Patent ID: 8334659

Claim:
An electronic driver apparatus for powering one or more large area solid-state light sources, the driver apparatus comprising: a DC current source operative to provide DC electrical current to power at least one large area solid-state light source according to a control input; a controller receiving a continuous dimming level setpoint signal or value indicating a desired brightness level for the at least one large area organic solid-state light source, the controller being operative for at least some values of the dimming setpoint signal or value to provide a pulse modulated control input to the current source according to the dimming setpoint signal or value, the pulse modulated control input being provided by the controller as a pulse modulated waveform having periodic transitions between at least two control input values in each of a plurality of pulse width modulation periods, wherein the periodic transitions have controlled increasing profiles with a rise time value of about 100 μs or more and about 2 ms or less between the control input values and controlled decreasing profile with a fall time value of about 100 μs or more and about 2 ms or less between the control input values to mitigate large surge currents in the at least one large area organic solid-state light source, and wherein the continuous dimming level setpoint signal or value is substantially constant during a time period which includes multiple pulse width modulation periods.