High power factor electronic ballast with low lamp current peak ratio

摘要

A high power factor electronic ballast for fluorescent lamps having low lamp current peak ratio and which includes a bridge rectifier for rectifying a commercial power supply voltage, a high frequency oscillator using an output voltage from a bridge rectifier as its supply voltage, a first supplementary power source to supply the high frequency oscillator a voltage by superimposing two supplementary voltages generated from a portion of high frequency current in a load on the output voltage from the bridge rectifier, and a second supplementary power source to supply the high frequency oscillator a direct offset voltage generated from a portion of high frequency current in the load to improve the input current waveform of the bridge rectifier.