We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
This is a very simple motor drive circuit with an LDR. The circuit simply powers a small motor. We...
This plug-in control was found in General Electric documentation from the 1970s. The SCR can be...
This circuit from an old 1978 publication uses germanium transistors but can be implemented with...