Startup/Striking the Bulb

Normal operation of the HID system starts at the ballast. The 2 wires at the ballast input connector contain the +12 volt power supply and ground return. As soon as the input power is applied, the ballast draws 20 amp from the battery for 5-10 seconds (depending on the input voltage level). The ballast is then able to charge the two outputs leading to the start to -360 volts and +800 volts. -360 volts and +800 volts are the voltages needed by the starter to strike, or start, the lamp. HID headlamps do not have filaments like traditional bulbs. Instead, the starter uses a high-voltage transformer to convert the +800 volts input power into 25,000 volts. The increased voltage is used in order to create an arc between the electrodes in the bulb. The creation of this arc begins the start up process.