Found in an American brochure from the 90s, this circuit shows how we can implement a 4-input AND gate with relays and switches.
The presented circuit produces the sound of a fireman's siren. In place of the output transformer with...
This circuit, which appears at other times on this site has this version obtained in a Hands On of...
This circuit was obtained from a Linear Technology manual from the 1990s. The sensor is of the...