Patent ID: 7294972
Filing Date: 2007-11-13
Classification: H05B,Y10S

Abstract:
1. A feedback circuit for a push-pull inverter which includes a first transformer and a second transformer connecting to input electrodes at two ends of a discharge lamp, the first transformer and the second transformer providing input electricity to the discharge lamp at a phase difference of 180 degrees, a control unit being provided in front of the first transformer and the second transformer to output frequency signals, and a driving unit being provided in front of the first transformer and the second transformer to receive the frequency signals and output an electricity conduction signal to drive the first transformer and the second transformer, characterized in that a feedback device is located on a power cord between the driving unit and the discharge lamp, the feedback device includes a first coil assembly on the power cord and an external second coil assembly corresponding to the first coil assembly and is connected electrically to the control unit, the feedback device gets a detection electricity of the driving electricity of the discharge lamp through non-contact coupling induction, and the detection electricity is transformed by the feedback device and output to the control unit to regulate the frequency signals in response to the luminance of the discharge lamp.