This is a circuit for receiving signals from the previous transmitter. The circuit uses a common phototransistor. It was found in the August 1984 issue of Radio Electronics magazine.
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...
This electronic roulette circuit with 10 numbers was found in a Popular Electronics from the 80s....
Based on a CA3059 zero-cross switch, this circuit was found in the July 1995 Electronics Now...