This circuit of dozens of watts uses germanium transistors and the critical components are transformers. The circuit is from the 1960 Mullard transistor application manual.
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
When the sensor receives light, the relay closes its contacts and remains so even after the light...
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...