[Electric engineering.] . h a number ofseparate commutators, the machines may easily be con-nected so as to operate a single circuit or a number of cir-cuits, as previously explained. CLOSED-COIL MACHINES. 29. The Wood Arc Dynamo.—This machine has asimple closed-coil ring armature and a commutator dividedinto a large number of segments so as to make the voltagebetween segments low and prevent undue sparking. Fig. 17shows one of these machines of 125 lights capacity, and,therefore, capable of generating about 6,250 volts at fullload. The controlling magnet m of the regulator here/. 26 E
[Electric engineering.] . h a number ofseparate commutators, the machines may easily be con-nected so as to operate a single circuit or a number of cir-cuits, as previously explained. CLOSED-COIL MACHINES. 29. The Wood Arc Dynamo.—This machine has asimple closed-coil ring armature and a commutator dividedinto a large number of segments so as to make the voltagebetween segments low and prevent undue sparking. Fig. 17shows one of these machines of 125 lights capacity, and,therefore, capable of generating about 6,250 volts at fullload. The controlling magnet m of the regulator here/. 26 ELECTRIC LIGHTING. 19 shown is connected in series with the line and operates thelever n. The brushes are moved by means of a small doublefriction clutch that is contained in the casing shown at the lever is pulled up beyond the normal position, theclutch moves the brushes forwards by means of the gearsb, e, d, thus lowering the current. If the current becomestoo weak, the lever moves down and the clutch moves the. Fig. 1. brushes back, thus increasing the current. These machinesoperate on a single circuit and are made as large as150 lights capacity. The largest size of machine is of a some-what different design from that shown in Fig. 17, but theprinciple of operation is the same. The connections usedwith the Wood system are very simple. The armature,fields, and regulating magnet are all connected in series,and the regulation is effected altogether by tipping the § 19 ELECTRIC LIGHTING. 27 brushes, there being no rheostat of any kind in shunt withthe fields. 30. The Excelsior and Western Electric machines alsohave closed-coil armatures. The larger sizes of the morerecent Western Electric machines are of the four-pole typeand have two pairs of brushes. This dynamo is providedwith two regulators and supplies two circuits in of the regulators controls one pair of brushes. This isa somewhat different multiple-circuit arrangement from thatof the Brush machine
Size: 1647px × 1517px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookidelectricengi, bookyear1902
