This circuit has the function of automating some type of equipment when a powerful transmitter is activated nearby. The circuit was found in a 1967 documentation.
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...