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#153237 - 08/18/06 08:22 AM 1955 Computer  
electure  Offline

Joined: Dec 2000
Posts: 4,262
Fullerton, CA USA
From our new member Albert
Welcome, Albert [Linked Image]

My first submission is a 1955 advertisement for a "Power Network
Computer", from my (very small)
electrical web page.

This ad is for a specialized analog computer used to solve electrical power network problems. These computers allowed the user to create a "scale model" of a network and directly measure its response to controlled inputs. The results from this simulated network would be scaled up to determine the values expected in the actual system.

The columns of knobs in the vertical part of the console are probably used for setting the
impedances of the simulated buses.

This computer is one of the smaller models I've seen pictured. Some filled an entire room! They were also called "calculating boards".

[Linked Image]

Tools for Electricians:

#153238 - 08/18/06 09:54 AM Re: 1955 Computer  
golf junkie  Offline
Joined: Apr 2001
Posts: 507
York, NE

When I joined the US Navy in 1976 the mechanical/analog fire control computers were on their way out but the schools still had working systems around.

The computer was about the size and shape of a washing machine and made a similar noise. They were full of gear sets and potentiometers. Mechanically they were works of art.

[This message has been edited by golf junkie (edited 08-18-2006).]

#153239 - 08/19/06 12:17 AM Re: 1955 Computer  
Albert  Offline
Joined: Aug 2006
Posts: 76
Falls Church, VA
Yes, sophisticated electromechanical analog computers were the foundation of several fire-control systems which proved to be very effective in WW II. In addition to the systems you mentioned, there were the Torpedo Data Computer, the Norden bombsight, and the Electrical Gun Director.

#153240 - 08/19/06 10:24 AM Re: 1955 Computer  
Trumpy  Offline

Joined: Jul 2002
Posts: 8,223
SI,New Zealand
Welcome Albert!.
Good to have you along. [Linked Image]

#153241 - 08/19/06 11:59 PM Re: 1955 Computer  
RODALCO  Offline
Joined: Dec 2005
Posts: 854
Titirangi, Akld, New Zealand
I love that old technology, fantastic dials instead of boring lcd displays.
Wonder how many valves are inside.

Welcome aboard Albert.

The product of rotation, excitation and flux produces electricty.

#153242 - 08/20/06 10:42 AM Re: 1955 Computer  
pauluk  Offline
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Glad to see you made it over to ECN, Albert. Welcome aboard! [Linked Image]

These days when mention is made of "computer," most people automatically think of a modern digital computer, forgetting that a whole range of analog computers were used for all sorts of problem-solving in the past.

One of the British electronics journals Practical Electronics, if I recall correctly) ran a constructional project for a general-purpose analog computer in the late 1960s/very early 1970s. Of course, by that time with operational amplifiers available in the form of integrated circuits (e.g. the ubiquitous 709) it had become feasible as a home project when to have built such a thing as a hobby project a few years earlier with hundreds of triode tubes would have been out of the question.

#153243 - 08/24/06 03:49 PM Re: 1955 Computer  
Albert  Offline
Joined: Aug 2006
Posts: 76
Falls Church, VA
Regarding the number of valves/tubes in the power network computer: that's a good question! I don't know anything about what was inside the machine; whether there were any active components, or if it was all resistors, capacitors, and inductors.

Certainly some analog computers did have a lot of tubes. A Western Electric booklet notes that the Electrical Gun Director (which the company built to control Army artillery) contained more than 100 tubes. It's pretty impressive that so many tubes could perform reliably in a combat environment!

One of the specs for a power network analyzer was the number of simulated power sources, or "generators". Presumably the sources were three-phase for AC analyzers, but I don't know if they were actual rotating machines (probably motor-alternators), or if they were transformers or electronic oscillators.

#153244 - 08/24/06 04:26 PM Re: 1955 Computer  
NJwirenut  Offline
Joined: Sep 2001
Posts: 806
Bergen County, NJ
There were actually 2 models of vacuum tube analog computers sold for home/hobbyist use, by Heathkit. The low end EC-1:

And the modular, expandable H-1:

#153245 - 08/26/06 10:08 PM Re: 1955 Computer  
Albert  Offline
Joined: Aug 2006
Posts: 76
Falls Church, VA
RODALCO wrote:
I love that old technology, fantastic dials instead of boring lcd displays.
Wonder how many valves are inside.
Welcome aboard Albert.

Thanks for the welcome!

You've touched on another important topic: the sad and ongoing decline in the aesthetics of electrical and electronic equipment. And there's no better example of that decline than the LCD display, unless maybe it's the membrane keyboard!

[This message has been edited by Albert (edited 08-26-2006).]

#153246 - 08/27/06 12:17 AM Re: 1955 Computer  
trobb  Offline
Joined: Jun 2006
Posts: 110
Iowa City, IA
Yeah, I'm only 21, and I can remember when I could rely on my CRT to keep me warm in my poorly-heated room. Not so with my LCD. Now I shiver... but have more desk space.

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