The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . ve both purposes, the resultingmachine is called a rotatory or rotary converter. In the formercombination the brushes of the continuous current part requireto be set with the usual lead or lag according as that part isgenerator or motor, but in the latter the armature reactions nearlyannul each other, and lead or lag is no longer necessary. Rectifiers are devices for transforming an alternating (gener-ally single-phase) current into a continuous but pulsatoryRecuners. *^^t. They may shortly be des
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . ve both purposes, the resultingmachine is called a rotatory or rotary converter. In the formercombination the brushes of the continuous current part requireto be set with the usual lead or lag according as that part isgenerator or motor, but in the latter the armature reactions nearlyannul each other, and lead or lag is no longer necessary. Rectifiers are devices for transforming an alternating (gener-ally single-phase) current into a continuous but pulsatoryRecuners. *^^t. They may shortly be described as appli-ances for separating out each alternate current fluxin an alternating current. An immense number of more orless imperfect methods of doing this have been proposed, andhere we shall describe two which may be called respectively themechanical and the electrolytic methods. Of the first class agood example is the Ferranti rectifier (fig. 11). This consists of asynchronous alternating current motor which is started up anddriven in step with the alternator supplying the current. The. Fig. II.—Ferranti Rectifier. motor drives a commutatorof insulated segments, each alternatesegment being connected to two insulated rings, against which press a pair of brushes. Another pair of brushes, so adjustedas to be in contact simultaneously with a pair of adjacentcommutator segments, are in connexion with the alternatorsupplying the current to be commutated. The insulated nogsare in connexion with the external circuit. It will easily beseen that when the commutator revolves at proper speed thecurrents delivered from the insulated rings are Ferranti rectifier is much employed for rectifying alter-nating current for arc lighting purposes. With this objectit is associated with a constant current transformer whichconverts alternating current supplied at constant potentialto one supplied at constant current. This is achieved bytaking advantage of the repulsive for
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
