This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern equivalent transistors like the BC557 for TR1 and BC547 for the others.
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...