Patent ID: 8547033
Filing Date: 2013-10-01
Classification: H05B,Y02B

Abstract:
1. A solid state light driving arrangement comprising: a single stage power factor correction switched mode power supply arranged to output a power signal; a light emitting diode string arranged to receive said output power signal from said single stage power factor correction switched mode power supply; a current governor in series with said light emitting diode string and arranged to limit current flow through said light emitting diode string responsive to a current limit reference; a current sense element in series with said current governor and said light emitting diode string; a feedback circuit in communication with said current sense element and comprising an error amplifier, said feedback circuit arranged to output a feedback signal to said single power factor correction switched mode power supply whose value is a function of the difference between the current sensed by said current sense element and a target current, said power factor correction switched mode power supply arranged to adjust said output power signal responsive to said feedback signal; and a feed forward circuit arranged to adjust the value of the feedback signal so as to reduce the response lag of said power factor correction switched mode power supply to the feedback signal when the voltage drop across said current governor is greater than a predetermined dissipative limit value.