. Journal of electricity, power, and gas . ed load, the ratio of friction to torque isrelatively great, therefore the lighter the load thegreater will be the retarding effect of friction. Inorder to overcome this friction effect, the compensat-ing field is connected in series with the armature sothat its flux will work in conjunction with the main orseries field. In the General Electric and Westing-house meters, the strength of the compensating fieldis constant, and the helping out or compensatingeffect is altered by moving it closer to or further fromthe armature, so that more or less of its
. Journal of electricity, power, and gas . ed load, the ratio of friction to torque isrelatively great, therefore the lighter the load thegreater will be the retarding effect of friction. Inorder to overcome this friction effect, the compensat-ing field is connected in series with the armature sothat its flux will work in conjunction with the main orseries field. In the General Electric and Westing-house meters, the strength of the compensating fieldis constant, and the helping out or compensatingeffect is altered by moving it closer to or further fromthe armature, so that more or less of its flux embracesthe armature. In the Duncan meter, the amount ofcompensation is altered by means of the multi-pointswitch shown in the illustration. This switch is con-nected to various taps on the compensating windingand the variation is accomplished by cutting in or outa certain number of the coils, thereby altering theflux. When the compensating field was first used, itwas permanently fastened to the inside of the series A. 1 c N wm I i y. Westinghouse. b. General 45.—Types of Commutating Meters. c. Duncan. been accomplished by increasing the resistance in thepotential circuit and by almost doubling the numberof conductors on the armature; the number of arma-ture conductors being increased to produce a greatertorcpie. General Construction. Fig. 45 illustrates interior views of three repre-sentative types of commutating meters, in which (a) isthe Westinghouse, (b) the General Electric, and (c)the Duncan, all of American manufacture. The meter shown at (c) is designed for use ondirect current circuits, although it may be said thatthe Duncan alternating current meter is very similarin construction, and its operation essentially the sameas the direct current meter. The use of the commu-tating type of meter on alternating current circuitswill be dealt with later in this chapter. The Compensating or Shunt Field. The function of the compensating or shunt field isto com
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Keywords: ., bookcentury1800, bookdecade1890, bookidjo, booksubjectelectricity
