REGULATED POWER SUPPLIES · 1-2 The Harrison Laboratories Model 6226A is a compact, flexible, regulated con stant voltage/constant current de power supply suitable for either bench

-

REGULATED

POWER SUPPLIES

A DIVISION OF

HEWLETT ~ PACKAR.D _________________ ,

Model 6226A Power Supply

Instruction eSc Operating Manual 1

HARRISON LABORATORIES 45 INDUSTRIAL ROAD. BERKELEY HEIGHTS, NEW JERSEY. 464·1234 • AREA CODE 201 • TWX·SUMMIT, N. J. 977

DIGITALY REMASTERED OUT OF PRINT

HEWLETT PACKARD MANUAL SCANS By

Artek Media 18265 200th St.

Welch, MN 55089

www.artekmedia.com“High resolution scans of obsolete technical manuals”

ALL HEWLETT PACKARD MANAULS ARE REPRODUCED BY PERMISSION AND UNDER LICENSE AGREEMENT WITH AGILENT TECHNOLOGIES, INC.

REMOVAL OF THIS DISCLAIMER IS INVIOLATION OF AGILENT TECHNOLOGIES AND ARTEK MEDIA’S COPYRIGHTS. DUPLICATION OR MODIFCATION OF THIS DIGITAL DOCUMENT WITHOUT PRIOR CONSENT

IS NOT PERMITTED

If your looking for a quality scanned technical manual in PDF format please visit our WEB site at www.artekmedia.com or drop us an email at [email protected] and we will be happy to email you a current list of the manuals we have available. If you don’t see the manual you need on the list drop us a line anyway we may still be able to point you to other sources. If you have an existing manual you would like scanned please write for details. This can often be done very reasonably in consideration for adding your manual to our library.

Typically the scans in our manuals are done as follows;

1) Typed text pages are typically scanned in black and white at 300 dpi. 2) Photo pages are typically scanned in gray scale mode at 600 dpi 3) Schematic diagram pages are typically scanned in black and white at 600

dpi unless the original manual had colored high lighting (as is the case for some 70’s vintage Tektronix manuals).

4) Most manuals are text searchable 5) All manuals are fully bookmarked

All data is guaranteed for life (yours or mine … which ever is shorter). If for ANY REASON your file becomes corrupted, deleted or lost, Artek Media will replace the file for the price of shipping, or free via FTP download. Thanks Dave & Lynn Henderson Artek Media

http://www.artekmedia.com/

http://www.artekmedia.com/

mailto:[email protected]

The infonnation contained in this booklet is intended for the operation and maintenance of H-Lab equipment and is not to be used or reproduced without written consent of the Harrison Laboratories.

HARRISON LABORATORIES DIVISION OF HEWLETT-PACKARD COMPANY

45 Industrial Road Berkeley Heights, N.J.

Phone 464-1234 Area Code 201

Model 6226A Power Supply

Instruction & Operating Manual 1

Scans by Artekmedia => 2012

The information contained in this booklet is intended for the operation and

maintenance of H-Lab equipment and is not to be used or reproduced without written

consent of Harrison Laboratories, a division of Hewlett-Packard Company.

PATENT NOTICE*

Patents have been applied for on circuits used in this power supply. Buyer is not

licensed to reproduce drawings or to utilize the circuit without written permission

from Harrison Laboratories, a division of Hewlett-Packard Company.

CLAIM FOR DAMAGE IN SHIPMENT

This equipment should be tested as soon as it is received. If it fails to operate

properly or is damaged in any way, a claim should be filed with the carrier. A full

report of the damage should be obtained by the claim agent, and this report should

be forwarded to us. We will then advise you of the disposition which is to be made

of the equipment and arrange for repair or replacement.

SEE WARRANTY NOTICE ON INSIDE BACK COVER

r~------------------------------------------------~'

HARRISON LABORATORIES 45 INDUSTRIAL ROAD. BERKELEY HEIGHTS. NEW JERSEY. 464-1234 • AREA CODE 201 • TWX-SUMMIT. N. J_ A77

Scans by ArtekMedia => 2012

TABLE OF CONTENTS

Section Page

I GENERAL INFORMATION 1-1 General Information 1-1 1-6 Instrument Identification 1-1 1-8 Cooling System 1-2 1-10 Power Cable 1-2

II PREPARATION FOR USE 2-1 Incoming Inspection 2-1 2-3 Installation 2-1 2-6 .•. Racic.Mounting 2-1 2-8 Adapter Frame 2-1 2-11 Power Requirements 2-3 2-14 Three-Conductor Power Cable 2-3 2-17 Repackaging for Shipment 2-4

III OPERATION 3-1 Operating Controls 3-1 3-3 Preliminary Considerations 3-1 3-5 Connections to Load 3-1 3-8 Operating Procedure 3-1 3-10 Remote Programming--Constant Voltage 3-3 3-12 Remote Programming--Constant Current 3-5 3-13 Remote Sensing 3-5 3-17 Constant Voltage Series Operation 3-6 3-21 Auto-Tracking Operation 3-8 3-23 Perau~toperaWo 3-9 3-26 Increasing Sensitivity of the Power Supply in

Constant Current Operation 3-9 3-28 Multiple Power Supply Loading 3-9 3-30 Negative Current Loading 3-9 3-32 Overload Protection Circuit 3-10 3-35 Rapid Turn-Down of the Power Supply 3-10 3-37 Automatic Crossover 3-10 3-41 Measuring the Performance of the Power Supply 3-11

IV PRINCIPLES OF OPERATION 4-1 Overall Block Diagram (Figure 4 -1) 4-1 4-3 Preregulator Circuit (Figure 4-2) 4-3 4-5 Preregulator (Figure 4 -3) 4-3 4-8 Series Regulator and Error Amplifier (Figure 4-4) 40.14

/-

i


Section

v

VI

4-11 Input Circuit Constant Voltage (Figure 4-5) 4-13 Input C1rcuit Constant Current (Figure 4-6) 4-15 Reference Circuit (Figure 4-7) 4 -17 Regulator Circuit Operation

MAINTENANCE 5-1 ·:Cover Removal and Replacement 5 -3 Top Cover Removal 5 -4 Top Cover Replacement 5 -6 Bottom Cover Removal 5-7 Bottom Cover Replacement 5-8 Side Cover Removal 5-10 Test Equipment Required 5-12 Trouble Shooting 5-14 Trouble Analysis 5-22 Detailed Trouble Shooting Procedure 5-26 Power Supply Adjustments 5-32 Zero-Setting the Meter 5-48 Performance Test 5-50 Constant Voltage Operation 5 -5 6 Constant Current Operation

REPLACEABLE PARTS 6-1 Introduction 6-5 Ordering Information

4-5 4-6 4-7 4-8

5-1 5-1 5-1 5-1 5-1 5-3 5-3 5-3 5-3 5-6 5-12 5-16 5-19 5-19 5-20

6-1 6-1

11


TABLE 1-1.

MODEL 6226A SPECIFICATIONS

Input: 105-125/210-250 VAC, single phase, 50-70 cps.

Output: 0-36 volts, 0"1.5 amps

Load Regulation: Constant Voltage--Less than 0.02% or 2 mv (whichever is greater) for a 1.5 amp load change.

Constant Current--Less than 0.05% or 300jJ.a (whichever is greater) for a 36 volt load change.

Line Regulation: Constant Voltage--Less than 0.02% or 2 mv (whichever is greater) from 105 to 125 VAC or from 125 to 105 VAC.

Constant Current--Less than 0.03% or 250jJ.a (whichever is greater) from 105 to 125 VAC or from 125 to 105 VAC.

Ripple and Noise: Constant Voltage--Less than 500 microvolts rms. Constant Current--Less than 200jJ.a rms.

Operating Temperature Range: 0 to 500 C

Temperature Coefficient: Output voltage change per degree Centigrade is less than 0.01% or 1 mv in constant voltage and less than 0.03% per degree Centigrade in constant current operation. *

Stability: As a constant voltage source. the total drift for 8 hours (after 30 minutes warmup) at a constant ambient is less than 0.05% or 5 mv.

Internal Impedance As A Constant Voltage Source: Less than .01 ohms from DC to 100 cycles. Less than .02 ohms from 100 cycles to 1 Kc. Less than. 5 ohms from 1 Kc to 100 Kc. Less than 3 ohms from 100 Kc to 1 Mc.

Transient Recovery Time: Less than 50 microseconds is required for output voltage recovery (in constant voltage operation) to within 5 millivolts of the nominal output voltage following a 1.5 amp change in outptt current. For this measurement, the nominal output voltage is defined as the mean between the no load and full load voltages.

* Using external programming resistor having temperature coefficient of less than 20 ppm/OCt

1-0


Overload Protection: An all-eleotronic, continuously acting current limit circuit protects the power supply for all overloads, including a direct short placed across the output terminals. The front panel control pennits continuous adjustment of the current limit value from less than 0.10 amps to 2.0 amps.

Controls: A Single coarse control makes possible continuous adjustment of the output voltage over the entire range from 0 to 36 volts. A vernier control, range I volt, is also provided. A coarse current control permits adjustment of the output current to the optimum value for protection of the load device and serves as the output current control when the supply is used as a constant current source. A vernier control, range 25 rna, is also provided.

Meters: A Single meter and meter switch make possible the monitoring of either output voltage or output current--meter accuracy 2%. Voltmeter range 0-40 volts, ammeter range 0-2 amps.

Output Terminals: "Five-way" output binding posts are provided on the front panel, and an output terminal strip is located on the rear of the chassis. All power supply output· terminals are isolated from the chassis, and either the positive or negative terminal may be connected to the chassis through a separate ground terminal located adjacent to the output terminals.

Remote Error Sensing: Error senSing is normally accomplished at the front terminals if the load is attached to the front terminals, or· at the rear terminals if the load is attached to the rear terminals. Also. provision is included on the rear terminal strip for remote error sensing.

Remote Programming: Remote programming of the supply output at 200 ohms/volt in constant voltage and 300 ohms/amp in constant current is made available on the rear terminal strip.

Cooling: Convection cooling 1s employed. The supply has no moving parts.

Size: 5-1/8"1N x 6-3/4"H x ll"D

Weight: 15 pounds, net; shipping weight, 18 pounds.

Finish: Light gray front panel with dark gray case.

Power Cord: A 3 wire seven foot power cord is provided with each unit.

1-00


SECTION I.

1-1 GENERAL INFORMATION

1-2 The Harrison Laboratories Model 6226A is a compact, flexible, regulated constant voltage/constant current de power supply suitable for either bench use or relay rack operation. This power supply is a completely transistorized general purpose power supply useful wherever a continuously variable 0-36 volt, 0-1.5 ampere wellregulated dc power source is required. The continuously variable current control may be used to set the maximum output current (overload or shortcircuit current) when the supply is used as a constant voltage source; or the voltage control may be used to set the maximum output voltage (voltage ceiling) when the power supply is used as a constant current source.

1-3 A front panel meter indicates either the output current or voltage.

1-4 The power supply has both front and rear output terminals. Power supply insulation permits it to be operated as high as 4~0 volts off ground, and either output terminal may be grounded.

1-5 There are a number of different optional modes in which the power supply may be operated:

a. Remote Programming The power supply may be programmed from a remote location by means of an external voltage source or resistance.

b. Remote Sensing The degradation in regulation which will occur at the load because of the voltage drop occuring in the load leads may be ameliorated by using the power supply in the remote sensing mode of operation.

c. Series Operation Power supplies are used in series when a higher output voltage than the maximum output voltage of the power supply is required or greater voltage compliance is required when the power supply is used as a constant current source.

d. Parallel Operation This power supply may be operated in parallel with similar power supplies when output currents greater than 1.5~peresare: reQuited.

1-6 INSTRUMENT IDENTIFICATION

1-7 This manual is applicable only for the Model 6226A power supply. Change

1-1


sheets will be supplied which will define differences between your instrument and this manual if the letter following the power supply type number 6226 is other than A.

1-8 COOLING SYSTEM

1-9 This power supply is convection cooled and requires no maintenance except for an occasional dusting. There should be sufficient space to the rear and along the sides of the instrument to pennit free flow of cooling air.

1-10 POWER CABLE

1-11 A 7-1/2 foot three conductor power cable is supplied with the instrument tenninated in a polarized three prong male connector recommended by the National Electrical Manufacturers Association (NEMA). NEMA recommends that the instrument panel and cabinet be grounded. All Harrison Laboratories instruments are equipped with a power cable which grounds the instrument when plugged into an appropriate receptacle. The offset pin on the power cable three prong connector is the ground pin.

1-12 To preserve the protection feature when operating the instrument from a two contact outlet, use a three-prong to two-prong adaptor and connect the green pigtail on the adaptor to ground.

1-2


SECTION II.

2 -1 INCOMING INSPECTION

2-2 Upon receipt, the instrument should be unpacked and inspected both mechanically and electrically. Observe packing method and retain packing materials until unit has been inspected. Mechanical inspection involves checking for signs of physical damage such as scratched panel surfaces, broken knobs, etc. If damage is apparent, file a claim with the carrier. The electrical inspection involves checking the instrument against its specifications. Section V includes a performance check, which is an in-cabinet check to verify proper instrument operation (see paragraph 5-47). It is a good test as part of incoming inspection. If there is any electrical malfunction refer to the warranty page in the appendix of this manual.

2-3 INSTALLATION

2-4 The Model 6226A is shipped ready for bench use. Connect the power cable supplied with the instrument to the POWER input; the instrument is ready for operation.

2-5 This instrument is air cooled. Sufficient space to permit free flow of cooling air along the sides and to the rear of the instrument should be considered when installing. It should be used in an area where the ambient temperature does not exceed 550 C (l31 0 F) •

2~6 RACK MOUNTING

2-7 The Model 6226A is a submodular unit that can be used as a bench or rack mounted power supply. The H-P adapter frame is designed specifically for rack mounting a submodular unit.

2 -8 ADAPTER FRAME

~-9 The adapter frame is simply a rack frame that accepts any combination of subnodular units (see figure 2-1). It can only be rack mounted. Instructions are given )elow:

a. Place the adapter frame on edge of bench as shown in step I, figure 2-1.

b. Stack the submodular units in the frame as shown in step 2, figure 2 -1. Place the spacer clamp between instruments as shown in step 3, figure 2-1.

2-1


/SU'MOOULAR UNIT ® /- ADAPTER FRAME: 0

", "-

G) SPACE~ CLAMP -.~

RACK OPERATION

FIG 2-1

® BLANK PANEL

2-2 Scans by ArtekMedia => 2012

c. Place two spacer clamps in ends as shown in step 4, figure 2-1~ and push the instrument combination into the frame.

d. Insert screws on either side of frame, and tighten until submodular instruments are tight in the frame.

e. The complete assembly is ready for rack mounting.

2-10 Blank panels are available which may be used as filler panels with the adapter frame.

2 -11 POWER REQUIREMENTS

2-12 The Model 6226A can be operated from either U5 or 230 VAC 50 to 70 cps source. The instrument as shipped from the factory is normally wired for 115 volt operation. If the instrument is to be used on a 230 volt line, the following changes must be made.

a. Unplug the line cord and remove bottom cover.

b. Remove screws along bottom edge of side frames and swing transformer chassis out of unit.

o. Remove the strap between 12 and 14, and 13 and 15 on the power transformer (T 1) •

d. Add strap between 13 and 14.

e. Replaoe fuse FI with a 1.5 amp 230 volt fuse.

f. Replaoe bottom chassis and cover. Turn on instrument and operate normally.

2-13 The input current and power~ when operating at 36 volts output, U5 volts line, and 1.5 amperes load is 1.3 amps, 110 watts; at no load 0.35 amps, 20 watts.

2-14 THREE-CONDUCTOR POWER CABLE

2-15 For the proteotion of 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 oab1e which, when plugged into an appropriate receptacle, grounds the instrument. The offset pin on the power cable three-prong connector is the ground pin.

2-16 To preserve the protection feature when operating this instrument from a two-

2-3


contact outlet, use a three-prong to two-prong adapter and connect the green pigtail on the adapter to ground.

2-17 REPACKAGING FOR SHIPMENT

2-18 The following list is a general guide for repackaging an instrument for shipment. If you have any questions, contact your authorized Harrison Laboratories sales representative.

a. Use the original container designed for the instrument. If a new container is required, a foam pack and container can be ordered from Harrison Laboratories. The stock number is given in the table of replaceable parts under miscellaneous.

b. Wrap the instrument in heavy paper or plastic before placing it in the shipping container.

c. Use plenty of packing material around all sides of the instrument and protect the panel with cardboard strips.

d. Use heavy cardboard carton or wooden box to house the instrumand and use heavy tape or metal bands to seal the container.

e. Mark the packing box with "Fragile-Delicate In strum ent", etc.

NOTE

If the instrument is to be shipped to Harrison Laboratories for service or repair, attaoh to the instrument a tag identifying the owner and indicating the service or repair to be accomplished. In any correspondence be sure to identify the instrument by model number and serial number.

2-4


SECTION III.

OPERATION

3 -1 OPERATING CONTROLS

3-2 Controls and indicators and their functions are shown in figure 3-1.

3 -3 PRELIMINARY CONSIDERATIONS

3-4 Check strapping pattern on rear terminals of the unit. (See Figure 3-2). The power supply as shipped from the factory is strapped for local programming, local sensing as indicated on the rear of the unit. It will be necessary to change the strapping pattern if the power supply is used in some other mode. Wiring instructions for other operating configurations are outlined later in this section.

3 -5 CONNECTIONS TO LOAD

3-6 The load may be connected to either the front or rear output terminals of the power supply. The leads should be twisted or shielded if they -are run past a source of interference.

3-7 Sensing is automatically accomplished at either the front or rear terminals of the power supply as shipped from the factory. The user should realize that the specifications describing the electrical characteristics of the power supply are written for measurements made on the sensing terminals of the power supply. The user should be cognizant of the voltage drop which will occur ·in the load leads. For example, if le;5,emperes flows through #16 stranded wire, the drop in the leads will be approximately 6 mv per foot. This drop can be minimized by using a larger size wire and minimizing the lead length to the load. Regulation at the load can be maintained within the specifications of the power supply by using remote sensing as described in this section of the manual.

3-8 OPERATING PROCEDURE

3-9 The step by step operating procedure for the instrument is outlined in Figure 3-1. The steps are keyed to controls and indicators on the figure.

3-1


(J) MODEL 6221\11 POWER SUPPLY

" -+ ON METE~

I. TURN AC POWER ON.

2. M!TER SWITCH IN VOLTS POSITION.

3. ADJUST COARSE AND fINE VOLTAGE CONTROLS UNTIL THE VOLTAGE ON THE VOLTMETER IS Of THE DESIRED VALUE.

4. M(1CR SWITCH IN AMPS POSITION.

5. SHORT CIRCUIT THE OUTPUT TERMINALS.

6. ADJUST COARSE AND FINE CUm.ENT CONTflOLS UNTIL THE CURRENT ON THE flMPMt. TER IS ()f THE DESIRED VALUE.

7. REMOVE SHORT AND CONNECT LOAD.

OPERATING PROCEDURE FIG 3-1


3-10 REMOTE PROGRAMMING -- CONSTANT VOLTAGE

3-11 The power supply may be programmed from the remote location by means of an external voltage sourer or a resistance. It is necessary to change the strapping pattern on the barrier strip on the rear panel. The front panel pot is disabled when the following remote programming procedures are followed.

A. Resistance Programming (See Figure 3-3A) (1) Stable, low noise, low temperature coefficient (Less than 30

ppm per degree centigrade) programming resistors should be used.

(2) The output voltage will vary at a rate determined by the programming coefficient--200 ohms per volt. (i.e. The output voltage will vary 1 volt for each 200 ohms connected across the programming terminals.) The programming coefficient is determined by the programming current. This current is adjusted to within 1% of 5 milliamperes at the factory. If greater programming accuracy is required, it may be achieved by changing the shunt resistor, RIO.

B. Voltage Programming (See Figure 3-3B) (1) The output voltage will vary in a one to one ratio with the

external programming voltage.

(2) The load on the programming voltage will be approximately 15 microamperes.

(3) The impedance looking into the external programming voltage should be approximately 1000 ohms.

C. Voltage-Resistance Programming (See Figure 3-3C) (1) Stable, low noise, low temperature coefficient (less than 30

ppm per degree centigrade) progremming resistors should be used.

(2) Rr and Rp should be selected so that the impedance looking into their junction is a maximum of 1000 ohms.

(3) The power supply may be programmed by varying the reference voltage. by varying resistor Rr or by varying resistor Rp.

(4) The output voltage will vary linearly as the reference voltage is changed.

(5) The output voltage will vary as the ratio of Rp to Rr when Rp is varied.

3-3


AI + +s -s - A2 A3 A4 A~ A6 A7

MON~:ORIN.J POINTS

FIG 3-2 NORMAL

AI + +5 -S - A2 A3 A4 A~ A6 A7

n l pr.10GRAMMIN6 RESISTOR

(RESISTANCE PR06RAMMIN6)

FIG 3-3A ~EMOTE PROGRAMMING CONSTANT VOLTAGE

AI + +s -$ - A2 A3 A4 A5 A6 A7

Rl

(VULTAbL-Ht.!>I!>TAN(.t: f..'HOukAMMINb)

FIG 3--3C REMOTE PR06RAMMING CONSTANT VOLTAGt:

AI + +5 -5 - A2 A3 A4 A5 A6 A7

fOk LOW AC IMPEDANCE AT l·)t-I.J, liE M0VE STRAP FROM + 1u A I c.. t,utJ CAPACITOR C

FIG 3-5 kI:.MUTt: 5I:.N!>ING

NOHS:

AI + +5 -$ - A2 A3 A4 A~ A6 A7

PROGRAMMING VOLTAGE

(VOLTAGE PROGRAMMI NG) FIG 3-38 REMOTE PROGRAMMING CONSTANT VOLTAGE

AI + +5 -S - A2 A3 A4 A5 A6 A7

PROGRAMMING RESISTOR

FRONT PANEL COARSE AND FINE CURRENT CONTROL MUST BE MAX CCW

(I1ESISIANCE .-I{OGRAMMING) FIG 3-4 REMOTE PROGRAMMING CONSTANT CURRENT

AI + +5 -5 - A2 A3 A4 A~ A6 A7

FIG 3-6 kEMOTE SENSING &. REMOTE PROGRAMMING

I. ")AI! MAY iii 1l\KfN HWM fRONT PI-.Nfl OU1.-UT TERMINALS. 7.. I. 1'1 HUI IHL PO!.IlIVl ,>If NE(JA1IVI:. OUTPUT. TERMINAL SHOULD BE GROUNDED.

3-4


(6) The output voltage will vary in accordance with the following equation when Rr is varied.

3-12 REMOTE PROGRAMMING -- CONSTANT CURRENT

A. Resistance Programming (See Figure 3-4) (1) Stable, low noise, low temperature coefficient (less than 30

ppm per degree centigrade) programming resistors should be used.

(2) The output current will vary at a rate determined by the programming coefficient--300 ohms per ampere in the 6226A. (i.e. The output current will vary 1 ampere for each 300 ohms connected across the programming terminals.) The programming coefficient is determined by the programming current. P5 will vary this current.

3-13 REMOTE SENSING

3-14 Remote sensing is used to maintain good regulation at the load and ameliorate the degradation of regulation which will occur due to the voltage drop in the leads between the power supply and the load. Remote sensing 1s accomplished as follows: (See Figure 3-5)

A. Disconnect the jumper between -8 and - and +8 and +.

B. Run a separate pair of leads from -S to the negative load terminal and +8 to the positive load terminal. CAUTION: Polarity must be observed.

C. It is not required that these leads be as heavy as the load leads. However, it is recommended that they be twisted or shielded to minimize hum pickup.

3-15 The above precautions will result in a low dc output impedance at the load. However, if a low ac impedance is required, it is recommended that the following precautions be taken.

A. Remove the strap between Al and +.

B. Reconnect capacitor C 17 or an equivalent capacitor across the load using a separate pair of leads and being careful to minimize the length of these leads.

3-5


3-16 A combination of remote programming and remote sensing may be used. The wiring for this combination is shown in Figure 3-6.

3 -17 CONSTANT VOLTAGE SERIES OPERATION

3-18 Two or more supplies may be operated in series to obtain a higher voltage (the 6226A may be operated as much as 400 volts above ground) than that obtainable from a single supply. Power supplies are operated in series by connecting the positive terminal of one of the power supplies to the negative terminal of the second supply. The load is then taken across the two unconnected output terminals.

3-19 The power supplies should be connetted in the Auto-Series configuration if itis desirable to have the voltage of two or more power supplies, connected in series, track each other or vary proportionally. (See Figure 3-70 for wiring diagram.) See Note.

Note:

A. Stable, low noise, low temperature coefficient (less than 30 ppm per degree centigrade) resistors should be used for Rx and Ry •

B. Rx and ~ should be selected so that a current equal to approximately 5 rna flows at maximum output voltage. The voltage across Rx will be equal to the output voltage of the master unit. The voltage acros s Ry will equal the output voltage of slave unit one.

O. The most negative supply must be selected as the master or control unit.

3-6


AI + +5 -S - A2 A3 A4 A5 46 A7

MASTER

AI + +5 -5 - A2 43 44 45 A6 A7

SLAVE

~--------~O&GNO

AI ,+ +5 -S - A2 A3 A4 45 A6 A7

Ry

Rl

AI +' +5 -S - A2 43 A4 45 A6 A7

"'---~'JJGNO

(3 UNITS)

FIG 3-78 AUTO SERIES

NOTES:

(2 UNITS)

FIG 3-7A AUTO SERIES

MASTER MASTER

SLAVE .ttl SLAVE-I

SLAVE #Z SLAVE" Z

AI + +5 -S - A2 A3 A4 A5 A6 A7

.... _--o(Q)GNO

(EXTENDING VOLTAuE COMPLIANCE)

FIG 3-7C AUTO St.RlfS

I. LOAD MAY BE TAKEN fROM fRONT PANeL OUTPUT TERMINALS, Z. EITHER THE POSITIVE OR NEGATIVE 'OUTPUT TUlMINAL SHOULD Iii 0HOUNIlUl.

3-7


AI + +S -5 - 1\7 +s -S - A2 A3 A4 45 A6 A7

MA'.lr fl

SLAVE *1

RLZ

.----tOJGNO .----((:;lJGNO

AI of +5 -$ - A2 A3 A4 115 A6 A7

SLAVE liZ SLAVf It 7

R13 ----(~:J) GNO '-----(!J}GNO

FIG 3-8 AUTO TRACKING FIG 3--9 PARALLH

NOTES: I, lOAI) MAY HllAKlN fllOM nWNT PANEL OUTPUT TE~MINALS. Z. tlTH[~ THf POSITIVE OR NEGATIvE. OUTPUT Tt:RMINAL SHOULD Bl GROUNDED.

3 -21 AUTO-TRACKING OPERATION

3-22 Auto tracking is useful when it is desirable to have several power supplies referenced to a common bus vary proportionally. The connections are made in accordance with Figure 3 -8 •

A. The most negative power supply must be selected as the master or control unit.

B. Resistors Rx and Ry are selected so that the current through the resistors Is approximately 5 rna at maximum output voltage.

C. Either the positive or negative output terminal of the slave units may be connected to the common bus.

3-8


3-23 PARALLEL OPERATION

3-24 Auto-Parallel operation is used when it is desirable to have a larger current than is available from a single supply. When the power supplies are connected in the Auto-Parallel configuration the currents in each of the paralleled supplies tends to equal (±10%) the current in the master supply.

3-25 Power supplies are connected in Auto-Parallel in accordance with Figure 3-9.

3-26 INCREASING SENSITMTY OF THE POWER SUPPLY IN CONSTANT CURRENT OPERATION

3-27 The operation of the power supply may be improved in the constant current mode of operation when operating at reduced current levels by increasing the size of the current sensing reSistor R51. The resistor should be selected so that at maximum operating current, the voltage drop across the resistor will be 0.9 volts. The line and load regulation of the power supply will now be 0.03 and 0.05 percent of maximum operating current rather than 0.03 and 0.05 percent of rated output current. The reSistor used to replace R51 sho~ld be a low noise, low temperature coefficient (less than 30 ppm/oC) resistor. It should be selected so that at maximum operating current, it dissipates no more than 5% of its rated power.

3-28 MULTIPLE POWER SUPPLY LOADING

3-29 It is imperative that each load taken from the power supply have two separate leads brought back to the power supply terminals if full advantage is to be taken of the low output impedance of the power supply and mutual coupling affects between equipments being powered from the same supply are to be avoided.

3-30 NEGATIVE CURRENT LOADING

3-31 A load on the power supply may cause current to flow into the positive terminal of the power supply rather than out of the positive terminal as in normal operation, i.e., the power supply may be subjected to negative current loading. The series regulating transistors are unilateral devices and must always conduct in the forwarcl direction if the .outpultregulatlon of the power supply is to be maintained, therefore, an external source cannot be allowed to pump current into the supply such that the direction of current flow in the series transistors will be reversed. It is necessary to load the supply with a dummy load so that the direction of current flow in the supply does not change if the power supply is to be subjected to negative current loading. A diode is conneoted across the output terminals of the power supply so that in the event a negative current is applied to the power supply, the current will be shunted across the output terminals by the protective diode. This diode is used to protect the series transistors and the electrolytio capacitor connected across the output terminals of the power supply.

3-9


3 -3 2 OVERLOAD PROTECTION CIRCUIT

3-33 Special notice should be taken of the action of the current regulating circuit. The power supply will automatically switch into constant current operation when the power supply 1s overloaded in the constant voltage mode of operation. The constant current regulating circuit will limit the output current to the magnitude established by the current control setting. Since the proteotion circuit must necessarily be a fast-acting circuit, it follows that the power supply will not perform properly if the current threshold is exceeded in constant voltage operation. For example, if the load on the power supply consists of a class B amplifier which is drawing peak currents in excess of the threshold current, the protection circuit will begin to limit the output current even though the ammeter (which reads only average current) indicates a current considerably less than the threshold value.

3-34 When the supply is used in the constant current mode of operation,· a voltage ceiling or threshold is established by the output voltage control. That is, if the IR product of the load and the oonstant current exceeds the threshold as established by the constant voltage control, the supply will operate as a constant voltage supply.

3-35 RAPID TURN-DOWN OF THE POWER SUPPLY

3-36 An overvoltage protection circuit is activated when the voltage across the series transistors exceeds approximately 7 volts under full load condition. This circuit will be activated if the programming control is turned down rapidly. When this circuit functions, the sedes transistor is turned off and the output voltage of the supply will go to zero and remain at zero volts until the voltage across the input capacitor has decayed to less than 7 volts. The supply will then turn on and come up· to output voltage.

3-37 AUTOMATIC CROSSOVER

3-38 There will be a time during which both Ql (constant voltage input tranSistor) and Q8 (constant current input transistor) will be conducting. This will occur when the power supply has been operating in the constant voltage mode of operation and is overloaded or when the power supply has been operating in the constant current mode of operation and the load is changed so that the output voltage increases and exceeds the voltage ceiling threshold. The transition period during which both transistors are conducting is called the crossover region.

3-39 The current threshold should be set a minimum of 50 ma greater than the maximum load current when operating in the constant voltage mode of operation.

3-40 The voltage threshold (open circuit voltage) should be set a minimum of 4.0 volts greater than the maximum operating output voltage when operating in the constant current mode of operation.


3-41 MEASURING THE PERPORMANGlL9F WE POWER SUPPLY

3-42 The measuring device (differential voltmeter, digital voltmeter, or oscillosoope) must be connected across the sensing leads of the supply or as close to the output terminals as possible when measuring the output impedance, transient response, regulation, or ripple of the power supply in order to achieve valid measurements. It is important that none of the output current flows through the lead lengths In serles with the monitoring device since such lead lengths can easily have an impedance of the same order of magnitude as the supply impedance and thus effectively invalidate the measurement.

3-43 Connect either the positive or negative terminal of the supply to the chassis ground and the scope case to the same point, making certain that the scope case is not also grounded by some other means such as the power cord when measuring the power supply ripple. Connect both scope leads sfmultane<!)usly to the power supply ground tenninal to be doubly certain that the scope Is not exhibiting a ripple or transient spike that is not coming from the power supply.

3-44 The monitOring device should be. connected to the +S and -8 tenninals (See Figure 3-2) or as shown in Figure 3-10. The performance characteristics should not be measured on the front tenninals when the load is taken off the rear tenninals. Please note that when measurements are made at the front terminals, the monitoring leads are connected at A, not B.

LOAD LEAD -_...-/

MONITOR HERE~c """1 f

FIG 3~IO

3-45 It is recommended that a four-terminal resistor be used to make constant current measurements. The reSistor should be a low noise, low temperature coefficient (less than 30 ppm/oC) resistor and should be used at no more than 5% of its rated power. The monitoring resistor is connected as shawn in Figure 3 -11.

CURRENT MONITORING TERMINALS

EXTERNAL lv-l TO UNGROUNDED LO~~ TO GROUNDED TERMINAL OF ..... __ ----~------- -----....... _ TERMINAL OF POWER SUPPLY ~ MONITORING I POWER SUPPLY

"\ RESISTOR I LOAD

FIG 3 ... 11 TERMINALS


THIS PAGE LEFT

BLANK

SCANS By

ArtekMedia


BIAS BIAS

r a - SUPPLIES HEGULATORS w :r: AND a REfERENCE -0

~ AC IN ~

l- S ( L a w

~ RS, -OUT

:t PRE - SERIES 0 v

CL REGULATOR REGULATOR (URl-lfNT C;CN':,ING RESISTOR ~) -s

V CONSTANT

p--'i~.;(!':_P M CURRENT INPuT

' V..1rvV

COARSE fiNE CURRENT ADJUST

-~ ? -

CONSTANT p:z P,:~ VOLTAGE ,t

.A v C v

INPUT CoAnSf. fiNE

5

VOLTAGE ADJUST

A +<fu T

FIG 4-1 BLOCK DIAGRAM

SECTION IV.

4-1 QYIMLL BLOCK DIAGRAM (FIGJ)'lUi 4-1)

4-2 Referring to Figures 4-1 and 4-2, note that the power line voltage passes through the power t:ransformer to a fullwave rectifier. The rectified ac is applied to the preregulater.- The preregulator functions to maintain an approximately constant voltage across the aedes transistor under any line, load, or output voltage condition, thus minimizing the power dissipated iJl the series transistor. Current passes through the series regulator to the neqative output terminal vta a current sensing reststor. The voltaoe developed across the current sensing reSistor is the input to the constant 'VOltage input circu1t through the senSing terminals. Any changes in oUtput voltage/C\Ur$1'1t are detected in a constant voltage/constant current input Circuit, ampl1fied in the error amplifier, and applied to the series requlator in a manner which tends to counteract the changes in output voltage/current. The bias supplies furnish voltages which are used throughout the instrument for reference and supply purposes. The ammeter is connected across a current senSing resistor to Indicate the output current of the pow'er supply. The voltmeter 1s connected directly across the output termiaals and 1pdicates the output voltage of the power supply.

NOTE: In tho follOWing discussions the negative sensing lead will be conSidered circuit ground.

4-1


,j:>.

I flo,,)

fJI T-I D-28

I ....

~~-1~~~

'Ie 0-29

i

32v +

- 15.5v 1(-15 -9AV ---4 ..... ,f\N. 1 BIAS

REGULATORS • ~

t----+6.5V

I + 2.0V

.0-9

0-26 E: ~ IJ

AC h IN e---.--." ~. ~ 1(-'6 t= 'iv ! I

(, D~5 t T + ',6'

4 0-30

~-TI+ 4;V o---~~~~II~ - I

L!)11(9 O~'

• J/ PREREGULATOR

Jilt t! -" 10 ~ +! 0-32 C-13

O-16~ >R-35

~-O.8v

0-17. ~D-21

SERIES -F

REGULATOR

R-3

0-1" CONSTANT CURRENT

INPUT

0-3 C-I _(-17 T+ +1

. -..,. CONSTANT VOLTAGE v

~r

0-6

R-58 -/VV

I 'NPUT I 0-' ! I I l ~ +S

"V

+r

~ Ai

fiG 4-2 SIMPLIfiED SCHEMATIC


-.

4-3 RECTIFYING CIRCUIT (FIGURE 4-2)

4-4 Referring to Figure 4-2 note that the alternating current is fed through transformer TI to the fullwave rectifiers D31 and D32. This rect:1fied output vo1ta'~Je is then applied to the preregulatDr.

+ 48V

-.-....--.JVV'_t__--' Q-12 ~---...... --...---t

1 TO

RfCTIFIER

I R-52 C-II

l

FIG 4-3 PRE-REGULATOR

4-5 PREREGUI..ATOR {FIGURE 4-3)

4-6 The preregulator permits line current flow only when the voltage across the series transistor is less than 3.0 volts and the voltage across the switching transistor is less than 25 volts.

4-7 Transistor QI0 is the preregulator detector transistor. A local reference voltage is developed across the zener diode, D22. If the collector to emitter voltage of the series transistor exceeds this local reference, the level detector diode, D19, oonducts turning Q10 on and the switching transistor, Q12, off. Transistor Q13 is the switching transistor driver. Tum off of Q12 is initiated by closure of D 19. This action is enhaneed by regenerative action through the inhibit circuit. This circuit, R54, R53, P7, Cl2 and D18 is arranged so that 012 is turned off whenever the voltage across the tranSistor exceeds approximately 25 volts. D27, CII and R52 olamp voltage spikes oocuring at the collector of Q12. Resistor R60 limits the current through the switching tranSistor. RS5 forces saturation of Q13.

4-3


PRE -REGULATOft

R-4_~ -+rt'f.l_R-

36 1 +4ev~+ ~-....--... -VVV'-- -161,1 +~_ __ R-37 R-34 _ C-14

0-23

R -51 ';------+-------""""'----+-----0" OUT

R-48

-16V R-41

C-9

9-----... Q-9 ,..-_

- 15.51,{ +

- O,8V

+ 1.6v-..... -I/V\"-..... ----....... -J~.:....... R-40

R-24

C-'6

0-15

CONSTANT .-...... -t CURRENT

0-14 INPUT

0--6 CONSTANT ~-"""-"""---4~~-I VOLTAGE

INPUT

+2,01,1

FIG 4-4 ERROR AMPLIFIER & SERIES REGULATOR

4-8 SERIES REGULATOR AND ERROR AM'PLIFIER (FIGURE 4-"1

4-9 The sedes regulator conslsta of transistors Q9 and Ql1. Transistor 09, connected as an emitter follower, 18 the driver for the series traDs~stor. Qll is the series t::ran..lstor which controls the output current. Diode D231s a protective diode.

4-10 Q3 i8 the error amplifier transistor. The signal applied to the base of Q3 is obtained from one of three gating dlodes--D6, D14, or DiS. Only one of the three gating diodes is nonnally closed (forward biased), the other two diodes are open (reverse biased). The signal from the voltage input eiroult Is applied through D6. The signal from the constant current input circuit Is applied through 014. Diode DIS 115 the gating diode for the overvoltage protection oircuit. This diode closes when the voltage across the aerie. transistors exceedsapprox:lmately 7 volts under full load conclit1ons in order to protect the series tranIJlstorl. 06 and P3 in conjunction with the output capacitor, 017, stabilize the feed_ok loop.


SERIES REGULATOR

CURRENT SENSING nESISTOR

~-----------------------'----------------------~--~~~r---~ R-51 - f

-15,5V

R-4 C-3 0-4 01

+ R-22 A6

", ,J

R-6 R-5

P-2

0-6

CONSTANT CURRENT

INPUT

R 23

+6_5V

nl

n-9 0-2

A4 p B

COARSE .VOLTA6r

ADJUST

Pc)

FINE VOUA0f

R i3 t- A(J.JU!:',T

- 9.4V -- --../v'\I'- -u- . ---() I ~;. C-2

If -----.---- -{)-----( ii,

FIG 4-5 INPUT CIRCUIT CONSTANT VOLTAGE

_4-11 INPUT CIRCUIT CONSTANT Y9LTAGE (FIGUR~ 4-5)

4-12 The input oircuit consists of the fine voltage adjustment (P9) and the coarse voltage adjus1ment (P8), the amplifier transistors Q1 and Q2. and associated circuits. Q1 and Q2 are silicon NPN transistors connected in a differential amplifier configuration. The base of 02 is grounded through the impedance equalizing reSistors R4 and R5 in order to achieve good thennal characteristics. The base of Q1 is connected to the junction of the programming resistors and the current pullout reSistor (R9) through a current limiting reSistor (R7). Diodes Dl and D4 limit voltage excursions on the base of Q1. R7 limits the current through the programming resistor under the condition of rapId turndown of P8. Capacitor C2 by-passes the programming resistors and increases the high frequency gain of the input circuit. Diode D2 and R8 decouple capacitor C2 from the base of Q1 during constant current operation. ReSistors R9 and RIO are used to set the programming current. Resistor RIO shunting reSistor R9 is used as a trimming adjustment for the programming . current. P2 and R25 are conneoted in a positive feedback configuration to increase the de: circuit gain. Capacitor C3 stabilizes this local feedba~k loop.

4-5


SERIES REGULATOR

0-14

R-2

CURRENT SENSING RESISTOR

R-~I

r--------.------QA~

P-II fiNE

CURRENT ADJUST

P-IO COARSE

CURRENT ADJUST __ fVV-.....

P-5 R-31

-15.5V

R-33

-OUT

R-49 C-IO

+

R-3Z

R-38

CONSTANT VOLTAGE

INPUT

~---~-------+------+-- -.... 6.5V

~---------------------------o+ OUT

FIG 4-6 INPUT CIRCUIT CONSTANT CURRENT

4-13 INPUT CIRCUIT CONSTANT CURRENT (FIGURE 4-6}

4 -14 The constant current input circuit consists of the fine current control P 11 and the coarse current control, PIO, the amplifier transistors 07 and 08, and associated circuit. 07 and 08 are silicon NPN transistors connected in a differential amplifier configuration. The base of 08 is grounded through the impedance equ,alizing resistor R49 in order to achieve good thermal characteristics. The base of 07 is connected to the junction of the programming resistors and the current pullout resistor, R29, through the impedance equalizing resistor, R30. PS Is used to adjust the programming current. R32 is used to increase DC circuit gnl:1. C10 stabilizes this local positive feedback loop. R2 and Rll are arranged in ,} network which changes the bias voltage of 07 as the output voltage changes. Thi:<) :letwork is required to compensate for an error CUITent generated by the volt ... m etE:f shunting the output tennmals.


U II (j -12

R-13

PI5

j I

-..NV"--.--- --9,4V

m.T[UENcr .

> N

~

R-14 R·ZO p-19

'( 4 D <)

o 13

'·HZ .---~~----.-----~~----~~-----+-----~~.---~~--

P·-4 R-Ie n··17

FIG 4 -7 BIAS REGULATORS AND REFERENCE CIRCUIT

4-15 ~ERENCE CIRCUIT (nG'QRE 4 -7)

VOLTAG(

4-16 Transistor Q5 is the series regulating transistor for the regulated negative 15.5 volt bias. Q4 in conjunction with R12 maintains the oollector voltage of Q5 at a relatively constant voltage level as the input voltage varies. This reduoes the power dissipated in transistor Q5 and increases the stability of the bias regulating circuit. Diodes Dl1 and D12 establish the base bias for 04 and in conjunotion with R14 is the coll$Otor bias source for Q6. The emitter of the elTOf

detecting transistor 06 is biased by zener diode D13. R17 and R20 are connected . across the output of the bias supply and establish the base bias of 06. RIg is used to adjust the output voltage of the bias regulator to approximately 15.5 volts. P4 and RIB are connected in a feed forward network to minimize changes in the bias voltage due to input line voltage variation. 04 stabilizes the bias regulator loop. The reference voltage for the power supply is developed across the temperature compensated zener diode, D9" R15 adjusts the oorrent through the diode. A positive 6.5 volt bias voltage is developed across zener diode DIO. A pos:l.tive 2.0 volt bias voltage is developed across the forward biased diodes D5, D7, and D8.

4-7

.,


4-17 REGULATOR CIRCUIT OPERATION

4-18 The circuit functions as follows when the output voltage changes. The change may be a slow shift in output voltage or an AC signal. AC Signals are fed to the base of 01 through C2 and D2. DC Signals are coupled through P8 and P9. The Signals are amplified, reversed in phase, and coupled to the base of Q3 through the gating diode D6.

4-19 The voltage on the anode of the gating diodes D6, D14 and DIS is established by the base voltage of Q3. The cathode voltage of D6 (constant voltage gate) is established by the collector voltage of Q1. The voltage on the cathode of D14 (constant current gate) is established by the collector voltage of transistor Q8. The cathode voltage of DIS (overvoltage gate) is established by the voltage at the junction of the divider resistors R34 and R3 7. Transistor 01 will be conducting when the supply is in the constant voltage mode of operation and diode D6 will be forward biased.

4-20 Transistor 08 begins to conduot when the supply goes into constant current operation. At this time the voltage across the output terminals decreases. The signal applied to the base of 01 will result in its collector voltage gOing positive and reverse biasing D6. D14 becomes forward biased due to conduction of Q8. There is a transition region during which both diodes will be forward biased. This region is called the crossover region.

4-21 The signal applied to 03 is amplified, inverted and applied to the base of the driver tranSistor 09. The signal is amplified by 09 and applied to the base of the series transistor 011 e The Signal is applied in the phase required to restore the original operating conditions, thus maintaining the output voltage/output current of the power Supply constant e

4-22 The DC output voltage is changed by varying the coarse and fine voltage controls _ Resistor R9 in conjunction with the reference voltage can be considered a constant current source since the voltage summing point, AS, is at circuit ground when the loop is in equilibrium. Potentiometers P8 and P9 are connected between the summing pOint and the positive sensing terminal, and since the current through them is constant, feedback action of the regulator loop will rna intain the output voltage of the power supply equal to the drop across these resistors. TherefCM'ft. changing the values of these resistors will change the output voltage of the power supply_'

4-23 Programming the power supply in constant current operation is Similar to constant voltage operation. The input to the supply is a voltage drop across the current sensing resistor. The feedback loop functions to maintain the drop across this resistor constant and consequently maintains the load current constant.


SECTION V.

MAINTENANCE

5-1 COVER REMOVAL AND REPLACEMENT

5 -2 Refer to figure 5 -1 when removing instrument covers. The cover is divided into top, bottom.· and side covers. Removal of the top cover provides access to a printed circuit bonrd, removal of bottom cover provides access to a second printed circuit board, transformer and switches. Instructions as to removal and replacement of covers. are given below.

5-3 TOP COVER REMOVAL

a. Remove the cover retaining screw at the rear of the instrument.

b. Grasp the top cover from the rear, slide it back about 1/2 inch, then tilt the forward edge of the cover upward, and lift the cover from the instrument.

5 -4 TOP COVER REPLACEMENT

5-5 Replace the top cover by resting the cover flat on the cast guides projecting inward near the top of each side fram (see 1, figure 5-1). Then slide the cover forward allowing its forward edge to slip under the edge of the front panel: replace the cover retaining screw.

5-6 BOTTOM COVER REMOVAL

a. Swing tilt stand into a vertical position as shown in figure 5 -1.

b. Remove the retaining screw at the rear of the bottom cover.

c. Slide the cover rearward about two inches to free its forward edge from the front foot assembly; then tilt the forward edge of the cover upward and lift the cover from the instrument.

5-7 BOTTOM COVER REPLACEMENT

a. Set the tilt stand in pOSition shown in figure 5-1.

b. Rest the bottom cover flat on the cast guides projecting inward. near the bottom of each side frame (see 2, figure 5-1).

c. Slide the cover forward on the guides so that the curved portion at the rear of the cover slides over the two short projections (see 3, figure 5-1) at the

5-1


fOOT ASSfMBLY

RELf A Sf BUTTON - BOTTOM C.OVER

--- TI LT STANO

REAR

SIDE C.OVE"R

FIG 5-1 COVER REMOVAL


rear comer of each side frame. Exert upward pressure at the forward edge of the cover to guide it under the front foot assembly.

5-8 SIDE COVER REMOVAL

5-9 The side covers cannot be removed until top and bottom covers have been removed. See paragraphs 5-3 and 5-6. Each side cover is held in place with four screws retained by nuts which are not fastened to the sdie frame.

NOTE

Reinstall side covers before replacing the top and bottom covers.

5-10 TEST EOUIPMENT REQUIRED

5 -11 The test equipment required for adjustment of the ·instrument is given in table 5-1. The table includes the· type of equipment required, critical specification, where the equipment is used, and recommended available commercial test equipment.

5-12 TROUBLE SHOOTING

5-13 The purpose of the trouble shooting procedure is to enable maintenance personnel to isolate troubles to a specific area, not necessarily a component. A systematic approach, such as is given later in this section, can speed up repair and minimize down time.

5-14 TROUBLE ANALYSIS

5-15 Before attempting to trouble shoot this instrument, make sure the fault is with the instrument and not with the associated circuit. The performance check will enable one to determine this without having to remove the instrument from the cabinet. The performance test will be found in paragraph 5 -48 •

5-16 A systematic trouble shooting procedure can be followed with this instrument. For instance, if there is no voltage throughout the instrument check for obvious faults such as burned out fuses (AC and DC). defective power cable, or power line failure.

5-17 Perform a visual inspection for broken leads, overheated resistors, or cold solder joints.

5-18 The circuit consisting of series regulators and amplifiers presents a difficult problem for systematic trouble analysis. This is a feedback circuit in which a faulty component anywhere will affect the operation of the entire loop. If it is necessary

5-3


Instrument Type

DC Voltmeter

DC Ammeter

AC Voltmeter

AC Voltmeter

Variable Transformer

Oscilloscope

Differential Voltmeter

Load Switch

TABLE 5-1

Required Characteristics

Accuracy of +2% Approx. ranges 0-2.5 volts 0-50 volts 0-150 volts

0-3 amps Accuracy ±1%

Accuracy of ±2% Approx voltage ranges 0-150 volts

Accuracy of ± 1 % 90-130 volts Expanded scale

100-130 volt ranges 5 amp current capacity

200 .... v/cm sensitivity differential input

1 mv resolution

l .... sec rise and fall time

Use

Measure DC Voltage

Measure DC

Measure AC Voltages

Measure Input Line Voltage

Change AC Input Voltage

Measure Ripple Trans-ient Response

Measure Line & Load Regulation

Measure Transient Response

Suggested Test Equipment

Simpson Model 269

HP Model 4288

Simpson Model 269

Triplett Model 420M

Superior Type Ql16U

HP Model 130C

Fluke Model 80lH

See Note.

Mercury Relay Clare Type HGP1002

5-4


Instrument Tyee

Load

Current Monitoring Resistor

Required Characteristics

12 ohms, 200 watts, .6 ohms 10 watts

1 ohm 1%, 200 watts 20 ppm temp"erature coefficient

Use

Measure, Loaded Characteristics at 36 volts and at 1 volt.

Suggested Test Equipment

Measure Constant Current Operation and Adjust Ammeter.

NOTE: A satisfactory substitute for a differential voltmeter is a stable reference voltage and null detector. One side of the reference voltage is connected to the power supply senSing terminal. The null detector is connected between the other power supply sensing terminal and the reference voltage. A null meter (H-P Model 425A) or DC coupled scope utilizing the differential input (H-P Model 130C) may be used as the null detector. A simple and satisfactory null detector Is a 50 millivolt meter movement. On a 100 division scale, a two millivolt change in voltage results In a meter deflection of 4 divisions which is adequate resolution.

CAUTION: Care must be exercised when using an electronic null detector In which one input terminal is grounded.

5-5


to replace any component refer to Table 5-2, Replacement Guide, for additional tests which may be necessary.

5-19 SEMICONDUCTOR REPLACEMENT

5-20 Before removing any transistors from the power supply the transistors should be labeled so that in the event a defective transistor is found, its circuit location may be identified and therefore aid in isolating the source of trouble.

5-21 The semiconductors in Harrison Laboratories power supplies generally have an H -Lab designation. Table 5 -3 lists the characteristics of the semiconductors used in this power supply and suggested commercial replacements.

5-22 DETAILED TROUBLE SHOOTING PROCEDURE

5-23 Measure Power Supply Voltages. The following precautions should be taken before power supply voltages are measured. The voltage control pot and current control pot should be turned to the maximum clockwise position. The power supply should be unloaded. It is advisable to make an ohmmeter check to be certain that neither the positive or negative output terminal is grounded. The power supply may now be turned on. The follOwing voltages which are particularly critical should then be measured first.

1. Reference Voltage

'rhis voltage is measured between -S and 12 and should be 9.4 volts .:to.4 volts. The 15.5 volt regulated bias voltage is out of tolerance or diode 09 is probably defective if this voltage is out of specification.

2. 15.5 Volt Regulated Bias Voltage

This voltage is measured between -S and 16. It should be 15.5 volts +0.5 volts. If this voltage is out of specification, P4 or R19 may be misadjusted. Diode 013, transistors Q4, QS or 06 may be defective.

3. +6 .5 Volts

This voltage is measured between -S and 17. It should be 6.5 volts +0.4 volts. Diode 010 is probably defective if this voltage is out of specification.

5-24 Table 5-4 lists other voltages to measure the tolerances of these voltages, and typical peak-to-peak ripple.

5-6


If you change:

01, 02

Q3

Q7, Q8

04, OS, Q6, 013

09, 011

010, 012, 013, D22

Dl, D2, D4

D5, D7, D8

DI0

D9

D11, D12

DIS

TABLE 5-2

REPLACEMENT GUIDE

Check the following and readjust:

Load regulation, constant voltage--P2

Load regulation, transient response, constant voltage

Load regulation, constant current--P5

Line regulation of 15.5 volt source, readjust P4 and R19

Load regulation, transient response, constant voltage

Voltage across 011 adjustment of P7

Load regulation

Line and load regulation

Line and load regulation

Line regulation

Line regulation, 15.5 volts, readjust P4 and RI9

Readjust R36

5-7


Component

01, Q2

Q3, OS, QG

04, 09, QIO

011

*Q13

TABLE S-3.

Characteristics

NPN S1 planar 70 hPE 200 1e = 1 rna, VCE = IV, leo .01JLa @ Vcbo = SV

PNP Alloy 70 hPE 200 1e = 1 rna, VCE = IV. leo 2tJ.a @ Vobo = 5 V

PNP Alloy 75 hPE 200 1e = 50 rna, VCE = IV, PMAX 90 mw @ 70°C Amb1ent

PNP Power 70 hPE 1e = 3.SA, VCE = 2V. leo I rna @ 2SoC and Veb = GOV, Veer GOV @ 1e = 50 rna

Rbe = 100 ohms

PNP Power 70 hpE @ 1e = 3. SA. VCE = IV, leo I rna @ 25°C and Veb = GOV Veer 70V @ 1e = 500 rna

Rbe = 30 ohms

H-Lab Des1gnation

4JXlIC710

GT2SSS

2N1377

2Nl90S

BI203

Suggested Replacement

2N2195A GE "' J

2N2219" Motorola

2NS20A GI 2N404 GE RCA

2N1377 TI

2NI90G RCA

2N1l37B Bendix 2Nl547 Motorola

5-8


Component

*012

TABLE 5-3 (Cont'd)

Characteristics

PNP Power 10 hpE @ ic = 10 amps Vces 70V

01,02, D4, 06, 81 D10de 014,015,018, Low Le~kage D19, D24

D3, 023

05,07,08,012 016,017, D20 021

025,026, D27 028,029, D30

010,013

D9

*031, 032

07, Q8

81 Rectifier 1.5 amps

81 8tabistor 0.5 amps

81 Rectifier

6.5V 400 mw zener

9. 4V Temperature compensated reference diode

81 Rectifier

NPN Alloy 70 HpE ic = 1 rna, VCE = IV

H-Lab Suggested Designation Replacement

B1203 2N1552A Bendix

1N484A 1N484A

1NI563A 1NI563A

P1105 1N2609 1N3253

IN3253 1N3253 1N2611

G3454 IN753A

1N2163 1N2163 1N2621

1N1564A IN1564A

N272 2N1304 TI

5-9


TABLE 5-3 (Cont'd)

H-Lab Suggested Component Characteristic s Designation Replacement

D22 4.3V, 400 mw zener lN749 IN149A

*NOTE: These components are mounted using a mica washer and silicon grease. When replacing transistors or diodes be sure to replace the insulating washer and the silicon grease so that these components will have good heat conduction to the chas sis.

5-10


TABLE 5-4

POWER SUPPLY VOLTAGES

Measured From Typical + to - Voltage Tolerance P-P Ripple

-S 12 9.4 .±O.4V 800 .... v

-S 16 15.5 +O.4V 1 mv

-S 15 6.5 +O.4V 1 mv

Anode D5' -S 2.0 +0.4V 1 mv

A7 34 0.7 +0.2V 10 mv

30 A7 1.6 ±,O .4V 30 mv

17 14 31 +5% IV

31 22 48 +5% 0.5V

30 19 16 +5% 1.2V

33 35 3.3 +0.3V -----Base of Q3 -S 1.8 ±.0.4V -----

A7 22 (no load) 3.7 ±.IV 0.5V

A7 22 (l.5A load) 1.8 +0.5V 2.5V

+ 36 ----- 200 .... v

NOTE: The voltages listed above are measured at no load and 115 volts line. These voltages will vary with line and load. The DC voltages were measured with a Simpson Model 269 voltmeter. The ripple voltages were measured with an H-P Model 130C oscilloscope using the differential mode of operation and grounded at the negative output terminal of the power supply.

5-11


5-25 Generally, malfunction of the supply is indicated by the absence of or excessive output voltage. Table 5-5 indicates the trouble shooting procedure to follow when there is excessive output voltage. Table 5 -6 indicates the trouble shooting procedure to follow when there is zero output voltage. Table 5-7 is a list of miscellaneous malfunctions and the circuit areas to check.

5-26 POWER SUPPLY ADJUSTMENTS

5-27 The following adjustment procedure is that which is followed in the factory and is normally not required when a unit is repaired.

5-28 Make sure that both the ac and dc fuses are inserted in the fuse holders. The front panel voltage control and current control pots should be turned on to the maximum clockwise position. Use an ohmmeter to make certain the negative output terminal, the positive output terminal, and the collectors of 011, 012 and 013 are not grounded. The line Switch is turned on. The output voltage should go to maximum. Vary the output voltage with the voltage control pot to be certain that the voltage control is operative. If the output voltage cannot be changed, follow the trouble shooting procedure as outlined in Section 5-25. NOTE: Do not short the output of the power supply until adjustments outlined in 5-29 through 5-31 have been made.

5-29 Overvoltage Adjustment. The voltage across diode DIS is monitored with a voltmeter. The supply is operated at 36 volts, 1.5 amperes load and 105 volts input voltage. R36 is selected so that DIS is reverse biased by 0.6 volts.

5-30 Regulated Bias Voltage Adjustment

A. A differential voltmeter is used to monitor the voltage between -S and 16.

B. R19 is adjusted so that this voltage is approximately 15.5 volts.

C. The input line voltage is varied from 102 to 127 volts. P4 is adjusted so that the voltage indicated by the differential voltmeter does not vary more than 3 mv as the input line voltage is varied.

D. Readjust R19 so that the voltage is 15.5 volts +0.5 volts.

5-31 Current Adjustments. The output voltage of the power supply is set to 36 volts. The coarse current adjust is set to the maximum clockwise position. The fine current control is set to the maximum counterclockwise position.

A. P5 is adjusted so the output current is limited to 2.0 amps as the load is increased.

5-12


TABLE 5-5

r.XCr.~;:.lvr OUTPUT VOLTAGE

Pull (;9

INCORR~C:T R[.';I'ONSL

V 1'0 "0" (J I CORRr.CT ~

RE~I'ONE;r

I f

Shorf A7 tu 28.

Check Oil ond Q14 for short ••• check for shor~ between 27. 'lnd A'1 ..

Vo to "0"

I I

Chf!(~k for .. 1. fI volts across 016 and D!7 ••• upen circuit bt'HfPf'n 2R -lnd R41.

1 Ch.'·('~ C..d for O~~rI •• .o

vu!t;j'W JCrOSS {H{)d~~s

lb. 7 (. I:i (should 0..' ,:lpproY..i!n~'ltdy ::.0 volt.;;) ••• ( r.mtlnulty L.pt· ... -ef:m c·,U(!'ctor or Q3 and bd~~t'~

01 (.'9.

Vo = OUTPUT VOLTAGE

TABLE :5-6 "0' VOLr:" OUTPUT

Pull Q3

'10 TO MAX INCORRECT ...- RE:PONSE I

I

I Short GoUt'ctot to em! tter of Q9 ..

Va to MAX.

1 I '\

Che(.k Q9 ••• Pull qlO.

conti!luHy bet'.'C2'n (09 "hor"'" C-E) bas(! of l.:l9 .1nu

Vo tu MAX. col1f:"clor Df (.)3.

1 I

I'RER~QJ.!l.AIO~ CONT!lQI. t Measure voltag<, across Cl3. 1<1ru< UIT n~rEC T!~

SHOULD BE APPROX. 44'1. Chec'k: :~'1{) for shorl ••• D~O (or short .... v,.'lt"'J'" drop dCr(\sS D22 (Shou!(; be approx. .1.WI.

l IMeuure voltage between 1 Check for opHn

circuit between 9-11 and 10-11 on TI. Cl3 H ~n<1 SHOULD BE APPROX. ~lV RMS. colh,,"lor of {,Ill.

I 1

I Rl..'jJj.lC~' C,II). ~'hn"f

B-Hif.' of <,3 tl.! -;'

Vo to "0"

I

J (;1;(1C' Ql lor ~':)··n. Mt:!i.slIre voJt ;q(' ',l(l ::,,$1' ("I 01. S~ll',lld 1)1' ~11qhtl~

PVSiUVf'--m,rX. G.7V. It nol, {'h'(;k, t',.r ~hort ;t!'t',.'.~n

s( of" 1 ·ad - ••• O)'JPJ\

9'-:-1,. (~t.'-\·dl AI. nd Ati •

l

.. ; ,Hi "" ~g L',II!n ;)rOt]t 'ImmlH~

rr'~ i S((lr ..... ~)pen ilf,'t\o" Pf'n C"'.,U()('ur ot '. t ' nd b.1S,-, uf C,~.

CORRr.CT RC:;PONf;E

J RI'pi.Jcf" " ~ .. Pull Ql.

Vo h. MAX.

I

1 PuH J

I I

I Pull

Chl.'r~: ',.1 fur ~'l"ll ••• \,~' fOf\':)j)£'U •• 1. S;1Qrl to -:' ••• m"·,surt' from b,.lsf' of

(, '1 (cm'tvp,-l) Ql to -:' (should ill' n.~g;)tive--Vo I" MAX. :'l,·,,,-imw,II..'1 O. 7 V,~h5)"

I U 080](1. 'f onl!,' Cfll'(:k: (;'.'f~fh ... _".1 ("ir'- vit,

end or DP,. i .f'. "' . 8; ft14 iihortf;·d'O ••

'10 to MAX. H';l npen 01 irwl"e<lspd ff'lstst.-)nce.

1_ Ch"r,k Qd,ustm"nt of J Check: Tl primary voltage ••• Cheek: for c(mUnui.ty l>etwep.n '_·3. Check dlOdrsJ R36 •• 'O volt.,qe across 101' open windings on Tl •• 'O Cll (~) and emitter 01 QIZ ••• 05,7 <. O. C14 "nd C16. 031 and 032 ••• for CORUnulty Cll (-I and collector of QI1 •• l>&_n031.032, ,,!>dela Check vo1taQ~ drop across (+1 ••• for conllnulty I>&tween R41, should be approl( 12 tap 11 on 11 and R60. volta. Check (,)12 and {,II 3.

-Vo OUTPUT VOLTAGr.

5-13


TABLE 5-7

MISCELLANEOUS TROUBLES

Trouble and Description

1. Escessive Output Ripple

2. Lock Out -- Supply turns on at no load, but will not when loaded. A supply will not come up to voltage when it is turned off and then turned on again. Voltage goes to zero and stays there when voltage is changed to a lower value.

3 • Poor Line Regulation

4 • Poor Load Regulation (Constant Voltage)

5. Poor Load Regulation (Constant Current)

Check

a. Check to see if output is grounded. (Use IlJ.f capacitor if it is impossible to DC ground) •

b. Check foltage across series transistor. Qll. Use a scope, DC coupled. Should never be less than 0.8 volts.

c. Voltage across DIS. For normal operation, this diode should be back biased.

d. Check 15.5 volt ripple. Should be maximum of 2 mv peak-to-peak.

Check voltage across DIS. Readjust R36.

Check 15.5 volt line regulation and adjustment of P4 and R19.

a. Measurement Techniques--should measure across the sensing terminals.

b. Check adjustment of P2. c. Incorrect strapping of sensing terminals.

D3, C I or C 17 leaky--External load acros s output terminals (i. e. low impedance voltmeter). Voltage control set too close to maximum operating voltage.

5-14


TABLE 5-1 (Cont'd)

Trouble and Description

6. Oscillates

1. Voltage Limited (Cannot reach maximum output voltage)

8 • Current Limited

9 • Stability (Constant Voltage)

10. Stability (Constant Current)

Check

At frequencies less than 500 cps--check preregulator circuit. At frequencies greater than 500 cps--check adjustment of P3 (equalizer), capacitor C 11 and strap between Al and +.

Check voltage across series transistor-- . should be greater than 1.SV (DC). If less, check preregulator. If greater check programming resistors (P8 and P9), current limit circuit, reference voltage (9.4V), R9 and RIO.

Check voltage across series transistor-Check preregulator if less than 1.5 VDC. If greater than 1.5 volts, check voltage drop acros s RS 1-- should be 1 volt at 1.6 amps--Resistance of R5l--should be 0.6 ohms +5%, voltage between -8 and 17-should be between 6 ·and1 volts (If not . check diode DlO) Q1, Q8, D14, PS, PlO, Pll--voltage adjustment.

Measure stability of reference voltage (9 -9. 8V). Change diode D9 if this voltage is unstable. Check programming resistor (use supply in Remote Programming with a good quality, stable 20 ppm programming resistor). Replace R9 and RIO--RIO should be a minimum of ten times larger in resistance than R9. Check Ql. Q2, Dl, and D3.

Measure stability of reference voltage (6.1 volts measured between -S and 11.) Change DIO if unstable. Operate power supply in constant current remote programming mode using a ~ood quality, stable, 20 ppm T.C. resistor, as programming resistor to check PI0 and Pll as source of drift. Check PS, 01, Q8, R29, and RSI.

5-15 .


5-32 ZERO-SETTING THE METER

5-33 The meter pointer must rest on the zero calibration mark on the meter scale when the instrument is at normal operating temperature, resting in its normal operating pOSition, and the instrument is turned off. To zero-set the meter proceed as follows:

a. Turn on instrument and allow it to come up to normal operating temperature (about 20 minutes) •

b. Turn the instrument off. Wait two minutes for power supply capacitors to discharge completely.

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

d. Turn the adjustment screw clockwise .until the pointer is exactly over the zero mark on the scale. If the screw is turned too far, repeat steps c and d.

e. Turn meter adjustment screw counterclockwise about 15 degrees to· break contact between adjustment screw and pointer mounting yoke, but no far enough to move the pointer back downscale. If screw is turned too far, as shown by the needle moving, repeat the procedure. The meter is now zero-set for best accuracy and mechanical stability.

5-34 Ammeter Calibration. An external ammeter accurate to 1% or better is used to measure the output current at 1.5 amperes. PI is adjusted so that the front panel meter indicates 1.5 amperes.

5-35 Preregulator Control Adjustment

a. An oscilloscope is connected between points 46 and 4S.

b. The power supply is operated at approximately 1 volt out, 1.5 amperes load and 127 volts line.

5-16


c. P7 is adjusted so that current pulses presented on the oscilloscope are of approximately equal amplitude as in the figure below.

1.2 m sec - I 5.7 I

~. m sec------1

f 13V

I 1.4 r--m sec

5-36 An oscilloscope is connected from A7 to 22 (across the series transistors). The voltage appearing across these points should appear as shown in the figure below when the power supply is operated at 1 volt and full load.

3V

.5V min

m sec I ...

8.3 ----~

t OV

5-37 Programming Current Adjustment

a. A differential voltmeter is connected between -8 and +8. The strap between A4 and AS is removed and a 7.2K. 0.5% resistor is connected in the position of RIO and the power supply is turned on.

b. The decade resistance is adjusted so that the output voltage of the power supply is 36 volts, ±.1%.

c. The value of the decade resistance is noted. The power supply is turned off and the decade resistance is replaced with a fixed reSistor of equal value <±5%).

5-17


5-38 Voltmeter Adjustment. An external voltmeter (accuracy of 1/2% or better) is used to measure the output voltage of the power supply. The output voltage is eet at 36 volts. P6 is adjusted so the front panel meter indicates 36 volts.

5-39 Load Regulation. The power supply is operated at 36 volts out. 115 volts line. A differential voltmeter is connected between -S and +S. The output load is varied from 0 to 1.5 amperes. P2 is adjusted so that the output voltage does not decrease more than 2 mv when the load is applied.

5-40 Line Regulation. The power supply is operated at 36 volts out and full load. A differential voltmeter is connected between -S and +S. The input line voltage is varied from 102 to 127 volts. The output voltage should not vary more than 1 mvas the input voltage is varied. The line regulation of diode D9 should be checked in the event that the output voltage varies more than 1 mv.

5-41 Output Ripple. The power supply is operated at 36 volts out, full load. and 102 volts Une. An oscilloscope is connected between +S and -S. One of the output terminals of the power supply must be grounded. The maximum 120 cycle peak-topeak ripple as indicated on the oscilloscope should not exceed 300 .... volts.

5-42 Transient Response. The power supply output voltage is set at 3 volts. A switch is used to vary the power supply load from no load to maximum. An oscilloscope is connected between +S and -S. P3 is adjusted so that the decay of the transient spike is a smooth exponential curve without undershoot, overshoot. or ringing for both the loading and unloading transients. The voltage should recover to within 5 mv of the nominal output voltage is less than 50 .... seconds. NOTE: The load should be non-inductive. The switch should have a maximum rise and fall time of 2 .... seconds. A mercury relay such· as the Clare relay type HGPI002 manufactured by C. P. Clare & Company, Chicago, Illinois operated at Une frequency is a satisfactory switch.

5-43 Constant Current Measurements

5 -44 A one ohm resistor is connected in series with an external load. This resistor' will be used to monitor the output current of the power supply. It should be a stable. low noise resistor, having a temperature coefficient of 20 ppm or better, and used at no more than 5% of its rated power. See figure 3-11.

5-45 Constant Current Ripple. An oscilloscope is connected across the current monitoring resistor. The output current of the power supply is adjusted to approximately 1.5 amperes. The maximum peak-to-peak ripple observed on the oscilloscope should not exceed 0.25 milliampere.

5-18


5-46 Line Regulation. A differential voltmeter is connected across the current monitoring resistor. The power supply is operated at 36 volts out and 1.5 amperes load. NOTE: The voltage control should be turned to the maximum clockwise position and the output voltage is adjusted by changing the external load. The input line voltage is varied from 102 to 127 volts, The output current should not change more than 0.25 milliamperes.

5-47 Load Regulation. A differential voltmeter is connected across the current monitoring resistor. The power supply is operated as in 5 -46. The indication of the differential voltmeter is noted. The external load is shortcircuited. NOl' E: The output current will go to zero and then return to 1.5 amperes, The current changes should not exceed 0.3 milliamperes.

5-48 PERFORMANCE TEST

5-49 These tests are in-cabinet speCification checks and'are made before disturbing any of the internal power supply adjustments. The tests may be used as an incoming inspection test, periodic maintenance, or to check the instrument after repairs. Refer to Section 3-41 before making measurements.

5-50 CONSTANT VOLTAGE OPERATION

5-51 Meter check. An external voltmeter having an accuracy of 1% or better is connected across the output terminals and is used to check the front panel voltmeter at 36 volts out.

5-52 Ripple check. The power supply is operated at 36 volts out and full load and at an input line voltage equal to 105 volts. Maximum peak-to-peak 120 cycle ripple should not exceed 500 .... volts.

5-53 Line regulation. The power supply is operated at 36 volts and maximum load (1.5 amperes). A differential voltmeter is connected across the senSing terminals. The input line voltage is varied from 105 to 125 volts. The output voltage should not vary more than 2 millivolts.

5-54 Load regulation. The power supply is operated at 36 volts out and 115 volts line. A differential voltmeter is connected across the senSing terminals. The output voltage should not decrease by more than 2 millivolts when full load is applied.

5-55 Transient response. The power supply is operated at 36 volts out and 115 volts line. A switch havlnga rtse'andfaU time of~2tJ.seconds or less is connected in " ,:' sedes with a 'non-inductive load resistor selected so that the power supply is operated at maximum output current. An oscilloscope is connected across the sensing terminals. The output voltage should recover to within 5 millivolts of the nominal output voltage within SO .... seconds for both the loading and unloading transients. The

5-19


decay of the transients should be a smooth exponential decay without ringing, overshoot, or undershoot.

5-56 CONSTANT CURRENT OPERATION

5-57 A one ohm, 200 watt, low temperature coefficient, wirewound resistor is connected in series with the load. This resistor is the current sensing or monitoring resistor. The power supply coarse voltage control is turned to the maximum clockwise position.

5-58 Ripple current. An oscilloscope is connected across a current monitoring resistor. The current control is adjusted so that the output current is 1.5 amperes. An external load is selected so that the output voltage of the power supply is equal to 36 volts. The maximum peak-to-peak 120 cycle ripple should be less than 500lla.

5-59 Line regulation. A differential voltmeter is connected across a current monitoring resistor. The power supply is operated at 1.5 amps and 36 volts out. The line voltage is varied from 105 to 125 volts. The output current should not change· more than 250~a.

5-60 Load regulation. A differential voltmeter is connected across the current monitoring resistor. The power supply is operated at 36 volts out and 1.5 amperes load. The output current is noted. The external load is shortcircuited. The output current of the power supply will go to zero and then return to its nominal value. The current as indicated by the differential voltmeter should hot have changed more than 0.3 milliamperes from that recorded at 36 volts output. NOTE: The coarse voltage control should be in the maximum clockwise position when this test is made.

5-20


TABLE 6.

REPLACEABLE PARTS

6-1 INTRODUCTION

6-2 This section contains information for ordering replacement parts for the Model 6226A DC power supply.

6-3 Table 6-1 lists parts in alpha-numerical order of their circuit designators and provides the following information. (See Table 5-3 for specific semiconductor characteristics and suggested replacements):

A. Circuit Reference Number B. Total Quantity Used In the Instrument C. Part Description (See list of abgreviations below) D. Manufacturer, Part Number, Type, and Stock Number

6-4 Miscellaneous parts not indexed in Table 6-1 are listed at the end of Table 6-2.

6-5 ORDERING INFORMATION

6-6 To order replacement parts, address order or inquiry either to your authorized Harrison Laboratories sales representative or to Customer Service, Harrison LaboratOries, 45 Industrial Road, Berkeley Heights, New Jersey

6-7 Specify the following information for each part:

A. model and complete serial number of instrument B. circuit reference designator C. description

6-9 To order a part not listed in Table 6-1 or 6-2. give a complete description of the part and include its function and location.

Reference DeSignators

C = capacitor P = plug D = diode Q = transistor DL = delay line R = resistor F '= fuse RT = thermistor FL = filter S = switch K = relay T = transformer . L = inductor V = vacuum tube, neon M = meter bulb, photocell, etc.

6-1


Abbreviations

coef = coefficient NC = normally closed com = common Ne = neon comp = composition NO = normally ooen conn = connection NPO = negative positive zero-zero dep = deposited temperature coefficient det = detector obd = order by description EIA = Tubes and transistors selected for p = peak

picofarads = 10-12 farads best performance will be supplied pf = if ordered by H-Lab stock numbers; pp = peak -to-peak tubes or transistors meeting Elec- pos = position (s) tronic Industries' Association pot = potentiometer standards will normally result in rect = rectifier instrument operating within specifi- rot = totary cations. rms = root-mean -square

elect = electrolytic s-b = slow-blow encap = encapsulated sect = section (s) f = farad Si = silicon fxd = fixed sl = slide Ge = germanium td = time delay grd = ground (ed) tog = toggle h = henrise tol = tolerance incd = incandescent trim = trimmer ins = insulation (ed) var = variable K = kilohms wi = with m = mill! = 10-3 W = watts M = megohms ww = wirewound rna = milliamperes wlo = without minat = miniature * = optimum value selected at mfr = manufacturer factory, average value shown mtg = mounting (part may be omitted) • my = mylar

Manufacturers

Kulka-----Kulka Electric Mot------Motorola, Inc.

Inc. RCA------Radio Corporation of America Reliance Mice--Rel1ance Mioa Corp. Semcor---Semcor Corporation

AB-------Allen Bradley Company B--------Bendix Corporation Beede----Beede Electrical Instr.Co., Buss-----Bussmann Mfg. Company Carl1ng--Carl1ng Electric Company CTS------CTS Corporation Elco-----Elco Corporation GE------General Electric Company GI-------General Instrument Company HH------Hardwick Hindle, Inc. Hoff-----Hoffman Electric Company

Sloan Co. Colorlite--Sloan Company Sprague--Sprague Electric Superior--Superior Electric Sylv-----Sylvanla Electric TI-------Texas Instruments ~------Ward Leonard


TABLE 6-1

Circuit Reference Mfg. Part # Mfg. Number De sCription Quantity of Type Mfg. Code* A

C1 fxd, elect, 40J.Lf 50VDCW 1 D28723 Sprague 56289 1 C2 fxd, elect, 5J.Lf, 150VDCW 1 D30392 Sprague 56289 1 C3,4,7,10 fxd. elect, 5td 50VDCW' 4 30D193Al Sprague 56289 3 C5,9 fxd, elect, 20td 15VDCW 2 30D167Al Sprague 56289 3 C6 fxd, film .0047 600VDCW 1 148P47296 Sprague 56289 2 C8 fxd, fUm. 22td 100V 1 148P22441 Sprague 56289 1 CII fxd, elect, 100.u 50VDCW 1 D32218 Sprague 56289 1 C12 fxd, film. 47J.Lf 100VDCW 1 148P47491 Sprague 56289 3 C13 fxd, elect, 3300td 50V 1 D362Q2 Sprague 56289 1

. \

Cl4 fxd, elect, 490td, 65V 1 D31443 Sprague 56289 1 CIS fxd. elect. 325td, 35V 1 D34656 Sprague 56289 1 C16 fxd, elect. 1200~, 20V 1 D33269 Sprague 56289 1 Cl7 fxd, elect, 1500J.Lf 50V 1 D36203 Sprague 56289 1 D1,2,4,6,14,15,18 19,24 Diode, Si 9 IN.4~..wa. Sylv. 93332 11

D3,23 Rect, Si, 1.5 amps 100 PRV 2 IN1563A Mot. 04713 2 05,7,8,11,12,16,17 20,21 Rect, Si, 500 rna 10 PRV 9 F1105 GI 11711 13

09 Ref Diode 9. 4V 5% 1 IN2163 Semcor 06751 1 010,13 Zener Diode 6.5V 5% 2 G3454 Hoff. 99942 2 022 Zener Diode 4. 3V 5 % 1 fN-749 Mot. 04-713 1 025,26.27,28,29,30 Rect, S1, 500 rna, 200 PRV 6 1N3253 RCA 02735 6 D31,32 Rect, Si, 1.5 amps, 200 PRV 2 IN1564A Mot. 04713 4 FI Fuse, Cartridge 3 amp 1 Buss. 71400 F2 Fuse, Cartridge 2 amp 1 Buss. 71400 Ll Indicator light. No 1 858-R Sloan Co. 08717 PI Var, WW, 250 ohms type 110 1 CTS 11236 1

cr P2 Var, Comp, lOOK ohms type 70 1 CTS 71450 2 w P3,5 Var, WW, lK ohms type 110 2 CTS 11236 1

P4 Var, Comp, 25K ohms type 70 1 CTS 71450 1


TABLE I (Cont'd)

Circui t Reference Mfg. Part # Mfg. Number Description Quantity or Type Mfg. Code* A

P6,7 Var. WW. 5K ohms type 110 2 CTS 11236 1 P8,9 Var, WW, 1 OK/50 dual 1 CTS 11236,... 1 PI0,ll Var. WW, 600/10 dual 1 CTS 11236 1 Ql,2 SS, NPN, Si 2 4JXl1C710 GE 03508 4 Q3, 5,6 SS, PNP, Ge 3 GT2555 GI 11711 3 Q4,10 PNP, Ge 2 2N1377 TI 01295 2 Q7,8 SS, NPN, Ge 2 N272 TI 01295 4 Q9 PNP, Ge 1 2N1378 TI 01295 1 Ql1 Pow, PNP, Ge 2 2N1905 RCA 02735 4 Q12,13 Pow, PNP, Ge 2 B1203. SA B 83298 1 Rl, 3,57 fxd, comp 100 ±5 % 1/2W 3 AS 01121 R2 fxd, comp 430K ±5% 1/2W 1 AB 01121 R4 fxd, comp 120 ±5% I/2W 1 AB 01121 R5,30,49 fxd, comp 1.5K ±5% 1/2W 3 AB 01121 R6 fxd, comp 24K ±5% 1/2W 1 AS 01121 R7 fxd, WW 490 ±5% 3W 1 Sprague 56289 1 R8 fxd, comp lOOK ±5% 1/2W 1 AB 01121 R9,17 fxd, WW 2K ±5% 3W 2 Sprague 56289 2 RIO,19,36 fxd, comp selected 1/2W 3 Sprague 56289 Rli fxd, comp 3.3 ±5% lW I AS 01121 I R12,53 fxd, comp IK ±5% 1W 1 AS 01121 2 R13 fxd, comp lK ±5% 1/2W I AB 01121 RI4 fxd, comp 1.6K ±5% I/2W I AB 01121 RI5 fxd, WW 390 ±5% 3W 1 Sprague 56289 I RI6 fxd, comp 750 ±5% I/2W I AS 01121 R18,25 fxd, comp 10K ±5 % 1/2W 2 AS 01121 R20 fxd, WW 4.3K ±5% 3W I Sprague 56289 I

en R21,45 fxd, comp 2K ±5% 1W 2 AS 01121 2 1 R22,23,28 fxd, comp 7 .5K ±5% 1/2W 3 AS 01121

R24 fxd, comp 18K ±5% I/ZW 2 AS 01121


TABLE 6-1 (Cont'd)

Circuit Reference Mfg. Part:lf: Mfg. Number De scription Quantity or Type Mfg. Code* A

R26 fxd, comp 560 :1:5 % 1/2W 1 AS 01121 R27,39 fxd, comp 2K :1:5% 1/2W 2 AS 01121 R29 fxd, WW 3K :1:5 % 3W 1 Sprague 56289 1 R31,33 fxd, comp 5.1K :1:5% 1/2W 2 AS 01121 R32 fxd, comp 150K :1::5% 1/2V{ 1 AS 01121 R34 fxd, comp 3.9K :1::5% 1/2W 1 AS 01121 R35 fxd, WW 135 :1:5% 3Vv 1 WL 63743 1 R37,43 fxd, comp 6.2K :1:5% 1/2W 2 AS 01121 R38 fxd, comp 200 :1:5% 1/2W 1 AB 01121 R40 fxd, comp 15K :1:5% 1/2W 1 AB 01121 R41 fxd, comp 150 :1:5% 1/2W 1 AS 01121 R42,56 fxd, comp 8.2K :1:5% lW 2 AB 01121 1 R44,59 fxd, comp 33K :1::5 % 1/2W 2 AB 01121 R46 fxd, comp 9 .IK :1:5 % 1/2W 1 AS 01121 R47 fxd, comp 360 :1:5% lW 1 AB 01121 1 R48 fxd, comp 82 :1:5% 2W 1 AS 01121 1 R50 fxd, comp 36K :1:5% 1/2W I AS 01121 RSI fxd, WW .6 :1:5% lOy\[, 20 ppm 1 WL 63743 I R52 fxd, WW 1.6K :1::5% 5W 1 WL 63743 1 R54 fxd, comp 6.2K :1::5% IW 1 AS 01121 1 RS5 fxd, WW 25 :1::5% 5W I WL 63743 1 RS8 fxd, WW .125 :1:5% .3W. 20 ppm I WL 63743 1 R60 fxd, WW 1.3 :1:5% 40Vv 1 WL 63743 1 R61 fxd, WW 250 :1::5% 40W I WL 63743 1 SI,2 Switch, toggle DPDT 2 83054 Arrow Hart 2 TI Power transformer I HT6226A H-Lab 09182 1

A Recommended spares per 10 units. * As listed 1n Federal Supply Code for Manufacturers H4-1 (October 62).

en I

c.n


Circuit Reference

en I en

Number

TABLE 6-2

Description - -- -- - - --- -

Stand 3rd Mod. Tilt Foot Assy 3rd Mod. Cord Fuseholder #342014 Assy Binding Post (black) As sy Binding Post (red) Knob (black) Knob (maroon) Barrier strip Binding post Terminal Transistor Socket Meter Movement Meter Face 0-20V. 0-4A Floater Pad Outer carton

"'7 5 /1 S' ;~ ~;l

_ Qyantity

1 2 1 2 2 1 2 2 1 1

13 10

1 1 2 1

Mfg. Part # Mfg. Qr Type Mfg. Code* A

1490-0031 H-Lab 09182 C-144H-15 H-Lab 09182 8120-0078 Belden 70903 1400-0048 Littlefuse 75915 G-10F . H-Lab 09182 G-I0E H-Lab 09182 G-74CT H-Lab 09182 G-74CS H-Lab 09182 10100 H-Lab 09182 137 HH Smith 83330 1200B USECO 04454 3305 Elco 91662

H-Lab 09182 1 10101 H-Lab 09182 100118 100119


I I I I I I I I I I I I I I I I I I I

L- J • £-59

~ F-/ 3A

12.

o ~5-J -

I 1 f I'

NOTES '.

F-2 24

f T-//1/IREPIOi? /15'V OPE/C.477ON,,,c-O.e Z30V O?ERR77C/./I/ KEMOVe

SreAPs BGTWeEN /3-/5 /2-/4 APO 5T.f?4P PETWc€tV /3-14 , /

2. * 20??m d//Rc 3, /9,U: RE5 /5TC/,e5 .~ W VA/LE5S OTllcLU//SE 5h/oa-A/

4, 'p-8, ,1"-9,/ ,0-/0 ~ p// r-'£OAl7" 'pHAlE" C:O,A/T,ee>,5

.5: ,F,::>,c NOC/1?/7t, .F~o"vT P/lkEL. C:OoN'T.-t:'oLs .5T.r.A'r' (~, "'6,HI) (-, -!S') (/1:<', ;;3) (/?~, #.5; /16) oN'REh',c LU',..e,e/E'A? 5T£/?,

"p - C?/V MOOEc:. 622.6/7 OEt:E Tc <OJ -/4 .. 5TR/I,P ,..e-62 ON M/?/N Poe. IJO/il/f!P

I 0

0 M + - S-2 }

., I 0

~

r® ~\'f) ~~r ~ \!)

/00

> ,e'£"7

V pol

~5"O I<

.19 <:ll\l ~"J QI'S

~

f. ~ "J' 'i '" ' '" "J .

'" '" '" ~ ~ ~ <:Ii: "-

PATE'NT$. A'PPL.I5'P FOR ON THIS

C,.1R,c..\JI-r. L,..ICE'NSe. TO USE' N\u5T 8e: OS,AINED IN WR.ITlNG FROM

HARRISO"-J L.AI!O~A;CAIE~.

.,.fft.7

~ c_ SCfI€MI?i'IC, O/;if(:,,f!/iM

~ ~:2

" ~J ~OGL"Z2'AIf76S- B Il,) ~j) IIARI<?/SO# LAB()NA~e'S ~ ~< ~ Ill";

".<>1 II BIf.e.cE'l.6'Y HEIGH'S,~ .DW OF HcWI..ETT-f'tIICK .


Model 6226

, REYIBIONI

Note the following changes in the aGbeaatl0, Fig. 5-8.

Rl2 should be lK lW Rl6 should be 7,0 iW D22 should be 1N749

Far serial cumbers 151 and above

R20 should be 4.3K 3W R2l should be 2K lW

Far serial numbers 2,1 and above

a60 should be 0.7 40w C13 should be ,OOOUF 45V.-

ENe U 7, 138, 170 4/1/63


Documents

REGULATED POWER SUPPLIES · 1-2 The Harrison Laboratories Model 6226A is a compact, flexible, regulated con stant voltage/constant current de power supply suitable for either bench