car:s body touch alarm
You could build a switched, isolated power supply for the circuit.
But I have my doubts that the circuit would work anyway as I am not clear on
its principle. Either it could be utilising the mains hum, which is picked up by our
bodies, but then it would only work in the presence of mains wiring.
Or it could use a charge transfer from the body to the touch plate - in which case
I believe the body of a car would be too big of a "plate", distributing the charge
over a large area. The example calls for a door knob as the touch plate,
which presumably gives a better effect.
So, back to the drawing board... :wink: