This circuit is from a Radio Electronics magazine from July 1979. It uses the well-known IC 7107, a liquid crystal exciter that became popular in circuits of this type at the time.
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...
We find this circuit in an American 80's documentation. No further information about the...
With this circuit, an external circuit can be controlled by turning it on or off and reversing it (if...