Beschreibung und Bedienungsanleitung des Präzisions-Analogrechners RA 800

Complete English translation of the original German-language document (54 pages).

Transistorized Precision Analog Computer RA 800

Description and Operating Instructions

Preliminary Note

[page 1: title page — “Transistorized Precision Analog Computer RA 800 — Description and Operating Instructions — TELEFUNKEN Aktiengesellschaft, Fachbereich Anlagen Hochfrequenz, Munich”]

(page 2)

Preliminary Description and Operating Instructions for the RA 800

Contents:

General
Mechanical Construction
Description of the Patch Panel
Operating Panel
Programming the Computing Elements
Operating Modes of the Computer
Brief Instructions for Clearing and Patching the Computing Elements
Eliminating Malfunctions
Data for the Computing Elements

Preliminary Note

(page 3)

The present description is intended to inform the user of the TELEFUNKEN Precision Analog Computer RA 800 about its construction, mode of operation, and technical data, and to provide guidance on operation and maintenance of the installation. It deals exclusively with the technical aspects of the computer. A separate “Computing Guide for Analog Computers” is available for practical use.

The description contains, distributed across the corresponding sections of the part “Circuit Diagrams,” all circuit diagrams. It should be noted that all switches and relays are shown in the unoperated (i.e., de-energized) state, regardless of the individual operating conditions depicted.

The “Operating” section consists — apart from the necessary general overview — predominantly of consecutively numbered brief instructions, whose sequence of steps corresponds to the chronological order of the actions required. This makes it possible to put the computer into immediate operation without prior knowledge of the remaining parts of the description.

Under “Maintenance,” all maintenance instructions for the computer are summarized. The “Troubleshooting” section enables the user of the computer to identify faults that may occur and to replace the relevant components himself in most cases, without having to call on the service department.

1. General

(page 4)

Intended Use

The Precision Analog Computer RA 800 occupies a special position among modern analog computing machines by virtue of its excellent component accuracy, its circuit concept (which takes into account the most favorable methods from the contemporary literature, including iterative methods), its flexible configuration, and its ease of operation. It can be used in all fields of scientific research and engineering for investigating, simulating, and optimizing systems, and is especially suited — wherever the governing equations cannot be solved exactly — to determining approximate solutions in the shortest possible time.

An ever-growing number of publications in the specialist literature demonstrates that the analog computer of the type described below is also well-suited as a permanently useful instrument for the foreseeable future.

Special Characteristics of the RA 800

High Accuracy

Computing component errors ≤ ±0.01 %
High long-term stability of computing amplifiers through chopper stabilization
Very precise modulation multipliers with extremely small null-point error; switchable to DC division at full bandwidth (Time-Division); switchable to DC multiplier mode
Complementary triggers and high-precision integrator/hold elements
Precise time generator for “Repetitive/Iterative Computing”
Very precise read-out of potentiometer settings by digital voltmeter with printer output
Automatic printout of measured values and potentiometer settings, including addresses

Convenient Operation

Central, interchangeable patch panel; operating-mode selection by indicator lights
Fast selection of computing elements; measuring, adjusting, and checking; built-in digital voltmeter with address display
Complementary triggers and
Integrators switchable — also for the individual integration time constants for time scaling — without program changes
Fast operating speed: short-circuit protection; monitoring of computing elements while the machine is running; substantial savings in volume, weight, and power consumption
Low expenditure for the installation space
High operating reliability and service life
High long-term stability; precise repeatability
Simple circuit engineering; easy servicing without special tools

(page 5)

Furthermore: up to 100 and more computing steps can be combined via a central parallel-switching facility
Convenient parallel operation with desk analog computers of the type RA-T… and with all future computers in the Telefunken program

Configuration of the Computer

(page 5, continued)

The basic unit of the Precision Analog Computer RA 800 is a double-width cabinet. An expansion cabinet may be added beside the double cabinet, as shown in Figure 0.1.

The double cabinet contains: 1 digital voltmeter, 1 ≥ 2-meter-long removable patch panel, and 1 thermostat (plus condensers with associated networks).

The double cabinet contains 10 (normalized) slots into which the plug-in units (Einschübe) carrying the computing elements can be inserted. See Figure 0.1. Different plug-in units with computing elements may be inserted into one slot (see Figure 3.1). When a plug-in unit is inserted, all operating voltages needed by the computing elements are connected via rear-panel connectors. Signals from the computing elements that must be brought to the patch panel are routed via flying-lead patch cables to the measuring strips at the rear of the plug-in units, at which the patch panel sockets are connected. A diagram (Figure 0.2) shows which sockets of the patch panel are connected to which measuring strips — e.g., the sockets of the servo-multiplier input field in Slot 1 of the patch panel are connected via measuring strip T to the servo-multiplier. This measuring strip T connects to the servo-multiplier of this plug-in unit regardless of which slot of the cabinet it is inserted into; when connected via this measuring strip, it is automatically connected to the sockets of the servo-multiplier input field in Slot 1. This is described in detail in Section 5.3.2.7.3 (Servo-Multiplier Input Field). Similarly, if the measuring strip is connected to a plug-in unit equipped with parabolic multipliers, then the parabolic multipliers are automatically connected to the sockets of the corresponding field, as described under point 5.3.2.7.3 (Input Field).

(page 6 — block diagram: “Precision Analog Computer RA 800 — Main Unit and Expansion Cabinet”)

The diagram (Figure 0.1) shows the RA 800 main (double) cabinet with the expansion cabinet. The expansion cabinet may contain, depending on configuration:

Servo-multipliers, or
Coordinate transformers, or
Function generators, or
Nonlinear networks

Double Cabinet — Content Summary (top to bottom):

Reference voltage supply: ±10 V, ±1 V; 400 Hz chopper voltage; relay voltage 25 V
Thermostat
Power supply 5/30 V
4 variable diode function generators
(same as above)
Setting unit for servo function generators
Servo plug-in units / Nonlinear networks / Oscillograph OMS 800 (in Patch Panel Slot 1)
Servo plug-in units / Nonlinear networks / Oscillograph OMS 800 (in Patch Panel Slot 2)
Servo plug-in units / Nonlinear networks
Patch Panel / Thermostat / Potentiometer field (Pot. 0…19)
(same as above)
Thermostat
4 variable diode function generators (W)
Setting unit for variable diode function generators
Digital Voltmeter / Operating unit / Potentiometer field (Pot. 50…99) / Computing amplifiers (0…45)
(same as above)
Modulation multipliers (01…98)
Computing amplifiers (50…95)
Or: Servo-multipliers / Coordinate transformers / Nonlinear networks
Modulation multipliers (31…88)
Comparators and noise generators

Expansion Cabinet — Content Summary:

4 variable diode function generators
Setting unit for servo function generators
Servo plug-in units / Nonlinear networks / Oscillograph OMS 800 (Patch Panel Slot 1)
Servo plug-in units / Nonlinear networks / Oscillograph OMS 800 (Patch Panel Slot 2)
Servo plug-in units / Nonlinear networks
Potentiometer field (Pot. 00…49)
Thermostat
Modulation multipliers (37, 38, 47, 48)
Servo-multipliers
Potentiometer field (00…49)
Computing amplifiers 23…45 (outputs)
Pot 50…99
Servo-multipliers
Var. diode function generators 59…99
Comparators 06…96
Servo-Resolver 21
Potentiometer fields
Servo-Resolver 22
Comparators 05…96 / Switches 0…9 / Servomultiplier S6, S1
Pot. 00…49 / Modulation multipliers 37, 38, 47, 48 / Servo-multipliers 4
Pot. 00…49 / Computing amplifiers 23…45 (outputs)
Pot 50…99
Servo-multipliers 5
Var. diode function generators 59…99
Comparators 06…96
Servo-Resolver 71
Pot 50…99
Servo-Resolver 77
Comparators 05…96 / Switches 0…9
Servo-multipliers 8
Pot 50…99
Modulation multipliers R71, R88, P44, P45, R…
Servo-multipliers (9)
Pot 50…99
Computing amplifiers 73…95 (outputs)

[pages 7–8: system block diagram / rack-assignment diagram — figure only with component labels]

3.7 Patch Panel (Programming Field)

(page 9)

The inputs and outputs of all computing elements, the inputs of the output devices, the machine reference voltages, and the break-out points for switching the computing amplifiers are accessible from the interchangeable patch panel. The connection points for the diode networks, diodes, capacitors, resistors, and function switches are also located there, as are sockets for connection to parallel-connected computers.

The patch panel consists of 10 fields (see Figure 3.7-1). Of these, Fields 0, 1, 3, 4, 5, 6, 8, and 9 are of identical design, as are Fields 2 and 7. The assignment of the sockets in these fields to the computing elements is shown in Figure 3.7-2 for Fields 0, 1, 3, 4, 5, 6, 8, and 9, and in Figure 3.7-3 for Fields 2 and 7.

The two-digit address of a computing element is formed from the field number (tens digit) and the number of its output (units digit).

3.7.1 Computing Amplifiers

Summator/Integrator/Hold, or Combined Integrator/Hold

The circuit of the amplifier with its networks and switching lines is shown in Figure 3.7.1-1.

Four (4) such switchable computing amplifiers are arranged on each of the 8 identical fields of the patch panel; units digit of address: 0, 1, 2, 3.

The input sockets of these computing amplifiers are green, the outputs are orange. The labeling on the input sockets indicates the input weighting factors. The green socket labeled “S” is connected via a relay contact to the summing junction of the amplifier. The green socket “P” is connected to the output during static checking of the computing circuit, while the computing amplifier with its networks is disconnected. Initial conditions for integration are entered via the green socket labeled “I” for the integrator.

The control lines for switching the computing amplifiers between Integrator and Summator modes, and for controlling the relays (see “Setting the Computing Elements,” Section …), are connected to brown sockets.

In the field of these computing amplifiers (yellow sockets), 2 grounded potentiometers are accommodated. The input is indicated by a green slash mark, the output by an orange cross-stroke.

In addition, each field has 2 sockets for + or − machine reference voltage.

Summator I

The circuit of this amplifier with its networks is shown in Figure 3.7.1-2.

Four (4) of these computing amplifiers are arranged on each of the 10 fields of the patch panel. Units digit of address: (as above, per field labeling).

The input sockets of the Summator I are green, the output sockets are orange. The labeling on the input sockets indicates the input weighting factors. The green socket labeled “SN” is connected via a relay contact directly to the summing junction of the amplifier. The feedback network of the amplifier is connected at one side to the amplifier output; the other side is brought out to a white socket. During computing it must be connected to socket “G”.

In the field of this amplifier there are additionally 2 grounded potentiometers (yellow sockets). The input is identified by a green slash mark, the output by an orange cross-stroke.

Summator II

(page 10)

The circuit of this amplifier is shown in Figure 3.7.1-3.

Two (2) of these computing amplifiers are arranged on each of the 10 fields of the patch panel; units digit of address: 3, 4, 5.

The input sockets of the Summator II are green, the output sockets are orange. The labeling on the input sockets indicates the input weighting factors. The input socket labeled “G” is connected via a relay contact to the summing junction of the amplifier. The input socket labeled “G” (direct) is connected directly to the summing junction of the amplifier. The feedback network of the amplifier is connected at one side to the amplifier output; the other side is brought out to the white socket. During computing it must be connected to “G”.

3.7.2 Variable Function Generators

One (1) function generator is housed on each of the 8 identical fields of the patch panel.

The input sockets are orange, the output socket is green. The 3 parallel-switched outputs of the output socket are identified accordingly.

3.7.3 Modulation Multipliers (Time-Division)

One (1) Modulation Multiplier (Time-Division) is housed on each of the 8 identical fields of the patch panel. The input sockets are green, the output sockets are labeled orange. To facilitate programming, the multiplier field contains 4 sockets (±, ∓) for machine reference voltage.

3.7.4 Coefficient Potentiometers

Ten (10) coefficient potentiometers are housed on each of the 10 fields of the patch panel. Of the 10 potentiometers, 8 are arranged in the 4 amplifier fields and are grounded. Two potentiometers (P4, P5) are floating (earth-free). The field labeling of the potentiometers is yellow, the inputs are marked with a green slash mark, and the outputs with an orange-colored diagonal stroke.

3.7.5 Comparator

One (1) comparator is housed on each of the 10 fields of the patch panel. The input sockets are green; the sockets for the 2 switching contacts are labeled brown.

3.7.6 Noise Generator

(page 10, continued)

The output of a noise generator is housed on each of the 8 identical fields of the patch panel. The sockets are labeled orange with a white diagonal stroke, and are designated “RG”.

(page 11 — Sheet 3, page 3)

3.7.7 Servo-Multiplier

Each of the eight identical fields of the patch panel contains a connection field for one servo-multiplier, with one guiding potentiometer and four computing potentiometers.

The inputs of the guiding potentiometers are green, the outputs of the computing potentiometers are orange.

If the RA 800 contains parabolic multipliers or fixed diode function generators (plug-in unit ST1 SCC), their connections are switched to the servo-multiplier input fields in place of the servo-multipliers (for the circuit, see Section 5). In this case, each servo-multiplier field receives two inverters: input via green sockets +A or +C, output via the sockets with an orange-colored cross-stroke: −A or −C.

3.7.8 Resolver

In each of the two identical fields 2 and 7 of the patch panel there are connection fields for two resolvers. The inputs are green, the outputs are orange, and the input of a control relay (required for certain resolver circuits — see Section 5) is brown. Within each resolver connection field there is one inverter, identified by the inverter symbol; input green, outputs orange.

3.7.9 Oscillograph

The sockets for Oscillograph 1 and 2 are housed on each of the 8 identical fields of the patch panel.

The sockets for X₁, Z and Y₁, Z are green and labeled with Os 1 for Oscillograph 1 and Os 2 for Oscillograph 2.

Corresponding sockets of the oscillograph connection fields from Field 2 and Field 7 are connected in parallel. For example, socket X₁ of Os 1 in Field 2 is connected to socket X₁ of Os 1 in Field 7. The two-beam oscillograph OMS 800 is connected to connection field Os 1, when it is inserted in the double cabinet directly above the function-generator setting device, or in the expansion cabinet directly below the servo-function-generator setting device. The OMS 800 is connected to connection field Os 2 when it is inserted in the expansion cabinet in the 3rd position from the bottom.

The sockets of connection fields Os 1 and Os 2 are accessible from the outside at connection field 2 (see Figure 5-1).

3.7.10 X–Y–T Recorder

(page 12 — Sheet 4)

The sockets for the X–T recorder are arranged on each of the 8 identical fields of the patch panel. The sockets for X and Y are green and labeled with the letters “Sch” (recorder). The recorder sockets of Field 2 are connected to Plug 5, “Recorder I,” of connection field 2 at the rear of the RA 800 double cabinet. The recorder sockets of Field 7 are connected there to Plug 6, “Recorder II.”

3.7.11 (K-Channel Recorder)

(page 12, continued)

The sockets for the K-channel recorder are located on each of the 8 identical fields of the patch panel. The sockets in the respective field are labeled with the letters “K” and numbered 1 through … (per field).

The K-channel-recorder sockets of Field 2 are connected to Plug 1, “K-Channel Recorder I,” of connection field 2 on the rear of the RA 800 double cabinet; those of Field 7 are connected to Plug 2, “K-Channel Recorder II.”

3.7.12 Dead-Time Device

The sockets for the dead-time device are arranged on each of the 8 identical fields of the patch panel. The inputs are green, the outputs are orange.

The dead-time-device sockets of Field 2 are connected to Plug 3, “Dead-Time Device 1,” of connection field 2; those of Field 7 are connected to Plug 4, “Dead-Time Device II.”

3.7.13 Stepping Magnet (Counter Magnet)

The sockets for the stepping magnet are housed on each of the 2 identical fields of the patch panel. The sockets are labeled brown with the digits 0–9 and “ZM.” Corresponding sockets of the stepping-magnet connection fields of Field 2 and Field 7 are connected in parallel.

3.7.14 Multiple (Bus) Sockets

Three (3) bus sockets are arranged on each of the 8 identical fields, and five (5) bus sockets on each of the 2 identical fields of the patch panel. They are labeled white and joined with a black center bar.

3.7.15 Function Switches

One (1) function switch is assigned to each of the 10 fields of the patch panel. The sockets are brown and labeled “FS” accordingly.

3.7.16 Free Diodes, Resistors, Capacitors

(page 13 — Sheet 5)

Except for Fields 2 and 7, each field contains diodes D1, D2, and two precision resistors R₁ = 100 kΩ and R₂ = 200 kΩ. These passive elements are identified by their schematic symbols. The socket color is white. Fields 2 and 7 contain computing capacitors.

(page 13, continued — field layout table:)

Field assignment table (typical — referring to Figure 3.7-1 field layout):

Field	Pots	Typical contents
0–1	P0…P9	Summators/integrators, SM or PM, function switches, diodes, resistors
2	(special)	Resolvers, K-channel recorders, dead-time, capacitors
3–4	P0…P9	Summators/integrators, SM or PM, function switches, diodes, resistors
5–6	P0…P9	Same
7	(special)	Resolvers, K-channel recorders, dead-time, capacitors
8–9	P0…P9	Same

3.7.17 Passive Networks for Dead-Zone and Limiting

(page 13, continued)

Each of the 8 identical fields contains the connections for 4 passive networks that, in conjunction with a computing amplifier, allow simple realization of nonlinear characteristics:

TZ: Network for generating a Dead Zone
B: Network for generating limiting circuits and bounded signum functions

The inputs of the networks are green, the outputs are orange.

3.7.18 Cross-Connection Sockets

The cross-connection sockets q0…q17 are located to the left and right of the patch frame. The color of the sockets is white. The connections leading to sockets q0 through q17 are freely accessible on connection field 2 at the rear of the RA 800 cabinet. Pairs of adjacent cross-connection fields are connected to a common bus bar (see Figure 5-1).

3.7.19 Miscellaneous Sockets

The patch panel also contains a number of individual sockets that fulfill the following functions:

Red sockets without label: Reference value +1
Blue sockets: Reference value −1
Half-red, half-white sockets: Reference value +0.1
Half-blue, half-white sockets: Reference value −0.1
Socket Z, orange: Output of the sawtooth voltage of the repetitive unit
Socket H, white with blue dot: Control socket for “Hold” position of the computer
Red-white, blue-white striped sockets: Hold sockets (brown mass sockets for each Hold class)
Brown-white striped sockets: Control sockets for the switching-level (threshold) control function (see Section 5.7.5)

[page 14: full patch panel layout diagram — Figure 3.7-1 — figure only showing the 10 fields (0 through 9) with symbolic representations of all socket types and computing element positions. Legend at bottom identifies symbols:]

Legend (Figure 3.7-1):

SM = Servo-Multiplier
PM = Parabolic Multiplier
SR = Servo-Resolver
Os = Oscillograph
Sch = Recorder / Schreiber
-/T = Voltage / Time generator
Multiple PL = Parallel switching
iR = Iterative Computing
TM = Time-Division Multiplier
Funktion switch
KV = Comparator
FG = Function generator
TZ = Dead Zone
B = Limiter
RG = Noise Generator
T = Dead-time device
- − PRH = switched ±

[page 15: Schematic diagram — Summator / Integrator — Figure 3.7.1-1. Shows the circuit for the switchable computing amplifier with its relay-switched networks for summator and integrator modes, including input resistors, feedback networks, capacitor networks, and relay contacts. The circuit includes connections to the patch panel sockets (S, P, I, G) and to the digital voltmeter (DVM). Component values visible include: 200k, 1MΩ, 600 pF, 5 µF capacitors; relays labeled Rel.I; supply connections to ±25 V; reference to Einschub (plug-in unit) PF800 and RV800.]

[page 16: Schematic diagram — Summator I — Figure 3.7.1-2. Shows the circuit of the Summator I computing amplifier with input resistor network, feedback resistor, patch panel socket connections (SN, G, white output socket), DVM connection, and relay contacts. Supply connections to ±25 V; reference to Einschub PF800 and RV800.]

[page 17: Schematic diagram — Summator II — Figure 3.7.1-3. Shows the circuit of the Summator II computing amplifier with multiple input resistors, feedback resistor to white socket, relay contact, and DVM connection. Supply ±25 V; reference to Einschub RV800.]

[page 18: Patch panel connector/socket assignment diagram — Figure 3.7-2 (partial). Shows the socket layout for Fields 0, 1, 3, 4, 5, 6, 8, 9, indicating positions of: computing amplifier sockets (Summator/Integrator, Summator I, Summator II), coefficient potentiometers, servo-multiplier/modulation-multiplier sockets, function generator sockets, comparator sockets, noise generator sockets, multiple bus sockets, oscillograph sockets, and function-switch sockets. Address numbering is visible in the field layout. Legend keys match those from Figure 3.7-1.]

5.1 Installation

The dimensions and weight of the system, the location of the mains connection, and the power consumption are shown in the installation plan given in Section 4. No special preparations are required for installation.

The individually delivered units are to be inserted into the spaces provided for them and connected by plugging in the labeled connecting cables.

The installation should be carried out in a dry, dust-free room with the least possible temperature fluctuations. The calibration of the computing elements is performed in the workshop at an ambient temperature of 20 °C ± 2 °C.

5.1.1 Mains Connection

Connect the equipment plug at connection panel 1 to the mains via a mains connection cable.

At this point the thermostats for the computing capacitors TH I BCO, TH II BCO, and TH III BCO, as well as the thermostat for the DC/V machine unit, are already in operation; that is, the lamps “Therm.” and “too low” at the relevant units will light up. After switching on and after some time (approximately 1/2 hour) the “too low” lamps go out, and after the set temperatures have been reached (approximately 3/4 hour) the “Therm.” lamp lights up subsequently. If the “too high” lamp then lights up at one of the thermostats, the regulation of the relevant thermostat is not in order and its fuse must be removed.

5.1.2 Connection of Output Devices

For display of the computing results, 2 dual-beam oscilloscopes, 2 two-coordinate plotters, and one printer may be connected. The output devices are connected to connection panels 1 and 2 (see Fig. 5‑1).

5.1.2.1 Oscilloscope

The Telefunken dual-beam oscilloscope OHS tCO is provided as the special oscilloscope for the RA 800. However, other suitable oscilloscopes such as the Tektronix 564 with 2 dual-beam plug-ins 3A72 and a graticule in tenth-division for X and Y directions may also be used.

The oscilloscopes are connected with a 30-pole Siemens connector Type I Rel. St F 12 at Bu 7 (Osc 1) and Bu 8 (Osc 2) of connection panel 2 (see Fig. 5‑1).

[page 20: figure — Fig. 5‑1, connection panel assignments on the rear of the RA 800 double cabinet, with connector pinout diagram for oscilloscope]

Contact assignments (connection panel 2):

Contact 6/7: Working contact (for self-control); closed during computation.
Contact 9/10: Used to start the computer when photographing for 1× computation.

Caution: With this computing mode the “Pause” key must not be pressed.
Contact 6/10: Here +3 V appears in pulse form during computation and drops away at the end.

5.1.2.2 Two-Coordinate Plotter

As a two-coordinate plotter, for example the X-Y plotter Type ZD-3, equipped for ±10 V external computing reference supply from Moseley, may be used.

The plotters are connected with a 30-pole Siemens connector Type I Rel. St P 12 at Bu 5 (Plotter 1) and Bu 6 (Plotter 2) of connection panel 2 (see Fig. 5‑1).

[page 21: figure — plotter connector pinout and wiring diagram]

Contact 9/10: Working contact (for pen lift); closes shortly before computation begins and drops out at the end of computation.
Contact 7/8: Working contact (for starting a plotter); closed during computation, opens at halt.

5.1.2.3 Printer

As a printer for printing out the values of the digital voltmeter, the Kienzle Digital Printer D 11 E 9 per Drawing No. 85.3004.120-00 is recommended.

The printer is connected with a 34-pole connector from Martin at Bu 3/4 of connection panel 1 (see Fig. 5‑1).

[page 22: figure — rear of RA 800 double cabinet, connection panel detail]

5.1.4 Parallel Switching Cable — Connection Panel

For parallel connection of adjacent computers, connect the Parallel Switching Cable at the socket strip Bu p “Parallel Switching” on connection panel 1 to the corresponding socket strip of the adjacent computer using the parallel switching cable.

For all computers, on the rear of the operating unit (accessible from the left rear cabinet door) at the left connection strip, the sockets 10/5 and 10/6 (the two lowest sockets) are to be connected using a short-circuit plug.

With the command unit switched on, press the “External Control” key on the control keypad; the “External Control” lamp on the parallel-connected computers lights up. The master computer is put back into the “Independent Control” position by pressing the “Ind. Control” key on the command unit; for the remaining parallel-connected computers the reference voltage is turned off. The fuses on the reference voltage power supply of the externally controlled computers therefore illuminate “O”.

In parallel-connected computers, independent operation of a single computer is only possible when the parallel switching cable has been removed again.

[page 23: figure — parallel switching cable connector, socket strip Bu v pinout and wiring diagram]

To operate a computer as the master, press the “External” key on that computer; the command unit can then only be that one. Independent operation is only possible when the parallel switching cable has been removed again.

5.2 Switching On

Press the “Mains” key on the operating unit.
Press the “Out” key on the control keypad of the operating unit.
Press the “Reset” key on the operating unit.

The “Mains,” “Out,” and “ACC” keys (if not several computers are parallel-connected) and the overload lamps of the power supplies light up. After a short time the overload lamps of the computers go out again, and the computer is ready for operation.

Pressing the fuse keys switches on and the fuses can be recognized again when they illuminate.

[page 24: figure]

5.3 Programming

Before initial operation it is advisable to carry out the functional checks described below.

5.3.1 Construction of the Computing Circuits

Normally the computer is programmed in the “Pause” operating mode. However, the computing circuits may also be changed during operation, since, because of the low computing voltage and the design of the computing patch cords, there is no danger to the operator and the unit is short-circuit-proof.

The computing elements are interconnected at the programming panel according to the problem setup using the computing patch cords (see Telefunken technical book “Computing Guide for Analog Computers”).

5.3.2 Adjustment of the Computing Elements

5.3.2.1 Computing Amplifiers

The computing amplifiers, which can optionally be used as summing amplifiers, integrators, complementary integrators, memories, or complementary memories, are switched by re-plugging the four-pole isolating plugs or by removing these isolating plugs and connecting specific sockets via patch cords.

The choice of weighting factors is determined by patching the corresponding input sockets of the amplifiers; the choice of integration factor for the integrator is made by inserting the appropriate short-circuit plug (then K₀ = also 1) or by leaving the short-circuit socket open (then K₀ = 1).

5.3.2.1.1 Summing Amplifier

The isolating plug is inserted so that its lower half covers the symbol “Z”.

5.3.2.1.2 Integrator (formerly 5.3.2.1.4 Integrator)

The isolating plug is inserted so that its lower half covers the symbol “J”. The short-circuit plug over “1A” or “J” must be inserted.

5.3.2.1.3 Complementary Integrator (formerly 5.3.2.1.3)

The isolating plug is inserted so that its upper half covers the symbol “I”. The short-circuit plug over “1A” or “J” must be inserted.

5.3.2.1.4 Memory

The isolating plug is removed. Charging time (constant). The short-circuit plug must be over socket “lO” — Buchse N is connected with Buchse h. A “tens input” is to be connected with the “lO-input”; a “units input” is the input with weighting factor 1. If one wishes to simultaneously add and store a value, it is to be applied via a resistor “R₁₀” (corresponding to “tens input”) or the respective R plus Punkt, “units input” to give weighting factor 0.1 is available.

5.3.2.1.5 Complementary Memory

The complementary memory is patched like the normal memory described above under 4, with the following modification: socket B is connected with socket 4.

5.3.2.1.6 Open-Loop Amplifiers

Open-loop amplifiers are obtained most simply from the non-switchable summing amplifiers: by pulling out the 2-pole short-circuit plug, the feedback of the summing amplifier is interrupted. For stability, a capacitor plug (300 pF) must be inserted between the output and the summing point. The summing-amplifier integrators may also be used as open-loop amplifiers. Required patching: see under 5.3.2.1.7. Caution: For amplifiers that are not patched, the short-circuit plug must be inserted!

5.3.2.1.7 Switching Options for the Summing-Amplifier–Integrator

The following table summarizes the socket connections that establish the various operating modes of the amplifiers (compare Fig. 5-2):

Operating mode	Socket connections
S (Summing amplifier)	H – d to chassis; H h’ f; R: short-circuit plug over I or 1Ω; N E; R: short-circuit plug over J or c/f
I (Integrator)	R h Pr; H – d Π; feedback from output to 10-input
Sp (Memory)	R Pr H 7; feedback from output to 10-input
Open-loop amplifier	H – d, R; no short-circuit plug over J or 10Ω; capacitor plug (300 pF) between summing point and output

[page 27: figure — Fig. 5‑2, switching diagram for summing-amplifier–integrator]

5.3.2.2 Multipliers

The RA 800 can be equipped with:

7 modulation multipliers (time-division multipliers)
Parabola multipliers
1 servo multiplier

The connection and programming notes for the individual multiplier types are given on the following pages. (The type of multiplier with which the RA 800 is actually equipped is noted in the data sheet and can be read from the labeling of the Anschlusfeld.)

5.3.2.2.1 Modulation Multiplier

In each of the 10 equal sections of the programming panel there is a connection panel for a modulation multiplier. The outputs for generating the outputs:

X·M (outputs M 7, both sockets connected in parallel)
X·M 8 (outputs M 8, both sockets connected in parallel)

[page 28: figure — Fig. 5‑3, modulation multiplier connection panel]

Square root extraction with the modulation multiplier

With the modulation multipliers of the RA 800, square roots can be extracted directly, without using the implicit technique, with an open-loop amplifier (Fig. 5‑4).

y = √x

[page 29: Fig. 5-4 circuit diagram for square root extraction]

In some cases, however, this circuit is not stable. A low-pass filter must then be connected before the denominator input (Fig. 5‑5). This somewhat reduces the bandwidth in square root extraction, but it is still larger than with the conventional square root circuit using implicit technique.

y = √x (with low-pass filter stabilization)

For the case x < 0: interchange connections at +M and −M; result: y = √|x|

[page 29: Fig. 5-5 circuit diagram with low-pass filter]

5.3.2.2.2 Servo Multiplier

In each of the 10 equal sections of the programming panel there is a connection panel for a servo multiplier with 4 computing potentiometers. The guide potentiometer is permanently connected to +1, chassis, and −1. The wipers of all computing potentiometers are connected to chassis. X is the input of the servo follow-up circuit; the outputs at which A·X, B·X, C·X, and D·X appear are located in the correspondingly labeled SM fields. The outputs must always be connected to the summing point of a downstream amplifier; the output resistance of the servo multiplier is then loaded by the amplifier with a constant load, so that connection of an additional load to the guide potentiometer is not necessary. The computing amplifier can be patched in any way (summing amplifier or integrator); the inputs may be used normally. An amplifier must always be connected ahead of the inputs of the computing potentiometers. If a positive quantity is applied to X and to +A, and a negative quantity to −A, then the product +A·X appears with the correct sign at the output of the downstream amplifier.

[page 31: Fig. 5‑6 circuit diagram for servo multiplier with computing potentiometers]

5.3.2.2.3 Parabola Multiplier

Instead of servo multipliers, parabola multipliers can be used. In one connection panel for a servo multiplier the inputs and outputs of 2 parabola multipliers are then present.

Each parabola multiplier contains, behind the positive upper input (+A for parabola multiplier 1, +C for parabola multiplier 2), a built-in inverter. Both are connected to the parabola networks. The multiplier is switched with a relay; so that the socket X does not need to be patched, both inverters are routed to the SM socket of the programming panel for use:

Inverter 1: input +A, output −A
Inverter 2: input +C, output −C

The inverters cannot be selected via the selection keys. For calculations they must be connected to outputs at TM 29 and at TM 30.

If the multipliers are to be used, socket X is to be connected to chassis. If the product A·B is to be formed, +A, −B, and −B are to be connected to the corresponding sockets (−A is the output of the parabola multiplier built into socket S; the built-in inverter of the parabola multiplier is connected in parallel with the open-loop amplifier). The summing point of this open-loop amplifier is to be connected to its output, and between the summing point and output a capacitor plug is to be inserted. The variables may only be applied to the inputs of the parabola multiplier directly from an amplifier output (Fig. 5‑7).

The inputs of the downstream amplifier that are not required in the multiplier circuit can be used for summation. These inputs have only 1/10 of the stated weighting (the 10-input now has weighting 1, the 1-input has weighting 1/10).

Divider with Parabola Networks

The parabola networks of the RA 800 can be used directly as feedback networks of an open-loop amplifier. From an open-loop amplifier and a parabola network, a divider can therefore be constructed (Fig. 5‑8). The numerator is to be connected to the 10-input of the open-loop amplifier, but is not multiplied by the factor 10, rather by the factor 1 (due to the input resistance of the parabola network). If Z > 0, then at +B; to the other B-input comes in each case the (inverted) output quantity. (This inverted input is necessary because the parabola network reverses the sign.)

[page 33: Figs. 5‑7 and 5‑8 circuit diagrams]

For the case Z/N < 0: interchange connections at +B and −B. Result: +|Z/N|.

Square Root Extraction with Parabola Multipliers

With the aid of a divider with parabola networks, a square root circuit can easily be constructed by feeding the output quantity of the open-loop amplifier back to the divider (Fig. 5‑9).

z > 0: y = √z

For the case z < 0: interchange connections at +B and −B; result: y = √|z|.

[page 33: Fig. 5‑9 circuit diagram for square root with parabola]

5.3.2.3 Computing Potentiometers

The computing potentiometers can be set for rough calculations according to the scale on their setting knob. For precise calculations, however, setting with the aid of the digital voltmeter in conjunction with the selection system (the floating potentiometers are automatically grounded during this process) is required. This setting is carried out only after programming, so that the values are not subsequently falsified by loading the potentiometers. It is performed as follows:

Press the “DVM” key on the digital voltmeter.
Press the “Addr.” key on the selection keyboard of the operating unit.
Press the “Pot” key of the selection system.
Select the address of the potentiometer in the selection system.
Press the “Pot” key on the control keyboard of the operating unit.

The address lights up in the indicator field of the digital voltmeter, and the value can be read directly.

If the digital voltmeter always shows the value 0, then the fine fuse of the potentiometer has blown and must be replaced (see Section 3.4.1).

In each of the 10 sections of the programming panel there are two “free” potentiometers (potentiometers No. 4 and 5), whose lower end is not connected to chassis but is instead brought out freely to the programming panel.

[page 35: continued — free potentiometers description]

The “free” potentiometers thus have two inputs: at the wiper an output quantity appears which, depending on the wiper position, lies between the two input quantities in the range 0 to 1 and the output quantities can have different signs. The output quantity can switch signs when the input quantities do so, which allows the construction of nonlinear circuits such as, for example, the signum function and limiting.

The “free” potentiometers can be used as coefficient potentiometers when their lower end is connected to chassis, which is easily done using a short-circuit plug.

5.3.2.4 Function Generators

The RA 800 can be equipped with:

Fixed-set diode function generators
Variable diode function generators
Servo function generators

The variable diode function generators have their own socket panels on the programming panel; the fixed-set diode function generators and the servo function generators are connected to the sections of the servo multipliers.

5.3.2.4.1 Fixed-Set Diode Function Generators

The fixed-set diode function generators are connected to the socket panels of the servo multiplier sections. In the socket panels of the servo multipliers, 4 fixed functions can be accommodated; the functions are interchangeable in any order. With the exception of the logarithmic functions, each function requires the argument with both signs.

Function 1 has its inputs at sockets +A, −A and its output at the upper associated SM socket. Function 2 has its inputs at sockets +B, −B and its output at the lower SM socket. Function 3 corresponds to +C; Function 4 corresponds to +D.

For generating the negative argument of the functions connected at B and D (as with the parabola multiplier, see 5.3.2.2.3), the built-in inverter is used. For this purpose the socket X must be connected to chassis.

The inputs of the function generators must be connected directly to amplifier outputs. The output of each function generator is (as with the parabola multiplier — the input is the 10-input) to be connected to the summing point of an open-loop amplifier fed back via a parabola multiplier, at whose output the function appears with the correct sign (Fig. 5‑10).

[page 36: Figs. 5‑10 and 5‑11 circuit diagrams]

[page 36: Fig. 5‑10 — circuit for fixed-set diode function generator with open-loop amplifier]

If logarithmic functions are used, then for each function only the negative argument is required. Function 1 has as input socket +B and as output the corresponding upper SM socket. Function 2: input −B, output lower SM socket. Function 3: input +D, output corresponding upper SM socket. Function 4: input −D, output lower SM socket. (Fig. 5‑11).

[page 36: Fig. 5‑11 — circuit for logarithmic function generators]

5.3.2.4.2 Variable Diode Function Generators

In each of the 10 equal sections of the programming panel there is a connection panel for a variable diode function generator. Each variable diode function generator with its function has 20 diode pieces. The breakpoint positions of the segments are fixed in the X direction, namely at x = −1.0; −0.9; −0.8; … 0; … +0.8; +0.9; +1.0, so that ±1 adjustable. The variable diode function generator input must be connected from the output of an amplifier; the output is to be taken to the summing point of a computing amplifier (summing point–type connection).

The variable diode function generators are set with the aid of the setting unit and the selection system as follows:

Prepare the f(x) curve or table for the values x = 0; +0.1; +0.2; …; as well as x = −0.1; −0.2; …; and note the corresponding values of y = f(x).
Press the “DVM” key on the digital voltmeter.
Press the “Mains” key on the selection keyboard of the operating unit.
Press the “FG” key (function generator) on the selection keyboard of the selection system.
Select the address of the function generator in the selection system.
Press the … key of the selection system — the address lights up in the indicator field of the digital voltmeter, and the value is to be read directly.
… set the adjustment value on the setting unit for x = 0; read the digital voltmeter in the operating mode of the setting unit for x = 0.
It is recommended to set all potentiometers of the function generator to 0 before setting them (the “dial” then points upward).
Press key “+1” on the setting unit. Set the potentiometer +1 of the function generator segment by segment; set the y value as described under step 6.
Perform settings for x = +0.1; +0.2; … to +1.0.
After the function generator has been set to the positive values of x, set the values for x = −0.1; −0.2; … to −1.0 in the same way as described under 9 and 10.
Note that the potentiometers of the negative section of the function generator are set in reverse direction.
For achievement of greater accuracy, repeat all settings in the prescribed order (possibly several times).

Sometimes the deviations and slope changes achievable with variable diode function generators with medium values are not sufficient. In this case a simple amplifier cascade of variable diode function generators and computing amplifiers is used to set the function 1/2·y(x) or 1/3·y(x). In this way 2-fold or 3-fold accuracy is achievable. (More cascading is not recommended as the noise of the variable diode function generator would be amplified too strongly.) For setting, the second (or third) function generator is first set up, and as described above the function generator set to 1/2·y(x) (or 1/3·y(x)) (see Fig. 5‑12).

[page 36: Fig. 5‑12 — cascade circuit for improved accuracy of variable diode function generator]

5.3.2.4.3 Servo Function Generators

The servo function generators are connected to the connection panels for servo multipliers in the 10 equal sections of the programming panel. Each connection panel of a servo multiplier accommodates a servo function generator for any desired variable X. The servo function generators with their adjustable functions can also be operated as normal servo multipliers, and can then form the products of the variable X.

Operation as servo multiplier:

The key associated with the servo function generator to be used for multiplication is pressed on the plug-in front panel, e.g., key B. By this means all potentiometer taps of servo function generator B are disconnected from the function shaper, and the beginning and end of the potentiometer are switched to the programming panel (in the example: beginning of the potentiometer to +B, end to −B), and the wiper of the potentiometer is grounded. The function generator potentiometer thus operates like a computing potentiometer of a servo multiplier.

See point 5.3.2.2.2: the input of the follow-up circuit is X; the inputs of the computing potentiometer are, in the example, +B and −B; and the output is the lower SM socket, which is to be connected to the summing point of a downstream amplifier. The value output of this amplifier is +(X·B). The inputs of the potentiometer (in the example +B, −B) must always be connected directly to the output of an amplifier.

One or more function generators can simultaneously be operated as multipliers (multiplier = X); the non-switched servo function generators operate as function generators and generate functions of X.

Operation as servo function generator:

The servo function generators allow the generation of a function of one independent variable, Y = Y(X), which can be multiplied by a variable, so that V = U·Y(X) is generated, or the generation of a function of two independent variables, Z = Z(X, Y).

Generation of V = U·Y(X):

The function shaper belonging to the desired function generator must be inserted, and the associated switching key on the plug-in front panel must not be pressed. Then the beginning, end, and 9 equally spaced between beginning and end taps of the function generator potentiometer are at the function shaper. It is thus possible to approximate any function of X using 10 segments whose starting points are fixed at x = −1.0; −0.8; …; 0; …; +0.8; +1.0.

At each of the 11 taps of the function generator potentiometer, an adjustable fraction kᵢ of the variable U can be applied, i.e., kᵢ·U. The kᵢ for the individual taps are individually adjustable, where kᵢ = −1.3; …; 0; …; +1.3 is permissible.

The setting is performed with the aid of the setting potentiometer assigned to each tap with sign switch. The difference between the values applied to two adjacent taps must not be greater than 1.

The common input of all 4 function generators is the socket U (the summing point of a summing amplifier, whose output is U_SM), connected to the summing point of a servo function generator; the output is the socket U_SM. U must be applied with both signs and in the designated polarity to the corresponding input sockets for the computing potentiometers; e.g., if function generator B is desired: +U to +B and −U to −B. Both inputs are to be connected directly to the output of respective amplifiers (Fig. 5‑13). If Y = y(X) is to be generated, +U and −U instead of +1 and −1 are to be connected.

[page 36: Fig. 5‑13 — circuit for servo function generator, V = U·Y(X)]

The servo function generators are set with the aid of the servo setting unit and the digital voltmeter. Set functions can be retained because the function shapers are interchangeable.

Generation of Z = Z(X, Y):

The function shaper belonging to the desired function generator is removed and in its place the function generator adapter cable is inserted and routed to a cross-connection plug of connection panel 1 on the rear of the RA 800 double cabinet (Fig. 5‑1).

The taps of the function generator potentiometer are then available on 2 consecutive cross-connection panels, specifically in the sequence from top to bottom: +1.0; +0.8; …; 0; …; −0.8; −1.0, routed to the adapter cable connected at the connection plug 9. The taps of the function generator potentiometer in section A0 and A1 lie:

Tap +1.0 (that is the tap for X = +1.0) at a00; tap +8 at a01; …; tap −8 at a09; tap −1.0 at …

The taps must always be connected directly to the output of an amplifier.

[page 36: Figs. 5‑14 and 5‑15 — example of Z = Z(X, Y) function generation]

As an example, Fig. 5‑14 shows a function of two variables X and Y, and Fig. 5‑15 shows the computing circuit in which particular emphasis was placed on the approximation of the function Z in the vicinity of X = 0. The taps of the function generator potentiometer are connected to the outputs of function generators that form the function Z = Z(Y) for the X = const. value associated with the corresponding potentiometer tap.

The function X is applied to the socket X of the connection panel (Fig. 5‑15); the output, socket SM, is connected to the summing point of a downstream amplifier, at whose output Z(X, Y) appears with the correct sign.

Sheet 17

[page 37: figure only — Fig. 5-16: Comparator switching diagram showing output states for positive and negative sum of compared voltages, with both changeover contacts shown deflected right to “+1” for positive sum and left to “−1” for negative sum; slider position adjusted by r · Z(Y, X)]

5.3.2.5 Comparator

If the sum of the voltages to be compared is positive, both changeover contacts are thrown to the right, connecting to “+1”. If the sum of the voltages to be compared is negative, both changeover contacts are thrown to the left, connecting to “−1”.

5.3.2.6 Coordinate Converter (Resolver)

The coordinate converters of the RA 800 operate as servo coordinate converters.

In fields 2 and 7 of the programming panel, two resolvers each can be connected. The connection panel of each resolver is unambiguously labeled: the inputs are green, the outputs are orange.

Scale for the permissible input: |a| ≤ 100 aᵣₑ f

The resolvers can each perform one of the following operations:

1. Conversion from polar coordinates to rectangular (Cartesian) coordinates

Given: R1, R2, θ

Formed:

X₁ = R1 cos θ
Y₁ = R1 sin θ
X₂ = R2 cos θ
Y₂ = −R2 sin θ

Sheet 18

The jacks +X1 … −Y2 are each to be connected to the summing junctions of summing amplifiers. At the outputs of the summing amplifiers the quantities X1 … Y2 appear with the sign as indicated at the jacks +X1 … −Y2.

The inputs 1R1, 3R2 are to be connected directly to the outputs of amplifiers.

2. Conversion from rectangular (Cartesian) coordinates to polar coordinates

Given: X, Y

Formed:

R = √(X² + Y²)
θ = arctan(Y/X)

3. Polar coordinates

The brown jack of the resolver connection panel is connected via a short-circuit plug to the adjacent black relay-ground jack. The orange jack θ is to be connected to the summing junction of a summing amplifier. At the output of this summing amplifier the quantity θ appears with the correct sign. The inputs +X, +Y are to be connected directly to the outputs of amplifiers. The quantity R appears with the correct sign at the orange jack R, since a separate amplifier is already incorporated in the resolver for R.

3. Rotation of a coordinate system about the origin

Given: x, y, φ (φ is the angle through which the coordinate system is to be rotated)

Formed:

U = X cos φ + Y sin φ
V = Y cos φ − X sin φ

The connections are made according to Fig. 5-17: input jack R1 receives Y; input jack R2 receives X (inputs always directly from the output of an amplifier). The outputs X1 and −Y2 are to be fed to the summing junction of one amplifier (since only one jack S is available, X2 and Y1 must be fed to the summing junction of another amplifier as a support point). At the outputs of these amplifiers the coordinates U, V of the point X, Y appear with the correct sign after rotation of the coordinate system about the origin by the angle φ.

Sheet 19

[page 39: figure only — Fig. 5-17: Resolver connection diagram for coordinate rotation, showing R1, +Y1; R2, −Y2; output jacks +oAo−R1, +oYo−R2; with connection points A and B for the two resolver channels, and output jacks for U and V]

4. Formation of products of the form sin θ · B

The brown jack must not be connected. The orange output jacks must be connected to the summing junctions of summing amplifiers. At the outputs of the summing amplifiers the product appears with the correct sign.

The amplifier situated between the resolver jacks (7 or 8 respectively) can, in cases 1 and 4, be used as an inverting amplifier with input weighting “1/1”.

5.3.2.9 Noise Generator

The “noise” signal is available directly at the jacks labeled RG. The power spectral density of the noise is constant at 0.15 V²s (at ±100 aᵣₑ f), from −45° to +45° Hz [i.e., the noise has a flat spectrum from DC to the machine bandwidth].

5.3.2.7 Time-Delay Generator

With the time-delay generator, the functional quantities F1(t), F2(t) are generated from the input quantities X1(t), X2(t):

F1(t) = X1(t − T)
F2(t) = X2(t − T)

These are available at jacks F1, F2. The quantity T is applied to jack T.

5.3.2.8 Control Jacks

The control jacks have the following functions:

Jack H (with white diagonal stripe, in field 6 or 7):

If ground (Masse) is connected to H, the computer leaves the states “Continuous Computing” and “Computing with Halt” and enters the state “Halt”. If ground is removed from H again, the computer remains in “Halt”. From the state “Computing”, the computer enters the state “Operate”; if ground is removed from H, the computer begins a new repetition cycle.

Black-and-white striped jacks P, R, H:

The black-and-white striped jacks P, R, and H supply ground in the states “Operate”, “Compute”, and “Halt”.

Red-and-white (or blue-and-white) striped jacks:

The red-and-white or blue-and-white striped jacks in field 6 or field 7 respectively supply—only in the state “Computing”—the positive or negative machine unit +1 or −1. These jacks can be used to introduce initial-condition functions at t = 0 into the circuit.

Orange jacks Z, t:

The jack Z located in each of the eight identical fields of the programming panel supplies the ramp voltage of the repetition device: in the state “Repetitive Computing”, a quantity that rises strictly linearly from −1 to +1 during each repetition cycle is available at this jack. It serves for X-axis deflection of oscilloscopes and chart recorders and facilitates checking the settings of function generators and nonlinear elements.

Sheet 20 (continued from sheet 19)

…if [ground is removed from H], the computer remains in “Halt”. From the state “Computing”, the computer enters the state “Operate”; if ground is removed from H, the computer begins a new repetition cycle.

Red-and-white striped jacks:

The red-and-white or blue-and-white striped jacks in field 6 or field 7 supply, only in the states “Computing”, the positive or negative machine unit +1 or −1. With the aid of these jacks, initial-value functions at t = 0 can be introduced into the circuit.

Orange jacks Z, t:

The jack Z situated in each of the eight identical fields of the programming panel delivers the ramp voltage of the repetition device: in the state “Repetitive Computing”, a quantity that rises strictly linearly from −1 to +1 during each repetition step is available at this jack. It serves for X-axis deflection of oscilloscopes and recorders and facilitates checking function-generator settings and nonlinear elements.

5.3.2.10 Stepping Magnet (Zählmagnet)

The stepping magnet has 10 inputs (0 … 9) and 1 output VM29, which can be selected via the selector switches. During “Computing with Periodic Halt”, as soon as the computer enters “Halt”, the output VM29 is connected successively and briefly to each of the 10 input jacks in turn: first to jack 0, then to 1, … lastly to jack 9.

During “Repetitive Computing”, the stepping magnet advances from one input jack to the next after each repetition step; the connection persists for the duration of the next repetition step. Thus:

Computation step	Jack connected to VM29
1st computation step	Jack 0 connected to VM29
2nd computation step	Jack 1 connected to VM29
3rd computation step	Jack 2 connected to VM29
…	…
10th computation step	Jack 9 connected to VM29
11th computation step	Jack 0 connected to VM29
…	…

Sheet 21

5.3.2.11 Function Switches (Programming Switches)

In each of the 10 fields of the patch panel there are 3 brown jacks SC, S9, which are assigned one-to-one to the function switches on the function-generator adjustment unit. The middle jack is:

… connected to the upper jack when the switch lever is thrown upward,
… connected to the lower jack when the switch lever is thrown downward,
… free (open) when the switch lever is in the center position.

5.3.2.13 “Dead Zone” and “Limiter” Networks

For generating the frequently required nonlinear functions “Dead Zone” and “Limiter”, each of the eight identical fields of the programming panel contains a suitable passive network.

The networks are always to be connected to the summing junction of a following amplifier. The connection panel of the “Dead Zone” network is separated from the connection panel of the “Limiter” network by a vertical black line.

“Dead Zone”:

The network has two additive inputs, i.e., it forms the “Dead Zone” for inputs x1 and x2, the function (x1 + x2), Fig. 5-18. Jack S is to be connected to the summing junction of an amplifier. The depicted shape of the function appears at the output of that amplifier. The value A is applied to the − jack of the connection panel, value B to the + jack.

“Limiter”:

The network has two parallel-connected inputs X. If the signum function according to Fig. 5-19 is desired, jack S is to be connected to the summing junction of a following amplifier; if the limiter function according to Fig. 5-20 is desired, jack S is to be connected to an input of a following amplifier. Value C is applied to the − jack, value D to the + jack. The depicted shapes of the functions appear at the output of the following amplifier.

[page 41: figure only — Fig. 5-18: Dead zone characteristic plot; Fig. 5-19: Signum function plot; Fig. 5-20: Limiter function plot, all showing the piecewise-linear input/output curves with labeled break points A, B, C, D]

Sheet 22

5.3.2.13 Free Resistors

The free resistors R1 = 200 kΩ and R2 = 20 kΩ in each of the eight identical fields of the programming panel allow the number of amplifier inputs at the summing junction of a computing amplifier to be increased. R1 = 200 kΩ gives a 1-weight input; R2 = 20 kΩ gives a 10-weight input. The inputs formed with free resistors have the same accuracy as the fixed inputs of an amplifier.

5.3.2.14 Free Capacitors

The free capacitors C1 = 0.5 μF and C2 = 5 μF in fields 2 and 7 have the same accuracy as the integrating capacitors of the integrators (and, like these, are installed in a thermostat). They are discharged through a resistor of 100 kΩ (Fig. 5-21) when the “Pause” key is pressed, but not when the computer enters “Pause” during repetitive operation.

[page 42: Fig. 5-21: circuit symbol showing free capacitor C discharged via 100 kΩ when “Pause” key is pressed]

Consequently, with these free capacitors one can construct integrators that operate independently of repetitive mode: the feedback resistor of a summing amplifier is removed (pull the feedback plug), and the free capacitor is connected between summing junction and output. Capacitor C1 gives an integrator with K₀ = 10 1/sec; C2 gives an integrator with K₀ = 1 1/sec.

By connecting an additional C₂ (between summing junction and output) to a standard integrator with K₀ = 1 1/sec, K₀ = 1/4 1/sec is obtained; connecting two C₂ capacitors in this way yields K₀ = 1/3 1/sec.

By connecting a free capacitor (between summing junction and output) to a standard summing amplifier, a first-order lag element (delay element) is obtained. If a 1-weight input is used: C1 gives T = 0.1 sec; C2 gives T = 1 sec.

Sheet 23

5.4 Operating Modes

The operating modes are selected by pressing the correspondingly labeled illuminated pushbuttons on the control keyboard of the operator panel.

5.4.1 Pause

Press the “Pause” key. This terminates every computing process. The integrating capacitors are charged to their initial values. In the operating mode “Pause”, the computing circuits are patched (set up).

5.4.2 Continuous Computing (Dauerrechnen)

Press the “Continuous Computing” key.
Halt or terminate the computing process at the desired time by pressing a corresponding key.

5.4.3 Computing with Halt (Rechnen mit Halt)

Set the computing time with the step switch and the potentiometer “0.1 sec” of the timer in the operator panel.
Press the “mit Halt” (with Halt) key. After the set computing time, the computation is halted (the “Halten” key illuminates), and any desired amplifier can be selected and printed out using the selection system.
The computing process is resumed for the set computing time by pressing the “Weiter” (Continue) key.
Terminate the computing process by pressing the “Pause” key.

5.4.4 Computing with Periodic Halt (Rechnen mit periodischem Halt)

Set the computing time with the step switches and potentiometer of the timer in the operator panel (“0.1 sec”).
Press the “period. Halt” key. After the set computing time, the computation is automatically halted (the “Halten” key illuminates) and the values entered into the jacks of the stepping magnet on the programming panel are displayed or printed out. (Displayed when the “Leiter-Band” (tape) key in the selection system is pressed; printed when additionally the “Druck Einz.” (single print) key is pressed.)
After this procedure is complete (for display: after approx. 40 sec; for printout: after approx. 5 sec), the computing process is resumed for the set computing time, halted again, displayed or printed, etc.
Terminate the computing process by pressing the “Pause” key.

Sheet 24

5.4.5 Repetitive Computing (Repetierendes Rechnen)

Set the computing pause with the step switch of the timer in the operator panel: set step switch to “×0.1” (giving 0.5 sec) or to “×1” (giving 2 sec). If integrators with the large capacitor switched in (short-circuit plug over ”/”) are used in the computing circuits, the computing pause must be at least 2 sec in order to recharge the integrating capacitors to the initial values with sufficient accuracy.
Set the computing time with the 2 step switches and the potentiometer “0.1 sec” of the timer in the operator panel.
Press the “Repet.” key. The computation begins and runs until the set computing time. A halt of 100 ms (the “Halten” key briefly illuminates) at the end of the computation permits display or printout of the value of the computing element selected in the selection system. In addition, to obtain a family of parameter solutions, the stepping magnet advances from one input jack to the next at the end of the computation.

After the halt, the computing pause begins to bring the integrators back to their initial values (duration approx. 200 ms or 2 sec). Then the next computation begins with: computing — halt — pause, etc.

To terminate the computing process, press the “Pause” key.

5.4.6 Iterative Computing (Iteratives Rechnen)

Set the computing pause with the step switch of the timer in the operator panel: set to “×0.1” (giving 0.5 sec) or to “×1” (giving 2 sec). If integrators with the large capacitor switched in (short-circuit plug over ”/”) are used in the computing circuits, the computing pause must be at least 2 sec in order to recharge the integrating capacitors to the initial values with sufficient accuracy.
Set the computing time with the 2 step switches and the potentiometer “0.1 sec” of the timer in the operator panel.
Press the “Iter. Rechnen” (Iterative Computing) key.
Press the “Repet.” key.

Sheet 25

The computation proceeds as in repetitive computing. The individual integrators, complementary integrators, and memories and complementary memories then have the following computing states:

	Integrators		Memories
	normal	complementary	normal	complementary
1st computing time	computes	Pause	halt	halt
1st Pause	Pause	computes	halt	halt
2nd computing time	computes	Pause	computes	halt
2nd Pause	Pause	computes	Pause	halt
3rd computing time	computes	Pause	halt	computes
3rd Pause	Pause	computes	halt	Pause
etc.

To terminate the computing process, press the “Pause” key.

5.4.7 Iterative Computing with Halt (Iteratives Rechnen mit Halt)

“Iter. Rechnen” (Iterative Computing) key must be pressed before the “Rechnen mit Halt” (Computing with Halt) key.

The individual integrators, complementary integrators, memories, and complementary memories have the following computing states during the individual computation steps:

	Integrators		Memories
	normal	complementary	normal	complementary
1st step	computes	halts	—	—
1st Halt	halts	halts	—	—
2nd step	halts	computes	—	—
2nd Halt	halts	halts	—	—
3rd step	computes	halts	halts	halts
etc.

[Table continues for memory states in analogous fashion]

Sheet 26

5.4.8 Iterative Computing with Periodic Halt

As for “Computing with Periodic Halt”, but press the “Iter. Rechnen” key before pressing the “period. Halt” key. Computing states of integrators, memories, complementary integrators, and complementary memories during the individual computation steps: as in Iterative Computing with Halt.

5.4.9 Single-Shot Computing (Einmal Rechnen)

A single computing cycle is triggered when the photo-contact of the beam-spot oscilloscope OM 800 (labeled F on the front panel of the computer, or at oscilloscope connection plug Bu 7 and Bu 8 of connection field 2, contacts a9–a0) is short-circuited. On the operator panel, all keys (including the “Pause” key) of the control keyboard must be released; the computer is then in the state “Pause”. When the photo-contact is short-circuited, the computer executes one computation step (the “Repetitive Computing” key illuminates), whose duration is set by the two step switches and the potentiometer of the timer in the operator panel, and then passes through a brief “Halt” pulse into “Pause”. The computer remains in “Pause” until the photo-contact is short-circuited again.

5.4.10 Halting (Halten)

To halt the computing process, press the “Halt” key. In contrast to the “Pause” operating mode, all computing voltages remain in place.
Resume computing in the desired operating mode by pressing the corresponding key.

5.4.11 Automatic Halting upon Overload (Automatisches Halten bei Übersteuerung und Überlastung)

If during computing an amplifier is overdriven or overloaded, the computation result is falsified and continued computing is often pointless. Automatic halting is provided for this case. To make it effective when needed, the “mit Halt” key on the operator panel is pressed.

Halting occurs at the moment of overdriving of an amplifier. The computing voltages are maintained. The overload condition is indicated by the illumination of the overload lamp “Ü” on the operator panel and by the lighting of the relevant amplifier indicator lamps. Automatic halting is indicated by the illumination of the “Halten” key.

5.5 Use of the Selection System (Anwahlsystem)

The various selection modes are chosen by pressing the correspondingly labeled illuminated pushbuttons of the selection system on the operator panel.

Sheet 27

5.5.1 Selection of a Computing Element

Enter the address of the computing element on the hexadecimal keyboard of the selection system; press key “P” or “I, S, K, M, F, Z”.
- For potentiometers: press remaining keys.
At the digital voltmeter: press the “E/H” key. The address and value of the selected computing element now appear in the display field of the digital voltmeter.
If the address and value of the selected computing element are to be printed out, press the “Druck Einz.” and “Druck Bef.” keys.

5.5.2 Automatic Sequential Selection of Computing Elements

Press key “P” or “I, S, K, M, F, Z” as desired.
Select the address at which automatic selection is to begin, on the hexadecimal keyboard of the selection system.
Press the “Automatik” key of the selection keyboard. From the preselected address number up to address 99, the computing elements are automatically selected in sequence, and their addresses and values are displayed in the display field (the “E/H” key on the digital voltmeter must be pressed) of the digital voltmeter. After display of the last address, the selection system switches back to “manual”.
If the addresses and values are to be printed out, press the “Druck EInz.” key. From the preselected address number up to address 99, the addresses and values of the computing elements are automatically printed out every 0.4 sec.
If the automatic sequence is to be halted temporarily, press the “Stop” key. If the “Automatik” key is pressed again, the automatic selection resumes from the address at which “Stop” was pressed.
If the automatic mode is to be switched off, press the “manual” key.

Sheet 28 [Section 10: Quick Reference Guide]

10. Quick Reference Guide: Adjusting and Zeroing the Computing Elements

Even transistorized computing elements require a certain warm-up time to reach their operating temperature. For this reason, the computing elements may not be calibrated until 1 hour after switching on the computer.

10.1 Operator Panel

Mechanical zeroing of the pointer instrument: Switch on the computer. Using a screwdriver, turn the zero-set screw on the front glass until the pointer reads 0.

10.2 (continued — Nulling of the instrument amplifier)

Zeroing of the instrument amplifier: The computer must have been switched on for at least 1 hour. Press the white key below the instrument. Turn the potentiometer to the right of the instrument until the pointer reads 0.
Zeroing the timer: Press the “Null” key on the control keyboard of the operator panel.
- Press the white “K” key. Turn the potentiometer next to the “K” key until the pointer reads 0.
- Press the white “L” key. Turn the potentiometer next to the “L” key until the pointer reads 0.
- It is recommended to repeat the zeroing of the instrument after zeroing the timer.

10.2 Digital Voltmeter

Press the “Null” key on the control keyboard of the operator panel.
Press the “Eichen” (calibrate) key on the digital voltmeter.
Press the “V” key on the digital voltmeter. Turn the potentiometer above the “V” key until the pointer of the instrument on the operator panel reads 0.
Press the “K” key on the digital voltmeter. Turn the potentiometer above “K” until the pointer reads 0.
Press the “+1” key on the digital voltmeter. Turn the potentiometer above the “+1” key until the digital voltmeter displays the value +10004.

Sheet 29 (continuation of zeroing procedure)

Press the “−1” key on the digital voltmeter. Turn the potentiometer above the “−1” key until the digital voltmeter displays −9999. (The adjustments using the “+1” and “−1” keys interact mutually; therefore repeat each step several times.)
Release all keys; display must show ±0000 to ±0004.
The digital voltmeter must then release “Eichen”.

10.3 Computing Amplifiers

10.3.1 Static Zeroing of the Summing Amplifier

Press “Null” on the operator panel.
Switch and select the amplifier as a summing amplifier.
Turn the potentiometer of the selected amplifier until the pointer of the instrument on the operator panel reads 0.

10.3.2 Dynamic Zeroing of the Integrator

(Required only for maximum accuracy demands. In general, the static zeroing of the amplifier per section 10.3.1 is sufficient, including when the amplifier is used as an integrator.)

Switch and select the amplifier as an integrator.
Connect the white jack at an arbitrary amplifier connection panel to ground (Masse).
Press “Pause” on the operator panel.
Press “Null” on the operator panel.
Turn the null-balance pot (Nullpot) of the selected amplifier until the pointer is stationary.

(The last two steps must follow immediately one after the other, since with an incorrectly nulled integrator the instrument pointer begins to drift from the moment the “Null” key is pressed and reaches the end stop if the null-balance pot is not corrected immediately. If the pointer hits the end stop, switch to “Pause”, adjust the null-balance pot until the pointer reads 0, then switch back to “Null” and try again.)

10.3.3 Dynamic Zeroing of the Integrator Initial Value

Press “Pause” on the operator panel. Select the integrator.

Sheet 30 (Sheets 3 continued — calibration steps)

Set the multiplier knob of the timer in the operator panel to “×1”.
Switch the amplifier as an integrator; short-circuit plug over ”/” must be inserted.
(Additional steps: short-circuit plug over “1R” must also be inserted.)
Press “Repet. Rechnen” on the operator panel; digital voltmeter must display +10004 to +10003.
Press “Repet. Rechnen” on the operator panel; wait during (run-up period).

Zeroing the comparators:

Press “Null” on the operator panel.
Select comparator. Turn the potentiometer of the selected amplifier until the pointer of the instrument reads 0.

Zeroing the multipliers (Servo-Multiplier):

Select multiplier.
Press “Null” on the operator panel.
Press in turn keys 3r, h, e, n, e on the modulation-multiplier.
Adjust the associated potentiometer until the instrument of the operator panel displays 0.

At press of keys e, display reads 0.0000; at press of key e again, display reads 10000.

Release all keys.

Zeroing the inverters in the “Nonlinear Networks” plug-in module:

The inverters built into the “Nonlinear Networks” plug-in cannot be selected with the selection keyboard. Their outputs (−a, or −O for the servo-multiplier connection panel) are to be connected in turn via a programming lead to the programming-panel jack “FM”.

Press “Null” on the operator panel.
Select VM29 using the selection keyboard.
Turn the null-balance pot of the amplifier connected to VM29 until the pointer reads 0.

Sheet 31

[page 51: partially visible — Section 11: Troubleshooting]

11. Commissioning, Maintenance, and Troubleshooting

11.1 Commissioning with Immediate Re-energization

[Text not fully legible in this section; page partially visible]

11.2 Brief Summary of the Fuses

11.3 Connector Assignment for External Devices

[page 51: figure only — Fig. 11-1: Patch-field connector block diagram showing the connector assignment matrix for the external connection fields of the RA 800]

Sheet 32 (Sheet − 2 −)

11.4 Fault Diagnosis (Fehlersuche)

In case of faults, always check first:

Whether one or more safety fuses on the power-supply units are lit. In this case press the fuse buttons.
Whether the indicator lamps “Netz”, “12V”, and “Relais” (network, 12 V, relay) on the reference voltage power supply unit are lit. If not, check the fuses below the indicator lamps.
If the computer was previously operating in parallel with other computers: whether the “Fremdsteuerung” (external control) lamp on the operator panel is illuminated. In this case it was forgotten to remove the short-circuit plug on the rear panel of operator panel 2 to disconnect the external control link.

Sheet 33 (page 53): figure only — Schematic diagram: Summerer (Z) — Integrierer (I), Speicher

[page 53: schematic only — Fig. 5-2 partial: Circuit diagram of the computing amplifier configured as summing amplifier (Z), integrator (I), and memory (Speicher). Shows the operational-amplifier stage with input resistors (200 kΩ standard inputs), integrating capacitors, relay switching for mode selection (Pause, Null, Repet., Halt states), dynamic null correction circuit (Dyn. Pr.), reference connections at −25 V, relay contacts labeled Rel.E, and the null-balance potentiometer (Pot. Null-stat., Dyn.). Control signal lines are carried at relay ground (Relaiserde).]

Sheet 34 (page 54): figure only — Schematic diagram: Summerer (Z), Integrierer (I), Speicher — complete circuit with control logic matrix

[page 54: schematic only — Fig. 5-2: Complete circuit diagram of the computing amplifier as summerer, integrator, and memory (Speicher), together with the control-state relay matrix (Steuerleitungen / Steuerfunktionen). The matrix (grid) on the lower left shows which relay lines are active for each operating mode:

Mode	Relay lines active
Null (static)	—
Dyn. (dynamic null)	—
Pause	—
Repet. (Repetitive)	—
Halt	—

(Filled squares in the matrix indicate active relay states for Summerer and Integrierer/Speicher modes respectively.)

Caption reads: Bild 5-2 — Rechenverst. als Summierer, Summierer-Integrierer und Speicher (Computing amplifier as summing amplifier, summing-integrator, and memory). Document: RA 800, Telefunken.]

Beschreibung und Bedienungsanleitung des Präzisions-Analogrechners RA 800

Transistorized Precision Analog Computer RA 800

Preliminary Note

Table of Contents

Preliminary Note

1. General

Intended Use

Special Characteristics of the RA 800

Configuration of the Computer

3.7 Patch Panel (Programming Field)

3.7.1 Computing Amplifiers

Summator/Integrator/Hold, or Combined Integrator/Hold

Summator I

Summator II

3.7.2 Variable Function Generators

3.7.3 Modulation Multipliers (Time-Division)

3.7.4 Coefficient Potentiometers

3.7.5 Comparator

3.7.6 Noise Generator

3.7.7 Servo-Multiplier

3.7.8 Resolver

3.7.9 Oscillograph

3.7.10 X–Y–T Recorder

3.7.11 (K-Channel Recorder)

3.7.12 Dead-Time Device

3.7.13 Stepping Magnet (Counter Magnet)

3.7.14 Multiple (Bus) Sockets

3.7.15 Function Switches

3.7.16 Free Diodes, Resistors, Capacitors

3.7.17 Passive Networks for Dead-Zone and Limiting

3.7.18 Cross-Connection Sockets

3.7.19 Miscellaneous Sockets

5.1 Installation

5.1.1 Mains Connection

5.1.2 Connection of Output Devices

5.1.2.1 Oscilloscope

5.1.2.2 Two-Coordinate Plotter

5.1.2.3 Printer

5.1.4 Parallel Switching Cable — Connection Panel

5.2 Switching On

5.3 Programming

5.3.1 Construction of the Computing Circuits

5.3.2 Adjustment of the Computing Elements

5.3.2.1 Computing Amplifiers

5.3.2.1.1 Summing Amplifier

5.3.2.1.2 Integrator (formerly 5.3.2.1.4 Integrator)

5.3.2.1.3 Complementary Integrator (formerly 5.3.2.1.3)

5.3.2.1.4 Memory

5.3.2.1.5 Complementary Memory

5.3.2.1.6 Open-Loop Amplifiers

5.3.2.1.7 Switching Options for the Summing-Amplifier–Integrator

5.3.2.2 Multipliers

5.3.2.2.1 Modulation Multiplier

5.3.2.2.2 Servo Multiplier

5.3.2.2.3 Parabola Multiplier

5.3.2.3 Computing Potentiometers

5.3.2.4 Function Generators

5.3.2.4.1 Fixed-Set Diode Function Generators

5.3.2.4.2 Variable Diode Function Generators

5.3.2.4.3 Servo Function Generators

Sheet 17

5.3.2.5 Comparator

5.3.2.6 Coordinate Converter (Resolver)

Sheet 18

Sheet 19

5.3.2.9 Noise Generator

5.3.2.7 Time-Delay Generator

5.3.2.8 Control Jacks

Sheet 20 (continued from sheet 19)

5.3.2.10 Stepping Magnet (Zählmagnet)

Sheet 21

5.3.2.11 Function Switches (Programming Switches)

5.3.2.13 “Dead Zone” and “Limiter” Networks

Sheet 22

5.3.2.13 Free Resistors

5.3.2.14 Free Capacitors

Sheet 23

5.4 Operating Modes

5.4.1 Pause

5.4.2 Continuous Computing (Dauerrechnen)