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; ) is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies. IEC standards cover a vast range of ...

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, also known as an incandescent lamp or incandescent light globe, is an electric light that produces illumination by Joule heating a #Filament, filament until it incandescence, glows. The filament is enclosed in a ...

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, to produce ultraviolet and make a phosphor ...

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 may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Math ...

, 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, often used in small bulbs for

automotive lighting Automotive lighting is functional exterior lighting in vehicles. A motor vehicle has lighting and signaling devices mounted to or integrated into its front, rear, sides, and, in some cases, top. Various devices have the dual function of illumin ...

. The bi-pin base was invented by

Reginald Fessenden Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-American electrical engineer and inventor who received hundreds of List of Reginald Fessenden patents, patents in fields related to radio and sonar between 1891 and 1936 ...

for the 1893 World's Fair in

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

. After Westinghouse won the

contract A contract is an agreement that specifies certain legally enforceable rights and obligations pertaining to two or more parties. A contract typically involves consent to transfer of goods, services, money, or promise to transfer any of thos ...

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

Thomas Edison Thomas Alva Edison (February11, 1847October18, 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 inventions, ...

's DC, Edison and his

General Electric General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the year ...

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 sufficiency of disclosure, enabling discl ...

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 (light bulb), Mazda trademark. The bulbs have S ...

-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 lighting device containing one or more light sources, such as lamps, and all the accessory components required for its operation to provide illumination to ...

: 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 letters that are in larger uppercase or capitals (more formally ''majuscule'') and smaller lowercase (more formally '' minuscule'') in the written representation of certain languages. The writing system ...

"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 incan ...

tubes that plug into a

light fixture A light fixture (US English), light fitting (UK English), or luminaire is an electrical lighting device containing one or more light sources, such as lamps, and all the accessory components required for its operation to provide illumination to ...

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 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