This Intersil circuit was found in a 1980s documentation. Operational are of the time, but current equivalents can be experienced. The graph with the circuit performance is given next to the diagram.
In this circuit the relay triggers on when light falls onto the sensor, a common LDR. Power supply...
This circuit has more sensitivity than the previous one (CB4114E) for using a full-wave detector...
This integrated amplifier was found in a non-existent British magazine from 1975. The used...