Patent ID: 8866403
Filing Date: 2014-10-21
Classification: H05B,Y02B

Abstract:
1. An LED driver, comprising: a rectifier circuit with an AC input having first, second, and third AC input terminals a pulse width modulated power circuit providing a DC output to drive at least one LED light source, the power circuit comprising: a sensing circuit coupled with the first and third AC input terminals and providing a sensor signal to the gain input of the pulse width modulation controller, the sensing circuit providing the sensor signal at a first level if an input voltage is applied to the third AC input terminal and providing the sensor signal at a lower second level if no input voltage is applied to the third AC input terminal; a first attenuator circuit comprising a first attenuator input coupled with the second AC input terminal and a first attenuator output coupled with the gain input of the pulse width modulation controller, the first attenuator circuit operative to selectively reduce a voltage of the gain input if an input voltage is applied to the second AC input terminal to decrease the power provided to the at least one LED light source; and a second attenuator circuit comprising a second attenuator input coupled with the third AC input terminal and a second attenuator output coupled with the amplifier input of the pulse width modulation controller, the second attenuator circuit operative to selectively reduce a voltage of the amplifier input if an input voltage is applied to the third AC input terminal to increase the power provided to the at least one LED light source.