Patent ID: 8461776

Claim:
A lighting system, comprising: at least three strings of solid state lighting devices that are respectively configured to emit at least a first light, a second light and a third light, respectively; a digital control system that is configured to generate a first pulse width modulation (PWM) control signal and a second PWM control signal and that includes a closed loop control system that is configured to generate the first and second PWM control signals in response to sensor output signals generated by at least one sensor, the first and second PWM control signals operative to cause an on-state drive current to be supplied to ones of the at least three strings of solid state lighting devices; and at least three current supply circuits coupled to the first, second and third strings, respectively, wherein each of the current supply circuits is configured to supply the on-state drive current to a respective string of the at least three solid state lighting devices in response to the first and second PWM control signals, and wherein each of the current supply circuits includes a controller having a control input, a first control output configured to provide the first PWM control signal, and a second control output configured to provide the second PWM control signal.