This Vox or sound activated relay was found in an American documentation from 1975. Equivalent transistors can be used, and the SCR can be a TIC106. The relay is according to the supply voltage.
This project is of great use as it serves both to feed test equipment as well as to the component...
This conventional slow-moving circuit uses incandescent light bulbs, but can be changed to use...
This circuit generates sawtooth signals whose frequencies depend on the values of the selected...