Based on the CA3161 and CA3162, this circuit was found in the July 1990 Radio Electronics magazine. The circuit is two digits only.
Suggested by Raytheon in 1967 documentation this circuit uses a lightbulb and LDR optical coupler of the...
Found in American documentation from the 90's, this circuit consists of a solid state relay with...
Indicated to be used at the sensor input of a PC, this circuit was found in an English...