With the indicated components, this circuit oscillates at 1232 Hz. Consider the tolerance of the components. The circuit is from a 1974 Ferranti transistor manual.
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...