A bipin or bi-pin (sometimes referred to as two-pin, bipin cap or bipin socket) is a type of lamp fitting. They are included in the

IEC The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...

standard "IEC 60061 Lamp caps and holders together with gauges for the control of interchangeability and safety". They are used on many small

incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...

s (especially

halogen lamp A halogen lamp (also called tungsten halogen, quartz-halogen, and quartz iodine lamp) is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a small ...

s), and for starters on some types of

fluorescent light A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet lig ...

s. Some sockets have pins placed closer together, preventing the low-power bulbs they use from being replaced by bulbs that are too high

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

, which may generate excessive heat and possibly cause a fire. These are sometimes called "mini-bipin". Where the terminals of the lamp are bent back onto the sides of the base of the bulb, this forms a

wedge base upright , W2.1x9.5d base, a common 5-watt bulb in landscape lighting and some interior automotive applications such as the dome light A wedge base is a type of electrical connector used as a fitting for small light bulbs. It is similar to the ...

, often used in small bulbs for

automotive lighting The lighting system of a motor vehicle consists of lighting and signalling devices mounted to or integrated into the front, rear, sides, and in some cases the top of a motor vehicle. They illuminate the road ahead for the driver and increase t ...

. The bi-pin base was invented by

Reginald Fessenden Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father. During his life he received hundre ...

for the

1893 World's Fair The World's Columbian Exposition (also known as the Chicago World's Fair) was a world's fair held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's arrival in the New World in 1492. The centerpiece of the Fair, hel ...

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

. After Westinghouse won the

contract A contract is a legally enforceable agreement between two or more parties that creates, defines, and governs mutual rights and obligations between them. A contract typically involves the transfer of goods, services, money, or a promise to tran ...

to wire and illuminate the first electrified fair with AC instead of arch-rival

Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventio ...

's DC, Edison and his

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...

company refused to allow his

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...

Edison screw Edison screw (ES) is a standard lightbulb socket for electric light bulbs. It was developed by Thomas Edison (1847–1931), patented in 1881, and was licensed in 1909 under General Electric's Mazda trademark. The bulbs have right-hand threaded ...

-base bulbs to be used. Westinghouse overcame this by developing the bi-pin base for use at the fair. An incandescent electric lamp with a bi-pin base was patented by the Westinghouse (G. Westinghouse, Jr.) in 1895.

Types

The suffix after the G indicates the pin spread; the G dates to the use of Glass for the original bulbs. GU usually also indicates that the lamp provides a mechanism for physical support by the

luminaire A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets fo ...

: in some cases, each pin has a short section of larger diameter at the end (sometimes described as a "peg" rather than a "pin"); the socket allows the bulb to lock into place by twisting it; in others, the base of the lamp has a groove which can be held by a spring or clip. A

lowercase Letter case is the distinction between the Letter (alphabet), letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowercase (or more formally ''minuscule'') in the written representation of certain lang ...

"q" at the end of the designation indicates that it is a quad-pin base, with two bi-pin pairs. These are used with

compact fluorescent A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent light bulb; some types fit into light fixtures designed for inca ...

tubes that plug into a

light fixture A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets fo ...

that has a permanent ballast. There are also double-ended halogen and fluorescent tubes with one pin at each end, and high-output fluorescents with recessed or shrouded contacts, which are not covered here. File:Lampg4.jpg, Halogen lamps with GU4 (left) and G4 (right) bases File:Lamp6-35.jpg, Halogen lamp with G6.35 base File:Halogenmetalldampflampe.jpg,

Metal halide lamp A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

with G8.5 base File:Lampg9.jpg, Halogen lamp with G9 looped-pin base File:Lampgu10.jpg, Halogen lamp with GU10 twist-lock base

References

External links

*
Cross-reference for EU/US
{{DEFAULTSORT:Bi-Pin Connector Types of lamp Electrical power connectors Mechanical standards

Types

See also

References

External links