This circuit is from a 1967 RCA publication. The components are of the time, admitting equivalents, including the SCR that determines the maximum power of the load.
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
With this circuit the visually impaired can easily locate important places inside the house, such...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...