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.
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....
For signals up to about 500 kHz modulated in amplitude and transmitted by the power network, the...
This circuit was found in the March 1984 issue of Radio Electronics magazine. The sensor is a...