This circuit was found in the July 1992 Radio Electronics magazine. Sensitivity adjustment is made at R6. Supply voltage is matched to that of the relay.
This experimental short-range transmitter came out in a 1972 publication and was designed to...
The search coil of this detector consists of 140 turns of wire 18 in an 8 inch diameter form. The...
We find this power oscillator circuit in a 90's Popular Electronics. The circuit can be powered by...