This SCR circuit can operate on frequencies from 1 to 20 kHz. We found it in an American documentation from the 60's. The SCR must be according to the load. No information is given about the transformer.
This circuit was found in old American documentation. Transistor is general purpose and relay is...
This simple alarm with latching uses a relay as the main element. The circuit is from a Radio...
This circuit is from an Italian publication called Fare Elettronica from 1987. What we have is an...