Lightning system in Automobile

INTRUDUCTION

The lighting system of a motor vehicle consists of lighting and signalling devices mounted or integrated to the front, rear, sides, and in some cases the top of a motor vehicle. This lights the roadway for the driver and increases the visibility of the vehicle, allowing other drivers and pedestrians to see a vehicle's presence, position, size, direction of travel, and the driver's intentions regarding direction and speed of travel. Emergency vehicles usually carry distinctive lighting equipment to warn drivers and indicate priority of movement in traffic.

Vehicle lighting systems are becoming increasingly complex. For a long time now, lighting systems have placed stringent demands on workshops when it comes to maintenance and installation. We offer you a good overview of the various lighting systems and their components along with their properties and special features. We provide a sound basic understanding of the topic in a practical fashion, meaning you acquire up-to-date, comprehensive knowledge ranging from the various light sources right through to explanations of the technical bases of legal regulations.

HISTORY

Early road vehicles used fuelled lamps, before the availability of electric lighting. The Ford Model T used carbide lamps for headlamps and oil lamps for tail lamps. It did not have all-electric lighting as a standard feature until several years after introduction. Dynamos for automobile headlamps were first fitted around 1908 and became commonplace in 1920s automobiles.

Silent film star Florence Lawrence is often credited with designing the  first "auto signaling arm", a predecessor to the modern turn signal, along with the first mechanical brake signal. She did not patent these inventions, however, and as a result she received no credit for—or profit from—either one.[1] Tail lamps and

brake lamps were introduced around 1915, and by 1919 "dip" headlamps were available. The sealed beam headlamp was introduced in 1936 and standardised as the only acceptable type in the USA in 1940. Self-cancelling turn signals were developed in 1940. By 1945 headlamps and signal lamps were integrated into the body styling. Halogen headlamp light sources were developed in Europe in 1960. HID headlamps were produced starting in 1991. In 1993, the first LED tail lamps were installed on mass-production automobiles.  LED  headlamps were introduced in the first decade of the 21st century

PRINCIPLE

VEHICLE LIGHTING TECHNOLOGY VARIABLES: BASIC PRINCIPLES

Below you will find a summary of the most important basic terms in  lighting technology and the respective units of measure for the evaluation of the properties of bulbs and lamps:

Luminous flux Φ

Unit: lumen [lm]

Luminous flux F is the term used to describe the complete light output radiated from a light source.

Luminous intensity I

Unit: candela [cd]

The luminous intensity is the portion of the luminous flux radiating in a specific direction.

Illuminance E

Unit: lux [lx]

Illuminance E specifies the ratio of the impinging luminous flux to the illuminated surface.

Illuminance is 1 lx when a luminous flux of 1 lm impinges an area of 1 m² evenly.

Luminance L

Unit: candela per square meter [cd/m2]

Luminance L is the impression of brightness the eye has from a luminous or illuminated surface.

Luminous efficiency ŋ

Unit: lumen per watt [lm/W]

Luminous efficiency h specifies the rate of efficiency with which the consumed electrical power is transformed into light.

Colour temperature K

Unit: Kelvin [K]

Kelvin is the unit for colour temperature. The higher the temperature of a light source, the greater the proportion of blue and the lower the proportion of red is in the colour spectrum.

A bulb with warm white light has a colour temperature of approx. 2700 K. However, at 4250 K, a gas discharge lamp (D2S) has a cool white light that is more similar to daylight (approx. 5600 K).

COLOUR OF LIGHTING EMITTED

The colour of  light emitted by vehicle lights is largely standardised by longstanding convention. It was first codified in the 1949 Geneva Convention on Road Traffic and later specified in the 1968 United Nations Vienna Convention on Road Traffic. With some regional exceptions, lamps facing rearward must emit red light, lamps facing sideward and all turn signals must emit amber  light,  while lamps facing frontward must emit white or selective yellow light. No other colours are permitted except on emergency vehicles. Vehicle lighting colour specifications can differ somewhat in countries that have not signed the 1949  and/or 1968 Conventions; examples include turn signals and side marker lights in North America as described in those lamps' sections later in this article.

FORWARD ILLUMINATION

Forward illumination is provided by high- ("main", "full", "driving") and low-("dip", "dipped", "passing") beam headlamps, which may be augmented by auxiliary fog lamps, driving lamps, or cornering lamps.

Headlamps

Main article: Headlamp

Dipped beam (low beam, passing beam, meeting beam)

Dipped-beam (also called low, passing, or meeting beam) headlamps provide a light distribution to give adequate forward and lateral illumination without dazzling other road users with excessive glare. This beam is specified for use whenever other vehicles are present ahead.

UN Regulations for headlamps specify a beam with a sharp, asymmetric cutoff preventing significant amounts of light from being cast into the eyes of drivers of preceding or oncoming cars. Control of glare is less strict in the United States-  based Society of Automotive Engineers (SAE) beam standard. It is contained in Federal Motor Vehicle Safety Standard 108 (FMVSS / CMVSS 108).

Main beam (high beam, driving beam, full beam)

Main-beam (also called high, driving, or full beam) headlamps provide an intense, centre-weighted distribution of light with no particular control of glare. Therefore, they are only suitable for use when alone on the road, as the glare they produce will dazzle other drivers. ECE and Japanese Regulations permit higher-intensity high-beam headlamps than allowed under US regulations.

Auxiliary lamps Driving lamps

Auxiliary high beam lamps may be fitted to provide high intensity light to enable the driver to see at longer range than the vehicle's high beam headlamps. Such lamps are most notably fitted on  rallying cars, and are occasionally fitted to production vehicles derived from or imitating such cars. They are common in countries with large stretches of unlit roads, or in regions such as the Nordic countries where the period of daylight is short during winter.

"Driving lamp" is a term deriving from the early days of nighttime driving, when it was relatively rare to encounter an opposing vehicle. Only on those occasions when opposing drivers passed each other would the low (dipped or "passing") beam be used. The high beam was therefore known as the "driving beam", and this terminology is still found in international UN Regulations, which do not distinguish between a vehicle's primary (mandatory) and auxiliary (optional) upper/driving beam lamps. The "driving lamp" term has been supplanted in US regulations by the functionally descriptive term "auxiliary high-beam lamp".

Many countries regulate the installation and use of driving lamps. For example, in Russia each vehicle may have no more than three pairs of lights including the original-equipment items, and in Paraguay auxiliary 

Front fog lamps

Front fog lamps provide a wide, bar-shaped beam of light with a sharp cutoff at the top, and are generally aimed and mounted low. They may produce white or selective yellow light, and were designed for use at low speed to increase the illumination directed towards the road surface and verges in conditions of poor visibility due to rain, fog, dust or snow.

They are sometimes used in place of dipped-beam headlamps, reducing the glare-back from fog or falling snow, although the legality varies by jurisdiction of using front fog lamps without low beam headlamps.

In most countries, weather conditions rarely necessitate the use of front fog lamps and there is no legal requirement for them, so their primary purpose is frequently cosmetic. They are often available as optional extras or only on higher trim levels of many cars. An SAE study has shown that in the United States more people inappropriately use their fog lamps in dry weather than use them properly in poor weather. Because of this, use of the fog lamps when visibility is not seriously reduced is often prohibited in most jurisdictions; for example, in New South Wales, Australia:

The driver of a vehicle must not use any fog light fitted to the vehicle unless the driver is driving in fog, mist or under other atmospheric conditions that restrict visibility.

The respective purposes of  front fog lamps and driving lamps are  often confused, due in part to the misconception that fog lamps are necessarily selective yellow, while any auxiliary lamp that makes white light is a driving lamp. Automakers and aftermarket parts and accessories suppliers frequently refer interchangeably to "fog lamps" and "driving lamps" (or "fog/driving lamps").

Cornering lamps

On some models, cornering lamps provide white steady-intensity light for lateral illumination in the direction of an intended turn or lane change. They are generally actuated in conjunction with the turn  signals, and they may be wired to also illuminate when the vehicle is shifted into reverse gear. Some modern vehicles activate the cornering lamp on one or the other side when the steering wheel input reaches a predetermined angle in that direction, regardless of whether a turn signal has been activated.

American technical standards contain provisions for front cornering lampsas well as rear cornering lamps. Cornering lamps have traditionally been prohibited under international UN Regulations, though provisions have recently been made to allow them as long as they are only operable when the vehicle is travelling at less than 40 kilometres per hour (about 25 mph).

Spot lights

Police cars, emergency vehicles, and those competing in road rallies are sometimes equipped with an auxiliary lamp, sometimes called an alley light, in a swivel-mounted housing attached to one or both a-pillars, directable by a handle protruding through the pillar into the vehicle.

DISTRIBUTIVE LIGHTING

In distributive light systems, the light from a single source is sent via opticalfibres or light guides to wherever it is needed in the automobile. Light guides  are commonly used to distributively light dashboard displays, and premium vehicles are beginning to use distributive systems for lighting such items as  door locks, window controls, and cup holders. Distributive exterior lighting has also been explored, with high-intensity central lightsources.

CONCLUSION

The main purpose is to understand the system of the Lighting System in automobile in deep and to work in future in appropriate manner that it would work perfectly.

To help the institutes future generations to understand the curriculum properly through our effort and to gain knowledge about Lighting system.