US Patent 10334676 LED luminaire with constant current per-module control

A lighting device includes multiple light emitting diode (LED) channels. Each LED channel is connected in parallel to an output rail of a power converter. The power converter may be a buck regulator. Each LED channel may include an LED string of one or more LEDs, a first transistor that is electrically connected between the LED string and ground, a second transistor that is electrically connected between the first transistor and ground, and a current sensing resistor that is electrically connected between the first transistor and the second transistor. This design provides for self-regulation of current across all LED channels when another LED channel is added to or deleted from the lighting device.