This circuit was found in a 73 magazine for radio amateurs from the 90s. The circuit uses high voltage transistors and the relay is high voltage as well.
This power supply can supply symmetrical voltages of 5, 6, 9 and 12 V according to the xx of the...
We found this circuit with SCRs and unijunction in a Radio Electronics magazine from June 1969. The...
This timer triggers high-powered loads powered by the power grid. Times are given by C1 and the...