Patent ID: 8569974

Claim:
A method of controlling a solid state lighting apparatus, the method comprising: providing a first model of a duty cycle of at least one light emitting device of the solid state lighting apparatus based on a temperature of the light emitting device and a level of current supplied to the light emitting device for a target chromaticity of light generated by the solid state lighting apparatus; controlling the duty cycle of the at least one light emitting device in response to change in at least one of the temperature of the light emitting device and the level of current supplied to the light emitting device in accordance with the first model; measuring an actual chromaticity of light generated by the solid state lighting apparatus in response to controlling the duty cycle of the at least one light emitting device in accordance with the first model; comparing the measured chromaticity of light output by the solid state lighting apparatus to the target chromaticity for light output by the solid state lighting apparatus; in response to a difference between the measured chromaticity and the target chromaticity, providing a second model of the duty cycle of the at least one light emitting device based on the temperature of the light emitting device and the level of current supplied to the light emitting device for an adjusted target chromaticity of light generated by the solid state lighting apparatus; and controlling the duty cycle of the at least one light emitting device in accordance with the second model.