Power supply for light emitting diodes (LEDs)

摘要

A power supply is provided. The power supply includes at least one light emission unit, a power source, an openness detection circuit, and a feedback control unit. The at least one light emission unit includes a plurality of serially connected LEDs. The power source supplies a DC voltage to the light emission unit. The openness detection circuit varies a reference potential with a voltage which is detected from both ends of at least one of the LEDs in the light emission unit. The feedback control unit regulates an output current of the power source according to the reference potential of the openness detection circuit.

主权项

1. A power supply comprising:
at least one light emission unit comprising a plurality of serially connected Light Emitting Diodes (LEDs); a power source supplying a Direct Current (DC) voltage to the light emission unit; an openness detection circuit varying a reference potential with a voltage which is detected from both ends of at least one of the LEDs in the light emission unit; and a feedback control unit regulating an output current of the power source according to the reference potential of the openness detection circuit, wherein the openness detection circuit comprises:
a voltage detector connected to both ends of the at least one LED;a reference voltage regulator outputting a reference voltage;a voltage comparator outputting at least one of outputs of the reference voltage regulator and voltage detector according to the voltage detected by the voltage detector;a switch turning on or off according to the output of the voltage comparator; anda load detector outputting different reference potentials to the feedback control unit according to an operating state of the switch.