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.
We found this circuit in an old neon lamp application manual. The circuit stores a call. The...
Poptronics recommends this circuit for use in the car when the headlights are left on. The circuit...
We found this circuit in a 1981 publication, when it was still possible to find 22.5 V batteries (used...