Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using common LDRs as sensors. Transistors can be modern PNP equivalents.
This circuit is from an Electronics World of 1964. The circuit can be made with modern...
We find this circuit in a Radio Electronics of July 1984. It consists of the traditional version of 1 A...
This circuit was found in the June 1990 issue of Radio Electronics magazine. The maximum current is 1...