High Intensity Discharge Lamp Hot Start With Mhz Electronic Ballast And Its Dimming

Because of the shortage of non-renewable energy, energy saving has become a world-wide topic. Being part of it, green lighting projects are attracting more and more attention. As a high efficacy, long life time lighting source, the High Intensity Discharge (HID) lamp plays an important role. Therefore development of the excellence in energy saving, light weight, etc., electronic ballast will gradually take the place of traditional electromagnetic (EM) ballast.Chapter 1 introduce the operation principles of HID lamp as well as the electronic ballast.Chapter 2 presents a novel hot-striking igniter for automotive headlamps. The igniter consists of two stages of step-up circuits. In the igniter, a saturable inductor is used to substitute the switch. Due to switch characteristics of the saturable inductor, high voltage pulse is generated. Its feasibility was verified by experimental results.Chapter 3 presents a MHz electronic ballast, which avoids the intrinsic problem of acoustic resonance of HID lamps. Its validity is proved by both theoretical analysis and experimental results.Chapter 4 proposes a novel electronic ballast with dimming feature. Based on T type filter, the new ballast can achieve a wide dimming range with a very narrow frequency variation range. Its validity is proved by theoretical results and experimental results.