This is a circuit that allows remote activation of a power supply. The circuit was used with a timer of the time. It appeared in the November 1973 issue of Radio Electronics magazine.
In fact, we can say that this circuit found in documentation from the 90s, consists of an intercom...
The basic integrated circuits of this 1988 multimeter are no longer very common today, but if...
This circuit is from an old publication of the 70's. It can be implemented with modern transistors like the...