Tektronix PS 505 User manual

Tektronix, Inc.
P.O. Box 500
Beaverton, Oregon 97005
TEKTRONIX®
PS 505
POWER SUPPLY
INSTRUCTION MANUAL
Serial Number
070-1784-00 First Printing JUL 1974

WARRANTY
All TEKTRONIX instruments are warranted against
defective materials and workmanship for one year.
Any questions with respect to the warranty should
be taken up with yourTEKTRONIX Field Engineer or
representative.
All requests for repairs and replacement parts
should be directed to the TEKTRONIX Field Office
or representative in your area. This will assure you
the fastest possible service. Please include the
instrument Type Number or Part Number and Serial
Number with all requests for parts or service.
Specifications and price change privileges reserved.
Copyright 1974 by Tektronix, Inc., Beaverton,
Oregon. Printed in the United States of America. All
rights reserved. Contents of this publication may not
be reproduced in any form without permission of
Tektronix, Inc.
U.S.A. and foreign TEKTRONIX products covered
by U.S. and foreign patents and/or patents pending.
TEKTRONIX is aregistered trademark of Tektronix,
Inc.

PS 505
TABLE
OF CONTENTS
SECTION 1
SECTION 2
SECTION 3
SECTION 4
Page
OPERATING INSTRUCTIONS
INTRODUCTION 1-1
Installation 1-1
OPERATING CONSIDERATIONS 1-2
Overheating 1-2
Load and Monitor Connections 1-2
Grounded and Floating Operation 1-3
Reverse Current Loading 1-3
Overvoltage 1-3
OPERATION 1-4
Setup Information 1-4
Series Operation 1-4
Parallel Operation 1-4
APPLICATIONS 1-5
Differential Voltage Measurements 1-5
FUNCTIONS AVAILABLE AT REAR CONNECTOR 1-6
CHARACTERISTICS 1-6
Table 1-1 Electrical 1-6
Table 1-2 Environmental 1-7
ELECTRICAL REPLACEABLE PARTS LIST 2-1
SERVICE INFORMATION 3-1
Symbols and Reference Designators 3-1
Controls and Connectors &Rear Connector
Pin Assignments
Adjustments
Parts Location Grid &Theory of Operation
(backside of foldout)
Power Supply
MECHANICAL REPLACEABLE PARTS LIST 4-1
Fig. 1Exploded
CHANGE INFORMATION
I

PS 505

Section 1—PS 505
OPERATING
INSTRUCTIONS
INTRODUCTION
The PS 505 is avariable-voltage, variable-current dc
power supply that provides aconvenient way to power
bipolar logic, level shifters, light-emitting diodes, in-
candescent displays, and analog devices. It is designed to
operate in the right-hand (high power) compartment of a
TM 504 or TM 506 Power Module. When operated in the
right-hand compartment of aTM 504 or TM 506, the
PS 505 provides afloating output that is variable between
3.0 and 5.5 volts at amaximum of 4.0 amperes.
NOTE
If the PS 505 is operated in acompartment other than
the right-hand (high power) compartment of aTM 504
or TM 506, the output current drawn from the PS 505
must be limited to 1.0 amperes maximum. However, the
negative output terminal should be grounded at the
front panel since there is apossible ground path of
uncertain characteristics through the rear connector
when the PS 505 is operated in anyplace other than in
the right-hand compartment.
Afront panel lamp, marked VOLTS, indicates the
presence of voltage at the output terminals. The light
intensity varies with the output voltage and verifies that the
output is indeed variable. Afront-panel, light-emitting
diode indicates when the PS 505 goes into current
limiting. Hard limiting causes the light emitting diode to
glow brightly and causes the VOLTS lamp to dim. Acheck
of the limiting circuitry and the operation of these lights
can be made by momentarily shorting the output ter-
minals.
Asecond front-panel mounted light-emitting diode
indicates that the PS 505 is being operated in acompart-
ment other than the right-hand (high power) compartment
of the Power Module and that the output current must be
limited to 1ampere or less. It also Indicates that the
PS 505 is to have its negative output terminal grounded
and operated in anon-floating mode.
Installation
The PS 505 is calibrated and ready to use as received.
Referring to Fig. 1-1, install the Power Supply and turn on
the Power Module. Press the OUTPUT button to apply
power to the PS 505. Check that the VOLTS indicator light
on the front panel comes on (the light will be very dim at
low voltages).
NOTE
Because of the high current drawn by the PS 505, it is
recommended that the Power Module be turned off
before inserting or removing the PS 505. Arcing at the
connector terminals can reduce connector life.
However, no internal damage will result if the monitor is
inserted into alive Power Module.
1-1

operating Instructions—PS 505
Fig. 1-1. Plug-In Intlallallon and ramoval.
OPERATING CONSIDERATIONS
Overheating
The PS 505 is designed to operate at an ambient
temperature from 0°C to +50® C. However, when
operating several power supplies in amulti-plug-in Power
Module, especially at low output voltages, or when
operating close to other heat-producing equipment, inter-
nal temperature may exceed safe limits and actuate a
thermal cutout in the Power Module. Refer to the Power
Module Instruction Manual for more complete informa-
tion.
Load and Monitor Connections
Improper connections between the power supply out-
put and the load(s) and/or monitoring device(s) are a
common cause of errors. Multiple loads or monitoring
devices must be connected directly to the output terminals
with separate pairs of leads as shown in Fig. 1-2. Avoid
using clip leads, since their contact resistance can exceed
the output impedance of the PS 505 and cause significant
measurement error. Fig. 1-2. Monitor artd load connacilona.
1-2

Operating Instructions—PS 505
Grounded and Floating Operation
The PS 505 is a"floating" suppiy (when instaiied in the
high power compartment of the Power Module) since no
internal connections are made to either the chassis or
ground. The supply can thus be used as apositive or
negative supply by simply connecting between the com-
mon and the negative or positive output terminal.
However, there may be undesirable effects caused by
grounding the supply to the chassis while the load is
grounded at some point removed from the supply chassis.
For example, if aremote load is connected as shown in Fig.
1-3, ground currents containing the power line frequency
could result and create excessive noise and ripple in series
with the load. Thus, floating operation is recommended to
insure against problems caused by undesirable ground
currents. \
Reverse Current Loading
In some applications as when driving an inductive load,
the load might behave as acurrent source for part of its
operating cycle. Since the output circuit of aseries
regulated siipply is unidirectional, reverse current will not
normally pass through the regulator. The internal reverse-
current diode (CR75) conducts only when the PS 505
terminal voltage reverses and therefore protects the series
regulator against reverse currents. However, when
operating aswitching or inductive load, connecting a
shunt resistor (Rs) of about 12 nas shown in Fig. 1-4
provides an external reverse current path so the power
supply sources or delivers current only.
Fig. 1-3. Ground loop created by grounded remote load.
If the power supply is operated into aswitching load
where the current demand changes abruptly, it is
recommended that a12 0shunting resistor be placed
across the output terminals. This will ensure that the
supply always sees aminimum load and improves regula-
tion.
NOTE
The PS 505 is ground referenced negative when
installed in any other compartment of aPower Module
except the high power compartment. If the PS 505 is
installed in any compartmentother than the high power
compartment, operate it with astrap between the minus
and ground terminals.
Fig. 1-4. Reverse current shunt (Rs) with active load.
Overvoltage
The PS 505 is protected from overvoltage conditions by
an overvoltage protection circuit which blows the fuse at
about? Vdc. Component failure In the PS 505 could result
in load damage if external protection is not provided. Like
wise, if the load (or other instruments connected to the
load) produce avoltage across the PS 505 terminals which
is the same polarity but of greater amplitude, damage to
the PS 505 may result, depending on the amount of
overvoltage and the impedance of the load.
1-3

Operating Instructions—PS 505
OPERATION
Setup Information
The following steps demonstrate the use of the PS 505
controls and connectors.
1.
Install the PS 505 into (preferably) the right hand
compartment of the Power Module.
2.
Press the OUTPUT button to apply power to the
PS 505. Observe that the VOLTS indicator light comes on
(the light will be very dim at low voltages).
3.
Set the VOLTS controls for approximately 3.5 V.
4.
Turn the CURRENT LIMIT control fully ccw (to
protect the ammeter). Connect an ammeter between the +
and —terminals and adjust the CURRENT LIMIT control
for the maximum desired current output.
5.
Remove the ammeter. Connect the load between the
+and —terminals. Adjust the VOLTS control for the
desired output.
Series Operation
The outputs of two or more supplies can be connected
in series as shown in Fig. 1-5 to obtain an output voltage
equal to the sum of the output voltages from each supply.
The maximum output is limited to 350 Vdc +peak ac (i.e..
the isolation voltage rating between the output terminals
and ground). Each supply must be adjusted individually to
obtain the desired output voltage.
NOTE
The PS 505 has internal diodes connected across
the output to protect any of the series-connected
supplies against reverse polarity if the load is
shorted, or one of the supplies is not on.
Fig. 1-5. Series-connected supplies.
Paraiiei Operation
Parallel operation is not recommended unless a
forward biased diode capable of handling the re-
quired current and voltage is inserted between each
power supply and the load. Failure to do this may
cause power supply damage.
The outputs of two or more current-limiting, automatic-
crossover supplies can be connected in parallel as shown
in Fig. 1-6 to obtain an output current equal to the sum of
the output currents from each supply. Each supply must
be adjusted individually to obtain the desired output
current.

Operating Instructions—PS 505
One supply should be set forthe desired output voltage
and the other should be set for aslightly higher voltage.
The supply set for the desired voltage will then become a
constant voltage source, while the supply with the higher
voltage output becomes acuri;pnt-limited source (due to
automatic crossover) which results in their output voltage
decreasing to that of the supply with the lowest output
voltage.
APPLICATIONS
Differential Voltage Measurements
Very small dc voltage changes or unknown voltages
can be measured by connecting the PS 505, anull
detector, and the source under test in adifferential
configuration as shown in Fig. 1-7. Comparison
measurements at nearly the accuracy and sensitivity of
costly differential voltmeters can be made with the
inexpensive PS 505. The ultimate accuracy and sensitivity
of the measurement depends on the PS 505 and the type
of null detector used. Acalibrated DC amplifier in ahigh-
gain oscilloscope such as the Tektronix 5100-Series
Oscilloscope with a 5A20N Differential Amplifier plug-in
will serve as aconvenient null detector, or a sensitive
milliameter with aseries resistor is also satisfactory.
NOTE
Examine the circuit for ground loops when using a
null detector with one input terminal grounded (see
Grounded and Floating Operation).
Fig. 1-6. Parallel-connected supplies.

Operating Instructions—PS 505
FUNCTIONS AVAILABLE
AT REAR CONNECTOR
Unassigned pins are available at the rear connector for
routing signals to and from the PS 505 for specialized
applications (see Rear Interface connector assignments at
the rear of this manual). One or more compartments of a
multi-plug-in Power Module can be wired with barriers
installed to provide specific functions between com-
partments. See Power Module instruction manual for
additional information.
CHARACTERISTICS
Performance Conditions
Unless otherwise noted, the electrical characteristics
are valid only if the instrument has been calibrated at an
ambient temperature between -(-20° Cand -f30°C and is
operated at an ambient temperature between 0°C and
-1-50° C.
TABLE 1-1
Electrical
Characteristics Performance Requirements Supplemental Information
Line Regulation
!
Within 10 mV for a±10% line
voltage change
Load Regulation Within 5mV for a0.5 to 4.0 Aload
change
Transient recovery <20 /js for a
constant voltage to recover within
20 mV of nominal output voltage
after a3.5 Achange in output cur-
rent
Ripple and Noise 3mV peak-to-peak or less Power supply output voltage set to
5Vwith asupply load of 4.0 A
Temperature Coefficient 0.01 %/°C or less
Stability 0.1% +5 mV of drift in 8hours Line voltage, load and temperature
held constant
Folcjback Current When output current exceeds 4.1 A,
current folds back to less than 1.5 A
and latches
To restore to normal operation, turn
PS 505 power off. Reduce current
load to <4.0 A, then turn PS 505
power on
1-6

Operating Instructions—PS 505
TABLE 1-2
Environmental
Characteristics Performance Requirements ^Supplemental Information
Temperature
Operating 0°C to +50° C
Storage -40° Cto +75° CL_
Altitude
Operating To 15,000 feet
1
Storage To 50,000 feet
Vibration
Operating and Non-Operating With instrument complete and oper-
ating, vibration frequency svrept
from 10 to 50 to 10 Hz at 1minute
per sweep. Vibrate 15 minutes in
each of the three major axes at
0.015" total displacement. Hold
3minutes at any major resonance,
or if none, at 50 Hz. Total time,
54 minutes.
Shock
Operating and Non-Operating 30 g's, 1/2 sine, 11 ms duration,
2shocks in each direction along 3
major axes, for atotal of 12 shocks
1-7

Section 2—PS 505
ELECTRICAL REPLACEABLE PARTS LIST
PARTS ORDERING INFORMATION
Replacement parts are available from or through your local Tektronix, Inc. Field
Office or representative.
Changes to Tektronix instruments are sometimes made to accommodate improved
components as they become available, and to give you the benefit of the latest circuit
improvements developed in our engineering department. It is therefore important, when
ordering parts, to include the following information in your order: Part number,
instrument type or number, serial number, and modification number if applicable.
If apart you have ordered has been replaced with anew or improved part, your
local Tektronix, Inc. Field Office or representative will contact you concerning any
change in part number.
Change information, if any, is located at the rear of this manual.
SPECIAL NOTES AND SYMBOLS
XOOO Part first added at this serial number
OOX Part removed after this serial number
ITEM NAME
In the Parts List, an item Name is separated from the description by acolon (:).
Because of space limitations, an Item Name may sometimes appear as incomplete. For
further Item Name identification, the U.S. Federal Cataloging Handbook H6-1 can be
utilized where possible.
ABBREVIATIONS
ACTR ACTUATOR PLSTC PLASTIC
ASSY ASSEMBLY QTZ QUARTZ
CAP CAPACITOR RECP RECEPTACLE
CER CERAMIC RES RESISTOR
CKT CIRCUIT RF RADIO FREQUENCY
COMP COMPOSITION SEL SELECTED
CONN CONNECTOR SEMICOND SEMICONDUCTOR
ELCTLT ELECTROLYTIC SENS SENSITIVE
ELEC ELECTRICAL SEP SEPARATELY
FXD FIXED VAR VARIABLE
INCAND INCANDESCENT WW WIREWOUND
LED LIGHT EMITTING DIODE XFMR TRANSFORMER
NONWIR NON Wl REWOUND XTAL CRYSTAL
2-1

Electrical Parts List—PS 505
CROSS INDEX MFR. CODE NUMBER TO
MFR.CODE MANUFACTURER ADDRESS
00213 Sage Electronics Corp., Subsidiary of
Nytronlcs, Inc., Orange St.
01121 Allen-Bradley Co. 1201 2nd St. South
03508 General Electric Co. ,Semi-Conductor
Products Dept. Electronics Park
04713 Motorola, Inc. ,Semiconductor
Products Dlv. 5005 E. McDowell Rd.
07263 Fairchild Semiconductor, ADlv. of
Fairchild Camera and Instrument Corp. 464 Ellis St.
07910 Teledyne Semiconductor 12515 Chadron Ave.
08806 General Electric Co., Miniature
Lamp Products Dept. Nela PK.
14099 Semtech Corp. 652 Mitchell Rd.
14936 General Instrument Corp., Semiconductor
Products Group 600 W. John St.
18324 Slgnetlcs Corp. 811 E. Arques
28480 Hewlett-Packard Co., Corporate Hq. 1501 Page Mill Rd.
56289 Sprague Electric Co.
58474 Superior Electric Co., The 383 Middle St.
71400 Bussman Mfg. ,Division of McGraw
Edison Co. 2536 W. University St.
71590 Centralab Electronics, Dlv. of
Globe-Union, Inc. 5757 N. Green Bay Ave.
73138 Beckman Instruments, Inc., Helipot Dlv. 2500 Harbor Blvd.
75042 TRW Electronic Components ,IRC Fixed
Resistors, Philadelphia Division 401 N. Broad St.
80009 Tektronix, Inc. P. 0. Box 500
81483 International Rectifier Corp. 9220 Sunset Blvd.
90201 Mallory Capacitor Co., Dlv. of
P. R. Mallory Co. ,Inc. 3029 E. Washington St.
MANUFACTURER
CITY,STATE,ZIP
Darlington, SC 29532
Milwaukee, WI 53204
Syracuse, NY 13201
Phoenix, AZ 85008
Mountain View, CA 94040
Hawthorne, CA 90250
Cleveland, OH 44112
Newbury Park, CA 91320
Hicksvllle, NY 11802
Sunnyvale, CA 94086
Palo Alto, CA 94304
North Adams, MA 01247
Bristol, CT 06010
St. Louis, MO 63107
Milwaukee, WI 53201
Fullerton, CA 92634
Philadelphia, PA 19108
Beaverton, OR 97005
Los Angeles, CA 90069
Indianapolis, IN 46206
2-2

Electrical Parts List—PS 505
Ckt No.
Tektronix
Port No. Serial/Model Mo. Eff Dscon> Name &Description
Mfr
Code Mfr Port Number
A1 670-3252-00 CKT BOARD ASSY:MAIN 80009 670-3252-00
CIO 283-0081-00 CAP.,FXD,CER DI:0.1UF,+80-203:,25V 56289 36C600
C12 290-052A-00 CAP. ,FXD,ELCTLT:A.7tIF,20%,10V 90201 TDCA75M010EL
CIA 283-0081-00 CAP. ,FXD,CER DI:0.1UF,+80-202, 25V 56289 36C600
C20 290-032A-00 CAP. ,FXD,ELCTLT:750UF,+75-102, AOV 56289 39D757GOAOHJA
C35 290-052A-00 CAP. ,FXD,ELCTLT: A. 7UF, 202,10V 90201 TDCA75M010EL
C6A 290-052A-00 CAP .,FXD ,ELCTLT :A.7UF ,202 ,lOV 90201 TDCA75M010EL
C75 290-0519-00 CAP. ,FXD, ELCTLT: lOOUF, 202, 20V 56289 196D107X0020MA3
CR20 152-0A88-00 SEMICOND DEVICE:SILIC0N,200V,1500MA 1A936 OP-02-8
CR35 152-01A1-02 SEMICOND DEVICE:SILICON,30V,150MA 07910 CD8220
CR36 152-01A1-02 SEMICOND DEVICE:SILICON,3OV,150MA 07910 CD8220
CR38 152-01A1-02 SEMICOND DEVICE:SILICON,30V,150MA 07910 CD8220
CR39 152-01A1-02 SEMICOND DEVICE:SILICON,30V,150MA 07910 CD8220
CRA2 152-01A1-02 SEMICOND DEVICE :SILICON ,30V ,150MA 07910 CD8220
CR65 152-01A1-02 SEMICOND DEVICE :SILICON, 30V, 150MA 07910 CD8220
CR75 152-OOAO-OO SEMICOND DEVICE :SILICON, 600V, lA 1A099 SC-6
OS 10 150-1001-00 LAMP ,LED :RED ,2V ,1OOMA 28A80 5082-AA03
OSAO 150-1001-00 LAMP ,LED :RED ,2V ,1OOMA 28A80 5082-AA03
DS75 150-00A8-00 LAMP ,INCAND :5V ,60MA 08806 683
FIO 159-OOlA-OO FUSE ,CARTRIDGE :3GA ,5A, 250V ,FAST-BLOW 71A00 MTH5
J75 129-006A-01 POST, BDG, ELEC: RED, 5-WAY MINIATURE 58A7A BB10167G2BX
J76 129-006A-00 POST, BDG, ELEC: CHARCOAL, 5-WAY MINIATURE 58A7A BINP BB10167G13T
J77 129-006A-02 POST ,BDG ,ELEC :WHITE ,5-WAY ,MINIATURE 58A7A DF21WTC
QIO 151-0515-01 TRANSISTOR: 50V, 8A 0A713 2NAAA1
Q25 151-03A2-00 TRANSISTOR :SILICON ,PNP 07263 2NA2A9
QA5 151-03A2-00 TRANSISTOR :SILICON ,PNP 07263 2NA2A9
Q50 151-036A-00 TRANSISTOR :SILICON ,PNP 03508 XA3C181
Q52 151-0190-00 TRANSISTOR :SILICON ,NPN 0A713 2N390A
RIO 315-0911-00 RES. ,FXD, COMP: 910 0HM,52,0.25W 01121 CB9115
R12 315-0121-00 RES. ,FXD, COMP: 120 0HM,52,0.25W 01121 CB1215
R22 301-0222-00 RES. ,FXD,COMP:2.2K OHM,52,0.50W 01121 EB2225
R2A 321-0129-00 RES. ,FXD,FILM:215 OHM, 12,0. 125W 750A2 CEAT0-2150F
R2S 321-0181-00 RES. ,FXD,FILM:750 OHM,12,0. 125W 750A2 CEAT0-7500F
R30 311-1563-00 RES. ,VAR,N0NWIR:1K OHM,202,0.50W 73138 91A-10000M
R31 321-0239-00 RES. ,FXD,FILM:3.01K OHM, 12,0. 125W 750A2 CEAT0-3011F
R32 321-0238-00 RES. ,FXD,FILM:2.9AK OHM, 12,0. 125W 750A2 CEAT0-29A1F
R33 321-02AO-00 RES. ,FXD,FILM:3.09K OHM, 12,0. 125W 750A2 CEAT0-3091F
R35 311-152A-00 RES. ,VAR,N0NWIR:20K OHM, 102, IW 01121 11M338
R37 315-0102-00 RES. ,FXD, COMP: IK OHM, 52,0. 25W 01121 CB1025
RAO 315-0911-00 RES. ,FXD, COMP: 910 0HM,52,0.25W 01121 CB9115
RA2 315-0273-00 RES. ,FXD, COMP: 27K OHM,52,0.25W 01121 CB2735
RA5 321-025A-00 RES. ,FXD,FILM:A.32K OHM, 12,0. 125W 750A2 CEAT0-A321F
RA8 315-0102-00 RES. ,FXD,CW1P:1K 0HM,52,0.25W 01121 CB1025
R50 301-0680-00 RES. ,FXD,COMP:68 OHM,52,0.50W 01121 EB6805
R52 315-0912-00 RES. ,FXD,COMP:9. IK 0HM,52,0.25W 01121 CB9125
R55 311-152A-00 RES .,VAR ,NONWIR :20K OHM ,102 ,IW 01121 11M338
R56 315-0331-00 RES. ,FXD, COMP: 330 OHM,52,0.25W 01121 CB3315
R57 315-0331-00 RES. ,FXD, COMP: 330 OHM,52,0.25W 01121 CB3315
R60 321-0192-00 RES. ,FXD, FILM: 976 OHM, 12,0. 125W 750A2 CEAT0-9760F
R61 315-0121-00 RES. ,FXD, COMP: 120 OHM,52,0.25W 01121 CB1215
2-3

Electrical Parts List—PS 505
Ckt No.
Telytronix
Porf No. Serial/Model No. Eff Dscont Nome &Description
Mfr
Code Mfr Port Number
R64 315-Olai-OO RES. ,FXD,COMP:120 OHM,52,0.25W 01121 CB1215
R65 3X5-0472-00 RES. ,rXD,C0MP:4.7K OHM,52,0. 25W 01121 CB4725
R67 315-0912-00 RES. ,FXD,C0MP:9.1K OHM,5!i;,0.25W 01121 CB9125
R70 308-0548-00 RES.,FXD,WW:0.1 0HM,32,5.0W 00213 1550S-R1000H
R75 315-0331-00 RES. ,FXD, COMP: 330 OHM,5X,0.25W 01121 CB3315
S35 260-1208-00 SWITCH,PUSH :DPDT 71590 2KAB0 10000-359
SIO 260-1310-01 SWITCH, PUSH: 71590 2KAA00 1000-437
U35 156-0158-00 MICROCIRCUIT, LI: DUAL OPERATIONAL AMPLIFIER 18324 S5558V
U65 156-0067-00 MICROCIRCUIT,LI :0PERATI0NAL AMPLIFIER 07263 UA741
VR12 152-0280-00 SEMICOND DEVICE: ZENER, 0.4W, 6. 2V,5Z 04713 1N753A
VR20 152-0175-00 SEMICOND DEVICE:ZENER,0.4W,5.6V,5Z 04713 1N752A
VR22 152-0306-00 SEMICOND DEVICE :ZENER, 0.4W, 9. IV, St 81483 1N960B
VR25 152-0212-00 SEMICOND DEVICE:ZENER,0.5W,9V,5Z 04713 SZ50646
2-4

Section 3—PS 505
SERVICE
INFORMATION
SYMBOLS AND REFERENCE DESIGNATORS
Electrical components shown on the diagrams are in the following units unless noted otherwise:
Capacitors =Values one or greater are in picofarads (pF).
Values less than one are in microfarads l/iF).
Resistors =Ohms (fi)
Symbols used on the diagrams are based on ANSI Y32.2 —1970.
Logic symbology is based on MIL-STD-806B in terms of positive logic. Logic symbols depict the logic function performed
and may differ from the manufacturer's data.
The following special symbols are used on the diagrams:
<s>
<2>
External Screwdriver adjustment.
External control or connector.
Clockwise control rotation in direction of arrow.
Refer to diagram number indicated in diamond.
Refer to waveform number indicated in hexagon.
Connection soldered to circuit board.
Connection made to circuit board with interconnecting pin.
Blue tint encloses components located on circuit board.
P/0 circuit board
3-1

INPUT-OUTPUT ASSIGNMENTS FOR PLUG-IN
REAR INTERFACE CONNECTOR
AMlgntiMnlt lor pint 1A 13A and IB —138 ara avallabla In all powar modulaa: bowavar, only
thoaa pint nurliad with an aatartak (*) ara uaad by tha PS $05.
'Conr>act voltaga batwaan pint 26B(+) and 23B(-). Parallal capadtora may ba naadad to atop
oadllatlona.

PS 505
CONTROLS AND CONNECTORS
VOLTS Control
and Indicator
Continuously vartabla
control that aatacts 3.0 to
5.5 volts. Indicator lights
whan power Is applied to
the PS 505 (OUTPUT
button pressed).
Brightness varies with the
output voltage.
NON-FLOATING
Indicator
Light-emitting diode
Indicates when the PS 505
Is Installed In astandard
compartment of aPower
Module, limiting the
currant output. The
negative output terminal
of the PS 505 should be
connected to ground to
prevent any accidental
shorting of the +11.5 V
Power Module supply,
since other plug-lns In the
Power Module may
reference this supply to
ground.
CURRENT
TfKTaONIXe PS 505 POWER SUPPIY
VOITS
MIS >4*
FOLD BACK LIMIT lA
3-S SV
04A >1A
OUTPUT Pushbutton
When pressed, applies
power from the Power
Module to the PS 505.
CURRENT LIMIT
Control and Indicator
Continuously variable
control that selects output
current limit from 0to at
least 4A. Light-emitting
diode Indicates when
hard limiting occurs.
Output Terminals
5-way binding-post
terminals that provide
floating 3.0 to 5.5 V, 4A
(plug-ln installed In TM
504 or TM 506 high power
compartment) or 3.0 to
5.5 V, 1Anegative
grounded (plug-ln
Installed In standard
compartment).

Adjustment is generally required after arepair has been
made, or after long time intervals in which normal aging of
components may affect instrument accuracy.
To ensure instrument accuracy, check the calibration
every 2000 hours of operation, or every six months if used
infrequently.
NOTE
OVERHAUL SERVICES AVAILABLE
Tektronix, Inc. provides complete instrument repair
and calibration at local Field Service Centers and at
the Factory Service Center. Contact your local
Tektronix held Office or representative for further
information.
Before complete calibration, thoroughly clean and
inspect this instrument as outlined in the Service section
of the Power Module manual. The Power Module manual
also contains information for general maintenance of this
instrument, including preventive maintenance, compo-
nent identification and replacement, etc.
WARNING I
Dangerous potentiais exist at several points
throughout this instrument. When the instrument is
operated with the covers removed, do not touch
exposed connections or components. Disconnect
power before cleaning the instrument or replacing
parts.
Equipment Required
1. TM 500 Series Power Module having ahigh power
compartment.
2. Variable autotransformer. Must be capable of
supplying sufficient wattage (depends on what plug-in
modules are installed) over arange of 90 to 132 Vac or 180
to 264 Vac. The autotransformer must also have an ac
voltmeter to indicate output voltage.
3. Adc voltmeter having an accuracy within ±0. 1%and
ameasurement range of 6volts. For example, aDM 501
Digital Multimeter (operates in aTM 500 Series Power
Module), or adc voltmeter may be used.
4. Adc ammeter having an accuracy within 3%and a
measurement range of 5amps. For example, aTriplett
630NA multimeter.
5. Test Oscilloscope. Must have aminimum bandpass
of 500 Hz and adeflection factor of 5mV/div with aIX
probe. For example, a5103N/D10 Oscilloscope with
5B10N Time Base/Amplifier plug-in, a5A18N Dual Trace
Amplifier plug-in, and aP6028 Probe. Any oscilloscope —
IX probe combination that will meet the listed re-
quirements may be used.
6. Load resistor: 1ohm, 20 watts, ±5%. To be obtained
locally.
7. Load resistor: 3ohm, 5watts, ±5%. To be obtained
locally.
Preliminary Procedure
NOTE
The performance of this instrument can be checked
at any temperature within the 0° Cto +50° Crange.
Make any adjustment at atemperature of +25° C,
±5°C.
a. Check that the correct nominal line selector block
(110 Vac or 220 Vac) has been installed on the TM 500
Series Power Module line selector pins and that the
regulating range selected includes the input line voitage,
see Installation section of Power Module manual..
b. Connect Power Module to the variable
autotransformer and the autotransformer to the line
voltage source.
c. Remove the PS 505 side covers and install the
Power Supply into the far right (high power) compartment
of the Power Moduie.
d. Set the autotransformer to the nominal line voltage
that the Power Module line selector is set to and apply
power to the PS 505 by pulling the Power Module Power
switch out.

ADJUSTMENTS
e. Set the following controls: 2. Check Line Regulation
VOLTS Fully ccw
OUTPUT Off (out position)
CURRENT LIMIT Fully ccw
1. Adjust 5.5 Ad], R30
Connect the meter leads from the dc voltmeter to the
PS 505 +and -binding posts at the monitor connection
points (see drawing insert). Press in the PS 505 OUTPUT
pushbutton.
Check for adc voltmeter reading between 2.5 and 3.5
volts. Slowly turn the PS 505 VOLTS control cw and check
for asteady increasing voltage that does not exceed 5.5
volts at the maximum cw position of the control.
If the check above is not met, adjust 5.5 Ad], R30 until
the maximum voltage obtained at the maximum cw
position of the VOLTS control is 5.5 V, ±0.05 V. Rotate the
VOLTS control fully ccw and check for avoltmeter reading
With the dc voltmeter still connected to the PS 505 and
the VOLTS control set fully ccw. connect a1ohm, 20 watt
load resistor in series with the dc ammeter, then connect
the combination between the +and —binding posts load
connection points (see drawing insert). Check that the
CURRENT LIMIT indicator is lit. Rotate the CURRENT
LIMIT control fully clockwise and check that the
CURRENT LIMIT indicator is not lit.
Turn the PS 505 VOLTS control cw until the ammeter
reads 4A. Note the dc voltmeter reading. Raise the
autotransformer voltage 10% and check that the dc
voltmeter reading does not vary by more than ±10 mV
from the noted dc voltmeter reading. Lower the
autotransformer voltage 10% below the nominal line
voltage and again check fora dc voltmeter reading within
±10 mV of the noted voltmeter reading.
Return the autotransformer voltage to the nominal line
voltage and check for adc voltmeter reading within ±5 mV