Patent ID: 8254068
Filing Date: 2012-08-28
Classification: G05F

Abstract:
1. A regulating system, comprising: an input port comprising a first input terminal and a second input terminal; an output port comprising a first output terminal and a second output terminal; and a regulating circuit comprising a metal oxide semiconductor (MOS) transistor, a first resistor, a second resistor, a third resistor, and a regulating unit, wherein the first resistor and the second resistor connects in series between the first output terminal and ground, a reference terminal of the regulating unit connects to a node between the first resistor and the second resistor, an anode of the regulating unit is grounded, a cathode of the regulating unit connects to the first input terminal via the third resistor, a gate electrode of the MOS transistor connects to the cathode of the regulating unit, a drain electrode of the MOS transistor connects to the first input terminal; an overvoltage protection circuit comprising a regulating diode, a first bipolar transistor and a second bipolar transistor, wherein a cathode of the regulating diode connects to the first output terminal, an anode of the regulating diode connects to a base of the first bipolar transistor via a fifth resistor, a collector of the first bipolar transistor connects to the first output terminal, an emitter of the first bipolar transistor is grounded, a base of the second bipolar transistor connects to the collector of the first bipolar transistor, an emitter of the second bipolar transistor is grounded, a collector of the second bipolar transistor connects to the second output terminal, when an output voltage of the first output terminal increases over a predetermined voltage, an electrical connection between the second output terminal and ground is cut off to stop providing output voltage from the output port; and an over-current protection circuit comprising a third bipolar transistor and a fourth resistor, wherein an emitter of the third bipolar transistor connects to the first output terminal, a collector of the third bipolar transistor connects to the gate electrode of the MOS transistor, a base of the third bipolar transistor connects to the source electrode of the MOS transistor and connects to the first output terminal via the fourth resistor.