Improved push-pull electronic ballast for reduction of input current harmonics

In this paper, we propose modified push-pull electronic ballast that can reduce input current harmonics. The proposed electronic ballast has various functions. There are 1) partial smoothing function, 2) charge pump function and 3) PWM control function. Those functions are effective for improvement of the luminous efficiency of a lamp and improvement in the circuit efficiency. The behavior of the proposed circuit is analyzed and experimental results will be shown. The experimental results show that the circuit can reduce the harmonic distortion of the input current. It is revealed that the harmonic distortion of the input current obtained by the proposed electronic ballast satisfies the maximum limit of IEC 1000-3-2 class C sufficiently.