Abstract: An analog-based dimmable LED lighting system includes a plurality of LED lighting modules, which emit light at different correlated color temperature (CCT) ranges. Each of the LED lighting modules is powered by a common dimming signal in the form of an AC voltage which corresponds to a dimming level in a dimming region. Each of the LED lighting modules includes an LED, an analog rectifier bridge to convert the AC voltage of the common dimming signal to a DC voltage, and an analog current limiter connected between the rectifier and the LED to control current through the LED according to the common dimming signal. The LED(s) in the different lighting modules are controlled, via respective analog current limiter, to produce a resultant light at a selected CCT and light intensity according to the common dimming signal.

Abstract: Electronic circuitry for color-mixing in an LED light fixture during AC power dimming is disclosed to achieve adjustable color temperature. According to one embodiment, a dimmable LED light fixture has first, second, and third LED light sources, the first and second LED light sources producing white light, the third LED light source producing colored light, the LED driver configured to power the LED light sources by providing a single-channel variable-DC current source having two output terminals, and a current regulator for maintaining the current in the third LED light source path substantially constant as the LED driver output current is decreased when the AC power is reduced by the dimmer module, thereby altering the color of the light produced by the combination of the LED light sources.

Abstract: An analog-based dimmable LED lighting system includes a plurality of LED lighting modules, which emit light at different correlated color temperature (CCT) ranges. Each of the LED lighting modules is powered by a common dimming signal in the form of an AC voltage which corresponds to a dimming level in a dimming region. Each of the LED lighting modules includes an LED, an analog rectifier bridge to convert the AC voltage of the common dimming signal to a DC voltage, and an analog current limiter connected between the rectifier and the LED to control current through the LED according to the common dimming signal. The LED(s) in the different lighting modules are controlled, via respective analog current limiter, to produce a resultant light at a selected CCT and light intensity according to the common dimming signal.

Abstract: Electronic circuitry for color-mixing in an LED light fixture during AC power dimming is disclosed to achieve adjustable color temperature. According to one embodiment, a dimmable LED light fixture has first, second, and third LED light sources, the first and second LED light sources producing white light, the third LED light source producing colored light, the LED driver configured to power the LED light sources by providing a single-channel variable-DC current source having two output terminals, and a current regulator for maintaining the current in the third LED light source path substantially constant as the LED driver output current is decreased when the AC power is reduced by the dimmer module, thereby altering the color of the light produced by the combination of the LED light sources.