This high-power shield is isolated from the control. The circuit was found in the June 1995 Electronics Now magazine. The Triac must be equipped with a heat sink.
This circuit is from a Modern Electronics from April 1990. The circuit can be assembled with BC558...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...
This photo-relay uses a Darlington stage to increase sensivity. Any photo-transistor can be used....