New type of ballast for HID lamps using series resonant circuit

摘要

A new type of solid state ballast, which can provide the high-frequency power to high intensity discharge (HID) lamps without an acoustic resonance, is presented. A ballast is needed to lighten the HID images, and is expected to be small and stably operating. The ballast equipment is composed of an inverter circuit, having variable switching frequency, a series resonant circuit, and a starting capacitor of the HID lamps. The operating characteristics of the ballast circuit are presented. The proposed circuit is useful for the HID lamps due to the small size and the low switching losses.