Patent ID: 8773035
Filing Date: 2014-07-08
Classification: H05B,Y10S

Abstract:
1. An electronic ballast, comprising: a converter for providing a DC voltage; an inverter circuit connected with said converter for converting said DC voltage into an AC output voltage, so that at least one gas discharge lamp is driven by electric energy of said AC output voltage, wherein said inverter circuit comprises plural switch elements; a controlling unit connected with said converter and said plural switch elements of said inverter circuit, wherein said controlling unit issues a first control signal to control said converter and issues a second control signal and a third control signal with opposite enabling/disabling states to control on/off states of corresponding switch elements, wherein during a dead time between said enabling state of second control signal and said enabling state of said third control signal, said plural switch elements are simultaneously in said off state; and a current crest factor improvement circuit connected with said controlling unit for receiving said second control signal and said third control signal, wherein during said dead time, said current crest factor improvement circuit is triggered to generate a restraining signal to said controlling unit, wherein according to said restraining signal, said first control signal is correspondingly adjusted by said controlling unit, so that an output power of said converter is decreased to a predetermined value in real time or said converter is suspended.