Suggested by Raytheon in 1967 documentation this circuit uses a lightbulb and LDR optical coupler of the time. The transistor determines the maximum current.
This circuit can gerenate square signals and be comanded by na external control. When the input...
This circuit is from an American 1967 documentation and can be implemented with modern equivalent...
This circuit was found in 1968 General Electric documentation. The circuit uses components from the era...