Light emitting diode driving device

摘要

A LED driving device comprises a rectification circuit, a holding current circuit and a driving circuit to drive and linearly regulates an illumination brightness of at least one LED by utilizing level variation of current magnitude. The rectification circuit rectifies and outputs a rectified voltage to the holding current circuit and the driving circuit by filtering impulses via a filter after receiving an alternating current voltage. The driving circuit outputs a driving current filtered by a filter capacitor to the LED, and the driving current is sensed by a sensing resistor to allow the holding current circuit outputting a holding current to the rectification circuit such that the whole circuit power can be improved to reduce problems of noise interference and twinkling.

主权项

1. A LED driving device disposed to a LED lamp board to drive and linearly regulate an illumination brightness of at least one LED, the LED driving device comprising:
a rectification circuit electrically connected to an alternating current power and disposed with a filter and a rectifier, a rectified voltage capable of being converted into variable constant current being outputted by the rectifier after the filter filtering impulses by receiving an alternating current voltage; a holding current circuit coupled to the rectification circuit and disposed with a current switch, the holding current circuit receiving the rectified voltage to output a holding current to the rectification circuit while conducting the current switch; and a driving circuit coupled to the holding current circuit and the LED, the driving circuit disposed with a filter capacitor, a transistor, a control chip, and a sensing resistor, the filter capacitor receiving and filtering the rectified voltage to form a driving current, the driving current outputted to the LED, the sensing resistor sensing the driving current to form a control signal to conduct or discontinue the current switch, wherein, an end of the LED is directly cascaded to a drain of the transistor, and then coupled to an input pin of the control chip after cascading the sensing resistor through a source of the transistor.