A Novel Low-Cost Electronic Ballast for Automotive HID Lamps

摘要

This paper presents a novel low-cost, two-stage, negative-voltage-driven electronic ballast used to drive automotive high-intensity-discharging (HID) lamps with a constant lamp-power control scheme. The presented ballast is comprised of a buck-boost-flyback converter to provide negative voltages and a half-bridge-type inverter to supply the lamp with low-frequency square-wave voltage/current. Owing to its low-frequency operation, no acoustic resonance occurs on the HID lamps. The paper demonstrates the operational principles, design equations and experimental results of the proposed ballast for one 35W automotive HID lamp operating at 400Hz switching frequency with battery input DC-voltage of 12V.