Found in a 1980s amateur radio QST magazine, this is the conventional circuit of a medium-wave radio. Coils and transformers are commercial types.
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...