English translation
EAI Report — Newsletter of EAI Electronic Associates GmbH, Issue No. 001, July 1965
This is an English translation of the original German document (EAI-Report Nr. 001, Juli 1965), published by EAI Electronic Associates GmbH, Aachen.
General Information Bulletin
EAI Electronic Associates GmbH, 51 Aachen, Martinstrasse 14 July 1965 — No. 001
Dear Sirs,
At the suggestion of many of our business associates, we have decided to consolidate the notifications (“circulars”) previously sent to you regarding “What’s New at EAI” into a simple information sheet and to publish it under the designation “EAI-REPORT.”
We take the liberty of presenting the first issue of this “EAI-REPORT” herewith.
The aim of the “EAI-REPORT” is to provide timely information on organizational, equipment-technical, and application-technical EAI matters. Furthermore, the “EAI-REPORT” is intended to serve as an information-exchange medium among EAI customers. Informational communications, especially in the field of EAI equipment applications submitted by EAI customers, will be gladly published without obligation in our “EAI-REPORT.”
We permit ourselves to send the “EAI-REPORT” to you regularly and free of charge. Colleagues and employees will, of course, be added to our “customer list” upon appropriate notification.
Suggestions regarding the content and design of the “EAI-REPORT” are welcome at any time.
With kind regards, Your EAI Electronic Associates GmbH
General Announcements
[1] EAI Electronic Associates GmbH, Aachen, assumes as of 1 July 1965 the exclusive representation in the Federal Republic of Germany and West Berlin for Electronic Associates Inc., USA, and Electronic Associates Ltd., England. As a result, the representation of this product line is withdrawn from the programs of the firms Präzisionstechnik GmbH and Rohde & Schwarz GmbH, Cologne. Sales, applications, and customer-service activities for EAI and EAL products will henceforth be carried out solely by EAI GmbH, Aachen.
[2] The next EAI GmbH analog computer course will take place from 20 to 24 September 1965 in Aachen. Participation fee: DM 150.–/person. EAI customers are admitted free of charge. A few participant places are still available for this course.
[3] At INTERKAMA ‘65 (13 October to 19 October 1965) in Düsseldorf, EAI will be represented with two facing stands, No. 6264 and No. 6161, on the first floor of Hall F2.
Individual Mode Control for Integrating Networks of the TR-10
Background
The operating modes “Reset” (initial conditions), “Hold” (hold), and “Operate” (compute) are normally controlled simultaneously for all integrators from a central switch. Control voltages switch the corresponding relays in all integrating networks.
In many applications, particularly in automatically operating iterative procedures, individual control of the operating modes of individual integrators is essential. This capability is provided in the integrating networks of the analog computers TR-48 and TR-20. The aforementioned control voltages are brought out to the patch panel and reach the relay coils of the integrating networks — whose terminals are likewise accessible at the patch panel — either directly or through switching logic. Three control voltages are decisive: for “Reset,” for “Operate” (the absence of both gives the “Hold” position), and for “Time-Scale.” The latter causes, in fast-repetitive operation, an automatically smaller time constant of the integrators.
Modification Procedure for the TR-10
All integrating networks of the TR-10 with repetitive operation can be brought up to the latest standard by a small modification. Only the plastic patch panel of network L2.425 is exchanged for a patch panel of the TR-20 integrator L2.1115, and the following connections are made (see TR-10 Maintenance Manual, sheet B 012 425 OS, Schematic Integrator Netw.):
- Contact R (Reset) of the rear connector P1 is routed via terminals 16 and 8 of the patch panel.
- Contact K (Operate) via terminals 15 and 7.
- Contact E (Time-Scale) via terminals 14 and 6.
To accomplish this, one simply removes the soldered bridges on the underside of the printed circuit for contacts R and K, and cuts the corresponding printed connection for contact E. Furthermore, the following terminals on the patch panels correspond to each other:
| Type L2.425 | Type L2.1115 | Connection point on card |
|---|---|---|
| IC | IC | 1 or 5 |
| O | O | 2 or 6 |
| IN | SJ | 3 or 7 |
| S | B | 4 or 8 |
The price of a plastic patch panel is DM 35.–. Of course, EAI can also perform this modification at cost price (material and labor).
The next issue of the “EAI-REPORT” will describe fundamental applications of individual mode control.
TR-48 — “Everything New Except the Name”
For more than three years, the fully transistorized TR-48/58 has been EAI’s largest desktop analog computer. This equipment has, however, undergone so many improvements in the meantime that essentially only the name and the fundamental design remain. These improvements have primarily:
- Expanded the equipment’s range of application.
- Increased operating speed.
The principal innovations are described below:
a) Display unit for repetitive operation: For output of computation results in repetitive operation, a display unit, Type 34.034, can be installed. It allows the display of up to 4 signals as a function of time or any arbitrary variable.
b) Digital voltmeters: The TR-48/58 is now optionally equipped with the 3½-digit digital voltmeter, Type 26.138, or the 4½-digit digital voltmeter, Type 26.258. The Type 26.258 has a resolution of 0.01% and normally allows 50 measurements/sec. For special purposes the measurement rate can be externally triggered and increased to 1,000 measurements/sec. Furthermore, results are available at an output connector in BCD form — e.g., for connection of a digital printer or for direct processing in a digital computer.
c) 58 computing amplifiers: Through a mixed complement of 2-channel and 4-channel amplifier plug-in units (Type 6.7044, same dimensions as the 2-channel unit), the fully expanded computer now has 58 computing amplifiers. The new 2-channel amplifier plug-in, Type 6.614, is distinguished from the previous Type 6.514 by substantially improved dynamic characteristics (rise time from 0 to 10 V at 10 kΩ feedback: 1.6 µsec versus 40 µsec).
d) Improved multiplier: The previous costly high-accuracy multiplier, Type 7.096, is replaced by the multiplier Type 7.117, which at equal accuracy (±0.05%) and improved dynamic characteristics is significantly less expensive. The medium-accuracy multiplier, Type 8.099, remains available.
e) Variable-breakpoint function generators: In addition to the variable diode function generators with fixed breakpoints, there are now also function generators with freely selectable breakpoints. The latter allow setting of nearly arbitrarily complex analytical or non-analytical function curves via ten or twenty contiguous linear segments. Furthermore, a modification has extended the programming possibilities of the sine/cosine diode function generator.
f) Delay-time and reactor-kinetics networks: For the component groups — previously available only in the TR-20 program — for the simulation of transport delays and for reactor-kinetics networks, there are now corresponding TR-48/58 units. In the transport-delay simulation, signal waveforms are sampled point-by-point, stored, and reproduced after an adjustable dead time. The reactor-kinetics networks simulate neutron emission in the decay process of U-235 using a passive network in the feedback loop of an amplifier.
g) Comparators and Digital Extension System DES 30: The fully electronic comparators, Type 40.488, have switching times of at most [value not legible in original]; they are therefore especially suited for fast-repetitive computing operation. They each consist of one analog-to-digital switch and two digital-to-analog switches, and can thus also be regarded as coupling elements between the analog computer and digital control equipment.
One such digital control device is the “Digital Extension System DES 30,” EAI’s newest equipment. It contains up to 32 flip-flops, 40 “And” gates, 4 monostable circuits, 8 4-bit registers, 16 relay control units, and corresponding control and monitoring facilities. Internal or external clock [generator]. A more detailed report on the DES-30 will be published shortly in the same venue.
EAI Electronic Associates GmbH — 51 Aachen, Martinstrasse 14 — Tel. 260-112