Interface circuit for industrial control systems

摘要: One contact of a controlling device connects to the input terminal an industrial control system and other positive voltage source through blocking diode high-voltage resistor. A transistor collector is connected system, feedback resistor its emitter negative source. bias current supplied base saturates it. When contacts close, applied across them insures that conduction established. Current then flows resulting in action which brings out saturation. The on transistor''s rises potential