Identifier: cyclopediaofappl04amer (find matches)
Title: Cyclopedia of applied electricity : a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric lighting, electric railways, power stations, switchboards, power transmission, alternating-current machinery, telegraphy, etc.
Year: 1916 (1910s)
Authors: American Technical Society
Subjects: Electric engineering
Publisher: Chicago : American Technical Society
Contributing Library: Northeastern University, Snell Library
Digitizing Sponsor: Northeastern University, Snell Library

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the armature, are squarely opposite the centers of, say, the north poles ofthe field magnet. Let d be the distancebetween the commutator bars to whichring 1 is connected. Ring 2 is connected • ^ ^ ^^ ^ to the -— equidistant commutator bars which are — of d ahead of the bars con- n a ^y^^ nected to ring 1; ring 3 is connected to p . . the — equidistant commutator bars which 2 Fig. 300. Brush and Commu- are — of d ahead of the bars connected tator Diagram for Six- ^j Ring Converter to ring 1; and so on. For example, a 6-pole direct-current dynamo with 72 commu-tator bars, to be made into a three-ring converter, would have ring1 connected to commutator bars 1, 25, and 49; ring 2 connected tocommutator bars 9, 33, and 57; and ring 3 connected to commutatorbars 17, 4U and 65. E. M. F. Relations for Rotary Converter. Let E be the valueof the steady electromotive force between the direct-current brushesof a rotary converter; and let E2, E^, E^, Eq, be the effective values 346 ■Z?
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GROUP OF FOUR-AMPERE SERIES RECTIFIER SETS AT PLUM STREET STA-TION, CINCINNATI, OHIO Courtesij of General Electric Company ALTERNATING-CURRENT MACHINERY 331 of the alternating electromotive force between adjacent collectingrings of a two-ring, three-ring, four-ring, and six-ring rotary con-verter, respectively. It is desired to find the relationship betweenthese various electromotive forces. Relationship between E and E^. The maximum value of thealternating electromotive force between the collecting rings of atwo-ring converter occurs at the instant when the commutatorbars to which the collecting rings are connected are in contact withthe direct-current brushes, and this maximum value is, of course,equal to E. Therefore, the effective value E2 of the alternatingelectromotive force between the slip-rings of a two-ring converter is Eequal to .—-. That is E E2 = v/2 (41) Relationship between E2 and E3. The discussion of the relation-ship between E2 and E3 will be carried out for a very

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