This circuit has a normally low output that is triggered by a high pulse. The circuit is from Radio Electronics from November 1984. The frequency is given by C1.
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...