This circuit can be used as an answering password system in a store, office, or other location. The circuit is from Intersil using components of the time. The circuit is from the 80's.
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...