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 circuit presented is an interface or shield for capacitance measurement as a PC. We found it...
This circuit for voltages up to about 20 V was found in a 90s Popular Electronics. The LED can be...
This circuit is from a 1966 General Electric documentation. The circuit applies to sensitive SCRs for...