Cigar lighter receptacle - AbsoluteAstronomy.com

The cigarette lighter receptacle in an automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

, initially designed to power an electrically heated lighter, became a de-facto standard DC connector

DC connector

A DC connector is an electrical connector for supplying direct current power. Unlike domestic AC power plugs and sockets, DC connectors are not generally standardized....

to supply electrical power for portable accessories used in or near an automobile. Examples of devices that can be operated from a cigarette lighter receptacle include lights, fans, beverage heating devices, and small motorized tools such as compressors for inflating tires. Many portable electronic devices such as music players or mobile telephones use a cigarette lighter receptacle to recharge their internal batteries or to directly operate from the vehicle electrical system. Adapters for electronic devices may change voltage to be compatible with the supplied device. Devices that require alternating-current power at 120 volts or 240 volts can be operated with a plug-in inverter.

Currently, automobiles may provide several 12-V receptacles that are intended primarily to operate accessories and are not to be used with a cigarette lighter. With the declining popularity of smoking in many countries (such as the USA), car manufacturers have stopped including an actual cigarette lighter with new cars, selling them as extra-cost accessories to customers who still want them. Usually, only one 12-V receptacle near the driver will accommodate an actual cigarette lighter, with the remaining receptacles (if present) being designated as "12-V auxiliary power outlets".

While the cigarette lighter receptacle is a convenient and nearly universal feature of automobiles, as a DC power connector it has the disadvantage of relatively low current rating and poor contact stability.

History

In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

cigar lighters started appearing as standard equipment in automobiles in 1925/26. In 1928 the Connecticut Automotive Specialty Company in Bridgeport

Bridgeport

Bridgeport is the most populous city in the U.S. state of Connecticut.Bridgeport may also refer to:-Places:In Canada:* Bridgeport, Nova ScotiaIn the United States:* Bridgeport, Alabama* Bridgeport, California, in Mono County...

patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

ed the first automotive cigar lighter with cord and reel. The modern "automatic" automotive V-Coil lighter was developed by Casco in 1956.

In the reel-type lighters, the igniter unit was connected with a source of current by a cable which was wound on a spring drum so that the igniter unit and cable could be withdrawn from the socket and be used for lighting a cigar or cigarette. As the removable plug was returned to the socket, the wires were reeled back into it. The circuit was closed either by pressing a button or removing the igniter from its socket.

In 1921, the Morris was issued for a so-called "wireless" or "cordless" lighter. This lighter eliminated the cables and the mechanism for winding and unwinding them. The igniter was heated in the socket then removed for use.

Use as a lighter

The traditional lighter is a metal or plastic cylinder containing a thin coil of nichrome

Nichrome

Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various...

wire, through which high current (~10 ampere

Ampere

The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...

s) passes when the device is activated, usually by pushing it into the socket as though it were a button. When pushed in, the lighter is held against the force of a spring by a hook attached to a bi-metallic strip

Bi-metallic strip

A bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand at different rates as they are heated, usually steel and copper, or in some cases brass instead of copper. The strips are joined together...

. The heating element

Heating element

A heating element converts electricity into heat through the process of Joule heating. Electric current through the element encounters resistance, resulting in heating of the element....

becomes glowing orange hot in seconds, causing the bimetallic strip to bend and unhook the mechanism, and the handle pops out. If the lighter is then promptly removed from its socket, it is capable of setting cigarette

Cigarette

A cigarette is a small roll of finely cut tobacco leaves wrapped in a cylinder of thin paper for smoking. The cigarette is ignited at one end and allowed to smoulder; its smoke is inhaled from the other end, which is held in or to the mouth and in some cases a cigarette holder may be used as well...

s, cigar

Cigar

A cigar is a tightly-rolled bundle of dried and fermented tobacco that is ignited so that its smoke may be drawn into the mouth. Cigar tobacco is grown in significant quantities in Brazil, Cameroon, Cuba, the Dominican Republic, Honduras, Indonesia, Mexico, Nicaragua, Philippines, and the Eastern...

s and tinder

Tinder

Tinder is easily combustible material used to ignite fires by rudimentary methods. A small fire consisting of tinder is then used to ignite kindling. Anything that can be ignited by a match can be considered tinder; or by more rigorous definition, anything that begins to glow under a shower of...

(among other things) on fire.

In newer cars, the socket often ships with a plastic dummy plug, without the lighter heating element due to declining popularity (and legality) of smoking

Smoking

Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...

. However, the socket continues to exist to power consumer electronics

Consumer electronics

Consumer electronics are electronic equipment intended for everyday use, most often in entertainment, communications and office productivity. Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver...

in cars as the primary purpose. Often, a vehicle may come with several outlets for convenience, some in the rear passenger area of the vehicle. Even the cargo area may be supplied with sockets for such purposes as powering portable GPS devices, recharging telephones, or powering a tire pump

Air compressor

An air compressor is a device that converts power into kinetic energy by compressing and pressurizing air, which, on command, can be released in quick bursts...

or a vacuum cleaner

Vacuum cleaner

A vacuum cleaner, commonly referred to as a "vacuum," is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors, and optionally from other surfaces as well. The dirt is collected by either a dustbag or a cyclone for later disposal...

. These usually have a plastic cap tethered to them, and are usually labeled as being only for DC power since they are not intended to withstand the heat produced by an electric cigarette lighter.

Use as an electrical outlet

Twelve volt automobile plugs are standardized in the United States by the "UL standard 2089

Underwriters Laboratories

Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...

" regarding vehicle battery adapters. This standard covers plugs and cord sets that insert into cigarette lighter receptacles. In Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, 12 volt plugs and sockets are regulated and require approvals to be able to display the CE mark

CE mark

CE marking is a mandatory conformity mark for products placed on the market in the European Economic Area . With the CE marking on a product the manufacturer ensures that the product conforms with the essential requirements of the applicable EC directives...

Technical details

The sockets and mating plugs are defined in the ANSI/SAE J563 specification.

For the 12-volt systems, the "contact point," which is the center part of the plug when viewed end-on, carries the positive voltage, whereas the "can" part, which is the outer part of the connector, carries the negative voltage (which is the "ground" connection for most automobiles, which have a negative ground electrical system).

12 volt auto connectors are made to comply with a standard by Underwriters Laboratories

Underwriters Laboratories

for safety. UL2089 was developed to cover the requirements for portable adapters rated 24 V DC or less that are intended to be supplied from the battery powered electrical system of a vehicle.
Products covered by the standard include cord assemblies of a plug that mates with the standard cigarette receptacle found in automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s.

12-V Sockets normally comply with SAE standard J563.

6-volt cigar lighter receptacle and plug:

Receptacle inside diameter: (median )
Plug body diameter: (median )

12-volt cigar lighter receptacle and plug, size A:

Receptacle inside diameter: (median )
Plug body diameter: (median )
Most often used in American automobiles.

12-volt cigar lighter receptacle and plug, size B:

Receptacle inside diameter: (median )
Plug body diameter: (median )
Most often used in European automobiles, and sometimes as a second socket in American automobiles expressly for DC power connections.

Plugs often include a pilot light to indicate a connection has been made.

Design considerations

Since the cigar lighter socket was designed to heat a cigar lighter, using these sockets as power connectors can lead to many problems. In addition to the issues with incompatible sizes, plugs can vibrate out of the socket under normal driving conditions, owing to poor retention. There have been reports of melted plug tips.

A second problem is that nominally "Twelve-Volt" power in cars fluctuates widely. The actual voltage will be approximately 12.5 volts when dormant, (less when cold) approximately 14.5 volts when the engine and the alternator/generator are operating, (more when cold) and may briefly drop as low as 5-6 volts during engine start. DC/DC converters will usually compensate for these small fluctuations.

Rarely, more extreme cases of voltage fluctuation can occur when the car battery is disconnected while the engine is running, or when the car receives a jump start. When the battery is disconnected, a load dump

Load dump

Load dump means the disconnection of a powered load. It can cause 2 problems:* failure of supply to equipment or customers* large voltage spikes from the inductive generator...

transient can produce very high voltages. A car receiving a jump start

Jump start (vehicle)

A jump start, also called a boost, is a method of starting an automobile or other vehicle powered by an internal combustion engine when the vehicle's battery has been discharged. A second battery is temporarily connected to provide starting power to the disabled vehicle...

from a truck will be subject to its 24 V electrical system. A "double battery jump-start" is performed by some tow truck drivers in cold climates.

Design wise one has to take into account intermittent contact, and voltages outside the nominal like top voltage continuously, top voltage at during , during , during . Protection component tolerance example ratings are to Additionally, issues can occur with temperatures varying between such as humidity and condensation. Equipment connected this way must tolerate large variations in electrical- and climate environment.

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