This circuit was obtained from Dutch documentation from 1967. It uses transistors of the time which can be the BFY50 and 51 for the output and the BC series for the others.
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...