Found in American documentation this circuit uses transistors of the time. The circuit can be made with current components. It works as a trigger working with 600 ohm signals.
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...