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



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.


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


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 ?
More specifically, on the need of all drivers to use headlights day and night.
We continue to be alarmed by the number of people on the road who don't use headlights in inclement weather,'' Ms.
The system devised by Narasimhan, Tamburo and the rest of the research team uses a DLP (Digital Light Processing) projector instead of a standard headlight or cluster of LEDs.
Turknett contracted Miami, Florida-based product management services leader Innovation Direct[TM] to represent the Smart Headlights to potential licensees for a 2 year period.
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.
Adaptive headlights and night vision are not strictly competing with each other as they each provide unique benefits to nighttime driving safety.
A number of motor vehicles now have High Intensity Discharge (HID), or bi-xenon headlights, which are significantly brighter and can cause increased headlight glare for other drivers.
I refer them to section 113 of the Highway Code which states "drivers must use headlights when visibility is seriously reduced".
Even if you didn't use high-pressure water, those headlights are still going to get some water inside.
I MUST take issue with MT Hancock concerning the use of headlights.
Sadly, it is far too evident that many motorists are not checking that both of their vehicle's headlights are working correctly," said Rick Wood, Head of Driver Training at the Royal Society for the Prevention of Accidents (RoSPA): "At the start of every journey, drivers should ensure that each headlight is working and adjusted correctly.
MORE than half of UK drivers say they have accidentally driven without headlights in the dark at least once in the last year.