This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be changed. The load depends on the relay. The circuit is old, from 1988 documentation, but totally viable today.
This circuit was found in a 1966 American publication. The critical component is the tunnel diode. ...
Found a documentation on PCs from 1996, this circuit can be used as a shield. The relay is rated at...
January 2017 - Mouser Electronics already has the new PMO Sonalert microphone elements from...