This TV remote control receiver uses a ratchet system to activate an old drum-type selector to change channels. A common system at the time. The circuit is from a Radio Electronics from February 1961.
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...