An electronic ballast for fluorescent lamps with no series passive elements

This exploratory study examined the possibility of driving a fluorescent lamp at high frequency with no serially connected passive elements. The proposed driver is a full bridge stage controlled by the phase shifted PWM scheme. Current feedback was used to stabilize the average of the rectified lamp current to a set value. The experimental results of this research confirm the conjecture that an all-electronic fluorescent driver is feasible. Lamp V-I characteristics and lamp resistances were found to be comparable to those measured when the lamp is driven by a conventional HF electronic ballast. The measured light output of a lamp driven by proposed ballast was found to be slightly higher than the light output of same lamp when driven by a conventional HF ballast for the same input power. The paper covers the issue of feedback consideration for ensuring dynamic stability.