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.
We found this circuit with duty cycle adjustment in the May 1988 Radio Electronics magazine. The...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...
Suggested by Motorola in a 1980s publication, this circuit is insensitive to changes in bias...