Patent ID: 8115406
Filing Date: 2012-02-14
Classification: H05B

Abstract:
1. A fluorescent lamp driver circuit, comprising: a switch module, coupled to a DC input voltage, for controlling the magnitude of an output electric power according to a plurality of control signals; a resonance module, coupled to the switch module, for converting the output electric power into a first AC signal and a second AC signal, and a phase difference between the first AC signal and the second AC signal falling within a predetermined range from 180 degrees; a first fluorescent lamp module, coupled to the resonance module for receiving the first AC signal; a second fluorescent lamp module, coupled to the resonance module for receiving the second AC signal; a detection unit, including a first detecting portion and a second detecting portion, one end of the first detecting portion and one end of the second detecting portion being coupled to a common ground, the other end of the first detecting portion being serially connected to the first fluorescent lamp module for generating a first detection signal, and the other end of the second detecting portion being serially connected to the second fluorescent lamp module for generating a second detection signal; a selection unit, for receiving the first detection signal and the second detection signal, and selectively outputting one of the first detection signal and the second detection signal as a select signal; a protection unit, for receiving the first detection signal and the second detection signal, and outputting a protection feedback signal; and a control unit, coupled to the selection unit and the protection unit, for generating the control signals to control the switching of the switch module according to the select signal, and stopping the switching of the switch module if a level of the protection feedback signal being higher than a predetermined value.