Abstract
The present invention is a single-stage electronic ballast circuit having emergency illumination function which combines the function of fly back charger, fly back discharger and semi-bridge type serial harmonic oscillation parallel load electronic ballasts, and is a single-stage electronic ballast circuit that integrates the said functions together into a single model. The circuit of the present invention needs only two active switches to complete the function of a general electronic ballast during normal operation, and an electronic ballast circuit for emergency illumination during power-off. The circuit of the present invention improves the functions of a general circuit for emergency illumination purpose greatly, wherein the charger, discharger and electronic ballasts are mutually independent and require more active switching devices and a more complicated circuit structure. Therefore, the present invention has a specific contribution to be novel and practical for the original design.