This 25 W phase photo control was found in a 1965 General Electric publication. The circuit uses a LASCR which is an unusual SCR photo today.
Originally this piezoelectric microphone preamp was designed to be built-in, but given the use of a...
This is the traditional configuration of Baxandall bass and treble control, using passive...
We found this circuit in an American publication from the 1990s. The triac must be equipped with a heat...