This sensitive three-transistor circuit was found in Electronics Now magazine and is earphone-readable. The tuned range depends on the coil.
We found this circuit in the March 1992 issue of Radio Electronics magazine. The circuit has a...
This super metal detector uses three coils, operating in differential form with two transmitter and...
The circuit in the figure uses two of the 4001's four gates to trigger a relay in a timed manner. The...