LIGHT EMITTING SYSTEM AND VOLTAGE CONVERSION DEVICE THEREOF

摘要

A light emitting system includes a series connection of a light emitting unit and a variable current source, and a voltage conversion device that includes a rectifier circuit and an output circuit. The rectifier circuit rectifies an AC voltage to generate a rectified voltage across a first rectifier output coupled to one end of the series connection of the light emitting unit and the variable current source, and a second rectifier output. The output circuit is coupled between the second rectifier output and another end of the series connection of the light emitting unit and the variable current source, and is configured to generate a direct-current (DC) output voltage.

主权项

1. A light emitting system comprising:
a series connection of a light emitting unit and a variable current source, said variable current source being disposed to receive an adjustment signal and generating a driving current to drive said light emitting unit according to the adjustment signal; and a voltage conversion device including:
a rectifier circuit disposed to receive an alternating-current (AC) voltage, and having a first rectifier output coupled to one end of the series connection of said light emitting unit and said variable current source, and a second rectifier output, said rectifier circuit being configured to rectify the AC voltage for generating a rectified voltage across said first rectifier output and said second rectifier output; andan output circuit coupled between said second rectifier output and another end of the series connection of said light emitting unit and said variable current source, having an input disposed to receive an input voltage associated with a difference between the rectified voltage and a voltage across the series connection of said light emitting unit and said variable current source, and configured to generate a direct-current (DC) output voltage according to the input voltage.