Patent ID: 8952624
Filing Date: 2015-02-10
Classification: H05B,Y02B

Abstract:
1. A Light Emitting Diode (LED) lighting system comprising: a main transformer transforming an input signal to supply the transformed input signal to an LED group; a voltage detector supplying a control voltage proportional to a level of an input voltage corresponding to the input signal; a current controller comprising: a first voltage storage storing the control voltage supplied from the voltage detector or discharging a stored voltage; a negative voltage applier connected to the first voltage storage, and connected to a ground to apply the control voltage to the ground when the control voltage is a negative voltage; a second voltage storage connected to the first voltage storage, and storing the control voltage applied through the first voltage storage or discharging a stored voltage; a switch connected to the second voltage storage, and activated by a driving signal to apply a ground voltage to the second voltage storage; and a current control signal generator generating a current control signal according to a voltage signal and gain of the second voltage storage, wherein the first voltage storage or the second voltage storage supplies the current control signal through the voltage detector; a second reference voltage supplier supplying the second reference voltage when the control signal supplied from the voltage detector is equal to or greater than the second reference voltage; and a power factor compensation circuit controlling a duty ratio of the driving signal according to a level of the current control signal, and controlling a peak value of a primary current in the main transformer according to a level of the second reference voltage.