This flip-flop controlled by an LDR-type photocell was found in Radio Electroinics magazine from June 1959. Note that it can be powered from the mains and directly controls a sensitive relay.
This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a...
This transistor source can supply currents up to 2 A and the voltage determined by the zener...
The circuit in the figure checks the continuity of components, making it ideal for students and...