An Electronic Ballast Using Modified Two-Switch Boost Converter

This paper proposes a modified two-switch boost converter with high power factor, and makes a report concerning the application of it to electronic ballast. First, the behavior of the boost converter with two switching devices is analyzed and experimental results will be shown. The experimental results show that the circuit can decrease the harmonic distortion of the input current like a former boost converter. But the problematic points possessed by the circuit are to be scrutinized. Next, a modified boost converter circuit that can improve the problem is proposed. The proposed circuit has both function of boost chopper and charge pump. The experimental results show that the circuit can improve the power factor. Lastly, it is shown that these two switching devices can be used not only as active switches of the modified boost converter but also as active switches of a half-bridge type inverter for fluorescent lamp. As a result, it is revealed that the harmonic distortion of the input current obtained by the proposed electronic ballast sufficiently satisfies the maximum limit of IEC 1000-3-2 class C. And the electronic ballast realized the high power factor of 0.99.