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".
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.
Glad to see you made it over to ECN, Albert. Welcome aboard!
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.
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.
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).]