This circuit was found in a Radio Electronics from 1970. The coupler with LDR is from that time, but the circuit can be adapted to use modern components and act as a shield.
The presented circuit was found in a 90’s Electronic Engineering. The circuit is based on CMOS...
We find the original version of this circuit in an English publication (1986). It is a...
Found in a 1990s Electronics Now, this circuit uses a period-specific integrated circuit that...