headlight


Also found in: Dictionary, Thesaurus, Medical, Legal, Idioms, Wikipedia.

headlight

, headlamp
a powerful light, equipped with a reflector and attached to the front of a motor vehicle, locomotive, etc.

Headlight

 

an electrical device on motor vehicles and other moving machines, used to illuminate, for example, roadways and work positions. The main components of a headlight are the optical element and a stamped housing.

Present-day headlights have a semireplaceable optical element that consists of a steel reflector coated with a thin layer of aluminum, a light source consisting of a single-filament or—more often—a double-filament incandescent bulb, and a lens made of ribbed glass. A high-wattage filament is located at the focal point of the reflector and produces a high beam that is aimed along the roadbed. A low-wattage filament is located above and to the left of the focal point and produces a low beam that is aimed downward and to the right. Such an asymmetric low beam, which is called a European low beam, reduces the danger of blinding the drivers of oncoming vehicles and improves illumination of the right side of the road. Iodine-vapor headlight bulbs are widely used. Such bulbs are filled with a rarefied gas containing an iodine vapor. As compared with conventional bulbs of the same wattage, iodine-vapor bulbs yield twice the roadway illumination and have a longer service life.

Figure 1. A headlight: (1) bulb, (2) bulb adapter, (3) retaining spring, (4) housing, (5) low-beam cable, (6) high-beam cable, (7) adjusting screw, (8) seals, (9) optical element, (10) rims, (11) reflector holder

Every motor vehicle must have at least one pair of headlights. Both headlights must be located symmetrically relative to the longitudinal axis of the vehicle. Many vehicles are equipped with two additional fog lights, the lenses and reflectors of which aim the beams in the horizontal direction closer to the level of the roadway; in such lights, the high beam is cut off by a metallic shield. Special-purpose vehicles, such as fire engines and ambulances, may be equipped with swiveling spotlights that can be turned in various directions. Headlights are sometimes installed at the rear of a vehicle, for example, on tractor trucks. The rear headlights on tractor trucks are used to observe the trailers and other equipment.

REFERENCE

Il’in, N. M. Elektrooborudovanie avtomobilei, 4th ed. Moscow, 1975.

headlight

[′hed‚līt]
(electricity)
A lamp, usually fitted with a reflector and a special lens, that is mounted on the front of a locomotive or automotive vehicle to illuminate the road ahead.
References in periodicals archive ?
The Impreza, Legacy, Outback and WRX qualify for Top Safety Pick+ when equipped with optional front crash prevention and specific headlights.
IIHS focused on the issue as automakers shift to LED or high-intensity discharge lamps for headlights instead of traditional halogen lamps, and use new technology for curve-adaptive headlights that turn based on the direction of the wheels.
The simplicity of this will hopefully remind motorist to turn their headlights on when their wipers are on,'' said John Paul, spokesman for AAA of Southern New England.
The processor can tell where the drops are headed and sends a signal to the headlights, which adjust the beams of light they send out so that there isn't any light where the raindrop is.
1 If your headlight isn't already in the fully up position, you'll need to get it there manually before removing the assembly.
A driver who is dazzled by HID headlights may be distracted, experience discomfort and not see as well.
You can either restore the old headlights with a restoration kit (Photo 1) and a spare hour, or spend $40 to $250 each on new headlights.
The mirrors and headlights get splattered with mud during missions, so it's up to you to clean them off after every operation.
However, changing a failed headlight bulb on a modern car may not be a quick and simple matter.
At night, when you can see only as far as your headlights allow, the situation is worse.
The site includes advice about what documents you will need or compulsory equipment you'll need to take such as GB sticker, headlight beam deflectors and warning triangle.