This circuit for a 6.3 V lamp was found in a 1970’s RCA documentation. The circuit applies to any triac and the LDR can be of any type.
Here we show how two 4017s can be cascaded to count above 10. The circuits are driven by a square...
The circuit in the figure represents a typical application of a phototransistor exciting a relay...
This circuit, in fact, what it does is a reactivation of the batteries through a brief pulsating...