This old circuit is suitable for signaling applications. The lamp must be incandescent, and the triac must be mounted on a heat sink. The frequency is adjusted in the 1 M trimpot.
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
Lockout shooting, due to the incidence of light, can be achieved with the circuit in the figure. In...
This circuit can function either as a crystal or galena receiver with a pre-amplifier using a FET...