. American telephone practice . hown in connection with commercial formsof magneto generators. Instead of shunting the generator armature when not in use, someforms of telephone service require that it shall be left on open cir-cuit when not in use. Such a device is called a generator cut-in,and is almost always automatically operated by the turning of thecrank, although, of course, they may be manually operated by abutton. These devices differ from the automatic shunts only inthat they serve to normally hold the armature circuit open and toclose it when the generator is operated, instead of s
. American telephone practice . hown in connection with commercial formsof magneto generators. Instead of shunting the generator armature when not in use, someforms of telephone service require that it shall be left on open cir-cuit when not in use. Such a device is called a generator cut-in,and is almost always automatically operated by the turning of thecrank, although, of course, they may be manually operated by abutton. These devices differ from the automatic shunts only inthat they serve to normally hold the armature circuit open and toclose it when the generator is operated, instead of serving to breakthe circuit around the armature when operated. MAGNETO CALLING APPARATUS. 119 Coming now to commercial types of magneto calling apparatus,the Holtzer-Cabot Company, of Brookline, Mass., are manufactur-ing an excellent magneto generator, two types of which are shownin Figs. 88 and 89. The end plates in which the generator armature is journaled areof cast brass and are secured directly to the cast iron pole-pieces,. FIG. -HOLTZER-CABOT FOUR-BAR GENERATOR. the ends of which are flanged and machined so as to fit accuratelythe internal curves of the pole-pieces. The armature core is of softiron laminations, the layers being in the form of punchings clampedtogether on a steel rod which therefore serves as the armature construction of the armature and the shape of one of the punch-ings or laminations is clearly shown in Fig. 90. After being built FIG.
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Keywords: ., boo, bookcentury1900, bookdecade1900, bookidamericantelepho00mill
