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 components of this circuit are exchanged for modern equivalent such as 470 K for the pot and...
This watt meter was found in an old telecommunications documentation. The circuit is interspersed...
This sensitive receiver with earphone was found in an English documentation from 1963. The...