. The principles underlying radio communication . ,c.,ctc Armature conducTora *l,S. - r~i<»l<J ^oles the brushes, which are thus seen to be alternately, one positiveand the next negative, as we go around the commutator. Ifa machine having more than two sets of brushes is examined,it will be found that all the positive brushes are joined by aheavy conductor and all the negative brushes by another. Thenone connection is made from the group of positive brushes tothe external circuit, and one from all the negative brushes. In speaking of alternators, the actual construction of arma-tures was
. The principles underlying radio communication . ,c.,ctc Armature conducTora *l,S. - r~i<»l<J ^oles the brushes, which are thus seen to be alternately, one positiveand the next negative, as we go around the commutator. Ifa machine having more than two sets of brushes is examined,it will be found that all the positive brushes are joined by aheavy conductor and all the negative brushes by another. Thenone connection is made from the group of positive brushes tothe external circuit, and one from all the negative brushes. In speaking of alternators, the actual construction of arma-tures was described; that is, the use of machine-wound coils inslots in the face of a laminated core. armatures are made 10 See section 63, p. Fig. 114 (upper)—Method of assembling commutator segments. (middle)—Commutator and armature core assembled showingrisers. Fig. 116 (lower)—Armature complete with windings con-nected to risers. 183 184 DYNAMO-ELECTRIC MACHINERY. the same way except that the ends of the coils are soldered tothe commutator The main steps are shown in Figs. 114, 115, and 116. Thefirst shows the copper segments, with their sheets of mica be-tween them, assembled in the form of a ring and held togetherby a firm temporary clamp. The next picture shows the com-mutator fastened on the front end of the armature core. The risers are to be seen coming up from the ends of the seg-ments for connection to the armature coils. On the core, builtup of thin laminations, note the teeth, slots, and three rows ofair ducts for ventilation. The last picture shows the coils inthe slots of the core. Their ends have been soldered to thecommutator. 88. Excitation: Separate, Series, Shunt, Compound.—Wh
Size: 1255px × 1990px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublisherwashi, bookyear1922
