System and method for controlling LED segments to provide lighting effects
A single board light engine includes an AC to AC step driver that selectively powers multiple LED segments by controlling tap points between the LED segments as the input voltage goes from zero crossover to maximum voltage and returns to zero crossover. The step driver may power a first LED segment, a second LED segment, both the first and second LED segments, or none of the LED segments depending upon the input voltage level. The LEDs within an LED segment may share a characteristic that differs from a characteristic shared by LEDs in another segment, which allows the LED fixture to provide a variety of lighting effects.
1. A multiple board light engine comprising a first single board light engine and a second single board light engine:
wherein each of the first and second single board light engines comprises:
a rectifier for generating a rectified line voltage;
an LED step driver having an input connected to the rectified line voltage;
a first LED segment comprising a first plurality of LEDs, wherein the first LED segment has a first characteristic;
a second LED segment comprising a second plurality of LEDs, wherein the second LED segment has a second characteristic, which is different than the first characteristic;
a first tap point between a last LED of the first LED segment and a first LED of the second LED segment;
a second tap point after a last LED of the second LED segment;
wherein the input to each of the LED step drivers on the first and second single board light engines is further controlled by a multi-position switch, and
wherein when the switch is in a first position, the first single board light engine receives a full cycle of the line voltage and the second single board light engine is not powered, when the switch is in a second position, the first single board light engine receives a first half cycle of the line voltage and the second single board light engine receives a second half cycle of the line voltage, and when the switch is in a third position, the second single board light engine receives a full cycle of the line voltage and the first single board light engine is not powered.
2. The multiple board light engine of claim 1 , wherein the first characteristic is a first location on the respective single board light engine and the second characteristic is a second location on the respective single board light engine, and the second LED segment at least partially surrounds the first LED segment.
3. The multiple board light engine of claim 1 , wherein the first characteristic is a first color and the second characteristic is a second color.
4. The multiple board light engine of claim 1 , wherein the first characteristic is a first color temperature and the second characteristic is a second color temperature, and the first color temperature is lower than the second color temperature.
5. The multiple board light engine of claim 1 , further comprising:
for each of the first and second single board light engines:
a first optical element that is associated with the first LED segment and provides a first light distribution, and
a second optical element that is associated with the second LED segment and provides a second light distribution;
wherein the first characteristic is the first light distribution and the second characteristic is comprised of the first light distribution combined with the second light distribution.
6. The multiple board light engine of claim 1 , wherein the first plurality of LEDs of the first LED segment includes discrete LEDs.
7. The multiple board light engine of claim 1 , wherein the first plurality of LEDs of the first LED segment includes chip-on-board (COB) LEDs.
8. The multiple board light engine of claim 1 , wherein the multiple board light engine is part of a downlight.