High-Intensity-Discharge Lamp Ballast With Igniter Driven by Dual-Frequency Inverter

摘要

An automotive high-intensity-discharge (HID) lamp ballast with an igniter which has a voltage doubler driven by a dual-frequency inverter is proposed. As in a conventional ballast, the proposed implementation consists of a high frequency dc/dc converter and a low frequency dc/ac inverter. However, in this implementation, the inverter is driven at a much higher frequency during the ignition stage, making it possible to use only one large capacitor to store the energy for ignition compared to two large capacitors required in the conventional implementation, resulting in a higher density igniter. Furthermore, to simplify the hardware, a low-cost micro-controller is employed to implement a software-based detection of lamp ignition, lamp status, and to regulate the lamp power. The performance of the proposed igniter, ignition and power controller were evaluated on a 35-W HID lamp ballast.