1995 Volume 79 Issue 11 Pages 648-655
A new electronic ballast for electrodeless fluorescent lamps using a zero-voltage-switched resonant inverter is presented. The characteristic of this circuit is analyzed using an equivalent circuit of an electrodeless lamp. From the analysis, the output power of the electrodeless fluorescent lamp, the semiconductor device's stresses and zero-voltage-switching condition are derived, and a procedure for designing the electronic ballast for an electrodeless fluorescent lamp is established. The analytical results are compared with the experimental results obtained under 10MHz operation. This circuit realizes both condition of applying high resonant voltage across the excitation coil within the rating of the switches at the start of the lamp and lighting the lamp stably at the rated output power. In the experiment of 10MHz operation, the conversion efficiency over 90% is realized by zero-voltage-switching.