This circuit was found in an article in Radio Electronics magazine. The issue is from July 1992 and the circuit uses components that are common today.
This triac circuit turns on a load after a time of 8 to 80 seconds adjusted by potentiometer R7....
This circuit generates a pulsed tone whose frequency depends on C2 and whose flashing depends on...
This high input impedance circuit uses a symmetrical source. Found in the October 1993 issue of...