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Created page with 'File:lighterstill.jpgright|frame ==Etymology== short for dynamoelectric machine. A machine for converting energy in the ...'
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==Etymology==
short for dynamoelectric [[machine]]. A machine for [[converting]] [[energy]] in the [[form]] of [[mechanical]] [[power]] into energy in the form of electric currents, by the operation of setting conductors (usually in the form of coils of copper wire) to [[rotate]] in a [[magnetic]] field.

The full name ''dynamo-electric machine'' was given by Siemens in 1867, to distinguish his [[invention]] from the magneto-electric [[machines]] previously used, in which the [[electric]] current was [[generated]] by means of a [[permanent]] [[magnet]]. But in the shortened [[form]] dynamo (recommended by Prof. S. P. Thompson early in 1882), the use of the [[word]] has been extended so as to include all [[forms]] of these [[machines]]:
*Date: [http://www.wikipedia.org/wiki/19th_Century 1882]
==Definitions==
*1 : [[generator]]
*2 : a [[force]]ful energetic [[individual]]
==Description==
A '''dynamo''', [[originally]] another [[name]] for an [[electrical]] [[generator]], now means a generator that produces [http://en.wikipedia.org/wiki/Direct_current direct current] with the use of a [http://en.wikipedia.org/wiki/Commutator_(electric) commutator]. Dynamos were the first [[electrical]] [[generators]] capable of delivering [[power]] for industry, and the [[foundation]] upon which many other later electric-[[power]] conversion devices were based, including the [http://en.wikipedia.org/wiki/Electric_motor electric motor], the alternating-current [http://en.wikipedia.org/wiki/Alternator alternator], and the [http://en.wikipedia.org/wiki/Rotary_converter rotary converter]. They are rarely used for [[power]] [[generation]] now because of the [[dominance]] of alternating current, the disadvantages of the commutator, and the ease of [[converting]] alternating to direct current using [http://en.wikipedia.org/wiki/Solid_state_(electronics) solid state] [[methods]].

The [[word]] still has some regional usage as a replacement for the word [[generator]]. A small electrical generator built into the hub of a bicycle wheel to [[power]] [[light]]s is called a [http://en.wikipedia.org/wiki/Hub_dynamo Hub dynamo], although these are invariably AC devices.

[[Category: Physics]]