Ah yes, .. chip detectors. I believe that Hueys had 4 of them. In peace-time, they having the luxury of jerking out the possibly bad component and sending it away to depot level maintenance, to get scrutinized. I don't recall if they (depot) would report back to the flying unit, about what they found, on that suspicious part, or not? I should add, .. a drain & flush of the oil, most likely happened then too, and an oil sample would be done, right away .. so maybe removing & replacing wasn't always done? I was a part timer, .. not really in the loop, about these kinds of things.All of the Military Helicopters I worked on had them also, yes some false alarms but prevented a lot of crashes, lost equipment & lives.
A magnet, led and a photosensor are all the basic parts. Im sure you can get 12v parts and not even need a regulator.Don,
Sounds like they must be pretty simple gadgets. If we are expected to build one, we would need to know how it works, what critical dimensions or detail characteristics it is to have, etc. Please tell the us (or the OP) the important details or point us to documents that have them.