Found in a 1969 British publication, this circuit uses a regenerative switch with two transistors to produce pulses that depend on C1. The relay must be in accordance with the supply voltage.
This circuit was found in the December 1977 issue of Radio Electronics magazine. The circuit uses...
This is an improved version of the previous circuit that includes speed control. The engine can be...
This electronic siren circuit, found in a 1982 documentation, uses three oscillators mounted...