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Ken Shirriff

We powered up the block that converts a temperature reading to a gear rotation but nothing happened. So I'm reverse-engineering the circuitry to figure out what's gone wrong. Maybe an old capacitor since some of the old capacitors have fungus or corrosion or something.

5 comments
Ken Shirriff

The servo loops use magnetic amplifiers. Mag amps look like transformers, but they are inductors that can be saturated to pass current. I wrote an article on mag amps in the IEEE Spectrum a while ago: spectrum.ieee.org/the-vacuum-t

Ken Shirriff

Keep watching as CuriousMarc, @tubetime, and I try to get the CADC working, but it will be a long process.

Elias MÃ¥rtenson

@kenshirriff @tubetime I'm always so surprised at how accurate these analogue devices can be.

I know I shouldn't be, but as someone who grew up at the beginnings of the calculator era when analogue computing was already underway being replaced by digital counterparts, it always feels like a miracle that these devices don't immediately accumulate so much error so as to become useless a few minutes into a flight.

Atkelar

@kenshirriff eeew. The caps remind me of the ones in the scope that is currently on my bench. Very similar look indeed. Water damage in my case. Currently rebuilding all the circuit, cause that white stuff was also all over the wiring. Would live to hear what it actually is...

rogerggbr

@kenshirriff those caps do not look good! Looking forward to the diagnosis and video in due course.

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