EAI TR-20 User manual

COMPUTER·
DPERATDR'S REFERENCE
HANDBODK
© ELECTRONIC ASSOCIATES. 1NC. 1964 • PR1NTED IN U.S.A. • PUBL. NO. 00 800.2003-1 • .JUNE 1967

RELATED PUBLICATIONS
The table below lists other publications which may be of interest to the
readers of this manual. Unless otherwise indicated by title or footnote,
all are maintenance handbooks. Note that maintenance handbooks directly
applicable to a particular system are normally supplied with the system.
Title
Handbook of Analog Computation
TR-20 Maintenance Manual
Repetitive Operation Display Units,
Models 34.034 and 34.035
Pub"lication Nl.nllber
00
800.0001-3
00 800.2006-0
00 800.2024-1

M226-3
NOTIC E
In order to enable us to process your requests for spare parts and replacement items quickly
and efficiently, we request your conformance with the following procedure:
1. Please specify the type number and serial number of
the basic unit as well as the EAI part number and de-
scription of the part when inquiring about replacement
items such as potentiometer assemblies or cups, re-
lays, transformers, preciSion resistors, etc.
2. When inquiring about items as servo multipliers, re-
solvers, networks, printed circuit assemblies, etc.,
please specify the serial numbers of the major equip-
ment with which the units are to be used, such as:
Console, Type 8811, Memory Module, Type 4.204,
Serial No. 000, etc. If at all possible, please in-
clude the purchase order or the EAI project number
under which the equipment was originally procured.
Your cooperation in supplying'the required information will speed the processing of your requests
and aid in assuring that the correct items are supplied.
It is the policy nf Electronic Associates, Inc. to supply equipment patterned as closely as possi-
ble to the requ':.:rements of the individual customer. This is accomplished, zt'ithout incurring the
prohibitive cos:is of custom design, by substituting new components, modifying standard com-
ponents, etc., wherever necessary to expedite conformance with requirements. As a result,
this instruction;. manual, which has been written to cover standa'rd equipment, may not entirely
concur in its cr:Jnte.nt with the equipment,supplied. It is felt, however, that a technically quali-
fied person wirJ find the manual a fully adequate guide in understanding, operating, and main-
taining the equ~pment actually supplied.
Electronic Associates, Inc. reserves
the right to make changes in design,
or to make additions to or improve-
ments in its product without imposing
any obligation upon itself to install
them on products previously manufac-
tured.
PRINTED IN U.S.A.

Printed in U.S.A.
EASTERI, REGION
UNITED STATES AND CANADIAN OPERATIONS
Marketing Division
SALES OFFICE
Eastern Regional Office: West Long Branch. N. J .. Te!: 201·229·1100, TWX 510·239·9208. Telex 01-26655, Cable: PACE West
Long Brar.::". N. J.
Special System Department: West Long Branch. N. L Tel: 201·229-1100, TWX 510·239·9208. Telex 01-26655. Cable: PACE
West Lon>: Branch, N. J.
Customer Services: West Long Branch. N. J., Tel: 201-229·1100. TWX 510·239-9208. Teiex 01-26655, Cable PACE West Long
Branch. 1';. J.
Northeastern District Office: 875 Providence HiJ<hway. Dedham, Massachusetts. Tel: [phone]
SOUTHEASTERN REGION
Southeastern Regional Office: 12260 Wilkins Avenue. Rockville. Maryland, Tel: 301·933-4100
CENTRAL REGION
Central Regional Office: 33166 Des Plaines Ave.. Des Plaines. Illinois, Tel: [phone]
Cleveland District Office: 6741 Ridge Road, Parma, Ohio, Tel: 216-842·1840
SOUTHERN REGION
Southern Regional Office: 3514 Cedar Springs Road, Room 211, Dallas, Texas. Tel: [phone]
Houston District Office: 7007 Gulf Freeway, Room 128, Houston, Texas, Tel: 713·MI-4-3678
Huntsville District Office: Holiday Office Center, Suite 2, 3322 South Memorial Parkway. Huntsville, Ala., Tel: 205·881·7031
WESTERN REGION
Western Regional Office: 1500 East Imperial Highway, EI Segundo, California, Tel: 213·322·3124, TWX 910·348·6284
San Francisco District Office: 4151 Middlefield Road. Palo Alto. California, Tel: [phone]. TWX 910·373-1241
CUSTOMER SERVICES OFFICES
EASTERN REGION
Eastern U.S. Headquarters: West Long Branch. N. J.. Tel: 201-229·1100. TWX 510-239-9208. Telex 01-26655. Cable: PACE
West Long Branch, N. J.
Northeastern District Office: 875 Providence Highway. Dedham. Massachusetts. Telephone: 617·326-6756
Princeton. New Jersey: U.S. Route No.1. Princeton, New Jersey, P.O. Box 582, Telephone: 609-452·2900
Resident Field Engineers: Bedford. Mass.!Florham Park, N. J./Washington, D.C./Baltimore, Md.!Eatontown, N. J.
SOUTHEASTERN REGION
Southeastern Regional Office: 12260 Wilkins Avenue. Rockville. Maryland, Telephone: [phone]
CENTRAL REGION
Central Regional Office: 3166 Des Plaines Ave., Des Plaines. Illinois, Tel: [phone]
Cleveland District Office: 6741 Ridge Road, Parma, Ohio, Telephone: [phone]
Resident Field Engineers: Detroit, Michigan/Pittsburgh, Pennsylvania/Dayton, Ohio/Warren. Michigan
SOUTHERN REGION
Southern Regional Office: 3514 Cedar Springs Road. Dallas, Texas. Telephone: [phone]
Houston District Office: 7007 Gulf Freeway, Room 128, Houston. Texas, Telephone: 713-MI 4-3678
HuntSVille District Office: Holiday Office Center. Suite 14, 3322 South Memorial Parkway, Huntsville, Ala., Tel: [phone]
Resident Field Engineers: San Antonio, Texas/Alamogordo, New Mexico/Tulsa, OklahomalHouston. Texas.
WESTERN REGION
Western U.S. Headquarters: CUSTOMER REPAIR FACILITY. 1500 East Imperial Highway, EI Segundo, California, Telephone:
213-322·3220, TWX 910·348-6284
Western U.S. Headquarters: CUSTOMER SERVICES FACILITY, 1500 East Imperial Highway, EI Segundo, California, Tele·
phone: [phone], TWX 910-348-6284
San Francisco District Office: 4151 Middlefield Road, Palo Alto, California, Telep
t
lOne: 415·321-0363, TWX 910-373-1241
Denver Area: 70 South Benton Drive, Denver, Colorado, Telephone: [phone]
Resident Field Engineers: Edwards, California/Pasadena, California/Moffet Field, California/Douglas Aircraft. Huntington
Beach, California
CANADA
Toronto Office: Allan Crawford Associates. Ltd., 65 Martin Ross Avenue, Downsview OntariO, Canada, Tel: [phone]
COMPUTATION CENTERS
Princeton Computation Center: U.S. Route No. 1. Princeton, New Jersey, P.O. Box 582. Tel: [phone]
Los Angeles Computation Center: 1500 East Imperial Highway, EI Segundo, California, Tel: [phone], TWX 910-348-6284
San Francisco Computation Center: 4151 Middlefield Road, Palo Alto, California, Tel: 415·321-7801. TWX 415-492-9211
Washington. D.C. Computation Center: 12260 Wilkins Avenue, Rockville, Maryland, Tel: [phone]
Research and Computation Division
Research and Computation Division H.adquarters: U.S. Route No. I, Princeton. New Jersey, P.O. Box 582, Tel: [phone]
Engineering and Manufacturing Division
Engineering Department: West Long Branch, N. J .• Tel: [phone], TWX 510-239-9208. Telex 01-26655, Cable: PACE West
Long Branch. N;. J. .
Manufacturing Ilepartment: West Long Branch, N. J., Tel: 201-229·1100, TWX 510-239·9208, Telex 01-26655. Cable: PACE
West Long Brani:h, N. J.
. Other Departments, Divisions and Subsidiaries
Instrument Division: Lon!: BranCh. New Jersey. Tel: [phone], TWX 510·239·9208, Cable: PACE West Long Branch. N. J.
Pacific Data Systems, Inc.: 1058 East First Street, Santa Ana. California. Tel: 714·547·9183, TWX 714·531·0188
Scientific Instruments Department: 4151 Middlefield Road, Palo Alto, California. Tel: 415·321·7801. TWX 910-373·1241
INTERNATIONAL OPERATIONS
SALES & CUSTOMER SERVICES OFFICES
UNITED KINGDOM & SCANDINAVIA
Electronic Associates. Ltd.: Burgess Hill, Sussex, England, Tel: Burgess Hill (Sussex) 5101-10, 5201-5, Telex: 87183. Cable:
PACE Burgess Hill
BURGESS HILL
Northern Area Office: Roberts House. Manchester Road, Altrincham, Cheshire, Tel: Altrincham 5426
SWEDEN
EAI·Electronic Associates·AB: Hagavagen 14, Solna 3, Sweden, Tel: Stockholm 82-40-96; 82-40·97, Telex Stockholm 10064,
Cable: PACE STOCKHOLM
EUROPEAN
CONTINENT
EAI-European Continental Regional Office: Centre International, 22nd Floor, Place Rogier. Brussels 1. Belgium. Tel: Brussels
18-40-04, Telex: 2.21·106. Cable: PACEBELG Brussels
FRANCE
EAI-Electronic Associates SARL: 72-74. rue de la Tombe Issoire, Paris '14e, France. Tel: [phone]
GERMANY
EAI.Electronic Associates GM8H: 5100 Aachen, Bergdriesch 37, West Germany, Tel: Aachen 2 6042; 26041. Telex 832.676 eai d
AUSTRALIA & NEW ZEALAND
EAI-Electronic Associates, Ply .• Ltd.: 26 Albany St., Leonards, N.S.W. Australia, Tel: [phone], Cable: PACEAUS,
Sydney
Victorian Office: 34 Queens Road, Melbourne S. C. 2. Australia, Tel: 26·1329, Cable: PACEAUS, Melbourne
JAPAN
EAI-Electronic Associates, (Japan) Inc.: 9th Mori Building, 1·3 Shiba-Atagocho, Minato-Ku. Tokyo 2, Japan; Tel: [phone],
Telex: 7814285. Cal'.,,: EAIJAPACE
ENGINEERING AND MANUFACTURING
Electronic Associates. Ltd.: Burgess Hill. Sussex, England, Tel: Burgess Hill (Sussex) 5101-10. 5201·5, Telex: 87183. Cable:
PACE BURGESS H:LL
COMPUTATION CENTERS
European Computation Center: Centre International, 22nd Floor, Place Rogier, Brussels 1. Belgium. Tel: Brussels 18-40·04.
Telex: 2.21-106. Cat:e: PACE9ElG Brussels
United Kingdom Computation Center: Electronic Associates, Ltd .. Burgess Hill. Sussex, England. Tel: Burgess Hill (Sussex)
5101-10. Telex: 871·183. Cabie: PACE BURGESS HILL
Australian Computation Center: 34 Queens Road, Melbourne S.C. 2. Australia. Tel: 26-1329, Cable: PACEAUS. Melbourne
I ~LECTRONIC
ASSOCIA TES,
I NC. West Long Branch, New Jersey
ADVANCED SYSTEMS ANALYSIS A~D COMPUTATION SERVICES/ANALOG COMPUTERS/DIGITAL COMPUTERS/HYBRID ANALOG-DIGITAL COMPUTATION EQUIPMENTiANALOG AND DIGITAL
PLOTTERS/SIMULATION SYSTEMS/SCIENTIFIC AND
u.eORATORY INSTRUMENTS/INDUSTRIAL PROCESS CONTROL SYSTEMS I PHOTOGRAMMETRIC EQUIPMENT / RANGE INSTRUMENTA·
TlON SYSTEMSITEST AND CHECK-OUT
SYSTH'S MILITARY AND INDUSTRIAL RESEARCH AND DEVELOPMENT SERVICES/FIELD ENGINEERING AND EQUIPMENT MAINTENANCE SERVICES.
Bulletin No. IL·64104-6
June, 1966

MANUAL REViSION NOTICE * ELECTRONIC ASSOCIATES INC.
~
TEM
PAGE
PARA
LONG BRANCH NEW JERSEY
REVISION
Included in the accessory items shipped with each computer is a
strip of 100 pressure sensitive labels (EAI 00 342.0572-0). These
labels may be attached to the connector blocks to identify the
computing components associated with a particular problem.
DATE 3/30/65 MANUAL TITLE TR-20 COMPUTER OPERATORS
REViSION NOTICE
NO. 65-13
P l<'k'l<'P k'l\Tr l<' U 1\ l\Tn p'oOJ(
*THIS MANUAL REVISION NOTICE IS ISSUED TO INCORPORATE IMPROVEMENTS OR
CHANGES OF ROUTINE OR MINOR NATURE IN THE SUBJECT MANUAL.
SH. 1 OF 1 SH.

CONTENTS (Cont)
6. QUARTER-SQUARE MULTIPLIER ......•••................•.•..• 26
~. General Description ....••.•••.••.•..•.....•.••.• ...• 26
b. Multiplication...................................... 26
£. Division. . . . . . . . . . . . . . . . . • . . • . ••. • . • • . •• . . • • • • • . • . • • 26
7. X2 DIODE FUNCTION GENERATOR •..•.••••.•.••.••••••••••. ,.. 28
a.
General Description ..•..•••..•.•....••.•.•...•..•...
28
E..
Generating the Square of an Input Voltage (Single
Polarity) ........•..•••...••••..•••..••..•.•.•••••
29
Generating the Square of an Input Voltage (Bi-Polar).
29
8. LOG X DFG AND 1/2 LOG X DFG .............................. 29
a. General Description................................. 29
E.. Pa tching •...•..•....••.•..•.••......••....•.....•••. 32
9. VARIABLE DIODE FUNCTION GENERATOR GROUPS 2.645 AND 2.713. 32
a. General Description ..•...••.•.•....•......•...•••••• 32
b. Setup Procedure (Fixed Breakpoint VDFG's) ••••••••••• 34
£. Setup Procedure (Variable Breakpoint VDFG's) ••.••.•. 34
d. Paralleling Fixed Breakpoint VDFG's ...•..•..•.....•. 46
10. SIGNAL COMPARATORS AND FUNCTION SWITCHES •.•...•••••.•.•. 47
a. Relay Comparator ..•••••••••••.•.......•.•••...•.•... 47
b. Electronic Comparator .•• ,............................ 47
c. Dual Function Switch Group 2.127 ...•.........•...••• 50
ii

CONTENTS (Cant)
11.
REPETITIVE OPERATION
......................
53
~. General Description
................... 53
~. Using Repetitive Operation
54
12. DISPLAY NETWORKS
54
APPENDIX I - COMPUTER SYMBOLS
AI-l
APPENDIX II - CIRCUITS USING COMPUTATIONAL COMPONENTS
AII-l
APPENDIX III - AMPLIFIER CIRCUITS FOR SIMULATING TRANSFER
FlJN'CTIONS •••••••••••••••••••• 0 0 ••••••••••••
AIII-l
APPENDIX IV - BIBLIOGRAPHY
AIV-l
iii/iv

Figure
Number
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
ILLUSTRATIONS
Title
The TR-20 Desktop Analog Computer with Display Units ••
4
Inserting the Pre-Patch Panel ••••••••..•••••••••••••••
9
The 6.712 Dual DC Amplifier, Showing Use of Bottle
Plug s ..... 0 • 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 10
The TR-20 Control Panel 0 ••••••••••••••• 0 ••••••••••••••
Readout Circuit, Simplified Schematics ••••••••••••••••
An At tenua tor •••••••••• ' •••••••••••••••••••••••••••••••
Schematics and Symbols for Attenuators ••••••••••••••••
Operational Amplifier, Simplified Block Diagram
Patching an Amplifier as an Integrator~ Showing
Simplified Schematic of an Integrator Network
Patching an Amplifier to a Rep-Op Integrator,
.......
Showing Simplified Schematic of Integrator Network .•
Quarter-Square Multiplier Patching
....................
Division Circuit for a Quarter-Square Multiplier ••••••
X2 DFG Patching
X2
Generating + 10
Patching the Log
.......................................
for -10 ~ X ~ +10 ••••••••••••••••••••
X DFG t s ••••••••••••••••••••••••••••••
VDFG Mounting Locations •••••••••••••••••••••••••••••••
±VDFG Patching •••••••.••••••••••••• e •••••••••••••••••••
Sample Function and Setup
Information •••••••••••••••••
Breakpoint Setup Patching
.............................
+ Variable Breakpoint Diode Function Generator
11
14
18
18
20
23
25
27
30
30
31
32
33
35
36
38
SBItlP le Curve s ••• 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 40
Breakpoint Location Plot Patching •••••••••••••••••••••
42
v

Figure
Number
22.
23.
24.
25.
26.
27.
vi
ILLUSTRATIONS (Cont)
Title
Function Setup Patching
..........................
44
Relay Comparator, Simplified Diagrams and Setup
Patching ...................................... . 48
40.538 Electronic Comparator Unit
................ 49
Comparator Unit, Functional Block Diagram
51
Electronic Switch Unit, Functional Block Diagram
52
12.987 Display Network Patching Terminal Functions
55

CHAPTER I
INTRODUCTION
Many problems encountered in scientific or engineering work involve mathematical
equations or sets of equations whose solution in most cases is difficult or practi-
cally impossible to obtain by the classical approach to equation solution. The TR-20
Analog Computer provides the technical worker with a general purpose computer which
permits the rapid solution of linear or non-linear equations.
Although the analog machine is correctly termed a computer, it does not perform its
computations by serial calculations as does the desk calculator or digital computer.
Instead it performs the required mathematical operations in a parallel manner on con-
tinuous variables. In the TR-20, as in most modern analog computers, the continuous
variables are direct current voltages. The electronic analog computer makes it pos-
sible to build an electrical model of a physical system, where the voltages on the
computer represent the dependent variables of the physical system. Except for a
constant of proportionality, or scale factor, each voltage will behave with time in
a manner similar to the physical system variable. Thus, if the vertical position
of the center of gravity of an automobile oscillates with time during a disturbance,
then the voltage representing the height of the center of gravity above the surface
will also oscillate; if the temperature of the coolant at the exhaust port of a con-
denser rises exponentially to a steady value, then so will the voltage representing
it on the computer.
It can be said that the actual system and the electrical mode~ are analogous in
that the variables which demonstrate their characteristics ar~ described by relations
which are mathematically equivalent. The actual system has thus been simulated
because of the similarity of operation of the electrical model and the physical
system. This capability of the analog computer is of great value in performing
scientific research or engineering design calculations because it permits an in-
sight into the relationship between the mathematical equations and the response
of the physical system. Once the electrical model is completed, well-controlled
experiments can be performed quickly, inexpensively, and with great flexibility
to predict the behavior of the primary physical system.
Although the analog computer utilizes electronic components in its operation, it
is not essential that the user have an extensive knowledge of electrical circuits.
The TR-20 is basically a set of mathematical building blocks, each able to perform
specific mathematical operations on direct voltages and capable of being easily
interconnected. By appropriately interconnecting these building blocks, an elec-
trical model is produced in which the voltages at the outputs of the blocks obey
the relations given in the mathematical description of a physical problem.
1

Since our interest is frequently in the dynamic behavior of physical systems, the
mathematical equations are usually differential equations having time as the in-
dependent variable. In order to solve such equations, the standard components of
the computer must perform the following operations: inversion, algebraic summation,
integration with respect to time, multiplication and division, and function generation.
The sequence of steps for constructing a dynamic model on an analog computer requires
first a mathematical description of the physical system, usually in equation form.
From this description the operator derives the information necessary to set up a
computer program for interconnecting the computing components and determines the
required initial conditions and forcing functions. The computing components are
interconnected with wires called patch cords. The input and output terminations of
the computing components are brought out to a patch bay which is usually fitted with
a removable Pre-Patch Panel so that patching may be accomplished away from the com-
puter. The problem is placed on the computer by inserting the patch panel and ad-
justing the problem parameters to the value of the first case to be investigated.
Selected voltages are applied to various components in the form of inputs or initial
conditions. These voltages are derived from a precise reference voltage.
Once the computing elements have been patched, adjusted, and energized, the computer
is switched into the operate mode. The.voltages on the computer change with time in
accordance with the equations that govern the physical system variables. The be-
havior of the computer model is viewed through an output device such as an X-Y plotter,
oscilloscope, strip-chart recorder, or digital voltmeter.
This TR-20 Reference Handbook has been prepared to serve as a working guide to the
analog programmer or computer operator. The information contained presupposes a
knowledge of the analog computer, its basic principles of operation, and programming
procedures. (Instructional information in these areas can be obtained from "Basics of
Analog Computer Programming" by the EAr Education and Training Group.) Reaaers
interestea in more detailed circuit information are referred to the TR-20 Maintenance
·Manual.
2

CHAPTER II
THE TR-20 COMPUTER AND COMPUTING COMPONENTS
1. GENERAL DESCRIPTION
The PACE® TR-20 (Figure 1) is a general purpose analog computer composed of solid-
state computing components. The TR-20 is compact in size and is able to operate with
stability and precision in a normal office or classroom environment. Reliable, with
simplicity in functional design, the TR-20 is easy to use and can be a powerful aid
to the individual engineer in the rapid solution of scientific and engineering prob-
lems.
Table I lists the currently available computing components and accessories for the
TR-20. The TR-20 utilizes a building block concept, in which individual computing
components may be easily interconnected to solve the required equations by forming
electronic models analogous to the system under study_ Each building block, either
individually or in combination with others, is capable of performing one or more
mathematical operations. The computing components in the TR-20 occupy the area
above the slanting control panel area. This area is divided into three rows; the
top row contains the coefficient attenuators; the middle row houses the integrator
networks, comparators, and other non-linear computing components; the bottom row
provides space for twenty (10 dual units) operational amplifiers. The computing
components are constructed on plug-in chassis, and the front of each computing com-
ponent consists of a color-coded plastic patching block that contains the input and
output terminations for the unit. The computing components are inter-connected by
placing patch cords or bottle plugs between the appropriate input and output ter-
minations. Most TR-20's are equipped with a removable pre-patch panel that allows
problem patching away from the computer. The pre-patch panel consists of a rigid
aluminum frame with individual rows that contain patching blocks identical with the
patching blocks that form the front panels of the components. Contact between the
pre-patch panel and the computing components is accomplished by means of gold-plated
contact springs.
Below the patching area is the monitoring and control panel area which contains con-
trols and components that permit (a) switching the computer on and off, (b) mode
control of the computer, and (c) measuring statioriary problem voltages. A hinged
cover plate directly below the control panel covers the amplifier balancing potenti-
ometers and the variable diode function generators.
2. OPERATING CONSIDERATIONS
The TR-20 is completely tested and calibrated at the time of manufacture and is
shipped with all components in place. ~fter perform!gg_tl1e-pr~e_l~t!llinar,y-chJ~_c::k-g.p'!
procedure outlined in the TR-20 Maintenance Manual,..>. the c0IIl:puter is ready for op~r-
a-tIo~':--'----' ~"------ ~- . .-------------- --.....,.. ---~ .. ------.,~-.----.- .. - ... ,
It should be noted that the low voltage levels used in the TR-20 eliminate any shock
hazard to the operator when patching components with the computer turned on. Current-
limiting circuits protect the reference supplies from damage during short-term over-
loading if they are inadvertantly patched to ground or to each other. A patching con-
nection that is dangerous to a component usually triggers the overload alarm system.
3

Figure 1. The TR-20 Desktop Analog Computer with Display Units
4

GROUP
1
2a
2b
3a
3b
4a
4b
4c
4d
5a
5b
5c
6a
6b
6c
6d
TABLE I. TR-20 COMPONENTS
COMPONENT
COMPUTING COMPONENTS
Dual DC Amplifier
Dual Integrator Network (Non Rep-Op)
Dual Repetitive Operation Integrator Network
Quarter-Square Multiplier
Bi-Po1ar Quarter-Square Multiplier
X2 Diode Function Generator
Log X Diode Function Generator
1/2 Log X Diode Function Generator
Sine/Cosine Function Generator
Variable Diode Function Generator Group
Consists of:
-Variable Diode Function Generator
+Variab1e Diode Function Generato~
VDFG Readout Module
Variable Diode Function Generator Group
Consists of:
+Variab1e Diode Function Generator
-Variable Diode Function Generator
VDFG Readout Module
Variable Diode Function Generator Group
Consists of:
+Variab1e Diode Function Generator
VDFG Readout Module
Attenuator Group
Attenuator Group
Attenuator Group
Attenuator Group
MODEL
NUMBER
6.712
12.1116
12.1115
7.045
7.137*
16.101
16.126
16.133
16.313/1016.004*
2.713
16.154-1
16.156-1
16.310
2.645-0
16.304-1
16.306-1
16.308
2.748
16.165-1
16.310
42.183
42.187
42.188
2.128
5
I

GROUP
7a
7b
Tc
8a
8b
9
10
11
12
6
COMPONENT
COMPUTING COMPONENTS (Cont)
Consists of:
Attenuator Panel
Readout Module
Reference Network
Tiepoint Network
Dual Function Switch Group
Consists of:
Function Switch Assembly
Readout Module
Relay Comparator
Electronic Comparator
POWER AND REFERENCE SUPPLIES
Regulated Power Supply
Reference Regulator
Dual DC Amplifier
OPTIONAL COMPONENTS AND ACCESSORY EQUIPMENT
Repetitive Operation Expansion Group
Consists of:
High Speed Repetitive Operation Control Panel
Repetitive Operation Timing Unit
Dual Repetitive Operation Integrator Networks
MODEL
NUMBER
42. 185
12.265
12.266
12.267
2.127
20.366
12.264
6.143
40.538
10.179
43.037
6.282
2.246
20.532
36.082
12.1115

GROUP
13
14
15
16
17
18
19
20
21
22
1
2
COMPONENT
OPTIONAL COMPONENTS AND ACCESSORY EQUIPMENT
Display Unit**
Reactor Kinetics Group
Transport Delay Simulator
Audio Overload Alarm
S lave Cable
Patching Kit
Service Shelf
AC Power Cable
Pre-Patch Panel
Rep-Op Slave Panel
AUXILIARY EQUIPMENT
VARIPLOTTER®
Repetitive Operation Display Unit
MODEL
NUMBER
12.987
2.475*
2.448*
13.017
510.038
100.007
51.039
51.040
5 .. 235
20.567
1110*
The operator should be familiar with the following paragraphs before attempting to
use the computer·.
*These Components described in separate manuals.
**This Component not required if the Electronic Comparator, Model 40.538 is provided.
7

a. Insertion of the Pre-Patch Panel
Before inserting the pre-patch panel, the operator should verify that the patch blocks
on the pre-patch panel are aligned in the same order as the computing components.
Hold the pre-patch panel at a slight angle and place it in the patch bay groove;
see Figure 2. Move the pre-patch panel to th~ right until it contacts the right-
hand side of the patch bay. Gently, push the pre-patch panel forward until it is
flush with the computer. Turn the locking lever down; the pre-patch panel will
slide to the left.
To remove the pre-patch panel, apply a light pressure to the panel to keep it from
falling forward when dis-engaged, and lift the locking lever.
b. Feedback for the Amplifiers
All operational amplifiers should be provided with feedback whenever the computer
is turned on. Bottle plugs, connected as shown in Figure 3a, provide feedback and
prepare the amplifiers for use as standard inverters or summers.
c. Application of Power
Connect the computer line cord to a receptacle following the precautions given in
the TR-20 Maintenance Manual, and place the OFF-ON switch to the ON position. Place
the RESET-HOLD-OPER switch to the RESET ~osition. Initially, the amplifier over-
load alarm system will be triggered due to transients; after a few seconds, the over-
load indication should cease.
d. Amplifier Balance
Under normal circumstances, the amplifiers will remain balanced for periods of weeks.
However, at intervals it is desirable to check this condition. If an amplifier is
found to be unbalanced, an adjustment should be made. If the check indicates that
the amplifier balance is rithin tolerance, no adjustment is necessary.
The amplifier must have some sort of feedback in order to be balanced. Normally,
this requirement is satisfied by the circuit in which the amplifier is used. The
amplifier may be balanced while normal inputs are applied. Each amplifier has a
balance potentiometer located behind a hinged cover plate below the Control Panel
(Figure 4). The balance controls are labeled with the number of the amplifier they
serve. To set a balance control, proceed as follows:
(1) Place the computer in the reset mode. Place the VoltmetEr Function
switch in the BAL position. Rotate the AMPL SEL switch to the number of the ampli-
fier to be balanced.
(2) Vary the appropriate Amplifier Balance control until the Vokmeter
reads within two or three divisions of zero. (The amplifier overload alarm system
may be triggered during the balancing process.)
8

l-
I
Figure 2. Inserting the Pre-Patch Panel
9

10
SJ
FOR SPECIAL
OUTPUTS
INPUT RESISTORS
INPUTS
Z
GAIN
GAIN
10
GAIN 0.1
GAIN I
1[>
b. AN INVERTER
GAIN OF
0.1
{
{
{
y
AMPLIFIER I
10
10
AMPLIFIER 2
10
O. PATCHING WITH BOTTLE PLUGS
X
:[>
-Z
-(X +y)
y
C.
A SUMMER
Z
-O.I(X+Y+Z)-A
GAIN OF I A
10 .
d. A HIGH -GAIN AMPLIFIER PATCHED FOR GAINS OF 0.1 AND I
Figure 3. The 6. 712 Dual DC Amplifier, Showing Use of Bottle Plugs

NULL POT
REFERENCE
SELECTOR
SWITCH
VOLTMETER
FUNCTION SWITCH
Figure 4. The TR-20 Control Panel
VOLTMETER
ANGE SWITCH
11