Color temperature controlled and low THD LED lighting devices and systems and methods of driving the same

摘要

The purposes of the devices described herein are to provide an LED lighting device capable of efficiently and economically emitting light having a selectable color temperature or a warm-on-dim feature when driven with AC power and to provide LED lighting devices which have an improved power factor and a reduced total harmonic distortion when powered with AC power.

主权项

1. An LED lighting device comprising:
at least one LED circuit having at least two LEDs connected in series; a first active current limiting device connected in parallel with at least one LED in the at least one LED circuit to bypass the at least one LED connected in parallel with the first active current limiting device until a voltage threshold is reached, the first active current limiting device setting an upper limit on the amount of current flowing through any LEDs in the LED circuit the first active current limiting device is not connected in parallel with.