Vehicles are equipped with headlights, taillights and windshield wipers to assist an automobile's driver in observing the roadway in front. Car headlights project a light beam forward of a vehicle to illuminate the roadway for a driver. , for example, are activated in dusk or night hours to illuminate the road directly ahead of a car. A typical Mercedes Benz Headlight is composed of a reflector and a lamp projecting through an opening into the interior of the reflector. The lamp's base is located in a holder of the reflector, so that the discharge vessel is arranged in an exactly defined location. The reflector surface is then illuminated by the emitted light. As a result, a headlight beam is formed and, depending on the shape of the reflector surface, radiated in a forward direction.
Despite its obvious importance, headlights were never included on the first cars produced. In fact, they never existed until they were compellingly created for obvious reasons. By 1885, "headlamps" were installed on cars and was initially powered by acetylene gas. Use of electric-powered headlights did not start until 30 years later. The most common types of headlights now since the 1980's are the halogen headlamps and recently, the so-called high intensity discharge (HID) lamps.As noted, car headlights typically employ filament-based light sources such as halogen lamps or HID lamps that produce electric arc illumination by electrical discharge between electrodes in a high-pressure gas ambient. Halogen lamps had been widely used in an older conventional Mercedes Benz Headlight. The halogen lamp is provided with two filaments, that is, a filament for irradiating a high-beam and a filament for irradiating a low-beam, so a high-beam mode or a low-beam mode may be selectively operated as desired.
Most luxury cars today however, namely the Mercedes Benz, BMW, and Porsche, equip their vehicles with HID lamps. The modern Mercedes Benz Headlight, made out of HID lamps, covers the mercury vapor, metal halide, high-pressure sodium and xenon short-arc type lamps. Most distinguishable about HID Mercedes Headlights are their color, which are blue-white as opposed to the halogen lamps. HID headlight systems generally utilize 35-watt lamps. This means that 35 watts of electric current must be delivered constantly. A dose of this electric current requires a ballast that helps in regulating the voltage and current going to the headlamps. Since HID headlamps emit light equivalent to what would be seen at several thousand Kelvin, a considerable amount of time is needed to build up enough pressure to reach its brightest intensity. The warm-up time usually lasts for several minutes with an ignition voltage of around 20 kilovolts. This is very impractical if used as a headlamp. This problem was solved by having constant power being delivered to the HID lamps, which would result in about only two seconds warm-up time to reach over a third of its full intensity. After the warm-up, only a small amount voltage is needed to keep them running.
There is no question that, as time went by, car makers have tuned their car parts to provide better visibility on the road. From the early acetylene lamps to todays HID's, seeing the roadways has become literally clearer and clearer.
