Light emitting diode light structures
A Light Emitting Diode (LED) light includes a bridge rectifier configured to be powered by an alternating current power source and to produce a rectified output. Control circuitry couples to the bridge rectifier and is configured to produce a shunt signal when the rectified output is less than a threshold voltage. A series connected Light Emitting Diode (LED) string includes a first group of LEDs and a second group of LEDs. A switch couples to a first side of the second group of LEDs and is controlled by the shunt signal to deactivate the second group of LEDs. The control circuitry may include a ratio metric series resistor string configured to sense a proportion of the rectified output and an inverter configured to generate the shunt signal based on the proportion of the rectified output.
1. A Light Emitting Diode (LED) light comprising:
a bridge rectifier configured to be powered by an alternating current power source and to produce a rectified output;
control circuitry coupled to the bridge rectifier, the control circuitry configured to produce a plurality of shunt signals based upon a voltage of the rectified output;
a series connected Light Emitting Diode (LED) string coupled directly to the bridge rectifier, the series connected LED string having a primary group of LEDs and a plurality of secondary group of LEDs; and
a switch coupled to the plurality of secondary group of LEDs and controlled by the shunt signal to selectively deactivate the plurality of secondary group of LEDs.