This circuit that can be activated by light or heat was found in an old American documentation, but the components it uses are perfectly current. The power transistor shall be fitted with a heat sink.
This circuit was found in a 1967 EEE. The components are from that time, but the circuit can be...
This is another one of the crystal oscillator configurations with the 4001. Many of them are on...
Using a 106 series SCR, this circuit was found in the May 1971 Radio Electronics magazine. The...