I don't think there are mechanical parts involved in JBC's stand detection. They just put a pull-up on the silver metal part where you put your iron into. The iron then shorts that to ground with it's metal shell.
Correct, only electrical contact.
And the source of my gripe with them not shutting off right, once either or both sides get dirty/oxidized. Yes, you can clean it, but at work I have enough stuff to do besides perform PM on my soldering station. Though I suppose someone will tell me to just put deoxit-gold on it when I'm doing the quartly application to scope BNC's also
I think the best design for a 'sleep mode' is the Metcal system. I don't have one, but the use of a magnet to lower the curie point is pretty darned simple (by which I mean the implementation) and effective. Of course I believe the actual shut off time can be programmed into the base, which is not quite as flexible as the motion based system, which in itself seems pretty cool.
Close! The output is a constant RMS current RF, the tip of the iron has a lossy inductor in it, when the iron tip is at the curie point or above, or enough external magnetic field is applied, the inductor saturates, the voltage/power going to the tip drops. I agree, its an awesomely simple and clever method. Though the accelerometer based system sounds very nice too.