (and Q5) serves as the driver (and predriver) element for the series regula-

tor.

4-22 CURRENT LIMIT CIRCUIT

4-23 The current limit circuit limits the output current to a preset value determined by the setting of R81. Switch S2B selects the proper sampling resistance to maintain an equal voltage drop acress the current sampling network in both ranges.

TM 11-6625-2965-14&P

4-28 The reference circuit consists of series regulating 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 refer-

ence voltage caused by variations in the input line.

Output capacitor C9 stabilizes the regulator loop.

4-29 METER CIRCUIT (Figure 4-2)

4-24 When S2 is set to the 20 Volt position, R54 and R55 are connected in parallel. When S2 is set to the 40 Volt position, the current sampling network consists solely of R54. Note that in the

twenty Volt range, twice as much current can be

delivered as in the forty Volt range. Since the twenty Volt range has a sampling resistance equal to half the value of that for the forty Volt range, an equal sampling resistor voltage drop is obtained in both ranges. This also applies to S2 in the 6206B.

4-25 R81 sets the bias of Q10, and thus, the threshold point at which Q10 conducts and current

limiting begins. If this threshold is exceeded, Q10 begins to conduct, forward biasing CR16 and send-

ing a turn-down signal to the series regulater via

the driver. If the current through the current sampling network decreases below the threshold point, Q10 turns off and no longer affects the operation of

the supply.

4-26 REFERENCE CIRCUIT

4-27 The reference circuit (see schematic) is a feedback power supply similar to the main supply. It provides stable reference voltages which are used throughout the unit. The reference voltages are a 11 derived from smoothed dc obtained from the full wave rectifier (CR22 and CR23) and filter capacitor C10. The +6.2 and -6.2 voltages, which are used in the constant voltage input circuit for comparison purposes, are developed across temperature compensated Zener diodes VR1 and VR2. Resistor

R43 limits the current through the Zener diodes to establish an optimum bias level.

4-30 The meter circuit provides continuous indications of output voltage or current on a single multiple range meter.

The meter can be used either

as a voltmeter or an ammeter depending upon the

position of the METER section of 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

of METER-RANGE switch S2, vari-

ous multiplying resistors and the meter movement. 4-31 When measuring voltage, the meter is placed

directly across the output of the supply between the +S and -S terminals. With the METER section of S2A in the higher voltage position (terminals A2

and A10) multiplying resistors R60, R61, R72, and

the parallel combination of R73 and R87, are in series with the meter. For low output voltages, the

METER switch S2A can be set to the first position

(terminals 1 and 9) which removes R61 from its series position allowing a larger percentage of the

output voltage to be felt acress the meter.

4-32 When measuring current; the meter circuit is

connected across the current sampling resistor network as shown on Figure 4-2 and indicates the output current that flows through the network. The RANGE section S2B connects the appropriate re-

sistance in series with the meter so that its maxi-

mum deflection range is full-scale in the high current (low voltage) operating mode and half-scale in the low current (high voltage) operating mode. This circuit obviates the need for a dual current scale

which would be necessary since the voltages drop-

ped across the current sampling network in both operating modes are equal for proportional currents.

4-3

TM 11-6625-2965-14&P

Figure 4-2.

Multiple Range Meter Circuit, Simplified Schematic

4-4

SECTION V

MAINTENANCE

5-1 INTRODUCTION

5-2 Upon receipt of the power supply, the per-

formance check (Paragraph 5-10) should be made.

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 procedures

(Paragraph 5-48). After troubleshooting and repair

(Paragraph 5-58), perform any necessary adjustments and calibrations (Paragraph 5-60). Before returning 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 ha if-hour warm-up, and read the general information regarding meas-

urement techniques (Paragraph 5-3).

5-3

GENERAL MEASUREMENT TECHNIQUES

Figure 5-1.

TM 11-6625-2965-14&P

Front Pane1 Terminal Connections

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 measur-

ing the output impedance, transient response, regulation, or ripple of the power supply in order to achieve valid measurements. A measurement made acress 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 as

shown in Figure 5-1. The performance characteristics should never be measured on the front termi-

nals if the load is connected across the rear termi-

nals. Note that when measurements are made at

the front terminals, the monitoring leads are con-

nected at A, not B, as shown in Figure 5-1. Fail-

ure to connect the measuring device at A will re-

sult in a measurement that includes the resistance

of the leads between the output terminals and the

point of connection.

Figure 5-2. Output Current Measurement Technique

5-6 For output current measurements, the current sampling resistor should be a four-terminal resis-

tor. The four terminals are connected as shown in

Figure 5-2. In addition, the resistor should be of 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.

When using an oscilloscope, ground one ter-

5-7

minal of the power supply and then ground the case

of the oscilloscope to this same point. Make cer-

tain that the case is not also grounded by some

other means (power line). Connect both oscillo-

scope input leads to the power supply ground terminal and check that the oscilloscope is not exhibiting a ripple or transient due to ground loops, pick-up, or other means.

5-1

TM 11-6625-2965-14&P

5-8 TEST EQUIPMENT REQUIRED

5-9 Table 5-1 lists the test equipment required to perform the various procedures described in this Section.

NOTE

A satisfactory substitute for a differential voltmeter is to arrange a reference voltage source and null detector as shown in Figure 5-3. The reference voltage source is adjusted so that the voltage difference between the supply being measured and the

reference voltage will have the re-

quired 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 input, or a 50mV

meter movement with a 100 division

scale. For the latter, a 2mV change in voltage will result in a meter deflection of four divisions.

Figure 5-3. Differential Voltmeter Substitute,

Test Setup

CAUTION

Care must be exercised when using an

electronic null detector in which one input terminal is grounded to avoid ground loops and circulating currents.

TYPE

Differential

Voltmeter

Variable Voltage

AC Voltmeter

Oscilloscope

Oscillator

DC Voltmeter

Table 5-1.

REQUIRED

CHARACTERISTICS

Sensitivity: lmV full scale

(min.). Input impedance:

10 megohms (min.).

Range: 90-130 Volts Equipped with voltmeter accurate within 1 Volt.

Accuracy: 2%. Sensitivity:

lmV full scale deflection (min.).

Sensitivity: 10µV/cm. Differential input.

Range: 5Hz to 600kHz

Accuracy: 2%

Accuracy: 1%. Input resistance: 20,000 ohms/Volt (min.).

Test Equipment Required

USE

Measure dc voltages; calibration procedures

Vary ac input

Measure ac voltage and ripple

Display transient response waveforms

Impedance Checks

Measure dc voltages

RECOMMENDED

MODEL

3420 (See Note)

403 B

140 A plus

1402A plug in.

200 CD

412A

Repetitive Load Switch

Rate: 60-400 Hz, 2µsec rise and fall time.

Measure transient response

5-2

See Figure 5-6

Table 5-1.

TM 11-6625-2965-14&P

Test Equipment Required (Continued)

TYPE

Resistor

Resistor Value: 5 , 0.5%, 4.5 Watts,

Resistor Value: 6204B and 6205B, 28 ,

Resister

Resistor

Resistor Value: See Paragraph 5-67.

Capacitor

Decade

Resistance Box

6204B, 6205B; 133 , ± 10% 15W

6206B; 120 , ±1O% 15W

20ppm, 4-Terminal.

2W (min.).

6206B, 27 , 10W (min.).

1Κ ± 1%, 2 Watt non-induc- Measure impedance

tive

100 ohms, ±5%, 10 Watt Measure impedance

± 0.1%, 5 Watt 500µf, 50WVdc Range: 0-150K (min.). Measure programming

Accuracy: 0.1% plus 1 ohm Make-before-break contacts.

REQUIRED

CHARACTERISTICS

USE

Load Resistor, HIGH range

Current sampling

Load resistor, low range

Calibrate programming current

Measure impedance

coefficients

RECOMMENDED

MODEL

----

R54 or R55, Section VI

----

5-10 PERFORMANCE TEST

5-11 The following test can be used as an incoming inspection check and appropriate portions of

the test can be repeated either to check the oper-

ation of the instrument after repairs or for periodic maintenance tests. The tests are performed using

a 115Vac 60 Hz, single phase input power source.

If the correct result is not obtained for a particular check, do not adjust any controls; proceed to

troubleshooting (Paragraph 5-48).

NOTE

For Model 6205B supplies, the following performance checks should be performed twice in order to check both independent sections of the supply.

5-12 CONSTANT VOLTAGE TESTS 5-13 For Constant Voltage measurements, the

measuring device must be connected acress the

rear sensing terminals of the supply in order to achieve valid indications. A measurement made acress 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 (1 milliohm at dc), thus invalidating the measurement.

5-14 To avoid mutual coupling effects, each monitoring device must be-connected directly to the sensing terminals by separate pairs of leads. The load resistor is connected acress the output terminals and must be selected according to the output voltage and current of the supply. When measuring the constant voltage performance spec-

ifications, the CURRENT controls should be set

well above the maximum output current which the

supply will draw, since the onset of constant cur-

rent action will cause a drop in output voltage,

increased ripple, and other performance changes not properly ascribed to the constant voltage operation of the supply.

5-15 Voltage Output and Voltmeter Accuracy. To check the output voltage, proceed as follows:

a. Connect 133 ohm load resistor (120 ohms

for Model 6206B) across rear output terminals of

supply.

b. Connect differential voltmeter acress +S and -S terminals of supply observing correct polarity.

5-3

TM 11-6625-2965-14&P

Set METER switch to highest voltage

range and RANGE switch to highest voltage mode and turn on supply.

d. Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage.

e. Differential voltmeter should indicate maximum rated output voltage within 3%.

5-16 Output Current and Ammeter Accuracy. To

check the output current, proceed as follows:

Connect test setup shown in Figure 5-4.

Set METER switch to lowest current

range and RANGE switch to high voltage mode.

Turn on supply and adjust VOLTAGE controls until front panel meter indicates exactly 300 mA (0.5 Ampere for Model 6206B supplies).

d. Differential voltmeter should read 1.5 ±

0.045Vdc.

ferential voltmeter.

e. Disconnect load resistors.

Reading on differential voltmeter should not vary from reading recorded in Step d by more than 8mVdc for Models 6204B and 6205B or 10mVdc for Model 6206B supply.

Figure 5-4.

Load Regulation.

5-17

Definition: The change static value of dc output voltage resulting from a change in load resistance from open circuit to a value which yields maximum rated output current (or vice versa).

To check the constant voltage load regula-

5-18

proceed as follows:

tion,

Connect test setup as shown in Figure

5-5.

b. Turn CURRENT controls fully clockwise.

c. Turn-on supply and adjust VOLTAGE con-

trols until front panel voltmeter indicates exactly the maximum rated output voltage.

d. Read and record voltage indicated on dif-

Output Current, Test Setup

∆Ε in the

OUT

Figure 5-5.

5-19 Line Regulation.

Definition: The change, static value of dc output voltage resulting from a change in ac input voltage over the specified range from low

line 10% less than nominal to high line 10% more than nominal or from

high line to low line.

5-20 To test the constant voltage line regulation, proceed as follows:

a. Connect variable auto transformer between input power source and power supply power input.

b. Turn CURRENT controls fuIly clockwise.

c. Connect test setup shown in Figure 5-5.

d. Adjust variable auto transformer for low line (104Vac).

e. Set METER switch to highest current range and turn on supply.

f. Adjust VOLTAGE controls until front panel voltmeter indicates exactly the maximum rated output voltage.

Read and record voltage indicated on

differential voltmeter.

h. Adjust variable auto transformer for high line (126Vac).

Load Regulation, Test Setup

∆Ε in the

OUT

5-4

Reading on differential voltmeter should

i. not vary from reading recorded in Step g by more than 8mVdc for Models 6204B and 6205B or 10mVdc for Model 6206B.

Ripple and Noise.

5-21

Definition: The residual ac voltage which is superimposed on the dc output of a regulated power supply. Ripple and noise may be specified and measured in terms of its RMS or (preferably) peak-to-peak value.

Ripple and noise measurement can be made at any input ac line voltage combined with any dc output voltage and load current within rating.

5-22 The amount of ripple and noise that is pres-

ent 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 particu-

larly important 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 output noise spikes of short duration could be present in the ripple and not appreciably increase the RMS value.

TM 11-6625-2965-14&P

5-23 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 5-31,

5-24 Ripple and Noise Measurements. Figure 5-6A 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 oscilloscope 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 of the difference in potential E

between the two

ground points causes an IR drop which is in series with the scope input. This IR drop, normally hav-

ing a 60

HZ line frequency fundamental, plus any

pickup on the unshielded leads interconnecting the power supply and 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 out-

put terminals of the power supply, and can com-

pletely invalidate the measurement.

5-25 The same ground current and pickup problems

Figure 5-6. CV Ripple and Noise, Test Setup

can exist if an RMS voltmeter is substituted in

place of the oscilloscope in Figure 5-6. However, the oscilloscope display, unlike the true RMS meter reading, tells the observer immediately whether the fundamental period of the signal displayed is 8.3 milliseconds (1/120 Hz) or 16.7 milliseconds (1/60Hz). Since the fundamental ripple frequency present on the output of an supply is

120Hz (due to full-wave rectification), an oscillo-

scope display showing a 120Hz fundamental component is indicative of a “clean” measurement setup, while the presence of a 60

HZ fundamental usu-

ally means that an improved setup will result in a more accurate (and lower) value of measured ripple.

5-26 Although the method shown in Figure 5-6A is not recommended for ripple measurements, it may prove satisfactory in some instances provided certain precautionary measures are taken. One meth-

od of minimizing the effects of ground current flow

(IG) is to ensure that both the supply and the test instrument are plugged into the same ac power buss.

5-5

TM 11-6625-2965-14&P

5-27 To minimize pick up, a twisted pair or (preferably) a shielded 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 both to the grounded terminal of the power supply and the grounded input terminal of the oscilloscope. When using

shielded two-wire cable, it is essential for the shield to be connected to ground at one end only to

prevent any ground current flowing through this

shield from inducing a signal in the shielded leads.

5-28 To verify that the oscilloscope is not displaying ripple that is induced in the leads or pick-

ed up from the grounds, the (+) scope lead should

be shorted to the (-) scope lead at the power sup-

ply terminals. The ripple value obtained when the

leads are shorted should be subtracted from the

actual ripple measurement.

5-29 If the foregoing measures are used, the

single-ended scope of Figure 5-6A may be adequate to eliminate non-real components of ripple so that a satisfactory measurement can be obtained. ever, in stubborn cases or in measurement situations where it is essential that both the power supply case and the oscilloscope case be connected to ground (e. g. if both are rack-mounted), it may be necessary to use a differential scope with floating input as shown in Figure 5-6B. If desired, two

single-conductor shielded cables may be substituted in place of the shielded two-wire cable with equal success. jection, a differential oscilloscope displays only 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. Before using a differential 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.

line, the scope is properly ignoring any common mode signal present.

line, then the scope is not rejecting the ground

signal and must be realigned in accordance with the

manufacturer’s instructions until proper common

mode rejection is attained.

Because of its common mode re-

If this trace is a straight

If this trace is not a straight

How-

5-31 Noise Spike Measurement. When a high frequency 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 bandwidth may conceal high frequency spikes detrimental to the load.

5-32 The test setup illustrated in Figure 5-6A is generally not acceptable for measuring spikes; a differential oscilloscope is necessary. Furthermore, the measurement concept of Figure 5-6B must be modified if accurate spike measurement to be achieved:

1. As shown in Figure 5-7, two coax cables, must be substituted for the shielded twowire cable.

2. Impedance matching resistors must be

included to eliminate standing waves and cable ringing, and the capacitors must be connected to block the dc current path.

3. The length of the test leads outside the

coax is critical and must be kept as short as pos-

sible; the blocking capacitor and the impedance

matching resistor should be connected directly from the inner conductor of the cable to the power

supply terminals.

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.

Since the impedance matching resistors

5. constitute a 2-to-1 attenuator, — the noise spikes observed on the oscilloscope should be less than

0.5mV p-p instead of lmV.

5-33 The circuit of Figure 5-7 can also be used

for the normal measurement of low frequency ripple

and noise;

simply remove the four terminating re-

5-30 To check the ripple and noise output, proceed as follows:

meter as shown in Figures 5-6A

meter indicates maximum rated output voltage.

less than 200µVrms and lmV p-p.

Connect the oscilloscope or RMS volt-

or 5-6B.

b. Adjust VOLTAGE control until front pane 1

c. The observed ripple and noise should be

5-6

Figure 5-7,

CV Noise Spike, Test Setup

sisters and the blocking capacitors and substitute a higher gain vertical plug-in in place of the wideband plug-in required for spike measurements. Notice that with these changes, Figure 5-7 becomes a two-cable version of Figure 5-6C.

Transient Recovery Time.

5-34

Definition: The time “X” for output voltage recovery to within “Y” mil-

livolts of the nominal output volt-

age following a “Z” Amp

step

change in load current - where:

“Y” is specified as 10 millivolts. The nominal output voltage is defined as the dc level half way between the static output voltage before and after the imposed load

change, and “Z” is the specified

load current change, which is 5

Amperes. A mercury-wetted relay, as connected in the

5-35

load switching circuit of Figure 5-8 should be used

for loading and unloading the supply. When this

load switch is connected to a 60Hz ac input, the mercury-wetted relay will open and close 60 times per second. Adjustment of the 25K control permits adjustment of the duty cycle of the load current switching and reduction in jitter of the oscilloscope display.

TM 11-6625-2965-14&P

cury-wetted relay contacts. Switching of larger

load currents can be accomplished with mercury

pool relays; with this technique fast rise times

can still be obtained, but the large inertia of mer-

cury pool relays limits the maximum repetition rate of load switching and makes the clear display of the transient recovery characteristic on an oscillo-

scope more difficult.

5-37 To check the transient recovery time of the supply, proceed as follows:

a. Connect test setup shown in Figure 5-8. b. Set METER switch to highest current

range and RANGE switch to lowest voltage mode.

Turn on supply and adjust VOLTAGE con-

trols until front panel meter indicates exactly the

maximum rated output current.

d. Close line on repetitive load switch set-

up.

Adjust 25 potentiometer until a stable

display is obtained on oscilloscope. Waveform

should be within the tolerances shown on Figure 5-9 (output should return to within 10mV of original value in less than 50 microseconds).

5-36 The maximum load ratings listed in Figure 5-4 must be observed in order to preserve the mer-

Figure 5-8.

Transient Recovery Time, Test Setup

Figure 5-9. Transient Recovery Time, Waveforms

5-38 OUTPUT IMPEDANCE 5-39 To check the output impedance, proceed as

follows:

a. Connect test setup shown in Figure 5-10. b. Set METER switch to highest voltage

range.

Turn on supply and adjust VOLTAGE con-

trols until front panel meter reads 20 Volts.

d. Set AMPLITUDE control on oscillator to

10 Volts (E

), and FREQUENCY control to 100 Hz.

e. Record voltage across output terminals

of the power supply (E

) as indicated on ac volt-

meter.

f. Calculate the output impedance by the

5-7

TM 11-6625-2965-14&P

following formula:

The output impedance (Z

less than 0,020 ohms.

h. Using formula of Step f, calculate output

impedance at frequencies of 50kHz and 500kHz.

Values should be less than 0.5 ohm and 3.0 ohms,

respectively.

) should be

out

supply should be placed outside the oven and should have a long term stability adequate to in-

sure that its drift will not affect the overall meas-

urement accuracy.

5-43 To check the temperature coefficient, proceed as follows:

Connect test setup shown in Figure 5-5.

b. Turn CURRENT controls fully clockwise and adjust front panel VOLTAGE controls until the front panel voltmeter indicates 10Vdc.

c. Insert the power supply into the temperature-controlled oven (differential voltmeter and load resistance remain outside oven). Set the temperature to 30°C and aIlow 30 minutes warmup.

d. Record the differential voltmeter indication.

Raise the temperature to 40°C and allow

30 minutes warm-up.

f. The differential voltmeter indication

should change by less than 90mV from indication

recorded in Step d.

5-44

Output Stability. Definition: The change in output voltage for the first eight hours following a 30 minute warm-up period. During the interval of

measurement all parameters,

such as load resistance, ambi-

ent temperature, and input line voltage are held constant.

Figure 5-10. Output Impedence, Test Setup

5-40 Temperature Coefficient.

Definition: The change in output voltage per degree Centigrade change in the ambient temperature under conditions of constant input ac line voltage, output voltage

setting, and load resistance.

5-41 The temperature coefficient of

a power sup-

ply is measured by placing the power supply in an oven and varying it over any temperature span within its rating.

(Most power supplies are

rated for operation from 0°C to 55°C. ) The power

supply must be allowed to thermally stabilize for a sufficient period of time at each temperature of measurement.

5-42 The temperature coefficient specified is the maximum temperature-dependent output voltage change which will result over any 5°C interval. The differential voltmeter or digital voltmeter used to measure the output voltage change of the

5-45

This measurement is made by monitoring the output of the power supply on a differential voltmeter or digital voltmeter over the stated measurement interval; a strip chart recorder can be used

to provide a permanent record. A thermometer

should be placed near the supply to verify that the ambient temperature remains constant during the period of measurement. The supply should be put

in a location immune from stray air currents (open

doors or windows, air conditioning vents); if pos-

sible, the supply should be placed in an oven which is held at a constant temperature. Care must be taken that the measuring instrument has a

stability over the eight hour interval which is at

least an order of magnitude better than the stabil-

ity specification of the power supply being measured. Typically, a supply may drift less over the eight hour measurement interval than during the ½

hour warm-up period.

5-46 Stability measurement can be made while the supply is remotely programmed with a fixed wire-wound resistor, thus avoiding accidental changes in the front panel setting due to mechan-

ical vibration or “knob-twiddling. “

5-8

5-47 To check the output stability, proceed as

follows:

Connect test setup shown

a. b. Turn CURRENT controls

in Figure 5-5.

fully

clockwise

and adjust VOLTAGE controls for 40Vdc output.

c. Allow 30 minutes warm-up then record

the differential voltmeter indication.

Mter

should

change by less than

8 hours, differential voltmeter

45mV

from indication

recorded in Step c.

5-48 TROUBLESHOOTING

5-49 Before attempting to troubleshoot this in-

strument, ensure that the

fault

is with the instrument and not with an associated circuit. The performance test (Paragraph 5-10) enables this to be determined without having to remove the instrument from the cabinet.

5-50 A operation is a helpful aid

gcod understanding of the principles of

in troubleshooting, and

it is recommended that the reader review Section IV of the

manua~

before attempting to troubleshoot the unit in detail. Once the principles of operation are understood, refer to the overall trouble-

shooting procedures in Paragraph 5-53 to

locate

the symptom and probable cause.

5-51 The schematic diagram at the rear of the manual (Figure 7-1) contains normal voltage

read-

TM 11-6625-2965-14&P

ings taken at various points within the circuits. These voltages are positioned adjacent to the applicable test points (identified by encircled numbers). Component and test point designations are marked directly on the main printed wiring board.

5-52

it and re-conduct the performance test. When a component is replaced, refer to the repair and replacements and adjustment and calibration para-

graphs in this section.

5-53 OVERALL TROUBLESHOOTING PROCEDURE

5-54 To locate the cause of trouble follow Steps

1, 2, and 3 in sequence.

open fuse, defective power cord, input power fail-

ure, or defective voltage or current meter. Next

remove the top cover (held by four retaining screws) and inspect for open connections, charred components, etc. If the trouble source cannot be detected by visual inspection, proceed with

Step 2.

caused by improper dc bias or reference voltages; thus, it is a good practice to check voltages in Table 5-2, before proceeding with Step 3.

5-3 to determine your symptom and probable cause.

a defective component is located, replace

(1) Check for obvious troubles such as

all

(2) In almost

(3) Disconnect the

cases, the trouble can be

load and examine Table

STEP

1 2

3 4

METER METER

COMMON

SYMPTOM

High output voltage

Low

output voltage

POSITIVE

37 41

Table 5-2. Reference Circuit Troubleshooting

NORMAL

INDICATION

6.2 * 0.3Vdc

6.2 + 0.3Vdc

12.4 *1.

OVdc

7.5 * .7Vdc

Table 5-3.

NORMAL

RIPPLE

(P-P)

3mV

4mV

2.8KV

IF INDICATION ABNORMAL, TAKE THIS ACTION

Check 12.4 Volt bias or VR1 (See next paragraph) Check 12.4 Volt bias or VR2 (See next paragraph) Check Q8, Q9, CR22, CR23, C1O,

lV Check C12, CR8, CR24, CR25

Overall Trouble shooting

CHECKS AND PROBABLE CAUSES

a. Front

panel

meter defective.

b. Series regulator feedback loop defective. Refer to

a. Fuses blown (Check

CR26-CR29 or C14 for short).

Table 5-4.

5-9

TM 11-6625-2965-14&P

Table 5-3. Overall Troubleshooting (Continued)

SYMPTOM

b. Front panel meter defective. c. Series regulator feedback loop defective. Refer to Table 5-5.

Will not current limit

High ripple a. Check operating setup for ground loops.

Poor line regulation a.

Poor load regulation

(constant voltage)

Oscillates (constant a.

voltage)

a. Q10 open. R81 defective.

b. If output floating, connect lµf capacitor between output and ground.

Ensure that supply is not crossing over to current limit mode under

loaded conditions.

Check reference circuit (Paragraph 5-55).

b. Check reference circuit adjustment (Paragraph 5-69). a. Measurement technique. (Paragraph 5-17)

b. Check reference circuit (Paragraph 5-55) and adjustment (Para-

graph 5-69).

Ensure that supply is not going into current limit.

Check C5 for open, adjustment of R30 (Paragraph 5-72).

CHECKS AND PROBABLE CAUSES

Poor stability

(constant voltage)

5-55 To check the zener diodes in the reference

circuit, proceed as follows:

Connect differential voltmeter across

zener diode.

b. Connect appropriate load resistor, given

in Figure 5-4, across (+) and (-) output terminals.

Turn VOLTAGE control fully clockwise.

d. Set METER switch to highest current

range and turn on supply.

e. Adjust CURRENT controls until panel meter reads exactly the maximum rated output current.

Read and record voltage indicated on dif-

ferential voltmeter.

Short out load resistor by closing S1.

h. If reading on differential voltmeter differs by more than 1.07mV for 6204B and 6205B or

.946mV for 6206B from the reading in Step f, re-

place zener diode.

Check ± 6.2Vdc reference voltages (Paragraph 5-55).

a. b. Noisy programming resistor R10. c. CR1, CR2 leaky. d. Check Rl, R12, R13, for noise or drift. e. Stage Q1 defective.

5-5b Series Regulating Feedback Loop. When

troubleshooting the series regulating loop, it is useful to open the loop since measurements made anywhere within a closed loop may appear abnormal. With a loop closed, it is very difficult to separate cause from effect. As described in

Tables 5-4 and 5-5, the conduction or cutoff ca-

pability of each stage is checked by shorting or

opening a previous stage, as follows:

Shorting the emitter to collector of a

transistor simulates saturation, or the full ON

condition.

2. Shorting the emitter to base of a transis-

tor cuts it off, and simulates an open circuit be-

tween emitter and collector.

5-57 Although a logical first choice might be to break the loop somewhere near its mid-point, and then perform successive subdividing test, it is

5-10

more useful to trace the loop from the series regulator backwards a stage at a time, since loop

Table 5-4. High Output Voltage Troubleshooting

TM 11-6625-2965-14&P

failures occur more often at the higher power levels.

STEP

ACTION

Check turn off of series regulator by shorting Q4 emitter to collector.

Check turn on of Q4 by disconnecting collector of Q3.

Check turn off of Q3 by disconnecting collector of Q1A.

RESPONSE

a. Output voltage

b. Output voltage

a. Output voltage remains high. b. Output voltage decreases.

remains high.

decreases.

PROBABLE CAUSE

a. Series regulator Q7

(or Q6) shorted.

b. Remove short and proceed

to Step 2.

a. Q4 open. b. Reconnect lead and pro-

ceed to Step 3.

a. Q3 shorted. b, Check Q1A for short,

Q1B for open. Check for

open strap between A6 and A8.

open.

Check R10 for

STEP

Table 5-5.

ACTION

Check turn on of Q7

(and Q6, if included) by opening the emitter of Q4 .

Eliminate the current limit circuit as a source of trouble by discon-

necting the anode of

CR16.

Check turn off of Q4 by

shorting Q3 emitter to collector.

Low Output Voltage Troubleshooting

RESPONSE

a. Output voltage remains low. b. Output voltage increases.

a. Output voltage increases.

b. Output voltage remains low.

a. Output voltage remains low. b. Output voltage increases.

5-11

PROBABLE CAUSE

a. Q7 (or Q6) open. b. Reconnect lead and pro-

ceed to Step 2.

a. Q10 shorted, R81 defec-

tive.

b. Reconnect lead and pro-

ceed to Step 3.

a. Q4 shorted. b. Remove the short and

proceed to Step 4.

TM 11-6625-2965-14&P

Table 5-5. Output Voltage Troubleshooting (Continued)

5-58 REPAIR AND REPLACEMENT

5-59 Before servicing a printed wiring board, refer to Figure 5-11. Section VI of this manual con-

tains a tabular list of the instruments replaceable parts. Before replacing a semiconductor device, refer to Table 5-6 which lists the special charac-

REFERENCE

DESIGNATOR

Check turn on of Q3 by shorting Q1A emitter to collector

Table 5-6.

Output voltage remains low

b. Output voltage increases

Selected Semiconductor Characteristics

CHARACTERISTICS

RESPONSE

teristics of selected semiconductors. If the device to be replaced is not listed in Table 5-6, the

standard manufacturers part number listed in Sec-

tion VI is applicable. After replacing a semiconductor, refer to Table 5-7 for checks and adjustments that may be necessary.

PROBABLE CAUSE

a. Q3 open b, Check Q1A for open, QlB

for short. Check R10 for

short or open strap be-

tween A7 and A6

STOCK NO.

SUGGESTED

REPLACEMENT

REFERENCE

Q3, Q4 Error amplifiers CV load regulation.

Q7 (Q6)

Q8, Q9 Reference regulator

CR1, CR2

Matched differential amplifier. NPN Si. planar

FE i

70 (min.) h

@ V

NPN Power hFE = 35 (min.) @ Ic = 4A; VCE = 4V.

Table 5-7.

cbo

5V,

Checks and Adjustments After Replacement of Semiconductor Devices

Constant voltage differential amplifier

Series regulater

Limiting diodes

= lmA, VCE = 5V, Ico = 0.01µA

FUNCTION CHECK

1854-0229 2N291 G.E.

1854-0225 2N3055 R. C,A,

Constant voltage (CV) line and load regulation. volt output.

CV transient response.

CV load regulation. Reference circuit line

regulation.

CV load regulation.

Zero

ADJUST

R6 or R8

R30

VR1, VR2, CR20

CR8

Forward bias regulator

Voltage across diode

2.0 to 2.4 Volts.

5-12

TM 11-6625-2965-l4&P

Table 5-7.

Checks and Adjustments After Replacement of Semiconductor Devices (Continued)

REFERENCE

FUNCTION CHECK

Q10, CR16 Current limit adjustment.

(CR21)

CR22 thru Rectifier diodes CR29

VR1

Positive reference voltage

Voltage across appropriate filter capacitor.

+6.2V line and load regu-

lation.

VR2

Negative reference voltage

-6.2V line and load regulation.

5-60 ADJUSTMENT AND CALIBRATION

Connect an 8K, 0.1% resistor (18K re-

sistor for Model 6206B supplies) between termi-

5-61 Adjustment and calibration may be required

after performance testing, troubleshooting, or repair and replacement. Perform only those adjustments that affect the operation of the faulty circuit and no others.

nals -S and A6 on rear barrier strip.

b. Disconnect jumper between A7 and A8

(leaving A6 and A7 jumpered).

Connect decade resistance box in place

of R13.

d. Connect differential voltmeter between

5-62 METER ZERO 5-63 Proceed as follows to zero meter:

a. Turn off instrument (after it has reached normal operating temperature) and allow 30 seconds for all capacitors to discharge.

Insert sharp pointed object (pen Point or

b. awl) into the small hole at top of round black plastic disc located directly below meter face.

Rotate plastic disc clockwise (

CW) until

+S and -S terminals on rear barrier strip.

Set RANGE switch to high voltage mode,

e. METER switch to high voltage range, and turn on supply.

f. Adjust decade resistance box so that differential voltmeter reads 40 ± 0.4Vdc for Models 6204B and 6205B or 60 ± 0.6Vdc for Model 6206B supplies,

Replace decade resistance with resistor

of appropriate value in R13 position. meter reads zero, then rotate ccw slightly in order to free adjustment screw from meter suspension, If pointer moves, repeat Steps b and c.

5-68 Zero Output Voltage. To calibrate the zero

5-64 AMMETER TRACKING 5-65 To calibrate the ammeter, proceed as fol-

lows:

a. Connect test setup as shown on Figure

5-4.

b. Set RANGE switch to low voltage mode

and METER switch to lowest current range.

Turn on supply and adjust VOLTAGE con-

trols so that differential voltmeter indicates ex-

actly 40Vdc.

d. Front panel meter should read 0.3 Amp

for Model 6204B and 6205B supplies, or 0.1 Amp

for Model 6206B supply. If it does not, adjust R72.

Volt programming accuracy, proceed as follows:

Connect differential 1 voltmeter between

+S and -S terminals.

b. Short out voltage controls by connecting

jumper between terminals A6 and -S.

Turn on supply and observe reading on

differential voltmeter.

If it is more positive than O Volts, shunt

resistor R6 with a decade resistance box.

Adjust decade resistance until differen-

tial voltmeter reads zero, then shunt R6 with re-

sistance value equal to that of the decade resist-

ante.

If reading of Step c was more negative

than 0 Volts, shunt resistor R8 with the decade

5-66 CONSTANT VOLTAGE PROGRAMMING CURRENT

5-67 Programming Accuracy. To calibrate the programming current, proceed as follows:

resistance box.

Adjust decade resistance until differen-

tial voltmeter reads zero then shunt R8 with a re-

sistance value equal to that of the decade box.

ADJUST

R81

R46, VR1

R46, VR2

5-13

TM 11-6625-2965-14&P

5-14

11-6625-2965-14&P

5-69 REFERENCE CIRCUIT ADJUSTMENTS

5-70 Line Regulation. To adjust the line regula-

tion capabilities of the instrument proceed as fol-

lows :

Connect the differential voltmeter be-

tween +S (positive) and 31 (common).

b. Connect variable voltage transformer be-

tween supply and input power source.

c. Adjust line to 105Vac. d. Connect decade resistance in place of

R46.

e. Set range switch to high voltage mode

and turn on supply.

Adjust decade resistance so that voltage

indicated by differential voltmeter does not change

more than 1.08 millivolts for 6204B and 6205B or

.946mV for 6206B as input line voltage is varied

from 105 to 125Vac.

g. Replace decade resistance with appropri-

ate value resistor in R46 position.

5-71 CONSTANT VOLTAGE TRANSIENT RECOVERY

TIME

5-72 To adjust the transient response, proceed

as follows:

Connect test setup as shown in Figure

5-8.

b. Repeat Steps a through f as outlined in

Paragraph 5-37.

Adjust R30 so that the transient response

is as shown in Figure 5-9.

5-73 CURRENT LIMIT ADJUSTMENT

5-74 To adjust the current limit so that the supply

can be used to furnish maximum rated output cur-

rent, proceed as follows:

Connect test setup shown in Figure 5-5. b. Short out load resistor (Ry). c. Set RANGE switch to low voltage (high

current) mode.

d. Turn on supply and rotate VOLTAGE con-

trols fully clockwise (maximum).

Adjust R81 until differential volt meter indicates 3.5Vdc for Models 6204B and 6205B supplies or 3.6Vdc for Model 6206B supply.

5-15

SECTION VI

REPLACEABLE PARTS

TM 11-6625-2965-14&P

6-1 INTRODUCTION

6-2 This section contains information for ordering replacement parts. Table 6-4 lists parts in alphanumeric order by reference designators and provides the following information:

Reference Designators. Refer to Table 6-1.

Description. Refer to Table 6-2 for ab-

breviations.

c. Total Quantity (TQ). Given only the first time the part number is listed except in instruments containing many sub-modular assemblies, in which case the TQ appears the first time the part number

is listed in each assembly.

Manufacturer’s Part Number or Type.

e. Manufacturer’s Federal Supply Code Num-

be r.

Refer to Table 6-3 for manufacturer’s name and

address.

f. Hewlett-Packard Part Number.

Recommended Spare Parts Quantity (RS)

for complete maintenance of one instrument during one year of isolated service.

Parts not identified by a reference desig-

nator are listed at the end of Table 6-4 under Me-

chanical and/or Miscellaneous. The former consists

of parts belonging to and grouped by individual assemblies; the latter consists of all parts not immediately associated with an assembly.

6-3 ORDERING INFORMATION

6-4 To order a replacement part, address order or inquiry to your local Hewlett-Packard sales office

(see lists at rear of this manual for addresses). Specify the following information for each part: Model, complete serial number, and any Option or special modification (J) numbers of the instrument; Hewlett-Packard part number; circuit reference designator; and description. To order a part not listed in Table 6-4, give a complete description of the part, its function, and its location.

Table 6-1.

= assembly = blower (fan)

= capacitor

= circuit breaker

= diode

= device, signal-

ing (lamp)

Reference Designators

= miscellaneous

electronic part

F = fuse

= jack, jumper

= relay L = inductor M = meter

Table 6-1.

= plug

= transistor

Reference Designators (Continued)

R= resistor s = switch T

= transformer TB = terminal block TS

= thermal switch

x z

Table 6-2. Description Abbreviations

ac =

ampere alternating

mfr . mod. =

current assy. = bd = bkt =

C .

cd = coef = comp . CRT =

assembly

board

bracket

degree

Centigrade

card

coefficient

composition

cathode-ray

mtg = n. NC = NO = NP =

Ω

obd =

OD =

tube CT = dc = DPDT =

DPST =

center-tapped

direct current

double pole,

double throw

double pole,

P= P.C. =

pot. =

p-p .

ppm =

single throw

elect =

encap=

F .

electrolytic

encapsulated

farad

degree

pvr =

rect =

rms =

Farenheit fxd = Ge = H= Hz = IC =

ID = incnd . k= m= M=

P= met. =

fixed

germanium

Henry

Hertz

integrated

circuit

inside diameter

incandescent

kilo = 10

mini = 10-3 mega . 10 micro = 10

-6

metal

Si SPDT =

SPST =

SS = T=

tan. = Ti =

var =

WW =

= vacuum tube,

neon bulb, photocell, etc.

= zener diode

= socket = integrated cir-

cuit or network

manufacturer modular or modified mounting nano . 10

-9

normally closed normally open nickel-plated ohm order by description outside diameter

pico =

10-

printed circuit potentiometer peak-to-peak parts per million peak reverse voltage rectifier root mean square silicon single pole, double throw single pole, single throw small signal slow-blow tantulum titanium volt variable wirewound Watt

6-1

TM 11-6625-2965-14&P

Table 6-3. Code List of Manufacturers

6-2

Table 6-3.

Code List of Manufacturers (Continued)

TM 11-6625-2965-l4&P

6-3

TM 11-6625-2965-14&P

Table 6-3.

Code List of Manufacturers (Continued)

6-4

TABLE 6-4. REPLACEABLE PARTS TM11-6625-2965-14&P

REF. MFR. hp

DESIG. DESCRIPTION TQ MFR. PART NO. CODE PART NO. RS

C1 FXD, ELECT 5µ 65VDC 2 09182 0180-1836 1

C2-4,6-8,

11,13,15,

17-19 NOT ASSIGNED - - - - -

C5 FXD, FILM . 001µ 200VDC 2 192P10292 56289 0160-0153 1

C9 FXD, ELECT 4.7ΩF 35VDC 2 150D475X9035B2 56289 0180-0100 1

C10,12 FXD, ELECT 100µUF 50 VDC 4 09182 0180-1852 1

C14 FXD, ELECT 490µF 85 VDC 2 09182 0180-1888 1

C16 FXD, CERAMIC .05µF 400VDC 2 33C17A 56289 0150-0052 1

C20 FXD, ELECT 80µF 300VDC 2 09182 0180-1851 1

CR1,2 RECT. SI. 250MA 200PRV 8 1N485B 93332 1901-0033 6

CR3-5,9,

10,12-15,

18,19,21,

30-33 NOT ASSEIGNED - - - - -

CR6 RECT. SI. 400MW 10PRV 2 1N4828 03508 1901-0461 2

CR7,8 RECY. SI. 400MW 10PRV 4 1N4830 03508 1901-0460 4

CR11 RECY. SI. 500MA 200 PRV 22 1N3253 02735 1901-0389 9

CR16 RECT. SI. 250MA 200PRV 1N485B 93332 1901-0033

CR17 RECT. SI. 500MA 200PRV 1N3253 02735 1901-0389

CR20 RECT. SI. 250MA 200PRV 1N485B 93332 1901-0033

CR22-29,34 RECT. SI. 500MA 200PRV 1N3253 02735 1901-0389

DS1 LAMP NEON 1 09182 2140-0244 1

F1 FUSE CARTRIDGE 2A 250V 3AG 1 312002 75915 2110-0002 5

Q1 SS NPN DIFF. AMP 2 09182 1854-0229 2

Q2,5,6 NOT ASSIGNED - - - - -

Q3 SS PNP SI. 4 09182 1853-0099 4

Q4 SS PNP SI. 2 09182 1853-0041 2

Q7 POWER, NPN SI. 2 09182 1854-0225 2

Q8 SS PNP SI. 09182 1853-0099

Q9,10 SS NPN SI. 4 09182 1854-0071 4

R1 FXD, WW 1KW ±5% 3W 2 242E1025 56289 0813-0001 1

R2 FXD, MET. FILM 6.2KW µ1% 1/8W 2 TYPE CEA T-O 07716 0698-5087 1

R3,4 FXD, MET. FILM 23KW µ1% 1/8W 4 TYPE CEA T-O 07716 0698-3269 1

R5 FXD, MET. FILM 1.5KW ±1% 1/8W 2 TYPE CEA T-O 07716 0757-0427 1

R6 FXD, COMP 360KW ±5% ½W 2 EB-3645 01121 0686-3645 1

R7,9,11

14-28,

32,35-40,

48,50,59

62-71,

74-79,

82-86 NOT ASSIGNED - - - - -

R8 FXD, COMP 560KW ±5% 1/2W 2 EB-5645 01121 0686-5645

R10 VAR. WW DUAL 10K-100 2 09182 2100-0997 1

R12 FXD, WW 1.3KW ±5% 3W 2 242E1325 56289 0811-1803 1

R13 FXD, COMP (SELECTED) ±5% 1/2W 2 TYPE EB (OBD) 01121 1

R29 FXD, COMP 5.1KW ±5% 1/2W 4 EB-5125 01121 0686-5125 1

R30 VAR. WW 5KW (MODIFY) 2 TYPE 110-F4 11236 2100-1824 1

R31 FXD, COMP NKW ±5% 1/2W 2 EB-1025 01121 0686-1025 1

R33 FXD, COMP 2.4KW ±5% 1/2W 2 EB-2425 01121 0686-2425 1

6-5

TM11-6625-2965-14&P

REF. MFR. hp

DESIG. DESCRIPTION TQ MFR. PART NO. CODE PART NO. RS

R34 FXD, COMP 300Ω ±5% 1/2W 2 EB-3015 01121 0686-3015 1

R41 RXD, COMP 12KΩ ±5% 1/2W 2 EB-1235 01121 0686-1235 1

R42 FXD, COMP 6.8KΩ ±5% 1/2W 2 EB-6825 01121 0686-6825 1

R43 FXD, MET, FILM 470Ω ±1% 1/4W 2 TYPE CEB T-O 07716 0698-3506 1

R44 FXD, COMP 47KΩ ±5% 1/2W 2 EB-4735 01121 0686-4735 1

R45 FXD, COMP 5.1KΩ ±5% 1/2W EB-5125 01121 0686-5125

R46 FXD, COMP 100KΩ ±5% 1/2W 2 EB-1045 01121 0686-1045 1

R47 FXD, COMP 680Ω ±5% 1/2W 2 EB-6815 01121 0686-6815 1

R49 FXD, MET. OX 3KΩ ±5% 2W 2 TYPE C42S 16299 0698-3642 1

R51 FXD, COMP 20KΩ ±5% 1/2W 2 EB-2035 01121 0686-2035 1

R52 FXD, MET. FILM 1.21KΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0757-0274 1

R53 FXD, COMP 470Ω ±5% 1/2W 2 EB-4715 01121 0686-4715 1

R54,55 FXD, WW 5Ω ±0.5% 1/2W 4 TYPE E-30 01686 0811-1920 1

R56 FXD, MET. FILM 1.69KΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0698-4428 1

R57 FXD, MET. FILM 3.57KΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0698-3496 1

R58 FXD, MET. FILM 196Ω ±1% 1/8W 2 TYPE CEA T-O 07716 0698-3440 1

R60 FXD, MET. FILM 4.81KΩ ±1% 1/4W 2 TYPE CEB T-O 07716 0698-5147 1

R61 FXD, MET. FILM 45KΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0698-5091 1

R72 VAR. WW 250Ω (MODIFY) 2 TYPE 110-F4 11236 2100-0439 1

R73 FXD, MET. FILM 42.2Ω _1% 1/8W 2 TYPE CEA T-O 07716 0757-0316 1

R80 FXD, COMP 33KΩ ±5% 1/2W 1 EB-3335 01121 0686-3335 1

R81 VAR. WW 1K

Ω

2 TYPE 110-F4 11236 2100-0391 1

R87 THERMISTOR 64Ω ±10% 2 LB16J1 02606 0837-0023 1

S1 SWITCH, PILOT LIGHT (RED)

PUSH ON/OFF SPDT 1 54-61681-26 A1H 87034 3101-0100 1

S2 ROTARY SWITCH CONCENTRIC SHAFTS 2 09182 3100-1913 1

T1 TRANSFORMER, POWER 1 09182 9100-1821 1

VR1 DIODE, ZENER 6.2V 2 1N821 06486 1902-0761 2

VR2 DIODE, ZENER 6-19V ±5% 400MW 2 1N753 04713 1902-0049 2

MISCELLANEOUS

COVER, TOP 2 09182 5000-6061

CHASSIS, RIGHT 1 09182 5060-6118

CHASSIS, LEFT 1 09182 5060-6119

PANEL, FRONT 1 09182 06205-00001

BINDING POST (MAROON) 2 09182 1510-0040 1

BINDING POST(BLACK) 4 DF21BC 58474 1510-0039 1

KNOB, BLACK (WITH POINTER) 2 09182 0370-0107 1

KNOB, RED 2 09182 0370-0101 1

KNOB, BAR, RED )WITH POINTER) 2 09182 0370-0102 1

KNOB, BLACK 2 09182 0370-0179 1

METER 2 1/2" DUAL SCALE 0-50V 0-.75A 2 09182 1120-1230 1

BEZEL, METER 1/6 MOD 2 09182 4040-0295 1

SPRING, METER 8 09182 1460-0720 2

GUARD, BARRIER STRIP 1 09182 5020-5541

CABLE CLAMP 1 T4-4 79307 1400-0330

STRAIN RELIEF BUSHING 1 SR-5P-1 28520 0400-0013 1

LINE CORD PLUG PH151 7 1/2' 1 KH-4096 70903 8120-0050 1

JUMPER, BARRIER STRIP 10 422-13-11 013 71785 0360-1143 2

PLASTIC EXTRUDSION BARRIER STRIP 1 09182 4040-0067

BARRIER BLOCK 1 09182 0360-1273 1

FUSEHOLDER 1 342014 75915 1400-0084 1

6-6

TM11-6625-2965-14&P

REF. MFR. hp

DESIG. DESCRIPTION TQ MFR. PART NO. CODE PART NO. RS

BRACKET, TRANSF. MFG 2 09182 06205-00002

BRACKET, HEAT SINK 2 09182 5000-6060

HEAT SINK, REAR 1 09182 0050-1035

RUBBER BUMPER (FEET) 4 MB50 87575 0403-0088 1

PRINTED CIRCUIT BOARD 1 09182 06205-20020

RUBBER BUMPER, PRINTED CIRCUIT

BOARD 3 4072 87575 0403-0086 1

HEAT DISSIPATOR (Q7, Q4) 2 NF-207 05820 1205-0033 2

MICA INSULATOR (Q7, Q4) 2 734 08530 0340-0174 2

INSULATOR, TRANSISTOR PINS (Q7, Q40 4 09182 0340-0166 4

INSULATOR (Q7,Q4) 4 09182 0340-0168 4

END CAPS 2 09182 9220-1218

CARTON 1 09182 9211-0848

OPTION 07

10-TURN OUTPUT VOLTAGE CONTROL

R10 VAR. WW 10KΩ ±5% (10 TURN) 2 09182 2100-1866

KNOB 2 09182 0370-0137

OPTION 13

10-TURN VOLTAGE CONTROL

WITH DECADIAL

R10 VAR. WW 10KΩ ±5% (10 TURN) 2 09182 2100-1866

DECADIAL 2 RD-411 07716 1140-0020

6-7

TM11-6625-2965-14&P

PART NUMBER - NATIONAL STOCK NUMBER

CROSS REFERENCE INDEX

NATIONAL NATIONAL

PART STOCK PART STOCK

NUMBER FSCM NUMBER NUMBER FSCM NUMBER

DF21BC 58474 5940-00-738-6269 150D475X9035B2 56289 5910-00-177-4300

0150-0052 28480 5910-00-797-4909 150D475X9035B2 56289 5910-00-752-4172

0160-0153 28480 5910-00-965-9728 1510-0039 28480 5940-00-738-6269

0180-0100 28480 5910-00-752-4172 1853-0041 28480 5961-00-931-8259

0180-1836 28480 5910-00-974-6135 1853-0099 28480 5961-00-450-4689

0180-1852 28480 5910-00-931-7060 1854-0071 28480 5961-00-137-4608

0180-1888 28480 5910-00-884-1194 1854-0087 28480 5961-00-824-7567

0370-0101 28480 5355-00-068-4557 1854-0225 28480 5961-00-072-0094

0370-0102 28480 5355-00-906-8933 1854-0229 28480 5961-00-867-9318

0370-0107 28480 5355-00-926-5508 1901-0033 28480 5961-00-821-0710

0686-1045 28480 5905-00-195-6761 1901-0460 28480 5961-00-867-9206

0686-2035 28480 5905-00-903-6304 1901-0461 28480 5961-00-937-3918

0686-3335 28480 5905-00-997-5436 1902-0049 28480 5961-00-911-9277

0686-4735 28480 5905-00-222-5571 1902-3002 28480 5961-00-252-1307

0686-5125 28480 5905-00-279-2019 192P10292 56289 5910-00-993-8305

0698-3440 28480 5905-00-828-0377 2N3417 03508 5961-00-937-3768

0698-3496 28480 5905-00-407-0106 2100-0281 28480 5905-00-918-7471

0698-3506 28480 5905-00-431-6844 2100-0439 28480 5905-00-851-3924

0698-5087 28480 5905-00-469-2837 2100-1824 28480 5905-00-892-9626

0757-0274 28480 5905-00-858-9105 2100-1866 28480 5905-00-110-0282

0757-0316 28480 5905-00-981-7475 2140-0244 28480 5240-00-951-3376

0757-0346 28480 5905-00-998-1906 242E1025 56289 5905-00-504-4892

0757-0427 28480 5905-00-917-0578 30D105G050BA2 56289 5910-00-691-1255

0757-0440 28480 5905-00-858-6795 30D105G050BA2 56289 5910-00-130-2712

0813-0001 28480 5905-00-932-0413 3101-0100 28480 5930-00-918-4381

1N4830 03508 5961-00-103-3950 3101-1248 28480 5930-00-476-9679

1140-0020 28480 5355-00-584-0840 312002 75915 5920-00-280-5062

1205-0033 28480 5999-00-871-9538 342014 75915 5920-00-881-4636

1400-0084 28480 5920-00-881-4636 734 08530 5970-00-840-5109

8120-0050 28480 5625-00-052-4921

6-8

SECTION VII

CIRCUIT DIAGRAMS

TM 11-6625-2965-14&P

This section contains the circuit diagrams neces-

sary for the operation and maintenance of this

power supply. Included are:

Component Location Diagram, Figure

7-1, which shows the physical location and refer- identified by encircled numbers on the schematic

ence designator of parts mounted on the printed and printed wiring board.

wiring board.

Schematic Diagram, Figure 7-2, which

illustrates the circuitry for the entire power supply. Voltages are given adjacent to test points,

7-1

APPENDIX A

REFERENCES

TM ll-6625-2965-14&P

DA Pam 310-4

DA Pam 310-7

TM 38-750

TM 750-244-2

TM 11-2019

TM 11-6625-203-12

TM 11-6625-654-14

TM 11-6625-822-12

Index of Technical Manuals, Technical Bulletins,

Supply Manuals (Types 7, 8, and 9), Supply Bulletins,

and Lubrication Orders.

US Army Equipment Index of Modification Work

Orders.

The Army Maintenance Management System

(TAMMS).

Procedures for Destruction of Electronics Materiel

to Prevent Enemy Use (Electronics Command).

Test Sets 1-49, 1-49-A, and 1-49-B and Resistance

Bridges

Operatorfsand

meter

ME-77/u and

operators, Organizational, Direct Support, and

ZM-4A/U

and

ZM-4B/U.

Organizational Maintenance:

AN/uRM-105

AND AN/URW105C (Including

ME-77C/[T).

Multi-

Multimeter,

General Support Maintenance Repair Parts and Special Tools List (Including Depot Maintenance Repair Parts and Special Tools List) for

Multimeter AN/USM-223.

Operator and Organizational Maintenance Manual;

Signal Generator

SG-321B/U.

TM 11-6625-2616-14

TM 11-6625-2658-14

TM 11-6625-2724-12

TB 43-180

Operator’s Organizational, Direct Support, and

General Support Maintenance Manual; Digital Voltmeter

AN/GSM-64A.

Operator’s, Organizational, Direct Support, and

General Support Maintenance Manual for Oscilloscope

AN/uSM-281C

(NSN 6625-OO-1O6-9622).

Operator’s and Organizational Maintenance Manual:

Voltmeter, Electronic

ME-202C/U

(NSN 6625-00-972-4046),

Calibration Requirements for the Maintenance of

Army Materiel.

A-1

ICOEIL

TM 11-6625-2965-14&P

APPENDIX B

COMPONENTS OF END ITEM LISTING

1 each Power Supply HP 6205B

BILL

Technical Manual TM 11-6625-2965-14&P

AAL

N/A

6625-00-437-4861

B-1

APPENDIX C

MAINTENANCE ALLOCATION

TM 11-6625-2965-14&P

Section 1.

INTRODUCTION

C -1. General

This appendix provides a summary of the main-

tenance operations for the PP-7548/U. It

authorizes categories of maintenance for specific maintenance functions on repairable items and

components and the tools and equipment required

to perform each function. This appendix may

be used as an aid in planning maintenance operations.

C-2. Maintenance Function

Maintenance functions will be limited to and defined as follows:

a. Inspect.

item by comparing its physical, mechanical, and/ or electrical characteristics with established standards through examination.

b. Test. To verify serviceability and to detect

incipient failure by measuring the mechanical or electrical characteristics of an item and comparing those characteristics with prescribed standards.

c. Service. Operations required periodically to keep an item in proper operating conditions, i.e., to clean (decontaminate), to preserve, to drain, to paint, or to replenish fuel, lubricants, hydraulic fluids, or compressed air supplies.

d. Adjust

by bringing into proper or exact position, or by setting the operating characteristics to the specified parameters.

Align.

of an item to bring about optimum or desired performance.

f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test measuring and diagnostic equipments used

To determine the serviceability of an

To maintain, within prescribed limits,

To adjust specified variable elements

in precision measurement. Consists of compari-

sons of two instruments, one of which is a certified

standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being compared.

Install.

ing into position an item, part, module (component or assembly) in a manner to allow the proper functioning of the equipment or system.

h. Replace.

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

Repair.

ices (inspect, test, service, adjust, align, calibrate, replace) or other maintenance actions (welding,

grinding, riveting, straightening, facing, rema-

chining, or resurfacing) to restore serviceability

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 condition as prescribed by maintenance standards (i.e., DMWR) in appropriate technical publications. Overhaul is normally the 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 of unserviceable 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 the act of returning to zero those age

measurements (hours, miles, etc. ) considered in classifying Army equipments/components.

The act of emplacing, seating, or fix-

The act of substituting a serviceable

The application of maintenance serv-

C-1

TM 11-6625-2965-14&P

C-3. Column Entries

a. Column 1, Group Number. Column 1 lists

group numbers, the purpose of which is to identify

components, assemblies, subassemblies, and mod-

ules with the next higher assembly.

b. Column 2, Component/Assembly. Column 2 contains the noun names of components, assemblies, subassemblies, and modules for which maintenance is authorized.

c. Column 3, Maintenance Functions Column 3 lists the functions to be performed on the item listed in column 2. When items are listed without maintenance functions, it is solely for purpose of having the group numbers in the MAC and RPSTL coincide.

d. Column 4, Maintenance Category. Column 4 specifies, by the listing of a “worktime” figure in the appropriate subcolumn (s), the lowest level of maintenance authorized to perform the function listed in column 3. This figure represents the ac-

tive 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, appropriate “worktime” 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 time, and quality assurance/quality 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 - Operator/Crew 0- Organizational F- Direct Support H - General Support D - Depot

e. Column 5, Tools and Equipment. Column 6

specifies by code, those common tool sets (not

individual tools) and special tools, test and support equipment required to perform the designated function.

f. Column 6, Remarks. Column 6 contains an alphabetic code which leads to the remark in section IV, Remarks, which is pertinent to the

item opposite the particular code.

C-4. Tool and Test Equipment Requirement

a. Tool or Test Equipment Reference Code. The

numbers

used in the tools and equipment column of the MAC. The numbers indicate the applicable tool

or test equipment for the maintenance functions.

b. Maintenance Category. The codes in this

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

c. Nomenclature. This column lists the noun name and nomenclature of the tools and test equipment required to perform the maintenance functions.

d. National/NATO Stock Number. This column lists the National/NATO stock number of the specified tool or test equipment.

e. Tool Number. This column lists the manu-

facturer’s part number of the tool followed by the

Federal Supply Code for manufacturers (5-digit)

in parentheses.

C-5. Remarks (sect IV)

a. Reference Code. This code refers to the ap-

propriate item in section II, column 6.

b. Remarks. This column provides the required explanatory information necessary to clarify items appearing in section II.

(sect Ill)

in this column coincide with the numbers

C-2

SECTION II MAINTENANCE ALLOCATION

FOR

POWER SUPPLY PP-7548/U

CHART

(1)

GROUP

NUMBER

COMPONENT/ASSEMELY

Power Supply PP-7548/U

o F

0.1

(4)

0.2

1.2

0.6

1.3

(5)

TOOLS

AND

EQPT.

2 1

3 3

3-11 3-11 3

3-11

(6)

REMARKS

A A B

c c

D D D

(2)

(3)

MAINTENANCE

FUNCTION

Inspect Service Test

Inspect Service Test Adjust Repair

Overhaul

MAINTENANCE CATEGORY

C-3

SECTION III TOOL AND TEST EQUIPMENT REQUIREMENTS

FOR

POWER SUPPLY PP-7548/U

TOOL OR TEST

EQUIPMENT MAINTENANCE NOMENCLATURE NATIONAL/NATO TOOL NUMBER

REF CODE CATEGORY STOCK NUMBER

1 0 MULTIMETER AR/URM-105 6625-00-581-2036

2 0 TOOL KIT, ELECTRONIC EQUIPMENT TK-101/G 5180-00-064-5178

3 H, D TOOL KIT, ELECTRONIC EQUIPMENT TK-105/G 5180-00-610-8177

4 H, D GENERATOR, SIGNAL SG-321/U 6625-00-674-7097

5 H, D MULTIMETER AN/USM-223/U 6625-00-999-7465

6 H, D MULTIMETER, ELECTRONIC ME-260()/U 6625-00-965-1534

7 H, D OSCILLOSCOPE AN/USM-281 6625-00-106-9622

8 H, D RESISTANCE BRIDGE ZM-4()/U 6625-00-500-9370

9 H, D TRANSFORMER, VARIABLE CN-16/U 5950-00-235-2086

10 H, D VOLTMETER, DIGITAL AN/GSM()/64 6625-00-022-7894

11 H, D VOLTMETER, ELECTRONIC ME-202()/U 6625-00-709-0288

C-4

REFERENCE

CODE

SECTION IV.

REMARKS

POWER SUPPLY PP-7548/U

REMARKS

Exterior

Operational

Interior

All

C-5

TM 11-6625-2965-14&P

APPENDIX

MANUAL BACKDATING CHANGES

Manual backdating changes describe changes necessary to adapt this manual to earlier instruments. TO adapt the manual to serial numbers prior to 7L2301 inspect the following table for your serial number and then make the appropriate changes.

CHANGE 1: In the replaceable parts table, make the following changes:

Delete Q10. Delete R51. Change R53 to fxd, comp 10 ±5% ½W, EB-1005,

01121, part No. 0686-1005.

Change R54 to fxd, ww 5.25 ±0.5% ½W, Type

E-30, 01686, Part No, 0811-1921.

Change R81 to var. ww 100 , Type 110-F4,

11236, Part No. 2100-0281.

On the schematic remove transistor Q10 in current limit circuit and connect circuit as shown in

Figure B-1.

The circuit description Paragraph 4-19 should now read as follows:

4-19 Current limiting occurs when diode CR16 becomes forward biased.

determined by the voltage at the base of Q4. The cathode potential of CR16 is determined by the voltage drop acress resistors R53 and R81

Its anode potential

For serial numbers 7L4450 and up check for inclusion of change sheet.

Figure B-1.

which, in turn, are connected across the current sampling resistor(s). The cathode potential of CR16 is a function of the output current.

S this current increases, the drop across the

sampling network increases, and CR16 will

start to conduct. clamps the base of Q4 to a potential which decreases the conduction of the series regulator, thus limiting the output current, R81 permits the cathode potential of CR16 to be varied and thus charges the current limiting threshold.

Paragraph 5-52, Step (e) should read:

“Adjust R81 until differential voltmeter indicates

2.55 Vdc . . . .”

Conduction of this diode

Potentiometer

D-1

TM 11-6625-2965-14&P

Option 11, Overvoltage Protection “Crowbar”

DESCRIPTION:

This option is installed in DC Power Supplies, 6200B, 6201B, 6202B, 6203B, 6204B, and 6206B, and tested at the factory. It consists of a printed circuit board, and six wires that are soldered to the main power supply board.

The crowbar monitors the output voltage of the power supply and fires an SCR that effectively shorts the output when it exceeds the preset trip voltage. CROWBAR ADJUST control on the front panel.

The trip voltage is determined by the setting of the

The trip voltage range is as follows:

screwdriver-type front panel potentiometer,

Model

Trip Voltage Range

To prevent transients from falsely tripping the crowbar, the trip voltage must be set higher than the power supply output voltage by the following margin: 4% of the output voltage plus 2V. The margin repre-

sents the minimum crowbar trip setting for a given output voItage;

than this margin.

OPERATION:

1. Turn the CROWBAR ADJUST fully clockwise to set the trip voltage to maximum.

Set the power supply VOLTAGE control for the desired crowbar trip voltage. To prevent false crowbar tripping, the trip voltage should exceed the desired output voltage by the following amount: 4% of the output voltage plus 2V.

3. Slowly turn the CROWBAR ADJUST ccw until the crowbar trips, output goes to 0V or a small posi-

tive voltage.

4. The crowbar will remain activated and the output shorted until the supply is turned off. To reset

the crowbar, turn the supply off, then on.

5. If the CROWBAR must be completely disabled, remove the lead attached to the CROWBAR ADJUST

potentiometer R5.

6200B 6201B

2.5-44V

2.5-23V

6202B 6203B

2.5-44V 2.5-10V 2.5-44V

the trip voltage can always be set higher

6204B

6205B

2.5-44V 2.5-65V

6206B

D-2

TM11-6625-2965-14&P

TABLE A-1. REPLACEABLE PARTS

REF. MFR. hp

DESIG. DESCRIPTION TQ MFR. PART NO. CODE PART NO. RS

C1 FXD, ELECT 1µF 50VDC 2 30D105G050BA2 56289 0180-0108 1

C2 FXD, MICA 510µF 500VDC 2 RCM15E511J 04062 0140-0047 1

CR1-CR3 RECT. SI. 200MA 200PRV 6 1N485B 93332 1901-0033 6

CR4 SCR 7.4A 100PRV 2 C20B 03508 1884-0032 2

Q1,2 SS NPN SI. 4 2N3417 03508 1854-0087 4

R1 FXD, MET. FILM 10Ω ±1% 1/8W 2 TYPE CEA T-O 07716 0757-0346 1

R2 FXD, COMP 3KΩ ±5% 2W 2 TYPE C42S 16299 0698-3642 1

R3 FXD, MET. FILM 1.21LΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0757-0274 1

R4 FXD, MET. FILM 7.5KΩ ±1% 1/8W 2 TYPE CEA T-O 07716 0757-0440 1

R5 VAR. WW 10KΩ ±5% 2 09182 2100-1854 1

R6 FXD, WW 1KΩ ±5% 3W 2 242E1025 56289 0813-0001 1

R7 FXD, COMP 22Ω ±5% 1/2W 2 EB-2205 01121 0686-2205 1

R8 FXD, MET. FILM 196Ω ±1% 1/8W 2 TYPE CEA T-O 07716 0698-3440 1

T1 TRANSFORMER, PULSE 1 09182 5080-7122 1

VR1 DIODE, ZENER 6.19V±5% 2 1N753 04713 1902-0049 2

VR2 DIODE, ZENER 2.37V±5% 2 1N4370 04713 1902-3002 2

MISCELLANOEUS

PRINTED CIRCUIT BOARD (BLACK) 1 09182 06205-20021

P.C. BOARD (INCLUDES COMPONENTS) 1 09182 06205-60021

HEAT SINK 1 09182 06205-00003

INSULATOR (CR4) 2 09182 0340-0462 1

MICA WASHER 2 09182 2190-0709 1

D-3

TM 11-6625-2965-14&P

D-4

Figure A-1.

*For Model 6205B the above circuit is duplicated on each half of the assembled

board, 06205-60021.

Models 6200B, 6204B, and 6205B* Overvoltage Protection “Crowbar”

MANUAL CHANGES

Model 6205B DC Power Supply

Manual HP Part No. 06205-90002

ITM 11-6625-2965-14&P

Make all corrections in the manual according to errata below,

supply serial number and enter any listed change(s) in the manual.

The primary wiring of the unit is now as shown

SERIAL

Prefix Number

ALL

7L lC

1140A

- 5900 1

5451 5901 - 6200 6201 - 6300 6301 - up 1,2,3,4

MAKE

CHANGE S

Errata

1,2 1,2,3

below.

ERRATA:

On Page 3-1, in Paragraph 3-2, delete step (b)

and reletter following steps appropriately; change

step (c) to read:

operating mode. . . ”;

“Set range switch to desired

change step (d) to read: “Ad-

just coarse and fine voltage controls until. . ."

On Page 5-4, in Paragraph 5-16, change steps (b) through (d) to read as follows:

The Serial Prefix of this unit has been changed to

1140A. This is the only change.

b. Set METER switch to low current range and

RANGE switch to high voltage mode.

c, Turn on supply and adjust VOLTAGE controls

until front panel meter indicates exactly 300mA

(0.5 ampere for Model 6206B supplies).

d. Differential voltmeter should read 1.5 ±

in the instructions for auto-series operation in paragraph 3-33, change the third sentence to

read:

0.045Vdc.

CHANGE 1:

In the replaceable parts table, make the following

change:

Terminal Strip: Add, HP Part No. 0360-0401.

CHANGE 2:

In the replaceable parts table, make the following

changes:

S1: Change to

HP Part No. 3101-1248.

In miscellaneous:

Panel, Front: Change to HP Part No. 06205-00004.

On page A-1 under Description, add “6205B” to the first sentence. Also change the second sentence of the second paragraph to read, “The trip voltage is determined by the setting of the crowbar adjust control on the front panel (except in the Model 6205B, where it is accessible through a hole in the top cover). “ Also on page A-1, change the last part of the third step under Operation to read “. . . output goes to O volts or a small positive voltage. “

CHANGE 3:

In the replaceable parts table and on the schematic

make the following changes:

Tl: Change to HP Part No. 9100-2611.

On the schematic and in the parts list, change

resistor R12 (for both dual supplies) to 1.4k

5% 3W 30 ppm, HP Part No. 0811-1804.

then check the following table for your power

CHANGE 4:

ERRATA :

“The value of Rx is this voltage divided by the

voltage programming current of the slave sup-

ply (l/Kp,

where K

is the resistance program

ming coefficient for constant voltage operation). “ The voltage programming current of the Model 6205B is 1/200 ohms per volt, or 5 milliamps.

D-5

Manual Changes/Model 6205B

TM 11-6625-2965-14&P

DESCRIPTION

Front Panel, Lettered

STANDARD

06205-00005

HP PART NO.

OPTION A85

06205-60004

OPTION X95

Chassis, Right Side

Chassis, Left Side

Cover, Top

Rack Kit (accessory)

Heatsink

ERRATA:

In parts list, change HP Part No. of rubber bumper (qty. 4) to 0403-0002.

In Figure 5-4, change Rx value listed for Model 6206B to 3 ohms.

In Table 1-1, change the INTERNAL IMPEDANCE

AS A CONSTANT VOLTAGE SOURCE (Output Impe-

dance) specification to read as follows:

Output Impedance (Typical): Approximated by a 25 milliohm resistance in series with a 1 micro henry inductance.

The standard colors for this instrument are now mint gray (for front panel) and olive gray (for all other external surfaces). Option X95 designates use of the former color scheme of light gray and blue gray. of a light gray front panel with olive gray used for all other external surfaces. New part numbers shown above.

Option A85 designates use

5060-7956

5060-7955

5000-9424

14523A

06205-60005

5060-6118

5060-6119

5000-6061

14523A-A85

06205-60002

ERRATA:

Effective January 1, 1977, Option 007 (1O-turn voltage control) has been redesignated Option 009,

and Option 013 (1 O-turn voltage control with deca dial) has been redesignated Option 015. Make these changes wherever Option 007 or 013 is mentioned in the manual.

The front panel binding posts have been changed to a type with better designed insulation. two types of posts listed on page 6-6 of the parts list and add :

0114 (qty. 4); and red binding post HP Part No.

1510-0115 (qty. 2).

black binding post, HP Part No. 1510-

Delete the

● The corrugated shipping carton for this model has

been changed to HP Part No. 9211-2570. Two 9220-2703 floater pads are used.

The blue-gray meter bezel has been replaced by a black one, HP Part No. 4040-0414.

In Figure 3-9, delete the six references to TP23.

These wires must be connected in the appropriate

power supply directly to the end of R54 that is

towards the rear of the supply. Another correction

needed in this figure is that the wire from terminal

A6 in Slave No. 1 in the two-unit example at the

top of the figure should be connected to the rear of R54 in the master supply. Note: The range switches of the master and slave supplies must be set to the same range when operating in autoparellel.

Add to the parts list the replacement lamp for illuminated switch 3101-1248, which is used in those supplies that include Change 2. The HP

Part No. of the type A1H lamp is 2140-0244.

D-6

8-5-77

TM 11-6625-2965-14&P

Figure 7-1. Component Location Diagram

Figure 7-2. Schematic Diagram, Model 6205B

By Order of the Secretary of the Army:

Official:

J. C. PENNINGTON

Major General, United States Army

The Adjutant General

Distribution:

Active Army:

TSG (l) USAARENBD (1)

USAINSCOM (2)

TRADOC (2)

DARCOM (1)

TECOM (2)

OS Maj Cmd (2) USACC (2) HISA Ft Monmouth (21)

Armies (1)

USASIGS (10) Svc Colleges (1) Ft Richardson (CERCOM Oft) (1) Ft Carson (5) Ft Gillem (10) USMR (1) USA ERDAA(l) USAERDAW (1) Army Dep (1) except:

LBAD (10)

SAAD (30)

TOAD (14)

SHAD (3)

USA Dep (1) Sig Sec USA Dep (1) Units org under fol TOE:

29-134 (1) 29-136 (1) 29-207 (2) 29-610 (2)

NG: None.

USAR: None.

For explanation of abbreviations used, see AR 310-50.

E. C. MEYER

General, United States Army

Chief

of Staff

THE METRIC SYSTEM AND EQUIVALENTS

PIN: 044061-000

HP (Hewlett-Packard) 6205B User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

WARNING

SECTION II

SECTION IV

SECTION V

SECTION VI

SECTION VII

APPENDIX A

APPENDIX B

APPENDIX C