We found this circuit in an old documentation. Its purpose is to turn on warning lights when the vehicle in a garage touches or passes a sensing bar preventing it from hitting the wall.
The 556 integrated circuit is actually a double 555. This circuit can be assembled from an...
The transducer used in this configuration that appears elsewhere on this site is a piezoelectric...
This modern XTAL radio replaces the galena crystal for a germanium diode as the 1N34 or...