We found this circuit in the May 1996 Electronics Now magazine. The relay must have a voltage according to the circuit power supply and a trigger current of no more than 50 mA.
The search coil of this detector consists of 140 turns of wire 18 in an 8 inch diameter form. The...
This circuit was found in a 1989 documentation and was intended to be part of a presence...
In the figure we show a configuration for a crystal controlled overtone oscillator using a...