Found in an 80's Electronic Design, this circuit is based on the ICL7107 which is not an easy component to obtain today. The circuit is compatible with TTL and CMOS.
This old receiver (1967) uses germanium transistors from the time and coupling transformers,...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
A negative pulse applied to the input of the circuit shown in figure bellow turns on the relay....