This circuit is from the time when slide projects were used. We find it in a 90's Wels’ Think Tank. The lead times can be adjusted from 5 to 30 seconds.
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...