This circuit was obtained from the April 1978 Radio Electronics magazine. The other circuit is a PLL of the time. The power supply must be 15 V symmetrical.
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...