Regulating system having overvoltage protection circuit and current protection circuit

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, an over-current protection circuit, and an overvoltage protection circuit connected in series between the input port and the output port, the 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, 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.