This circuit was found in Ferranti's 1967 documentation. The circuit drives a 40 V relay, but it can be adapted to operate with sensitive lower voltage relays.
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...