This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The circuit uses CMOS components, and the relay must be a sensitive type.
This circuit, suggested by Texas Instruments, is based on the integrated TL497A, designed for...
In the figure we have the way to implement a sinusoidal oscillator with the 4093 IC. The component...
This circuit was found in an old American documentation. It can operate with signals from 40 Hz to...