VOLTAGE REGULATOR, UNDER-VOLTAGE PROTECTION CIRCUIT THEREOF AND VOLTAGE REGULATION SYSTEM

摘要

A voltage regulator coupled between a batteryless alternator and a ground includes an under-voltage detection circuit and an exciting current regulating unit. The under-voltage protection circuit includes a voltage detection unit, a plurality of switching circuits, and a power switch. The voltage detection unit generates a first control signal according to an output voltage of the batteryless alternator. The switching circuits are connected in series and controlled by the first control signal. The power switch is coupled to one of the switching circuits and a rotor coil of the batteryless alternator. The exciting current regulating unit controls the operation of the power switch according to the output voltage of the batteryless alternator. The voltage detection unit detects whether the output voltage is lower than a threshold and selectively cuts off the power switch by sequentially controlling the operations of the switching circuits according to the detection result.

主权项

1. A voltage regulator, configured for regulating the electrical power generated by a rotor coil of a batteryless alternator, comprising:
an under-voltage protection circuit coupled between the batteryless alternator and a ground, the under-voltage protection circuit comprising:
a voltage detection unit coupled to the batteryless alternator, operative to generate a first control signal according to an output voltage of the batteryless alternator;a plurality of switching circuits respectively coupled between the rotor coil of the batteryless alternator and the ground, the switching circuits being controlled by the first control signal; anda power switch, respectively coupled to one of the switching circuits and the rotor coil of the batteryless alternator; and an exciting current regulating unit coupled to the power switch, operatively controlling the operation of the power switch according to the output voltage to regulate the current flow through the rotor coil;wherein the voltage detection unit detects whether the output voltage is lower than a threshold, and the voltage detection unit outputs the first control signal according to the detection result to sequentially control the operations of the switching circuits so as to selectively cut off the power switch.