Antique mil-spec user interface teardown

[mikeselectricstuff]

Look inside the control panel for a Decca navigation system - Mil-Spec porn!

[david77]

Very cool stuff as usual Mike. The mechanical construction of that thing nearly makes me slobber.
I should have a couple control light similar to the ones in your device in a box somewhere, they're off a 707's cockpit. Very satisfying things.

[quantumfall]

Thanks for that, very nice and interesting.

[SeanB]

You want mechanical perfection look at old Autopilots. Synchro and resolvers, with a whole lot of precision gearboxes thrown in as well. 100 000 parts in each, and around 1000 km of very fine wire. Beautiful when they work, but when they did throw a wobbly my ex colleagues would spend a few months fixing it up again. We had a big box of old modules that we used to raid for replacement parts, and there were common maths modules, like  a sine/cosine converter, adders, multiplier and subtractors. Even one that did logs. All ran off 115VAC 400Hz, with an internally generated 26VAC reference that was used for the IO parts. 

Modern electronics just made the box have 3 redundant portions, but the box stays the same size, as most of the real world inputs still use the same reliable sensors. No silicon sensor survives on an engine, all magnetics and coils there. They operate in a tough regime, where the pins on a connector wear through from vibration of the pin in the socket. Wire locking a socket to the plug is standard so it will not disconnect in use.