Patent ID: 6657838
Filing Date: 2003-12-02
Classification: H02H,H02M,H05B,Y02B

Abstract:
In an LCD backlight inverter having a buck switch for determining power supply to a DC/AC converter for converting voltage, said buck switch being connected between a supply voltage input terminal and said DC/AC converter, the improvements comprising:an overvoltage protection circuit connected to an input terminal of said DC/AC converter for dividing voltage while providing a current path at the time of initial drive; a first comparing block for comparing the dimension of a feedback signal with the dimension of a first reference voltage, the feedback signal representing the dimension of the voltage according to an on/off status of the backlight in the rear end; a second comparing block for comparing the dimension of the voltage divided in said overvoltage protection circuit with the dimension of a second reference voltage; and a switching controlling block for receiving comparison signals from said first and second comparing blocks and controlling an on/off status of said buck switch according to the comparison signals.