The automobile headlamp is also called the headlamp, the headlamp mainly has the low beam lamp, the high beam lamp. The control circuit is mainly composed of light switch, dimmer switch, headlamp relay and headlamp.

Light switch: turn the end of the switch to turn on the low beam of the headlamp, press forward to change it into high beam, and press backward to return to the low beam.

The control principle of automobile headlamp is shown in the figure below:

At present, the bulb specifications and models of the headlights are generally H1, H4, H7, 9004, 9005, 9006 or 9007. Retail prices in the parts market vary from place to place. This modification method has limited effect. However, the serious increase of power load of the line, switch and power supply, the increase of heat energy of the bulb and the increase of the temperature of the lamp cup will easily cause overload burning of the line and switch, accelerate the aging of mercury in the lamp cup, and cause the deformation of the melting and melting of the lamp cup, and even cause fire accidents. The most common fault is that after a period of time, the contacts of the headlamp combination switch are burned. The principle of its luminous is to boost the DC voltage of 12V to 23000V, which produces high color temperature light by the discharge arc. Many national laws do not allow the replacement of xenon bulbs only without assembly modifications. Because the lens without focusing will cause serious interference to other drivers, which will cause safety hazards.