Patent ID: 7881084

Claim:
A DC to AC cold cathode fluorescent lamp inverter circuit, comprising: a step-up transformer with a primary winding and a secondary winding for providing increased voltage to a cold cathode fluorescent lamp, wherein said primary winding and said secondary winding are electrically coupled to ground; a first MOSFET switch coupled to said step-up transformer for selectively allowing direct current of a first polarity to flow through said step-up transformer; a second MOSFET switch coupled to said step-up transformer for selectively allowing direct current of a second polarity to flow through said step-up transformer; a capacitor divider electrically coupled to said cold cathode fluorescent lamp for providing a first voltage signal representing a voltage across said cold cathode fluorescent lamp; a first feedback signal line coupled to said capacitor divider for receiving said first voltage signal from said capacitor divider representing said voltage across said cold cathode fluorescent lamp; a timer circuit coupled to said first feedback signal line for providing a time-out sequence of a predetermined duration when said first voltage signal exceeds a predetermined threshold; and a protection circuit coupled to said timer circuit, said first switch and said second switch for shutting down said first switch and said second switch when said first voltage signal exceeds said predetermined threshold after said predetermined duration.