Transistorisierter Differentialanalysator MEDA 42 TA — Technische Beschreibung und Bedienungsanleitung

Complete English translation of the original German-language document (71 pages).

TRANSISTORIZED DIFFERENTIAL ANALYZER MEDA 42 TA

Technical Description and Operating Instructions

1 Introduction

1.1 Overview

The transistorized differential analyzer MEDA 42 TA is an analog computer for solving technical and scientific problems. It is designed primarily for use in research and higher educational institutions. Its principal applications include:

Solving differential equations with constant or time-varying coefficients, as well as nonlinear differential equations
Simulation and investigation of control systems, using the machine for continuous-time simulation of all types of control-loop problems

Repetitive Operation

Repetitive operation with maximum iteration rate of 200 s, repetitive operation with fast iteration rates of 2/3 Hz.

Repetitive operation, synchronized to a frequency of 1/6–2/3 Hz from the control-signal input, with steep-flanked trigger pulses of 50 Hz.

Iterative adjustment guided by the smallest error criterion.

Direct Operation

Single-run with max. iteration time 500 s, repetitive operation at the rate determined by the quality of the control signal, with rapid frequency up to 2/3 Hz.

Hybrid Operation

Connection to a digital machine of the type DES 70 (GDR) is possible.

1.2 Technical Principles of the Description

This technical documentation provides technical instructions for commissioning and operation of the differential analyzer MEDA 42 TA. In keeping with the published literature, it uses the terminology and notation conventions of analog computing as uniformly as possible. It avoids describing the technical parameters or the type of the individual electronic components, because this depends upon the specific Rechner version or the problems involved. Technical descriptions of the sub-assemblies of differential analyzers of the MEDA 42 TA series therefore use these sub-assembly designations of the manufacturer or the ADC-series designation.

Designated Use

The differential analyzer MEDA 42 TA is intended for the solution of ordinary differential equations up to 10th order and for linear problems up to about 30th order — in simulation and computing tasks. It is to be used by persons who have been trained in the use of this machine and in analog computing, and who are familiar with analog programming.

Detailed instructions for programming the differential analyzer MEDA 42 TA are to be found in the separate booklets “Analog Programming — Programming and Solving of Problems on the MEDA 42 TA” (J. Jalynin — V. Bauer — M. Kirya).

1.2 Essential Characteristics for the Description

1.2.1 Electrical Characteristics

Potentiometer (for 10-turn linear potentiometers with at most 10 kΩ)

10-turn precision potentiometer 10 kΩ with scale (C-20000)
Linear potentiometer 2.5 kΩ, single-turn, for the time scale (Coefficient-Scaling Module RA 4 1–2 with indication DP 4500, NM 0.1 mA)

Operational amplifiers (with balancing)

Differential operational amplifier … 10 (1 quadratic functional amplifier) with maximum offset: Einstellbarer Nullabgleich Funktionsverstärker

Rapid Repetitive Operation — Computer with balancing feature

Repetitive operation synchronized to the frequency of the control signal — 1/6–2/3 Hz range.

Repetitive operation with steep-flanked trigger pulses of 50 Hz, variable phase.

Iterative adjustment guided by the smallest error problem.

Auxiliary Equipment

Millivoltmeter with fine scale … 1
Cathode-ray oscilloscope, synchronized to the Problem frequency … 1

”Hybrid” for Digital Interconnection

Dual comparator, synchronized by the problem frequency of the computer … 1
All analog-digital converters (ADC) … 1
Digital-to-analog converters (DAC) … 1

1.2.2 Technical Specifications

Absolute Dimensions (Chasis with breakout boards)

Display/front dimensions: 0.1 to 20 V (1 kΩ, Typ: OSL-7, NM 0.1 mA) OP reading: ± 100 V/s, max: ± 100 V/s Coefficient-Scaling Module RA 4 1 to 2 ± Digit voltage … DP 4500, NM 0.1 mA

Boundary Conditions for Solving Differential Equations

ADC boundary conditions for the RA with reference voltage linear (with max. 100 000%):

Coefficient-Scaling Module — Typ OS 210 0035 (max. Integrator constant TS 10/4, max 100%) Boundary condition, max.: Typ OS 290 0054

Version

Coordinate recorder, e.g. (Item 1 11564) for two-channel
X-Y-Plotter — Typ OS 291 0020

Environmental Conditions (DIN 34 3100)

Parameter	Values
Operating temperature	5 to 45 °C
Storage temperature	−40 to +55 °C
Relative humidity	max. 80 % (tropical)

Power Supply

Mains supply … 220 V ± 10% Frequency … 50 Hz Power consumption … 300 VA Fuses … max. 60 S

1.2.3 Application

The differential analyzer MEDA 42 TA can solve linear and nonlinear differential equations. The equation order ranges from 10 to 30 (depending on the problem type). With 10 multipliers and an even number of additional computing elements, integration-function problems up to 30th order can be solved.

The differential analyzer MEDA 42 TA uses this computer to make iterative calculations. It uses 2 to 10 integrators, and allows the computation of problems as well as the computation of Rechner 10 to 50. The machine uses the Rechner parameters 2 to 50 and allows the problems of the machines of the Iteration variants Rechner 41 to 50 to be computed.

If amplifiers are used, the quality that is achieved in computation is that of a good computation. The amplifier also uses the Rechner together with the Rechner parameters 2 to 10 and allows MEDA 41 to 50 to compute.

2 TECHNICAL DESCRIPTION

2.1 Description of the Mechanical Construction

The transistorized differential analyzer is as it comes from the laboratory: it is transported, in typical laboratory construction, on a frame with 5 shelves, 3 storage trays and 2 patch-panel sections (cf. Fig. 2.1) assembled.

[page 5: figure only — Fig. 2.1 Differential Analyzer MEDA 42 TA]

Detailed instructions for programming the differential analyzer MEDA 42 TA to solve given problems have been published as a separate book.

The ADC service manual (G) describes in detail the operation, construction, and types of the computing elements, and on 3 to 8 gives a description of the individual elements for operators and users. The detailed information of the manual (G) occupies 4 to 8 shelves. To facilitate solutions of linear and nonlinear problems, the book provides a guide for the user. Up to 3 to 4 books are included in its program. For solving nonlinear problems in the Rechner, the service manual describes the construction and use of the computer; for each type and version of the solver, the solution range is likewise described.

2.2 Power Supply and Powering of the Machine

2.2.1 Mains Power Supply and Earthing of the MEDA 42 TA

The differential analyzer MEDA 42 TA is operated on a supply voltage of 220/50 V, 50 Hz. For this purpose the Rechner has a special power distribution lead of 50 m length; all power-supply subassemblies of the Rechner have a common connection and are all connected together. These connections form the chassis “ground” (Earth) of the Rechner. At this point it should be noted that with larger recorders and multiplier chassis the Earth connections of the machine must be checked from the outside.

The supply voltages for the computing operations are:

±1 V for the Rechner plug-in chassis (via switch S1)
±24 V, ±14 V, ±10 V to be switched automatically via the power-supply chassis

Note: In this design the power and control voltages can be switched on via special Sonderversorgung switches.

The typical Rechner is fully self-contained, and by means of the switch on the front of the computing chassis a self-contained Rechner is available and provides a stable platform for Rechenbetrieb (computation operation). The Rechner supports, by the use of breakout switches, the switching and control elements on which depend the chassis up to 10 in the current system.

The Rechner up to the chassis ±75-5 is an electronically controlled chassis and can control any number of multi-chassis devices to independently switch certain connections.

On the Plattenseite of the Rechner, as seen from the front panel, the chassis is 375-5, where up to 10 different switchable chassis chassis can be operated, and can in some chassis allow up to five (5) different connections to be switched and combined.

For the chassis of the Rechner, the connections 50-poliges (50-pin) “chassis S” are arranged in the chassis S-Chassis. The chassis S-Chassis is arranged by four fixed rails and can also be connected to the chassis ground through these connections.

In the lower part of the computing chassis there is an In-Betrieb area with the E9-Kries chassis of the Integrators that carries out the computing functions. In the Plattenseite there are also for the chassis of the IN-Betrieb of the computer elements the technical assistance and stabilizing elements, and various other chassis.

In the upper part of the Rechner chassis there are five power-supply modules and a collection of 5 complete and switchable chassis. These modules carry the 5 potentiometers, 5 comparators and 5 sampling modules that provide the “switchable modules” chassis arrangement.

The Plattenseite and Bodenplatte modules are arranged with the E9-Kries below, which carries the Stabilizing modules from the chassis and which also carries the comparators. In the Rechner, via the stabilizing chassis are also switchable the E9-Kries connections and breakout boards u. a.

The Stabilizing modules are connected by a common Chassis-Sammler and the chassis is equipped with a full chassis earthing Verbindung, which ensures the common chassis earthing of each individual chassis. The chassis also provides the chassis an automatic disconnection via relay contacts connected to the common chassis circuit. The connections are for chassis TRl (Sammler circuit) to chassis TR2.

The Rechner modules are at the bottom of the Rechner chassis and are provided by two parallel connected chassis, which connect the chassis ground by multiple breakout boards.

2.2.2 Power Supply Module NL-1 (TYP 80_990_221)

TB 10/2 contains the power supply for the Stabilizing and the Rechner modules of the differential analyzer MEDA 42 TA. The power-supply module is connected to the bottom of the chassis via a breakout-board. In operation, the connection TB 10/2 also sets the Plattenseite functions such that the output voltages of the power supply modules are carried. The supply voltage of the differential analyzer is ±1 V (chassis ground voltage).

All of the power supply of the differential analyzer MEDA 42 TA has 4 supply channels: The pin assignment of the TB 10/2 provides the stabilization of the supply at the position TR 1/0, which establishes the supply of the TR module (breakout pins 1, 8 and 9 supply positions).

2.2.3 Stabilizing Power Supply Module NL-2 (TYP 80_890_152)

In the power supply module NL-2 there is one complete Stabelement which sets the power supply of the Rechner with 4 complete power supply chassis for the computing modules. The module NL-2 is housed in a Vollmetall (all-metal) chassis. A power-supply module NL-2 provides the power supply stabilization for the differential amplifier. The connection to the full supply chassis TR 1 is via this module; it also carries the connection to the NL2 chassis connector which can supply the full stabilizing voltage Ue to the chassis.

Fig. 2.2 — Mains voltage distribution in the chassis of the Rechner; NL-1, TL-1 socket connection; NL-2 Stabilizing Module; Power-supply stabilizing connection.

The individual supply voltages of the Rechner are formed and thus also via some supply chassis also additionally connected via Dioden (diodes). All circuits within the supply chassis are connected within the module NL-2, with the result that the main supply chassis stabilizes the output via the connection.

The pin assignment of the NL-1 chassis is:

Chassis S: ±1 V, ±14 V, ±10 V (Pins from 5 to S)
In particular the Stabelement connection carries the chassis voltage ±1 V as long as the supply is available via the supply-pins.

2.3.1 Stabilizing Power Supply Module TL-1/A (TYP 80_990_221)

In the power supply module TL-1/A, four stabilizers work. These four stabilizers supply the computing modules and the comparator modules on the Rechner, both at the positive polarity and at the negative polarity. Each stabilizer is constructed as a two-stage transistor series-pass regulator. For these stabilizers the operating point for the stable state is given on a common set-point reference on the Rechner chassis connection; the connection is to the chassis voltage stabilizer supply “TL 1/A”.

The stabilizers TS 10/2 and TS 10/1 supply the stable voltage to the connected computing modules. In the comparator and comparator area of the Rechner, it is possible through the TS 10/2 stabilizer to supply ± voltages; each stable voltage has its own supply voltage from TS 10/2. The two stabilizers TS 10/2 and TS 10/1 are on a common chassis board, which also determines via the common connection supply TS 10/2 the comparison level to the chassis-connected comparator and functional inputs. A schematic block diagram of the complete chassis is given in Fig. 5.2.

2.3.2 Stabilizing Power Supply Module TL-1/B (TYP 80_890_245)

The power supply module TL-1/B is also housed in the computing chassis. The chassis holds two further transistor stabilizer stages which — besides providing the ±14 V and ±10 V output-voltage stabilization — also provides a chassis stabilization of ±5 V to ±5 V (relative, ±5/±5). Via this module a Bode-plot of the Rechner supply can be generated for the voltages from the Rechner computer-stabilizing chassis.

The TL-1/B chassis also provides the reference voltages for the multiplier ± correction and supplies the precision comparators (from the Rechner bus).

Fig. 2.3 — Stabilizer connections of the two-stage power supply module. Connection from TL-1/A to TS-10/2 and TS 10/1 (Rechner-stabilizer chassis). Connection from the stabilizing reference TS 10/2 to the functional-amplifier stabilizer supply and to the Rechner bus stabilization.

2.3.3 Stabilizing Power Supply Module TL-1/B (TYP 890_260_345)

The TS 10/2 is constructed as a two-stage transistor series-pass regulator. Two transistors (T 21–F 21/A) are compactly constructed and one transistor supply is generated.

The Plattenseite chassis supplies 10 V of the amplifier supply and also supplies the Rechner stabilizing of the voltage function between the TS 14/2 and TR 14/3 stabilizer (depending on the position F 21/A and connections to the supply 80).

The chassis of the Rechner units TS 14/2 and TS 14/2 supply the following voltages:

Stabilizer supply voltages:

±2 × 17 V/0.25 A
±2 × 24 V/0.12 A
Nennstrom (rated current): 1 × 14 V/1.5 A

Summary of output voltages:

Chassis supply voltage … ±12 V/0.25 A
Mains supply voltage … ±2 × 12 V/0.12 A
−14 V/1.5 A

2.3.4 Trigger-Voltage Supply (TYP 80_890_345)

The Stabilizers TS 14/A supply the Trigger point and the Nennstrom output. Both boards provide breakout and the stabilizer supply for the Rechner chassis; the comparators reference the chassis to the connection to the common chassis point TS 14/2. Each stabilizer chassis uses the reference from the TS 10/2 chassis via the Rechner connection-pin TS 14/2 for the stabilizer comparison.

Fig. 2.4 — Connection of the two-stage comparator supply chassis with TS 14/2 and TS 10/2; Rechner-stabilizer chassis TS 14/2; connection pins: PW1-7 → Verbindung → TS 10/2

Power supply voltage:

Chassis supply voltage … ±2 × 17 V/0.25 A
Mains supply voltage … ±2 × 12 V/0.25 A
Ausgangsspannung (output voltage) … 14 V/0.5 A

2.3.5 Trigger-Voltage Module TL 10/2 — TYP 80_890_345

In the power supply module TL 10/2, the Rechner stabilization is arranged via two separate Galvanic supplies and two comparators. The amplifier supply module NL-2/1 (Falk, NL 2):

Specification:

DP 1/A: Dimensions (Gehäuse): 2 × 17 V/0.5 V, 5 b
10 s from the supply module is housed at 0.1 (NL 2) — DIN from dimension
Gehäuse (chassis): … 120 × 160 × 275.2 mm
Output voltage:

Pin	Ue (V)	Description
DP	1/A	Supply module: 2 × 17 V/0.5 V, 5 b
10 s	—	−2 × 10 V/0.05 A
—	Stabilizer	−1.10 pF
—	Chassis	−20 pF

Supply Voltages (Summary)

In the supply module the Rechner is stabilized via supply pins:

Output voltage … −0.10 to −1.1 V
Schwellspannung (threshold): −1.5 V/0.05 A
Chassis stabilizing voltage … max. −0.7 µF

Fig. 2.5 — Course of the Rechner stabilization “VORBEISTEUERN” (oversteering). A — breakout designation; B — Stabilizing position “SCHMER”

2.3.6 Computing Module Chassis TYP 80_890_250 HZ

The computing module TL-1/B of the computing chassis MEDA 42 TA is linked at the Rechner via the Netzwerkmodul (network module). In this way the Rechner connection proceeds through the following pins:

TB 10/2 and TB 10/2 from the computing module (see Fig. 2.5)
TB 10/2 — 1 from the computing supply chassis (at the Rechner connection breakout)

The Rechner chassis STA chassis (2) provides the supply of the TB 10/2 chassis. In this chassis is the TS NL 10/2 chassis:

Pin assignment: F2-1; TYP F0.2; NM 0.7 TYP 80_890_340
Connection: … −2 × 10; Typ F0_2; …−2 × 10 V/0.25.25 mm
Pin assignment: 125 × 240 × 275.5 mm
Power output from chassis: … −1.7 µF

2.4 Control Board (CTO NM 40)

The control board CTO/NM 40 (NM 40 40) is housed in the Rechner chassis and handles the computer mode control and the timing of the Rechner operations. The name plate of the chassis shows that the control board occupies the central chassis position in the MEDA 42 TA.

The control board provides, for the chassis, the following functions:

a) Push-button “RESET” (RAILS) switches ON the computing voltage to ±10 V for setting the integrator initial conditions.

b) Same push-button “OUTPUT” (COMPUTE) activates computing mode, at the same time setting the integrators to the RUN state (START computation).

c) Another push-button “STOPPER” (HOLD) freezes the state of the integrators — “holds” them in the condition at the moment of pressing. This permits the examination and reading of the integrator outputs at a particular point during the computation.

d) One push-button “STOPPED OPERATING” (HOLD) transfers the state of the integrators to the “held” state and simultaneously permits the correction of the integrator output-point values (Anfangswertsteuerung — initial value control).

e) Key push-button “INITIAL COND.” (IC): returns the integrators to the initial-conditions mode (IC 2/3) and simultaneously enables the setting of the initial values at the integrators. This permits running the computation again or examining the computing elements.

f) Volatile push-button “MODE REPETIERUNG” (REPETITION INIT.): transitions the computer from the current operating mode to the repetitive-operation mode. In repetitive operation the computer cycles automatically between the IC state and the COMPUTE state. The IC 2/3 is set at the fastest repetition rate (1/6–2/3 Hz). At the maximum repetition frequency the output of the machine’s integrators are switched between IC and COMPUTE at the rate of 2/3 Hz.

g) Volatile push-button “TIMER REPETIERUNG” (REPETITION INIT. 2.3): sets the repetitive-operation timing at the frequency 1/6–2/3 Hz. The computing cycle is set up as follows.

Fig. 2.12 — Front view of the Rechner chassis with the control buttons and operating elements. Key: 1 — Mode switch (“VORBEISTEUERN” / oversteering) 2 — “COMPUTE” push-button 3 — Ammeter (galvanometer) 4 — Patching field 5 — Null-balance control knobs 6 — Potentiometer drive knobs 7 — “RESET” push-button 8 — “HOLD” push-button 9 — “REPETITION” push-button

2.7 Computing Boards FPS 12 — FPS 13

Potentiometer Board FPS 12 S

In the Rechner board FPS 12 S there are 30 manually-settable potentiometers of the type AKTPF 10 kΩ (10-turn) with coefficient-setting from 0 to 1.000. In the Rechner, each of the potentiometer ranges can be set by the coefficient readout. Every coefficient potentiometer can be connected in parallel to the Rechner bus via a switch.

Sets and null-balance potentiometer: each board in Solidarform has a single-line Null-balance group, and each potentiometer in this board is allocated a specific Rechner computing-element position.

2.7.1 Potentiometer Board FPS 12

In the Rechner board FPS 12 there are 30 potentiometers of the type AKTPF 10 kΩ (10 turns) for setting the coefficients of the differential equations from 0 to 1.000. The potentiometer board is incorporated in the Rechner. Each of the Rechner computing positions connects to the breakout bus.

Settings from 0 (Vollausschlag = 0): all potentiometers are set to 0, which is the null value for the differential equation coefficient setting in the Rechner. A group voltage P 38 with PW/S contacts, via contacts S 3, A, and G, through computing-element switch GW50, is applied. This applies the coefficient values via PS 21 100 Ω and 500 Ω breakout to the computing chassis 50 (values of 21 100 Ω and 50 Ω).
Potentiometer group connections: The coefficient value of the Rechner chassis P38 is controlled via a switch with contacts (1 until S 3, 4, 5 in the Null 1-4 setting). These positions set the group connection voltages at the computing chassis.
The switch-board groups (VORBEISTEUERN = oversteering) with 10 to 40 Rechner connections, which can supply the 10 groups for the Rechner computing groups, also include the two connectors to the computing groups for the independent Rechner.
Two groups of dual-operated Rechner group modules (VORBEISTEUERN) with max. 80 groups, which can then work in the Rechner to supply the parallel independent Rechner groups.

Fig. 2.9 — Potentiometer board (FPS-12 B): a) Schematic (layout) of the potentiometer board (PA) b) Schematic view of computing positions (PS-12 B)

Fig. 2.10 — Arrangement of trip- and potentiometer-switches for the Rechner: PR 1 — Kippschalter (toggle switch) PR 2 — Drehknopf (rotary knob)

In the potentiometer-boards FPS 12 B, 10 potentiometers from the group are on a breakout, accessible from Doppelknöpfe (double-knobs). Due to the limited space for the computing-group output, two Potentialverstärker (potential-followers / buffer amplifiers) are connected on each Rechner-group line. These two potentials can each independently provide the various computing functions — constants, additions and subtraction, integration in the Rechner. As well, the inner and outer Rechner-bus connections can be coupled (simultaneously and independently) to one another.

2.4.1 Connection of the Integrator Circuits

Fig. 2.9 — Connection of the integrator circuit: U_E — Input voltages of the integrators; U_G — Output voltage of the integrators (integral); U_A — Initial condition voltages; f — value of f; — function; S — switch; R — Rechner M

Designation of the status R:

Betriebszustand (operating state): f, phi, e, S — initial (start), f — value

2.5 Potentiometer Board (Continued) and the Rechner-Connection Breakout

Table 2.1 Setting of the integration switch of the Rechner for different operating modes

Operating mode	Switch position
	S1	S2	S3	S4
VORBEISTEUERN	1	0	0	1
LÖSEND	1	0	1	0
PRÜFEN	0	1	0	1
BEREITSTAND	1	1	0	0

Note: 1 = Relay pulled in; 0 = Relay falls ab (drops out)

Table 2.2 Positions of switches PR 1 and PR 2 on the Rechner boards

Function-switch PR 1	Setting	Function
Kippschalter PR 1	Y	Zeitkonstante 1 s
	M	Zeitkonstante 1 s
	N	5 ms
Drehknopf PR 2	S	Amplituden-steuerung des Anfangs-werts; Zeitsteuerung der nachfolgenden Amplitudensteuerung

As the breakout is connected to the integrators, it enables reading from Rechner computing positions. Each mode of the Rechner is set electrically in the table described above. The function control of the breakout group is thus done through Kleinstrom control (small-current switching) in the Rechner:

PR 1, PR 2, PR 1, PR 2 are the control switches for each potentiometer group in the computing chassis. The Rechner (see Table 2.2) shows the positions of the switches PR 1 and PR 2 on the Rechner chassis.

Fig. 2.9 — Integrator circuit connection: S_1, S_2 — Eingangsspannungen (input voltages); U_A — Ausgangsspannung of the integrators; U_G — integral output; f — value of f; phi — angle; — function; S — Schalter

Designation of function R:

start: f, phi, S — initial, f — value

2.7 Computing Board — Continued

In the computing board FPS 12 S, the 30 potentiometers of the precision type are mounted with dial (10-turn), range 0 to 1.000. The individual coefficient setter for each potentiometer is in the computing chassis. Each potentiometer is provided with a lockable knob.

The connection and assignment of the Rechner board (FPS 12 B):

right group Schaltungsgruppe (circuit group): 2 — Buttons for switching the steps
Groups with computing potentiometers include switching channels grouped as: a) grid (raster): Bl. (so-called), Bl. (so-called), etc. b) row assignment 1, 2, 3 … to the Rechner pin c) with a connection Bl., etc.

Further arrangement of the potentiometer board:

Bl. (row 1 to 8 buttons): 2 × Bl. for each computing element of the Rechner potentiometer group
f: grid — BL1, BL2, BL3 to BL10; 13
g: right group — BL 1 to 30
BL (group): 1 m, 2, 3, 4, 5 bl., 6, 7, 8, 9, 10, 11 bl.

Fig. 2.13 — Arrangement and assignment of Rechner groups a) and b): Arrangement of the Integrations-group 1–2, 4, 6, 8, 10, 11, 13.
Assignment of the Rechner-group BL 1, 2, 3, 4, 7 and above (so-called).
Breakout arrangement of the Rechner boards — top position of the list.

2.6 Buffer and Auxiliary Amplifier TZP-7 — 2 Typ 90-950-0962

2.6.1 Rechner and Auxiliary Amplifier TZP-7 with Gleichstrom- (DC) or Wechselstromverstärker (AC-amplifier) type

The Rechner board TZP-7 with two DC- or AC-amplifiers is used in the Rechner chassis system MEDA 42 TA in the computation of the computing chassis in Rundfunkkompensation (RF compensation), and in Grundschaltung (basic circuit) is used as an additional compensation amplifier.

Fig. 2.14 — Gegenkopplungsschaltung (feedback connection) of the Rechner-Verstärkers (Rechner amplifier): U_E — Eingangsspannung; U_A — Ausgangsspannung of the Integrators; f = -dU_A/dt

As the name suggests, one element (G) is in the chassis at one end of the Rechner chassis. The computing elements of the Rechner Verstärker (including the computing-element multipliers, integrators, initial-condition setters, summation points) comprise all the functions associated with the standard analog computing elements.

The Rechner amplifier is selected by the type of the computing function to accomplish:

Constants, additions and subtraction: Integration, summation in the Rechner (see Fig. 2.15)

Fig. 2.13 — Arrangement and assignment of the Rechner computing groups: a) Grouping of the Integrations-group from 1, 2, 4, 5, 6, 7, 8, 10, 11, 13 b) Grouping of the Rechner BL 1, 2, 3 (from BL 7 above to BL set) Breakout of the top portion of the list for the Rechner board.

2.7 Summary of the Parallel Feedback Circuits

The three feedback branches, mounted from three parallel feedback groups, are given: from slow 50 to 100 kHz amplifiers; the Rechner connection is synchronized to the switching frequency. The Rechner connection is determined by the noise-signal on the feedback amplifier and the switching frequency.

The two test modules provide the following in measurement, as the Rechner bus:

Transfer up to about 200 Hz and the Schaltfrequenz (switching frequency); the Rechner-bus noise is filtered above this frequency.
The Rechner-bus noise is also reduced by the Amplifier feedback to the Schaltfrequenz (switching frequency) at 200 Hz and 50 MHz.

The Rechner provides these noise and computing signals, regulated by the Rechner to the Millivoltmeter as measured and the input-signal measured values to the oscilloscope. The measurement-point output connects, via two parallel feedbacks, to the computing chassis output.

The feedback is done by the feedback amplifier chassis (TFP-64 at once 0 to 80 kHz) and will produce 115 measured output parameters from the Rechner-level connection (in mV).

These parallel connections are the (from TFP-04 to TFP-64) in Groß (0 to 80 kHz) connection. These connections are in the Rechner (from 4 to 80 kHz). The Rechner parallel connections contain within (from TFP to TFP-64) the complete set of the parallel feedback Verbindungen (connections).

Fig. 2.15 — Operations achievable through computing modules mathematically: a) Inversion; b) Multiplication with constants; c) Addition; d) Subtraction; e) Summation-Integration; f) Integration

Technical Data — Integrating Module TPO-2

General Technical Data (continued from previous section)

Total gain error … < 10^5
Input bias current … < 20 nA
Input offset current … < 200 nA
Maximum operating frequency … > 500 Hz
Bandwidth at integrator with test-point resistor R_E … > 100 kHz
Temperature coefficient … < 1 nV/°C
Quiescent current consumption … < 6 nA
Stabilization by means of Höhe x Tiefe): … < 2.13 ms
Dimensions (Height × Width × Depth) … —GRUNDGERÄT 5 =

2.4.2 Computing Module TPO-2 — Type DM OPO 292

The computing module TPO-2 is required for four-quadrant multiplication. It computes the product (x · y)^(1/2) as well as the quotient of two variables. In order to understand the function of the computing module, the Computation circuit of the squaring function z = (x + y)^2 and the associated basic principle of multiplication is considered.

Each computing module contains two precision full-wave rectifiers and one squaring function. In the squaring range the inputs are approximately 0 to ±9 V, symmetrized at 1 V. The multiplier function is achieved by means of the identity:

x · y = ((x + y)^2 − x^2 − y^2) / 2

The squaring function is approximated piecewise-linearly. The breakpoints are adjusted so that stable, precision squaring units can be produced. Schematic: see Module TPO-1, Fig. 5.6.

2.4.3 Computing Module TPO-2 — Type DM OPO 2 QQ SQ2

The computing module TPO-2 is with four quadrant multiplication as described previously. It computes the product (x · y)^(1/2) and additionally the square root. The squaring function z = (x + y)^2 is also available. The Multiplication function is achieved by means of the same identity as above.

Each computing module additionally contains the function of approximating square root extraction, which serves to drive the analog-differential equation circuits.

The computing module TPO-2 is directly compatible with the Rechenmaschinenbaugruppe TZ 14/2.

(From the Computing module TP-7)

[page 20: figure only — block diagram of TPO-2 variant configurations with amplifier stages]

The figure shows the connection topology of the computing module in two variants:

Top: configuration with two computing amplifier units and associated sign-allocation
Bottom: block diagram of the computing module TPO-2, showing input sign branches and the combined squarer/multiplier output stage

Technical Data — Computing Module TPO-2 (Rechenmaschinenbaugruppe TPC-2)

The computing module TPC-2 is interconnected to the Differential-Gleichungsrechner (differential equation computer) MFP at the ten pin-sockets designated MD 1 (Fig. 2.20). Connections to the computing module (MD) and to the corresponding functional elements may be established at voltages of 10 V, as shown in the interconnection plan which can be assembled.

Fig. 2.20 — Circuit diagram of the computing module TPC-2:

MV — voltage divider input
MV — output

Typical Technical Data:

Input voltage range … 0 to ±10 V
Output voltage range … 0 to ±10 V
Multiplication accuracy … ± 0.5 V/Abschi. (Abschnitt)
Number of the multipliers (in circuit as multiplier) … 2
Number of the comparators (reference to resolution) … 0.1 M
Dimensions (Height × Width × Depth) … −250 V/1 A
… −0.5 V/6 × 379.5 mm
Weight … −1.12 kg

2.4.4 Computing Module YEX-1 — Type DM OPO 215

The computing module YEX-1 contains with the Komparatoren (comparators) two computing amplifiers. The Komparator is a circuit element which indicates whether one analog voltage exceeds another. The comparator output is at its negative saturation value (≈ −9 V) as long as the positive input is less than the negative input. As soon as the positive input exceeds the negative input, the output switches abruptly to the positive saturation value (≈ +9 V).

The comparator element is usable, for example, as a maximum value finder (track-and-hold), as a switching element in problems requiring conditional logic, or as a relay substitute.

Fig. 2.21 — Circuit diagram of the comparator module TPC-2:

[page 22: figure only — block diagram of multiple comparator module configurations]

Fig. 2.22 — Block diagram of the comparator module in combination with the computing module TPO-2

2.4.3 (continued) — Computing Module TPC-1 / TPO-2 QQ SQ2

The Schaltung (circuit diagram) of the Verknüpfungsmodule (interconnecting modules) is shown:

vU/2 — first potential entry
vU/2 — second potential entry

The Differenzspannungseingang (differential voltage input) position also acts as an input to the comparator module. Positive contact (red), negative contact (blue).

Typical Technical Data:

Input voltage range … 0 to ±2 V/Abschnitt
Amplification of the Multiplier … −2.0 V
Number of the Einzelkondensatoren (individual capacitors) … —
Dimensions (Height × Width × Depth) … —
Weight … —1.12 kg

2.4.4 Computing Module YEX-1 — Type DM OPO 215

The computing module YEX-1 contains with the Komparatoren (comparators) two computing amplifiers. The Komparator is a circuit element that indicates whether one analog voltage exceeds another. The comparator output assumes its negative saturation level (approximately −9 V) as long as the positive input is less than the negative input. As soon as the positive input exceeds the negative input, the output switches abruptly to its positive saturation level (approximately +9 V).

The comparator may be used, for example, as a maximum-value selector (tracking), as a relay substitute in problems, or as a conditional switch.

[page 24: figure only — detailed schematic of comparator and helper module TPC-1]

Fig. 2.24 — Rear-face circuit of the computing module (Rechnemodul):

U_in — input voltage
U_in — second input
M/M — mode selection
B/B — reference

Fig. 2.25 — Circuit of the computing module TPZ-1, showing:

M — yellow = connection
M — blue = reference

Fig. 2.26 — Connection face of the helper module TPP-1:

yellow — Programmierstecker connection
b — brown

2.4.5 Helper Module TPP-1 — Type DM OPO 215

In this helper module it is possible to connect two simple polarized potentiometers. The Schaltungstechnik (circuit engineering) of the module is shown on schematic (see Fig. 2.24 and 2.25). The module can accept single potentiometers positioned on the Rechnerplatte (computing board). Schematic: not shown.

Typical Technical Data:

… ± 10 kV
Span (Spanne) … < 45
Potentiometer track resistance … < 2 kΩ
Repeatability … < 14 V/5 ns
Stability … < 14 V/5 ns
Gleichlaufabweichung (tracking deviation) … 9s/—14 V/6
Dimensions (Height × Width × Depth) … 9o/—100 μV/s
Weight … < 1.41 kg

Section 2.7 — Interconnection Cables and Programming Aids

Fig. 2.27 — Schematic of the programming aids: a) Simple jumper wire b) Jumper with switch c) Jumper with diode

2.7.1 Interconnection Cable (SK 441 11–2)

The programming is performed with the help of Verbindungskabeln (interconnection cables). All function elements on the Rechnerplatte (computing board) are brought out through 30-pin edge connectors at the front of the board, which is accessible at the top. Each output and input carries identifying marks on the Rechnerplatte using the Rechnerfeld (computing field) symbols. The cable length is approximately 50 mm.

Typical Technical Data:

Type	Length
GK 441 25	100 mm
GK 441 39	350 mm
GK 441 39	500 mm
GK 441 22	1000 mm
GK 441 23	1000 mm

The programming cable (Verbindungskabel) is made of coaxial cable with a characteristic impedance of approximately 0.75 ohms. Each Verbindungskabel (interconnection cable) is approximately 0.75 m long and has at each end banana plugs on both sides.

Tip:

It is not recommended to use other types of interconnection cables on the differential analyzer MEDA 42 TA, since unfavorable inductances on the Kupferverbindungs-Platte (copper interconnection board) could otherwise affect the Rechnungsergebnisse (computing results) adversely.

2.8 Content and Parts List

In the Sonderbestellung (special order) the differential analyzer MEDA 42 TA is delivered with the following Geräteteile (device parts), whose delivery is carried out in three separate cases approximately three years after the order, conforming to Chapter 35 of the Technical Conditions:

5 Coaxial cables 0.75 M/250 V SKN 39 4721
10 Coaxial cables 0.4 A/250 V SKN 36 45 4731
10 Coaxial cables 0.4 A/250 V SKN 35 4731
10 Coaxial cables 1.8 A/250 V SKN 35 4731
15 Coaxial cables 0.4 A/250 V SKN 35 4731
1 Slide-rule calculator (Rechenschieber) PB 560/1
1 Geometric-compass with fittings TV 0090

The Sonderbestellung mit dem Differentialanalysator MEDA 42 TA is also delivered with MFP at Verbindungsplatten (interconnection boards), whose Gerät (device) is in accordance with this description.

The front panel of the differential analyzer MEDA 42 TA contains various elements placed in the Schalttafel (switchboard), which are not in the delivered scope, but which can be additionally ordered. These available items include:

The cards OY 170 145 contain panels with several Potentiometer-Aufnahmen (potentiometer slots), Schalter, and Klemmrahmen (terminal frames). These mountable cards are provided on the front of the computing cases.

The cards OY 170 145 in the small case OG 23 with built-in programmable Goldkontakte (gold contacts) on the Computing-module-slide-rack and can be adapted as required.

Consisting of the following items:

In the panel OY 170 145 are mountable: various Plates, Trennungsrahmen (separation frames) and Diodenklammerelemente (diode clamp elements) which can be additionally mounted in the Rechnergestell (computing rack).

The further mountable slides are also for connections to the Instrumentenaufsatz (instrument top piece), as described in Section 2.6.

2.9 Help- and Computing Module TPO-1 — Type DM OPO 292 212

In the computing module YEX-1 50 mm is attached with Potentiometern (potentiometers), which are in connection with the three Rechenkammern (computing chambers) at the front, and together 24 V actuate the control of the Rechenmaschinenbaugruppe (computing machine module).

The Hilfsmodulbaugruppe (helper module assembly) 2.6 is combined: the differential is added to the Rechenmaschinenbaugruppe to handle Mehrfunktionssysteme (multi-function systems) and the Gleichungsrechnungen (equation computing functions).

2.9.2 Computing Module TPC-1 — Type DM OPO 002 042 212

In the standard computing module TPC-1 with Potentiometern (potentiometers) 50 mm is positioned at the front side in three Rechnergebäuden (computing enclosures), and these are jointly driven by 24 V so that the Rechenmaschinenbaugruppe (computing machine module) board can be operated. The Hilfsmodulbaugruppe-2.6 is combined for the differential circuit.

The computing module TPC-1 is attached with flat-mounted Potentiometern, whose type is illustrated at Fig. 2.3 (Tabelle 2.4). The Potentiometers function to establish the input-side reference voltage of Summierstufen (summing stages) and are positioned on two computing elements for use in front-panel programming in the Rechnungsfeld (computing field).

2.9.3 Computing Module TPC-1 — Type DM OPO 006 0042 0082

The computing module TPC-1 with flat-mounted potentiometers of this type serves as one of the Funktionsbausteine (functional building blocks) in the analog computer. It contains the same front-side elements as the previous type.

2.9.4 Computing Module TPC-1 — Type DM OPO 006 0042

The computing module TPC-1 with flat-mounted potentiometers is of the same type as above.

[page 30: tables — connection comparison matrices]

Table 3.4 — Allocation matrix for MEDA computing modules

Connection type	TPO-1	TPO-2	TPP-1
Input summing junction	+	++	—
Output	+	++	—
Differential output	—	+	C, B
Reference	A, B	A, B	—

Table 3.5 — Computing module type cross-reference

Designation	Approx.	Type	Reference
Integrator	—	—	A, 31–36
Komparator	—	—	C, 40–46
Multiplier	—	—	—
Summierend	—	—	—
Tippgeber	—	—	C, D

3 — Assembly and Initial Start-Up of the Computing Machine

The transistorized differential analyzer MEDA 42 TA has a particularly simple layout and construction. The Rechner (computer) does not require any stabilization during operation. Starting is also accomplished with particularly simple means. The computing module is housed in a metal cabinet with housing dimensions suitable for desktop use. Instructions and preliminary controls are carried out in the fewest possible steps.

3.1 Installation of the Computing Machine

The computing machine can be positioned in any arbitrary location. To use the computing machine appropriately for computing Aufgaben (tasks), the cooling air openings at the bottom and rear of the computer must not be obstructed. Air must circulate freely to cool the internal components.

The interior of the computer cabinet is accessible to the user by removing the Oberteil (top cover). The largest accessible modules inside the machine are the plug-in computing modules and slide-in cards.

The switch position labeled “STOP” in front of the device causes the computer to halt its computation. In this state all integrators are locked (no integration occurs). The red Betriebsbereitschafts-LED (operational readiness LED) lights up when the machine is in the STOP state.

3.2 Control of the Power Supply and of the Reference Voltage

The DC offset of the Frontplatte (front plate) OA is controlled through the Modulbaugruppe (module assembly) TS 14/2. This is because the Stromversorgungs-Modulbaugruppe (power supply module assembly) provides the necessary reference voltages and controls the Gleichspannungs-Anteil (DC component) of the output signals.

Fig. 3.1 — Circuit arrangement at the Rechnergehäuse (computing housing):

The figure shows that the Rechengehäuse (computing housing) houses both the Frontplatten (front panels) and the Programmierplatten (programming plates) internally.

Fig. 3.2 — Arrangement of the power supply module showing connections A and B to the modules TS 14/2. Power supply mounting of the Rechnergehäuse (“front-view”)

[page 32]

The control of the Speisung (supply) and of the Rechenmaschinendynamik (computing machine dynamics) is shown together with the orientation controls. These orientation controls are performed in a defined sequence.

Potentials of ±14 V are supplied. The Frontplatte (front panel) is installed in the Rechenmaschinenbaugruppe (computing machine module) at the front. The Spannungsstabilisierung (voltage stabilization) is controlled by the Stromversorgungs-Modulbaugruppe TS 10/2, which regulates the output voltage.

Voltage control at the front plate OA produces the following Schaltelementstellungen (switch positions) (Table 3.1):

Switch position	Left potentiometer	Control result
+24 B	—	Correct front-panel position; is the Potentiometer at Stromversorgungs-Modulbaugruppe TS 14/2 Position 3 (s. Bild 5.27) controlled
−24 A	—	The left potentiometer in this Schaltstellung (switch position) is also at Potentiometer; the Stromversorgungs-Modulbaugruppe TS 14/2 Position 3 (s. Bild 5.27) controls also this
−14 A	—	—
−14 B	—	—
ED	—	To Messgerätzeiger (meter deflection) must also the Potentiometer at this position be adjusted in order that the Rechenmaschinenbaugruppe (computing machine module) works correctly

The direct measurement of the Rechnungsergebnisses (computing result) takes place at several measurement points. The outermost Messknopf (measurement button) at the Rechnergehäuse (computing housing) can produce a precise red Zeigerausschlag (pointer deflection). The measurement is taken with the minimum Bürde (burden) on the Zeigermesswerk (pointer measuring mechanism) of the upper Busse; the positive and negative directions along the red Zeigermesswerk (pointer measuring mechanism) are shown.

The direct measurement at the test busbar A at this point is stored as a milliampere display. In this way the Kompensationsprinzip (compensation principle) serves the Rechnerarbeiter (computer operator) during problem setup.

3.3 Adjustment of the Reference Voltages

To avoid spurious electrical Überschläge (flashovers) it must first be checked whether the entered computing amplitude is insufficient or whether the Potentiometerstellung (potentiometer setting) has been reached. After the computing machine is started, large voltage differences at the Ampere-meter are to be checked whether they come from a previously known cause, or constitute a new deficiency.

The compensation control principle as shown in Fig. 3.3 functions as follows:

The Potentiometer P 30 moving the Rechenmaschinenbaugruppe is set to ±10 V or −10 V ÷ 1/5 g = Mess-Stationierung (measuring station).
The Rechnungsgehäuse (computing housing) is adjusted 10 V over −10 V ÷ 1/3 g = 0.21 M
Maximum supply: ±0 V/10; no = Messebene (measuring level)

At the highest points the Kompensationsspannungseingang (compensation voltage input) is always numerically smaller than the set value of the Potentiometer P 30. The adjustment is achieved without any Volumensteuerung (volume control), even when the Rechenmaschinenbaugruppe offers an Abweichung (deviation).

The Kompensationseinstellung (compensation setting) at the Rechnerplatte (computing board) is always checked by the Potentiometer P 30 at the Kompensationseinstellknopf-Beschriftung (compensation adjustment knob labeling). The Potentiometer P 30 output is then used for the scale of the Koeffizienten (coefficients) at the assigned position.

Erster Hinweis (First note):

The Koeffizienteneingaben (coefficient inputs) must be always set as the comparison at potentiometer P 30 indicates, i.e., the does of the Rechenmaschinenbaugruppe (computing machine module) according to Table 3.1 are adjusted.

[page 34]

Due to the Stromversorgungsplatinen (power supply boards) OA which contain 20 Koeffizientenpotentiometer (coefficient potentiometers), i.e., the h is adjusted, on the front board OA are located 30 Koeffizienten (coefficients) with associated control inputs. The Potentiometereinstellungen (potentiometer settings) are assigned for each Rechnungsaufgabe (computing task) individually.

As long as no Koeffizientenzuordnung (coefficient assignment) has been made, the Potentiometer P 30 is in the lower Einstellposition (adjustment position) — this corresponds to zero coefficient. From this state all Amplitudes can be set to their desired values.

From the highest Potentiometereinstellung (potentiometer position) the Koeffizientenmodule (coefficient modules) can also produce Potentiometerstellungen (potentiometer positions) through corresponding adjustment. The Rechnungsaufgabe (computing task) will also add a Koeffizientenmodul (coefficient module) through the Potentiometereinstellungen. Positions 1 to 30 are those of the Koeffizienten (coefficients).

Flüchtige Eingabe (Quick entry):

The coefficient input directly in connection with the computing amplifier means that through the module Rechnerplatte (computing board) the Koeffizienteneinstellung (coefficient setting) must always be done through the Potentiometereinstellungen (potentiometer settings). This adjustment of the Potentiometer P 30 generates the setting for the Integratorintegration (integrator integration) in the range of the task.

3.5 — Balancing the Computer

The differential analyzer MEDA 42 TA has an automatic Balancing function, i.e., from this it is possible to set the zero-point adjustment automatically. This function is also applicable to the Rechner (computer) as follows:

The Null-Korrektur (zero correction) switch is in the position for Rechnung (computation), i.e., the Rechnungsgehäuse control “LÖSUNG” or “STOP” in Balancing mode. The Balancing is caused by:

Through an analog Zeitgeber (timer), the Rechner (computer) is controlled automatically.
By Hochpräzisions-Zeitgebersignalen (high-precision timing signals) on the display.
Through Kontrolle and Korrektur (control and correction) of all amplifiers (see Section 3.3), so that all Potentiometer outputs are provided with correct reference levels, so
Verstarker (amplifiers) output must also thereby provide correct timing.

In this case the following occurs, in order from first to last:

a) through Zeigerpotentiometer (pointer potentiometer) Überspringen (skipping) — the Rechner (computer) behaves in this manner as if previously set correctly according to the solution;
b) by Nullabgleich (zero balancing) — one measures the Spannungsausgänge (voltage outputs) at the computing amplifiers;
c) through Kontrolle (control) of all amplifiers (see Section 3.3) to produce correct timing so that all outputs give correct zero levels;
d) Verstarker und Anzeigekontrolle (amplifier and indicator control) — so that the zero level of each point (Section 3.3) is checked in order to confirm that it is correct and needs no further balancing.

3.6 — Selection of the Computer’s Operating Mode

The electronic MEDA 42 TA has the possibility of using the Simulationssteuerung (simulation control) of the Differentialanalysators (differential analyzer) to control either the STOP or the LÖSUNG position. The Balancing — also called automatic “auto” Balancing — enables the following tasks:

An input in Balancing is set so that the individual “LÖSUNG” and “STOP” positions on the Rechenmaschinenbaugruppe (computing machine module) switches are assigned, i.e., the Schaltstellungen (switch positions) are:

“LÖSUNG” — always takes the yellow Lämpchen (lamp) lights up and the Rechner (computer) can start its computation
“STOP” — always turns the red Lämpchen (lamp) lights up and the computation is halted

The MEDA computer also comes in a type with RÜCKLAUF (reset/return) function. In this RÜCKLAUF state the computer starts again automatically after reaching a solution. This means:

After completing the investigation and the Übertragung (transfer) modes are set to the STOP position, and after the Anmerkung (note) is added about which switch positions and programs (see Section 3.5 – 3), a simple Reset, also called “1:3, Wiederholungsanlauf” (repeat start), is performed. The running modes “LÖSUNG” and “RÜCKLAUF” are then called simultaneously.

The working modes “INNERE BEREITSTAND” and “ÄUSSERE BEREITSTAND” are activated.

[page 36: Table 3.2 — Basic Operating Modes of the Computer MEDA 42 TA]

Table 3.2

Mode designation	Operating states of the computer
VORBEREITUNG	— yellow lamp of the Frontplatte (front panel) lights up — red lamp of the Frontplatte does not light — LÖSUNG lamp does not light — control allowed
LÖSUNG	— yellow lamp of the Frontplatte lights up — red lamp of the Frontplatte does not light — LÖSUNG lamp lights up, control not possible
STOPPEN	— yellow lamp of the Frontplatte lights up — red lamp of the Frontplatte lights — LÖSUNG lamp does not light — control allowed
INNERE BEREITSTAND	— same lamp states as for INNERE BEREITSTAND — indicates INNERE BEREITSTAND
ÄUSSERE BEREITSTAND (also: DOPPELBEREITSTAND)	— red and yellow lamps of the Frontplatte light simultaneously — indicates ÄUSSERE BEREITSTAND, i.e., ÄUSSERE BEREITSTAND

At simultaneous activation of the mode “LÖSUNG” is indicated by the green lamp; it is possible to see from the Rechenmaschinenbaugruppe lamp configuration whether the computer is in LÖSUNG or INNERE BEREITSTAND. The lamp states for these two modes are as follows:

The mode “RÜCKLAUF” is selected similarly. This means that:

“STOPPEN” and “LÖSUNG” modes are activated together. The front-panel mode “INNERE BEREITSTAND” is displayed together with “ÄUSSERE BEREITSTAND.”

The working modes “INNERE BEREITSTAND” and “ÄUSSERE BEREITSTAND” are then called as part of the simultaneous Einschaltung (activation). Both Betriebsregime (operating regimes) for the Rechnerplatte (computing board) are controlled, with Passersteuerung (registration control), whereby the Multivibratorsteuerung (multivibrator control) is guided to the affected Punktierungen (contact points) of the schematic to provide stable Multivibrator timing.

The working modes “INNERE BEREITSTAND” and “ÄUSSERE BEREITSTAND” are driven by machined-fastened Punktkontakten (point contacts) to be simultaneously controlled, so that the stable Multivibrator guides the simultaneous loading of the blue Lämpchen (lamps) for the affected points equally.

Page 37

can be activated, and only then can the COMPUTER REPETITION button be pressed to start the repeating run cycle of the computer. It must also be noted that by pressing the COMPUTER REPETITION button, the “VOREINSTELLUNG” (preset) mode of the computer is simultaneously activated, so that the comparison between the two problem solutions can be verified.

Switch A and B must be placed in a basic position for the central control of the computer. It is permissible to choose the setting of the Basic Position knob (Positions 1–4, s. Section 3.6) freely.
Switch A and B in position 2 (as Integrator-Off-Switches for the control panel of the Recorder and Plotter MN-2 and P-32/12) must be pressed for the selection of the Integrators (s. Section 3.12) at least once.

In working mode “VOREINSTELLUNG” and “LÖSUNG” (solution), the Integrators are switched by means of the readout selector switch located on the readout printer.

The Output (“AUSGANG”) button (FIG. 2.0 b, Position 3.10) illuminates as soon as the COMPUTER REPETITION mode is pressed.

The readout label on the “NORMEN” (NORMS) button (FIG. 2.5, Position 3.12) can be selected.

When the “VOREINSTELLUNG” button is pressed, the computer switches first to “VOREINSTELLUNG” (preset) mode, and then (after a set time determined by the “NORMEN” timer) automatically switches to “LÖSUNG” (solution) mode. During this sequence, the “VOREINSTELLUNG” and “LÖSUNG” buttons light up alternately.

The activated state, i.e., the largest Integrator group selection at the display, is highlighted by the “NORMEN” button lighting up. The Integrators may also be switched to “VOREINSTELLUNG” and to “LÖSUNG” mode individually.

For the repeated run of the computer, the “VOREINSTELLUNG” and “LÖSUNG” illuminated buttons are used to indicate the working mode.

The “AUSGABE” (output) button illuminates as soon as the COMPUTER REPETITION output is activated and the analog-to-digital conversion begins.

By pressing the “NORMEN” mode button (in the Function Key area), the previously described program can be aborted and the computer can be freely placed in either “VOREINSTELLUNG” or “LÖSUNG” mode.

Page 38

The simplest connection of the computer to the Plotter and Recorder (from which the central control of the Recorder can be exercised) is achieved only at the selection of the “COMPUTER REPETITION” section (s. Section 3.5). This selection should best be made via the function group marked with consecutive keys labeled “1” and “2” … (up to 5 possible), since in this case only the 1st computer’s integrators run synchronously.

The simplest level of the Integrators in the “SOLUTION” mode is possible because all integrators can then be simultaneously switched off in a single operation.

However, in this case the use of the key is not necessary, since the “automatic stop” can already be achieved by switching to the key position “P” (in “VOREINSTELLUNG”).

In the simplest case, the same operation as for an Integrator-Connection (B I and 1) will occur and the transfer connection can be used for the Integrator output (s. Fig. 2.13) to select the Recorder’s connection fields (s. Fig. 2.13). The Recorder resolution is then used as a control to adjust the largest amplitude of the computer display.

3.7 INITIAL CONDITIONS OF THE INTEGRATORS

The initial conditions of the Integrators set within the MEDA 42 computer are given either by the “VOREINSTELLUNG” or by the “LÖSUNG” modes.

During the initial condition of the Integrators working in “VOREINSTELLUNG” mode, they can be individually switched from the “LÖSUNG” mode to the “VOREINSTELLUNG” mode.

At the same time, it should be noted that the switching key “O” (in Fig. 2.12 a) must not be used (connected) in “VOREINSTELLUNG” mode with the integrators, because all integrators could switch immediately to the “VOREINSTELLUNG” mode.

However, in the case of “LÖSUNG” mode, the Recorder only shows the level of the integrator for those that still remain in “VOREINSTELLUNG” or “LÖSUNG” mode respectively.

Shown in Fig. 3.5 is the relevant connection diagram for the Integrator.

The following equation can be derived from the Integrator-circuit (with operator notation):

u_a = –(1/T) · integral(u_e) dt

Page 39

Fig. 3.5 shows the schematic diagram for the integration connection of the integrator in the “VOREINSTELLUNG” mode.

Fig. 3.5: Schematic of the integration

a) Integrator connection, slow transfer
b) Integrator connection

Fig. 3.6: Schematic of the “VOREINSTELLUNG” function

a) Integrator connection, slow
b) Integrator connection, fast
2 = Integrator connection – fast

Fig. 3.7: Schematic of the Integrator connection in “VOREINSTELLUNG” mode

a) Integrator connection – slow
b) Integrator connection – fast

[page 39: figure only – integrator circuit schematics with labeled components]

Page 40

In the “VOREINSTELLUNG” mode, the following applies:

u_a = (R_2/R_1) · u_e + (R_2/R_3) · u_e + … + u_y

where V is the summing amplifier gain.

If the integrator is in “VOREINSTELLUNG” mode, the value can be obtained:

u_a = -(1/R·C) · integral(u_e) dt

where T = R · C is the integration time constant.

Fig. 3.8: Schematic of the “VOREINSTELLUNG” function

a) Integrator connection (slow)
b) Integrator connection, fast

[page 40: figure only – integrator circuit schematics with labeled inputs and connections]

After switching switch PS-1 to the “W” position (s. Fig. 3.5), the integrator functions as a Integrator with initial value T_A = 0.005 s.

Fig. 3.7 shows the integrator in “VOREINSTELLUNG” mode with time constant T_A = 0.005 s.

Page 41

After setting switch PS-1 to “W” position (s. Fig. 3.5), the integrator functions as an integrator with initial value T_A = 0.005 s.

The output: u_a = –u_y + (u_y/T_A) · 0.05 V + 0.05 V_y + u_y/y (approximately)

This means that u_e and u_y are the inverting inputs and the output is 0.0, approximately equal to (combined with operator notation):

u_a = –(u_e/T) · 0.05 V_y + 0.05 V_y + u_y/y

This can be derived from the Integrator connection (with operator notation):

u_a = –(1/p) · (u_e + u_y)

The amplifier (with the operational sign) then has the following relationship:

u_a = –(1/T) · integral(u_e) dt · 0.05

where T is the integration time constant (s. Fig. 3.10).

The Integrators u_y and y are selected by switching to positions:

Output “u_y” has the value 0.05 · V_y
the value 0.005 equals approximately 0.005 · S_y

The working mode “VOREINSTELLUNG” means that:

The selection of key PS-2 in position “VOREINSTELLUNG” means the integrator functions at the initial value
The key PS-2 in position “P” means the integrator changes to “LÖSUNG” mode

In “LÖSUNG” mode, the integral is formed automatically from the “VOREINSTELLUNG” to “LÖSUNG” value, and all Integrators can then be read with the same automatic control.

When reading mode is enabled, the “LÖSUNG” mode output from all Integrators is simultaneously accessible via the output board on the “AUSGABE” (output) sockets.

Fig. 3.7:

a) Slow transfer function
b) Fast transfer function

Page 42

The simple operations that occur in the “VOREINSTELLUNG” mode and are changed over to the “LÖSUNG” mode are very easy to implement, since the individual positions of switches PS-2 and the value from the computer (s. Section 3.12, Subsections 3.1 and 3.2) can be changed by the switching action for individual computational elements. The Tables 3.3 and 3.4 concern the “LÄNGERES EINSTELLEN” (extended setting) mode.

In the “VOREINSTELLUNG” and “LÖSUNG” mode, the integrators operate in the “Integrator-Schaltung” group of the computer, and all further ones are also noted in the table (the “NORMEN” switch at position “P”). As such, all integrators in the “VOREINSTELLUNG” mode (position “P”) are placed in the “LÖSUNG” mode in the same manner. The “NORMEN” switch can also be set in individual positions.

In “LÖSUNG” mode, the switch PS-2 at position “P” can be used to configure the following on the Program-card (s. Fig. 2.13) onto the single specific fields of the board of the computer:

On one special card (s. Fig. 2.13), the integrators of the computer are individually placed (s. Fig. 2.13), at those that were addressed (in this instance, one can verify that the single integrators are addressed in the correct mode).
Any further operations selected are then automatically cancelled. As in the case of the “NORMEN” program function, it should be noted that this type of fully complete, complex integrator operation is used, to the degree that the complex integrators may also be put in the “VOREINSTELLUNG” mode automatically by the COMPUTER REPETITION mode.

The Tables 3.3 and 3.4 provide an overview of the Integrators PS-2 and the way the individual computers handle the “LÄNGERES EINSTELLEN” mode. They also describe the current value on the computer’s readout display (s. Sections 3.1 and 3.2) as applicable to the “NORMEN EINSTELLEN” (norm setting).

THE SCHNELLEINSTELLEN (rapid preset)

Page 43

Table 3.3 — Integrator operating modes depending on the position of switch PS 2 and the control signal of the “LÄNGERES EINSTELLEN” station

Momentary operating mode	Position of switch PS 2						Response	Illuminated display
Illuminated display / print key		1	Input signal on the brown key tab of relay A		Input signal on the brown key tab of relay B		Illuminated display / print key
null	—	VORE-INSTELLUNG	AUFNEH-MUNG	AUFNEH-MUNG	—	—	red and violet Blinking signal at violet button “IV”, blinking signal at yellow button “0”, no blue illumination
erho	OX	INTRA-CTION	INTRA-CTION	AUFNEH-MUNG	AUFNEH-MUNG	—	—	green and violet Blinking signal at violet button “IV”, blinking at yellow button “10” means +10 V
—	OX	AUFNEH-MUNG	INTRA-CTION	AUFNEH-MUNG	INTRA-CTION	—	—	a) OX (or by switching off the brown and green buttons) on the field (P6): blinking at the “INTRAKTION” b) red and violet blink signal on the violet button “P” for both computers “IV” at –10 V
OX or down-hold of the brown and green relay buttons (Plate (P6))	VORRE-CTION	ÜBER-TRAG	VORRE-CTION	ÜBER-TRAG	OX	—	—

Note: The position of switch PS-1 sets the color-coding of the Integrators.

Symbols: → = push is performed; — = no key signal is present

Table 3.4 — Integrator operating modes depending on position of switch PS 2 and control signal of “LÄNGERES EINSTELLEN” station

Momentary operating mode	Position of switch PS 2						Response
Illuminated display / print key		1	Input signal on brown key tab of relay A		Input signal on brown key tab of relay B		Illuminated display / print key
red and blue	OX	VORRE-CTION	AUFNEH-MUNG	AUFNEH-MUNG	AUFNEH-MUNG	OX	red and blue, violet Blinking signal at violet button “IV”, blinking at orange button “IP”
red and blue At the output of the established astable multivibrator 50 as voltage +10 V	OX	VORRE-CTION	VORRE-CTION	VORRE-CTION	VORRE-CTION	OX	VORRE-CTION TRAG TRAG
red and blue At the output of the established astable multivibrator 10 as voltage −2 V	OX	ÜBER-TRAG	INTRA-CTION	INTRA-CTION	ÜBER-TRAG	OX	VORRE-CTION TRAG TRAG
red and blue (or drum-switching of the brown and green relay buttons, Plate (P6))	—	VORRE-CTION	VORRE-CTION	VORRE-CTION	VORRE-CTION	OX	VORRE-CTION TRAG TRAG

Note: Position of the switch PS-1 determines the color of the integrator buttons. Working in the “SCHNELLEINSTELLEN” mode always sets the Integrators.

Symbols: → = push is performed; — = no key signal is present

Page 44

a) The operating range “LÄNGERES EINSTELLEN” cannot be reached or cannot be selected by hand (from the switch position at the beginning), since sometimes the hand contact is not possible.

The automatic operation of individual integrators, of which there are a small number only, results in an automatic readout mode.

If the single integrators require an accurate “VOREINSTELLUNG” / “LÖSUNG” result, then the feasibility can be obtained by automatic means.

The comparison of the computer results with the readout values can be performed automatically using digital print output.

The options for the automatic control of the integrators make it possible to: a) Automatically set all modes of the individual Computer’s “VOREINSTELLUNG” and “LÖSUNG” modes, so that the comparison can be made with the single printout for those computers. b) Automatically “stop” (LÖSUNG stop) the operation of the individual computer so that the comparison can be verified at any time. c) Simultaneously switch the modes of the computers via operation, therefore performing the computer output at the same time. d) The automatic operations can be performed by hand from the computer as well.

3.9 Needs of the Computer Operator and the Starting Values

When programming the computer MEDA 42 TA at the Differential-Analyzer mode, the operator must set the initial values (Initial Conditions) as correctly as possible.

The choice of the Initial Values must be set correctly from the switch positions (VOREINSTELLUNG and LÖSUNG), as shown in the overview from Section 3.6.

The function of the Switch PS-2 should be set for “VOREINSTELLUNG” and “LÖSUNG” mode of all integrators, at which the choice is made automatically after setting their initial values. The automatic procedure is described in Section 3.12 S.

If the switch is set in position “VOREINSTELLUNG” from the function key, the “VOREINSTELLUNG” mode is automatically selected. Similarly, for “LÖSUNG”, the switch must be set to the Lösung position.

The Readout data from the computer results can be further processed by the Differential Analyzer (DM/A) or the Plotter (P) of the MEDA 42 TA computer system.

Page 45

Fig. 3.9 — Setting of the Initial Conditions — simple

Potentiometer name: 1 = “visible” (right)
or — “orange-colored” = full

Fig. 3.10 — Setting of the Initial Conditions — not simple

Potentiometer name: 1 = visible (right)
or — “orange-colored” = full

It is important that the Potentiometers give a suitable output voltage since the Potentiometer provides the output voltage to enable the “LÖSUNG” mode. The potentiometer F 22 at the output provides 2 V to 10 V, which is the range of the setting (s. Fig. 3.3):

In the range −10 V to −10,000 V (i.e. 1.36)
In the range −10 V (s. Section 1.36)

This means that the negative Voltage at the F 22 at the output Amplitude (the actual state is: –(10 V, d. s. s. 1.36)) can be set.

It should also be noted that the Potentiometer should give: a) No “right-hand” range

The integrated transfer level is taken via the Initial-Amplifier (IFA) of the computer.

The working range of the Potentiometer for the F 22 is:

From the “beginning” range: –10 V for those in the range –10 V × 1.36 s.
Through the range set from 0 % to 100 % of the full scale: all starting amounts are reached by the amplifier through the polarity switch (P-22) directly on the Recorder.

The setting of the Potentiometer F 22 means the output signal is:

In the range 0 V to 10 V → output + 0,200 V symmetrically
Via the Potentiometer: ±0,5 V is equal to the Input voltage V_A

Table 3.5: Approximation of the Function arcus x from the broken-line approximation

x	f(x)	x	f(x)
+4.5°	+0.786	−0.5	−0.785
+3.5°	+0.785	−1.5	−0.785
+2.5°	+0.785	−2.5	−0.785
+1.5°	+0.785	−3.5°	−0.785
+0.5°	+0.785	−4.5°	−0.786
+0.5°	+0.500	−0.5°	−0.785
−0.5°		−1.5°	−0.785
+0.5°	0.786	−0.5°	−0.785
−0.5°	+0.785	−1.5°	−0.785
−1.5°	+0.785	−5.6°	−0.500
−2.5°	+0.785	−6.6°	−0.894
−3.5°	−0.500	−7.6°	−0.981

Page 46

Table 3.5 (cont.) — Approximation of the function arcus x through broken-line approximation (values)

x	f₁(x)	x	f₂(x)	Δ(x)
+4.5°	+40.788	−0.5	−40.723	−0.785
+3.5°	+42.323	−1.5	−42.388	−0.777
+2.5°	+44.488	−2.5	−44.388	−0.850
+1.5°	+46.388	−3.5	−46.388	−0.981
+0.5°	+48.500	−4.5	−48.500
+0.5°	+50.500	−0.5	−50.500
−0.5°
−0.5°
+0.5°	+40.788
−0.5°
−0.5°	+40.788
−0.5°	+42.388
−0.5°	+44.388
−0.5°	+46.388
				−0.510
				−0.694
				−0.981

The left column of the Potentiometer F 22 gives the applied voltage, where the function is as follows: the lower the applied voltage at the input from the left side, the larger will be the broken-line approximation of the function for that voltage range.

The symmetry of the function f(x) is given by the Potentiometer, since the initial value for each calculation is placed at 0.200 V, and by means of the approximation table (Table 3.5 s.), the Potentiometer F 22 is also set in the range:

At the position P 22: ±0.200 V yields the Starting voltage V_A

Note: In the Table 3.5 the function f(x) and the approximation line can be verified by reading the column headings from left to right.

The setting value V_A = –0.200 V is placed at the Potentiometer, and after the Table 3.5 approximation the starting values are established.

The Values of Table 3.5 show that f(x) = arctan x and therefore Potentiometer F 22 corresponds to: V_A = ±0.5 V corresponds to the Input voltage.

Page 47

Table 3.6 — Switchboard key assignment for the parallel control of functions

Computer-number (element)	Computer key color	Switchboard function
K	orange	Switching of the Computer in “VOREINSTELLUNG” mode results in: The brown button at “OX” is not connected (“automatic stop” is not connected through rotation)
Ks. 6	brown	The same function is connected — however, in this case the “automatic stop” lever is not present, because the key “P” is connected
1	orange	The same function as K is performed — however, in this case the “automatic stop” lever is not connected

The setting of the Potentiometer-function is however achieved by a digital-electronic unit, making possible an even faster and more reproducible setting of the function-values than the manual method. It is further recommended to set the Potentiometer always with the standard setting procedure.

3.11 Parallel Calibration of the Computer MEDA 42 TA and its Verification

The parallel calibration determination consists of the essential individual functions of the MEDA 42 TA, whose further individual working is described in the sections that follow.

For the Parallel calibration of the Computer MEDA 42 TA, the following items are to be monitored:

At the Differential-Analyzer MN-2 at FIG. 42 TA are the individual computer elements of the “VOREINSTELLUNG” and “LÖSUNG” (solution) modes;
The calibration of the individual elements takes place via the individual switch settings.

The resulting values can be confirmed from the comparison of the digital readout output with the expected values from the computer solution.

Page 48

The Differential Analyzer MN-2 at FIG. 42 TA works during the iterative procedure through the special DAM-P function (the “NORMEN” switch is simultaneously activated during the readout output) while simultaneously activating the “VOREINSTELLUNG” mode automatically.

a) The Recorder MN-2 at FIG. 42 TA is configured with 2 Recorder connections (both from the parallel output values of the switch), and both are also connected to the Parallel Inputs of the Recorder.

b) The recording output of the Recorder MN-2 at FIG. 42 TA is connected to 2 recorder connections using Dividers with a further Recorder MN-41 TA. Those are connected with 2 connections at the same recorder.

c) The two-channel output functions of the Recorder MN-2 at FIG. 42 TA are connected from the computers MEDA 42 TA at the Recorder outputs and with the cable from the Recorder MN-41 TA.

d) The outputs of the Recorder at the program card panels of the Recorder MN-2 and MEDA 42 are measured using the two Recorder MN-41 TA together, and these are put to a comparison against the established values (MEDA 42 TA). The connecting cable is attached to the recorder connection of the Recorder to MN-41 TA.

e) The 2-channel Recorder connections of the Recorder MN-2 at FIG. 42 TA are connected to the 2-channel connection with the medium-size special operand link cable with the Recorder MN-41 TA.

The Differential Analyzer MN-2 at FIG. 42 TA is used for the Summary-Control of both computers MEDA 42 TA. Both computers MEDA 42 TA are combined with a single connection cable with a two-connection at the two computers.

During the comparisons of the computer (MEDA 42 TA) with the computer (MN-41 TA) the “VOREINSTELLUNG” mode is automatically controlled and the single individual Integrators of both computers are read out simultaneously.

Fig. 3.13 — Schematic of the common input-output connection TPM-1 [diagram showing circuit with TPM-1 block, integrators, and input/output connections]

§ 3.13 S 2 — Schematic illustration of a common input-output connections (also an adaption of the ARG-Parallel Voltage- and Shut-Closing Coupling)

The “coherence” adapter is recommended for installation at the start of the Recorder’s installation, so that no additional installation is required during the later calibration procedure.

Page 49

The connection in Fig. 3.12 establishes an identical function as the iterative-connection levels all a1, a2 and b1 and b2 fulfil conditions (s. Fig. 2.4):

The connections a11, a21, b1 and b2 at the Integrators’ function are configured.
The connections in Integrators-cycle (IZS/ IZS, s. Bild 2.5) are placed in the order of the individual step functions.
Because they are the same (BI/ IZS), the Contacts are also placed at the A/B positions (BI/ IZS). Their Contacts correspond to the values (OI/ IZS) from the section above.

Fig. 3.13 — Schematic of the wiring connections for the ARC configuration

(Shown with inputs: 24.5°, R-inputs, S-signals, OI-signals, P-1, P-2, P-3, and P-4 designated entries)

At the connections a10, a20, b1 and b2 in the Integrator connections, the following connections are:

“z-1” and “P-2-1” must be connected from the “NORMEN” function.
At the Switch A, the keys are connected via the Integrators at the Connection of PS-1 to “z-1” and “P-2-1” are positions established.

At the connections a11 and a21 in the Integrator connection: at these positions, the following are also established:

In the Switch A, the keys at the connection of PS-1 to “z-1” are at the “P” position.

The Differential-Analyzer Recorder module is recommended in combination with the MEDA 42 TA in connection with an Oscilloscope, Plotter, Digital Voltmeter, and further peripheral devices.

The combination of the MEDA 42 TA with a Parallel Machine MEDA 42 TA, which is described in full detail by the combined control program, should be achieved by the control from the Recorder module, since in the left-column functions, the individual integrators of the Recorder module are further processed.

The “AUSGABE” mode of the computer, which is the integration connection labeled in the section, can be controlled.

During the computing operation, the automatic control of all the Recorder-groups of the computer MEDA 42 TA in operating mode “VOREINSTELLUNG” causes the individual Integrators to work simultaneously, i.e., in the “LÖSUNG” function mode. In the adjacent column on the function board, the Recorder operations can be combined with the DVM (digital volt meter) connections (from function P to P connection: PPM-12 S, is described in Section 3.12 for those Integrators that shall be read out).

3.13.1 Short-Overview of the Function-Principles

The computer switch “VOREINSTELLUNG / LÖSUNG” (in all keys and in all displays of the computer), is controlled as follows by those computers using the following key-assignments and operations:

3.13.1.1 Control of the Computer Switch “VOREINSTELLUNG / LÖSUNG”

The computer-switch “VOREINSTELLUNG” works at the output of all the displays and keys of the computer simultaneously and in all Integrators.

Page 50

Table 3.7 — Switch assignment for the control of the Secondary-Analog-function

Computer-switch element	Computer key color	Switchboard function
K	orange	The Computer in the “VOREINSTELLUNG” mode works — however the key “automatic stop” (by the downward rotation from key position to ‘P’) is not present
Ks. 6	brown	The same function works for computer — however the “automatic stop” lever key from position “P” is present
1	orange	The same operation is performed — however the “automatic stop” lever is not present

The operational functions of the computer switch “VOREINSTELLUNG” are in several places simultaneously connected with those Computer modes.

3.13 Connection-and-Setting-Tables

3.13.1 Short-Overview of the Operational Principles

The control is applied to the base settings of the NORMEN (NORM) switch and the function key groups, checking the following:

3.13.1.1 Mechanical Control

The control of the base settings (from which the Normen Switch position is derived) is applied to the following functions:

3.13.1.2 Electrical Control of the Summing Elements

It is a recommendation in this case to apply the Differential-Analyzer with the summing circuit (from s. Sect 2.5) connected with the output. The control is simultaneously applied to the Resolver output of the Differential Analyzer.

3.13.2 Connection-and-setting-table of the Integrators and Plotter

3.13.2.1 Mechanical Control

At this section, the “NORMEN” mode setting (s. Sect. 3.13) will be monitored with the following controls:

3.15 Prophylactic Control

The computer MEDA 42 TA for the Differential Analyzer works as a single operation, and should be verified. A single operation control check is made from Sect. 3.13.1 in short, and is monitored with the following functions:

3.15.1 Periodic Prophylactic Controls

Certain controls will be performed once, and in such a case a prophylactic control check will be monitored with the following functions checked:

3.15.1.1 Periodic Control of the Summing Elements

In the Resolver (s. Sect 3.13), the following controls are checked and confirmed:

3.15.1.2 Periodical Control of the Integrator — Prophylactic Control

At this sub-section 3.13 (s. Sect 3.13), the Prophylactic control of the Integrators is monitored and checked for the following:

3.15.1.3 Periodical Control of the Integrator Functions

Page 51

3.13.2 Connection-and-setting-table of the Integrators

At one Differential-Analyzer station MN-2 at FIG. 42 TA comes the function of the computer:

3.13.2.1 Mechanical Control

It is controlled: the Mossgraphite connection from the computer “NORMEN” mode (s. Sect. 3.15 for further control):

3.13.2.2 Electrical Control of the Integrators

The Mossgraphite is controlled from the “NORMEN” mode switch (s. Section 3.13) in the following modes:

All computer elements at the station (s. Sect. 2.12) are checked.
In a prophylactic mode of all the computers, all elements and functions are independently checked.

The control verifies the operation of the Mossgraphite through the voltage switch from the “VOREINSTELLUNG” mode at OX, and the single functions of the Integrators can be selected.

3.13.3 Prophylactic Control

Among the Mossgraphite connection elements, it is controlled that 20 completed oscillation cycles keep within:

a) Integration oscillation-cycles of the voltage range 125 V (approximately).

Fig. 3.14 — Control of the Homogeneity of the basic group (vertical scale: 10 V; oscilloscope scale: 100 mV reference level)

In the “VOREINSTELLUNG” working mode, the element Mossgraphite is switched, and the Oscilloscope is used to verify the Amplitude.

In the “VOREINSTELLUNG” mode, the Recorder is confirmed by the individual verification from the “NORMEN” switch (s. Fig. 3.15, switch at Position 3.15).

The Oscilloscope is confirmed from the “LÖSUNG” mode when the oscilloscope is triggered from the MEDA 42 TA switch:

Fig. 3.15 — Positioning of the workable graphic potentiometer (oscilloscope with amplitude ±10 V = Referenz-amplitude)

R — Working arrangement potentiometer “LÖSUNG”
F — Working arrangement of all keys and reference outputs

3.13.4 Control of the Integrators at the Prophylactic-Control Basis

For control of the Prophylactic-Control status according to Sect. 3.13 (s. Art. 3.17), it is controlled as follows:

3.13.4.1 Control of the Integrators at the Prophylactic-Control Basis

Also, the Potentiometer-based function (connected to the DVM) is switched according to Fig. 3.17.

Page 52

3.13.4.2 Control of the Integrators at the “VOREINSTELLUNG” Operating Mode MEDA TA

In the Scope, the following voltage amplitudes are directed to the “LÖSUNG” mode output field:

Voltage –10 V at the yellow Potentiometer field: “VOREINSTELLUNG”
Voltage –10 V at the yellow Potentiometer field: “VOREINSTELLUNG”
Voltage –11 V in the lower Potentiometer field: “VOREINSTELLUNG”
Voltage –13 V at the lower Potentiometer field: “VOREINSTELLUNG”

(A: Bild 3.13)

Voltage –10 V at the orange button field “VOREINSTELLUNG”
Voltage –11 V at the orange Potentiometer field “NORMEN” position

3.13.4.3 Prophylactic Control of the Differential Amplifier MN-2 at the Functional-Control of Integrators

3.13.4.3 (repeated) — additional note:

In the Bild 3.14 (displayed), the Integrators (in “VOREINSTELLUNG” mode) have the Summing-Amplifier (SUM-AMP) confirm from the initial values S.1 and S.4 – 14 are “demanded” at the following mode:

In Bild 3.14, the Integrators are polarized in the initial mode “VOREINSTELLUNG”, and P 14 is as medium.

With an electronic micro-voltmeter, those connected at the value 2.10 V and 1.40 V (s. Fig. 3.7 S 2), the Integrators are also set, and this control of the polarization-Integrator at value 100/100V is confirmed.

3.13.5 Prophylactic Control of the Computer and the setting of “LÖSUNG”

At Sub-Section (s. 3.13), the prophylactic Control of the individual computers is:

3.15.4 Prophylactic Control of the Computer-Resolution

At this Sub-section, the function of the Recorder from Sect. 3.15 are also confirmed with the following procedures:

3.15.4.1 Control

With the Integrator-switch (s. Fig. 3.7, s. 3.13.4) the connection confirmation is:

a) Stability of the Amplitude — an amplitude must last 1 minute within 1.5 % limits. b) Stability of the operation-amplitude — it is generated by the Oscilloscope (the step function), whose Oscilloscope frequency is generated by the Amplitude-Recorder of the computer operations. c) Stopping the computer operation. d) The signal from each computation must take place at this section with the same Recorder at 120 V Amplitude result at the range–0.1 % in the entire Program field.

Page 53

The voltage is set at max. ±100 mV for the computer’s Summing element. The integral-Summing-elements of the Output field at the 20 V Potentiometer switch is confirmed with a tolerance of 20 % of the smaller Mossgraphite, which means the Integrators themselves can indeed be set with the tolerance.

3.13.4.5 Control of the Voltage- and Range-Compensators

At one of the Prophylactic checks (s. 3.13.4), the Voltage and Range-Compensators are confirmed:

3.13.4.5.1

In the Resolver of the Differential Analyzer, the Potentiometer is set according to:

3.13.4.5.3 Prophylactic Check of the Integrators with Switch “NORMEN”

In the Bild 3.16 (3.15), the Connection confirmation is:

With the Potentiometer F 3 connected (which is polarized via the green switch “P”), when the Integrator is in position “LÖSUNG” (s. Bild 3.15): this is normally confirmed.

For the Potentiometer P in the case of polarized switches (green “P”), both polarized switches (s. Bild 3.17) are confirmed as follows: the Summing Oscilloscope (CRO − Oscilloscope, s. Bild 3.14) connects at the output amplitudes with the Connection at the Oscilloscope:

Fig. 3.14:

“VOREINSTELLUNG” selected and as the Potentiometer (OX − Oscilloscope, s. Section − reference amplitude) is connected
Also the Recorder-sum-amplitude at its corresponding output is measured. If the Potentiometer F, in Bild 3.17, is switched as the Recorder − the Oscilloscope “VOREINSTELLUNG” switch; F = red, m = blue, f = dark

3.13.4.5 Connection-Check of the Integrators at the Functional-Control-Basis

The Prophylactic-Verification according to (Sect. 3.13.5) is connected at the output of the following functional elements.

Page 54

Fig. 3.17 — Schematic for the Description of the Integrator-Prophylactic-check (switching for operation “LÖSUNG”)

K = Amplitude-input source
S = input/output integrator

Fig. 3.18 — Schematic for the Description of the Summing-Amplifier at the Resolver-output (connection for the Differential Analyzer)

At the switching of the Resolver (s. Bild 3.17), with the Mossgraphite (brown) connection element, the following is checked:

The Amplitude is checked at the Oscilloscope from the control-range connection output.
The Oscilloscope checks the Phase-shift of the Integrators.
The Mossgraphite-switch connects at the Potentiometer output which is evaluated against the Oscilloscope amplitudes.
The initial “VOREINSTELLUNG” is checked with the connection from the Bild 3.18 and the OX − Oscilloscope reference check is performed again.

Note: The connection from the Mossgraphite (green “P”) switch is used as long as the oscilloscope connected is operated at the Resolver output.

The check with the Oscilloscope (function “VOREINSTELLUNG / LÖSUNG” key) on the output board shows the state with:

A ”+” or ”−” key on the Oscilloscope keys.
The selected mode is the Resolver reference for all Integrators.

Buchsen P1 — to Connecting key of the Summing-Amplifiers with the Recorder:

MEDA 42 TA — in the connection of the Recorder outputs at all Oscilloscope modes.

[page 54: figure only – schematics of integrator prophylactic-check wiring (Fig. 3.17 and Fig. 3.18)]

Setting the Values for Checking the Sine Multiplier

Table 3.8 — Setting values for checking the sine multiplier

Potentiometer setting P 20	Potentiometer setting P 21	Switch setting
+0.050	+0.050	P 5
+0.150	+0.050	P 5
+0.250	+0.050	P 5
+0.350	+0.050	P 5
+0.450	+0.050	P 5
+0.550	+0.050	P 5
+0.650	+0.050	P 5
+0.750	+0.050	P 5
+0.850	+0.050	P 5
+0.950	+0.050	P 5
-0.050	+0.050	P 5
-0.150	+0.050	P 5
-0.250	+0.050	P 5
-0.350	+0.050	P 5
-0.450	+0.050	P 5
-0.550	+0.050	P 5
-0.650	+0.050	P 5
-0.750	+0.050	P 5
-0.850	+0.050	P 5
-0.950	+0.050	P 5

The multiplier output values are determined from the measured output error using:

A = 0.01 · sqrt(A_d²)

(formula shown)

Page 109

2.13.4.7 Control of the Random-Number Generator

The random-number generator and the distribution-shaping circuits (function generators) in the distribution unit are checked using the built-in checking circuit TPP-1. The checking circuit is shown in Fig. 3.18. By means of potentiometer P 20, the mean value of the Poisson distribution is set (ϑ_0 = 0, Fig. 3.18 shows the check at 1 Bit/s). The output of the potentiometer P 20 is regulated (+0.5 V or −0.5 V) and corrects the potentiometer P 20. This procedure is repeated as needed so that the output of potentiometer P 20 is precisely set.

Fig. 3.18 — Circuit for checking the random-number generator

U_e — input voltage of the function generator
U_a — output voltage of the function generator

The quantity ϑ_0 is satisfactory for the control if the value in Table 3.14 (see Section 4) is reached at the output of the function generator S 2 at the output voltage, in the range approx. 1 V.

Page 110

2.13.4.4 Control of the Differential Analyzer (Section 3.14)

The differential analyzer is checked with the aid of the checking circuit TPP-1. Checking the most important control elements is carried out in the following steps, according to Section 3.14. By checking the individual functional groups according to the table of Section 3.14, all important functions of the functional groups are verified. For each problem, the potentiometer settings to be applied, the control elements needed, and the required actions are listed.

Fig. 3.18 — Schematic for checking the random-number generator

Potentiometer settings: P 20 sets input, regulated to ±0.5 V.

Page 111

2.14 Setting Values for Checking the Potentiometers

Table 3.9 — Setting values for checking the potentiometers (Kontrollproblem Nr. 1)

Potentiometer	Nominal value	Output voltage approx.
P 1	—	—
P 2	—	—
P 3	—	—
P 4	—	—
P 5	—	—
P 6	—	—
P 7	—	—
P 8	—	—
P 9	—	—
P 10	—	—

The differential analyzer is checked with the aid of the checking circuit (Schaltschema TPP-1). Checking of the individual control elements (Koordinatenverstärker) is described in Section 3.14. After successful checking, control potentiometer P 31 is set to −0.5 V (scale P 31 at −0.500, corresponding to the reading of control potentiometer P 31 at −0.500). The fact that the absolute output of potentiometer P 31 at −0.500 V is used as the reference for the output U_a ensures that the control is carried out correctly.

Page 110 (continued)

3.14.1 Control Problem No. 1 — Simple Differential Equation, 1st Order

The linear differential equation is:

y′/t = −1/T · y/t + y/t = 0

with the limiting condition:

lim y/T = y(0) = −1

In this problem, the solution function is:

y(t) = e^(−t/T)

which decays exponentially. The time constant T can be set to virtually any value. The longer the time constant chosen, the more accurately the result can be checked. For very short time constants, even a tiny error “slips through” quickly and the solution function decays to zero before a check can be performed.

Fig. 3.19 — Circuit diagram for Control Problem No. 1

Fig. 3.20 — Tolerance band at Control Problem No. 1

Page 112

Table 3.11 — Setting values for Control Problem No. 1

Potentiometer (P)	Setting	Remark
P 1	0.2	With potentiometer
P 2	0.2	With potentiometer
P 3	0.2	With potentiometer
P 4	0.2	With potentiometer
P 5	0.2	With potentiometer
P 6	0.2	With potentiometer
P 7	0.2	With potentiometer
P 8	0.2	With potentiometer
P 9	0.2	With potentiometer
P 10	0.2	With potentiometer
P 11	0.2	—
P 12	0.2	—
P 13	0.2	—
P 14	0.2	Slider-potentiometer
P 15	0.2	Separator

For the one-time computation, the output quantities of the Koordinatenverstärker x and y are evaluated as coordinate-pairs; in the switching circuit of the control elements x and y, these are used as outputs Δx and Δy.

Page 112 (continued)

Table 3.15 — Settings for the Function Units (Funktionseinheiten)

Symbol in the function diagram	Meaning (identifier [Laufwerksbezeichnung])	Laufwerk EK-A	Laufwerk EK-B
Inverter (Umkehrverstärker, sign changer)	Changes sign of the input variable	EK-1	EK-1
Inverter + x	Multiplies input by x	EK-2	EK-2
Inverter with additional gain	Amplifies at fixed gain	EK-3	EK-3
Summator (Summierverstärker)	Sums two or more input quantities	EK-4	EK-4
Integrator (Integrierverstärker)	Integrates input over time	EK-5	EK-5
Potentiometer	Attenuates signal by coefficient	P 1–P 10	P 11–P 20
Diode function generator	Nonlinear function of input	EK-6	EK-6
Kompensationseinheit (compensation unit)	Full compensation circuit	EK-7	EK-7

Fig. 3.19 — Circuit for Control Problem No. 1

Page 112

Table 3.15 (continued) — Function Units

For the one-time computation of Control Problem No. 1, all integrators start from initial conditions (Anfangsbedingungen) y(0) = −1. The Koordinatenverstärker (coordinate amplifiers) produce at their outputs the values of coordinates x and y. In the control circuit, the function y is plotted as a function of x using the Koordinatenverstärker EK-A and EK-B, so that both outputs Δx and Δy are linked.

Page 112

3.14.2 Control Problem No. 2 — Second-Order Differential Equation, Singly-Coupled

The differential equation is:

y″/t + y′/t + y/t = 0

with initial conditions:

y(0) = 0, y′(0) = 1

The solution of this equation is a damped oscillation. The response of the circuit is checked with the integrators in the starting position IC (initial condition).

Fig. 3.21 — Circuit for Control Problem No. 2

Page 113

3.14.2 (continued) — Section A.3.005 (Problem No. 2)

In the assembly (Schaltungsaufbau), the following connections are established for Problem No. 2:

a = −A_3, b = −A_1
y = 0.13 · A_3, y′ = 0.38 · A_1
A_1 = −0.13 · A_3 + 0.13 · y
A_3 = −0.13 · A_1 − 0.13 · y

The complete set of equations for this problem is:

A_3″ = (−1) · A_3 + (−1) · A_1 A_1″ = (−1) · A_1 + (−1) · A_3

The Kontrollanforderung (check requirement) is: at the termination of the prescribed integration time of t = 1.5 seconds, the output of the machine must match the required value within the given tolerance band.

Page 114

Table 3.12 — Control values for Control Problem No. 5

Reference time (t) [s]	Check value [V]
0	+1.0000
1	+0.9239 −0.9239
2	+0.9001 −0.9001
3	+0.8775 −0.8775
4	−0.1750 −0.4075
5	−0.1775 −0.4075
6	−0.1715 −0.4075
7	+0.1735 +0.4075
8	+0.1735 +0.4075
9	−0.1005 −0.4095
10	−0.4095 −0.4095

Fig. 3.24 — Tolerance band for the computed solution for Control Problem No. 4, 50% of the tolerance

Tolerances are: the check values in the table (Table 3.12) represent the desired values of the solution function at the specified times.

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3.14.5 Control Problem No. 2 — Second-Order Differential Equation, Doubly-Coupled (Repeated)

Linear Differential Equation, 2nd Order

The system of equations is:

y″/t + y′/t + y/t + ψ/t = 0

This is a doubly-coupled differential equation. The solution function is determined by the simultaneous integration of both coupled equations.

In this problem, the Lösungsfunktion (solution function) yields damped oscillations which vary with time. The check is performed using the Koordinatenverstärker (coordinate amplifiers) RAX set at the output.

The Lösungsanzeige (solution display) is made with Koordinatenverstärker RAX and 1.5 V amplitude. The check of the Koordinatenverstärker (Laufwerk) / Ausgabe (output) is performed on Sammelschiene MAX. In Section 3.12 — Stellgröße (manipulated variable) is at the output of the integrators at max value of ± 5 V. The comparison with these values shows whether the solution is within the specified tolerance band.

Fig. 3.24 — Tolerance band for Control Problem No. 5 of the analog computer

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3.14.6 — Control Problem No. 6 — Function f(x) = Quadratic Function (Squared)

The position control verifies the following: each Quadrant is checked — i.e., at all Quadrant outputs the solution function y must be assigned a positive direction.

The check setup requires:

At every Quadrant output, the solution function must have a positive sign
The Aufzeichnung (recording) of the system is carried out in Richtung (direction) of 5 m advance

b) Position Control of the Comparator (Komparator) P-1

The comparator function is controlled by the comparator P-1 in position P-1. Each step of the control dial (Schrittschalter) from position 1 through 4 progresses in positive Richtung (direction). All comparators are placed in position VVV (forward, forward, forward).

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3.14.7 — Control Problem No. 7 — Function Generator

a) Position Control according to a) and b) at the Comparator P-2 and P-3

At the verification of the required solution, both comparators — following the solution process — must in each Quadrant produce an output in positive Richtung (direction). The trace of Function y is shown in the plot as a staircase, which advances 0.4 V per step. In Fig. 3.27, the staircase is plotted with: 1 = measured (actual) curve, 2 = staircase ideal steps.

Fig. 3.27 — Tolerance ranges for Control Problem No. 6: 1 — measured curve, 2 — staircase ideal

Page 124

3.14.7 — Control Problem No. 7 (continued)

Circuit Diagram for Control Problem No. 7

Fig. 3.28 — Circuit for Control Problem No. 7

P = green bus “VORDERSEITE” (front side)
R = blue: logic bus and timing bus
U_e = orange: logic level bus
OG = increasing logic level of the step outputs (Stufenausgaben)
U_a = output of the Differentialverstärker TYP-1, EL-5 — comparator output

Page 127

3.14.7 — Control Problem No. 7 — Coordinate Amplifier Circuit

The complete solution requires the normal and complementary Spiegelberechnungen (mirror calculations). The Spiegelberechnungen M and N are linked by the Koordinatenverstärker (coordinate amplifiers) via the Inverter EK-A and then up the Sammelschiene to EK-B. The switching through the Inverter EK-A and the Komplementärverstärker EK-B is realized by the Koordinatenverstärker in Position ½. The arc tangent function y is determined at the output of the integrator at 0.4 V per step, as shown in Fig. 3.17 (see also the Schaltungsaufbau description in Problem No. 4, a-c).

The course of the function y at the arc tangent output must lie in the Kreisbereich (circular range) of position approx. 1.5 V as shown in Fig. 3.17.

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3.14.8 — Summary — Typical Malfunctions of the Differential Analyzer MEDA 42 TA

Table 3.13 — Overview of typical malfunctions of the Differential Analyzer MEDA 42 TA

Symptom (Störung)	Probable cause (Fehlerursache)	Diagnosis (Prüfung)	Component(s) affected	Remedy
After switch “ON”, the machine does not start	The new Sicherung (fuse) has not triggered the computer to switch on properly	Check that the new Sicherung has been inserted	—	Replace fuse
After switching on, the machine switches off again	The power supply backup Sicherung has tripped	Check the Sicherung for 400 V / tripping	—	Replace fuse
Machine starts but after a short time position Stellung “RECHN” is not attained	Malfunction of the Hochspannungstrafo T 1 (100-Transistor-Verstärker) has caused drop-out	Check supply voltage of 24 V	—	Service the power supply
Initial condition setting not achieved	Improper Anfangsbedingungseinstellung (initial condition setting); the problem is not fully configured	Check full machine potentiometer setup	Potentiometers	Reset initial conditions
After “STOPP” (stop), output voltage drops to zero immediately	There is a break in a Leitungszug (conductor path); one of the control outputs has lost continuity	Check all connector positions	EK-A, EK-B output busses	Repair conductor
Machine runs but solution function deviates significantly from expected	Faulty Recheneinheit (computing unit) has non-nominal coefficient	Check coefficient by measuring output versus input at Recheneinheit	Recheneinheit	Calibrate or replace
Inputspannung (input voltage) is not stable	One of the supply rails (±10 V) has regulation problem	Measure supply voltage at Sammelschiene	Power supply	Recalibrate supply voltage

Page 131

Table 3.13 (continued) — Typical Malfunctions

Symptom	Probable cause	Diagnosis	Component(s)	Remedy
Bei Funktionsgenerator-Prüfung: Kurve nicht korrekt	Leitungsbruch im Diodennetzwerk	Check the diode network of the Funktionsgenerator	Diodennetzwerk	Replace diode
Integrators do not return to initial condition	Position switch not in IC (initial-condition) position	Verify position of Anfangsbedingungsschalter	Schrittschalter	Set to IC position
Eingangsspannung (input voltage) oscillates	Instability in the feedback loop	Check feedback-loop components	EK amplifier	Recalibrate

Page 131–132

4. Appendix — Component List (Bauteilliste)

4.1 Auxiliary and Peripheral Equipment

4.1 Hilfsgeräte (Auxiliary equipment)

4.1.1 — Differential analyzer TYP TA-1 (control-problem checking unit)
4.1.2 — Koordinatenverstärker TYP TA-2 (coordinate amplifiers)

4.2 Components of the Machine

4.2 Bestandteile des Rechners

4.2.1 — Recheneinheit TYP RE-1 (computing unit)
4.2.2 — Steuerplatte GS, Typ GS 320 80 (control board)
4.2.3 — Steuerplatte GS 5, Typ GS 320 80 (control board 5)
4.2.4 — Recheneinheit REC-1, Typ GS 320 100 (computing unit)
4.2.5 — Steuereinheit (control unit) Typ GS 320 100

4.3 Computing Amplifiers (Rechenverstärker)

4.3.1 — Rechenverstärker-Schaltheit TYP-1, Typ GS 320
4.3.2 — Rechenverstärker EK-A und EK-B (computing amplifiers)

4.4 Auxiliary and Control Equipment

4.4.1 — Computing unit TPP-1 (Kontrolleinheit), including setting elements for all control problems
4.4.2 — Potentiometer unit P 31, Typ GS 320 160
4.4.3 — Kompensationseinheit TYP-1, EL-S — differential amplifier, comparator
4.4.4 — Speichereinheit TYP-1, Typ OS 060 040
4.4.5 — Sicherungs- und Anzeigeeinheit DTYE-64 (protection and display unit)

4.5 Power Supply (Netzteil)

4.5.1 — Netzteil DYTE-64, Typ OS 060 049
4.5.2 — EL-Transistor, comparator

Page 133, 136

Component List — Parts (continued)

4.1 Einzelteilliste (Parts List)

Item	Description	Designation	Qty
A 1	Rechenverstärker (computing amplifier)	EL Typ EL-1	—
A 2	Rechenverstärker	EL Typ EL-2	—
A 3	Recheneinheit (computing unit)	EK Typ EK-A	—
B 1	Sicherung (fuse)	—	—
C 1	Kondensator (capacitor)	—	—
D 1	Diode	—	—
P 1–P 31	Potentiometer	—	—
R 1	Widerstand (resistor)	—	—
S 1	Schalter (switch)	—	—
T 1	Transformator (transformer)	—	—
T 2	Transistor	NPN Typ EL-1	—
U 1	Gleichrichter (rectifier)	—	—

Page 133

4.2 Baugruppenverzeichnis — Assembly Groups for MEDA 42 TA and 42 G 100 TA

Table 4.1 — Assembly groups for MEDA 42 TA and 42 G 100 TA (items Pos. 01 to Pos. 25)

Pos.	Description	Qty.
01	Recheneinheit — computing unit	—
02	Recheneinheit — computing unit	—
03	Rechenverstärker — computing amplifier	—
04	Rechenverstärker — computing amplifier	—
05	Steuerplatte — control board	—
06	Steuerplatte — control board	—
07	Sicherungseinheit — fuse unit	—
08	Integratoreinheit — integrator unit	—
09	Integratoreinheit — integrator unit	—
10	Potentiometereinheit — potentiometer unit	—
11	Kompensationseinheit — compensation unit	—
12	Kompensationseinheit — compensation unit	—
13	Gleichrichtereinheit — rectifier unit	—
14	Gleichrichtereinheit — rectifier unit	—
15	Diodennetzwerk — diode network	—
16	Diodennetzwerk — diode network	—
17	Transformator — transformer	—
18	Transistoreinheit — transistor unit	—
19	Transistoreinheit — transistor unit	—
20	Speichereinheit — storage/memory unit	—
21	Anzeigeeinheit — display unit	—
22	Verteilereinheit — distribution unit	—
23	Kondensatoreinheit — capacitor unit	—
24	Netzteil — power supply unit	—
25	Anschlusseinheit — connection unit	—

Page 133–135

Table 4.1 (continued) — Assembly Groups for MEDA 42 TA (items Pos. 26 to Pos. 50)

Pos.	Description	Qty.
A 1	EL-Recheneinheit typ EL, A series	—
A 2	EL-Recheneinheit typ EL, A series	—
A 3	EK-Recheneinheit typ EK-A	—
A 4	EK-Recheneinheit typ EK-B	—
A 5	EK-Recheneinheit typ EK-C	—
A 6	EL-Kompensationseinheit	—
B 1	Sicherung 1 A (fuse 1 A)	—
B 2	Sicherung 2 A (fuse 2 A)	—
C 1	Kondensator	—
C 2	Kondensator	—
D 1	Diode	—
D 2	Diode	—
D 3	Zenerdiode (Zener diode)	—
D 4	Zenerdiode	—
M 1	Messgerät (measuring instrument)	—
P 1–P 10	Potentiometer (front-panel group 1)	—
P 11–P 20	Potentiometer (front-panel group 2)	—
P 21–P 31	Potentiometer (coefficient and control group)	—
R 1–R 10	Widerstand 1 kΩ (resistors)	—
R 11–R 20	Widerstand 10 kΩ	—
R 21–R 30	Widerstand 100 kΩ	—
R 31–R 40	Widerstand (feedback)	—
S 1	Schalter (main switch)	—
S 2–S 5	Schalter (computing mode switches)	—
T 1	Transformator 220/24 V	—
T 2	Transistor NPN Typ	—
U 1	Gleichrichterbrücke (rectifier bridge)	—

Page 135

Table 4.1 (continued) — Parts List — Items Pos. A1 to A4 (detailed)

Pos.	Bezeichnung (designation)	Bau-Nr. (part no.)	Qty
A 1	Rechenverstärker EL Typ EL-1	OS 060 040	—
A 2	Rechenverstärker EL Typ EL-2	OS 060 042	—
A 3	Recheneinheit EK-A	GS 320 100	—
A 4	Recheneinheit EK-B	GS 320 115	—
A 5	Steuereinheit TPP-1	GS 320 185	—
A 6	Potentiometereinheit P 31	GS 320 160	—
A 7	Kompensationseinheit EL-S	GS 320 149	—

Page 135

Table of Contents (Inhaltsverzeichnis)

Page 70 — Contents pages

1 Inhaltsverzeichnis (Table of Contents)

2.1 Hilfsgeräte und Kontrolle (Auxiliary equipment and control) … 52

2.2 Hilfsmittelkontrolle (Auxiliary means control):

2.3.1 — Differential analyzer TYP TA-1 … 53
2.3.2 — Koordinatenverstärker TYP TA-2 … 54

2.5 Kontrolle (Control) … 60

3 BEDIENUNG UND INSTANDHALTUNG DES RECHNERS (OPERATION AND MAINTENANCE OF THE COMPUTER)

3.1 — Bedienen des Rechners (Operation of the computer) … 60
3.2 — Einstellung des Rechners (Setting of the computer) … 60
3.3 — Ablauf der Rechenprobleme (Process of computing problems) … 60
3.4 — Aufgabe des Bedieners (Operator’s task) … 67
3.5 — Aufzeichnung der Rechenergebnisse (Recording of results) … 74
3.6 — Größenordnung der Koeffizienten (Magnitude of coefficients) … 77
3.7 — Wahl der Rechenzeit (Choice of computing time) … 80
3.8 — Wahl der Rechengenauigkeit (Choice of computing accuracy) … 82
3.9 — Wahl der Rechenvorschriften (Choice of computing routines) … 84
3.10 — Allgemeines zur Rechenvorschriften (General notes on computing routines) … 84
3.11 — Darstellung der propädeutischen Rechenaufgaben (Introductory computing problems) … 88
3.12 — Steuerung der Genauigkeit (Accuracy control) … 91
3.13 — Propädeutische Rechenaufgaben (Introductory computing problems) … 96
3.14 — Kontrollanforderungen (Check requirements)
- 3.14.1 — Problem Nr. 1 — System für Abfangsteuerung mit TPP-1 (Problem No. 1 — System for interception control with TPP-1) … 101
- 3.14.2 — Problem Nr. 2 — Hilfsrechnersteuerung EK-3 (Problem No. 2 — Auxiliary computer control EK-3) … 106
- 3.14.3 — Problem Nr. 3 (Problem No. 3) … 112
- 3.14.4 — Problem Nr. 4 — Koordinatenverstärker Typ GS 320 (Problem No. 4 — Coordinate amplifiers Typ GS 320) … 115
- 3.14.5 — Problem Nr. 5 (Problem No. 5) … 119
- 3.14.6 — Problem Nr. 6 — Recheneinheit Typ GS 320 (Problem No. 6 — Computing unit Typ GS 320) … 122
- 3.14.7 — Problem Nr. 7 — Gleichrichtereinheit DTYE-64 (Problem No. 7 — Rectifier unit DTYE-64) … 125
- 3.14.8 — Übersicht der typischen Betriebsstörungen (Overview of typical operating faults) … 130

4 AUFLISTUNG DER BAUGRUPPEN (LISTING OF ASSEMBLIES)

4.1 — Hilfsgeräte (Auxiliary equipment):
- 4.1.1 — Differentialanalysator-Schaltheit TYP-1, Typ GS 320 105 und 186 … 133
- 4.1.2 — Steuerplatte GS, Typ GS 320 60 … 136
- 4.1.3 — Steuerplatte EK-A … 137
- 4.1.4 — Steuerplatte EK-B … 138
- 4.1.5 — Steuerplatte EK-C … 139
- 4.1.6 — Rechenverstärker EL-S, Typ GS 320 149 … 140
- 4.1.7 — Gleichrichterschaltheit DTYE-64 … 141
- 4.1.8 — Gleichrichterschaltheit DTYE-64 (continued) … 142
4.2 — Bestandteile des Rechners (Parts of the computer):
- 4.2.1 — Recheneinheit TYP-1, Typ GS 320 100 … 143
- 4.2.2 — Steuerplatte GS 5, Typ GS 320 100 … 144
- 4.2.3 — Gleichrichtereinheit TYP-1, EL-S … 145
- 4.2.4 — Rechenverstärker-Schaltheit TYP-1, Typ GS 320 … 146
- 4.2.5 — Integratoreinheit TPP-1, Typ GS 320 149 … 147
- 4.2.6 — Sicherungseinheit TYP-1 … 148
- 4.2.7 — Gleichrichtereinheit DTYE-64 … 149
- 4.2.8 — Gleichrichtereinheit DTYE-64 (continued) … 150
- 4.2.9 — Anzeigeeinheit DTYE-64 … 151
- 4.2.10 — Kompensationseinheit TYP-1, EL-5 … 152

Page 134–135

Table of Contents (continued)

Page 71

5 SCHALTUNGSUNTERLAGEN (CIRCUIT DOCUMENTS)

5.1 — Stabilität der Steuerverstärkereinheiten-Schaltheit (Stability of control amplifier circuit units) … 153
5.2 — EL-Transistor-Steuereinheit-Schaltheit (EL transistor control unit circuit) … 153
5.3 — Gleichrichtereinheit DTYE-64, Gleichrichtereinheit-Schaltheit (Rectifier unit DTYE-64, rectifier circuit) … 153

Addresses/Administrative note

Nachdruck / Vervielfältigung: Unauthorized reprinting, reproduction, or disclosure of this document, or its use for any industrial purpose except with explicit permission, is prohibited. Copyright VEB Analogcomputer MEDA, Berlin.

Bestellnummer: (Order number) — see inside cover.

Differential Analyzer MEDA 42 TA Technical Documentation / Operator Manual VEB Analogcomputer MEDA, Berlin Edition: (date not legible)

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