Transistor switching circuit is used to protect the communication port of a microprocessor against load faults

摘要

The port switching circuit has transistors [T1-T3]. Resistors [R1-R8] and a diode [D1] coupled to a load resistor [RL]. The microprocessor activates the port [P] and if a short circuit on the load occurs one transistor [T3] responds to switch off the output [A]. A capacitor [C2] provides protection against transient peaks.