Power supply having a plurality of light emission units

摘要

A power supply is provided. The power supply includes a plurality of light emission units, a power source, a plurality of boards, a plurality of board resistors, and a feedback control unit. The light emission units are connected in parallel, and include a plurality of LEDs. The power source supplies a DC voltage to the light emission units. The boards have at least one light emission mounted thereon. The board resistors are disposed in each of the boards, and electrically connected to each other. The feedback control unit varies a current supplied from the power source, according to sum of the board resistors which are changed according to the number of connected boards.

主权项

1. A power supply comprising:
a plurality of light emission units connected in parallel, and comprising a plurality of Light Emitting Diodes (LEDs); a power source supplying a Direct Current (DC) voltage to the light emission units; a plurality of boards having at least one light emission mounted thereon; a plurality of board resistors disposed in each of the boards, and electrically connected to each other; and a feedback control unit varying a current supplied from the power source, according to sum of the board resistors which are changed according to the number of connected boards, wherein the feedback control unit comprises:
a resistor connected to a reference voltage;a reference potential unit outputting a voltage-divided value which is obtained through voltage division by the resistor and the board resistor; anda comparator comparing an output of the reference potential unit and a value of an output terminal in each of the light emission units to output a signal to the power source according to the compared result, thereby controlling an output current of the power source.