Hid Lamp Electronic Ballast And Dimmable Design,

Compared to the traditional halogen lamps, HID lamps have much higher luminance and longer life time. Its color temperature is around 4000～6500 k, very close to the sun light's. Thus, this kind of lamps has a very wide use including illumination of indoor and outdoor stadium, fire fighting etc. Large amounts of luxury shopping malls use HID lamps as their major mean of illumination because of the high color rendering. Nowadays, the demands of HID lamps still maintain a high increasing, about 13% per year, in Europe. But all mentioned above must be based on the stable working of HID lamps. So the study of HID ballast is always the key to the improvement.As the special characteristic of HID lamp, it has to experience a sudden change from open circuit to stable discharge and work with the power constant. The major constant power control method now used is to keep the input voltage and current constant. But there are many factors will influence the result. This article will give a real constant power control method of HID.Along with the more strict demands on HID lamps, a much more quickly and reliable ignition become one of the key points of the ballast study. To avoid acoustic resonance, high frequency ignition has to design a frequency changing circuit which increases the cost. On the other hand, low frequency ignition always fails to start the lamp because it cannot supply enough power. To solve these problems, this article will suggest a high reliable igniter circuit with low frequency and long pulse width which will also decrease the cost.To decrease the energy consumption, new ballast with dimming control has been studied. As a result, the last part of the article will suggest an HID lamp ballast with wireless dimming control for both convenience and low energy consumption.