. American telephone practice . is that of puttingthe receiver in inductive relation to the line without subjecting it tothe passage of direct current through it. In Fig. 258 is shown the current arrangement of the common bat-tery sets manufactured by the Stromberg-Carlson Telephone Manu-facturing Company. In this the induction coil has one of its wind- m 1 FIG. 259.—SIMPLIFIED KELLOGG SUB-STATION CIRCUIT. ings placed directly in series with the transmitter when the hook isup, this path shunting the path containing the bell and receiver is placed in an entirely local circuit in s
. American telephone practice . is that of puttingthe receiver in inductive relation to the line without subjecting it tothe passage of direct current through it. In Fig. 258 is shown the current arrangement of the common bat-tery sets manufactured by the Stromberg-Carlson Telephone Manu-facturing Company. In this the induction coil has one of its wind- m 1 FIG. 259.—SIMPLIFIED KELLOGG SUB-STATION CIRCUIT. ings placed directly in series with the transmitter when the hook isup, this path shunting the path containing the bell and receiver is placed in an entirely local circuit in series with theother winding of the induction coil. This arrangement accomplishesthe removal of the receiver from the action of direct current in avery simple manner. The method by which the Kellogg Company places the receiverin proper relation with the line without subjecting it to the passageof direct current is shown in simplified form in Fig. 259, which showsthe condition when the hook is raised. In this the transmitter is. FIG. 260.—KELLOGG SUB-STATION CIRCUIT. placed in series across the line with an impedance coil of low resist-ance, but of high retardation. Direct current from the central office,therefore, flows readily through this path for the operation of thesignals and for the supply of current to the transmitter. Around theimpedance coil is placed a shunting circuit containing the receiverand a two-microfarad condenser, and through this path, instead 310 AMERICAN TELEPHONE PRACTICE. of through the impedance coil, the fluctuating voice currents might be thought that the presence of the impedance coil wouldmaterially reduce the receiving efficiency of the station, but what-ever reduction of efficiency does occur due to its presence is so slightas to be unnoticeable even by an expert. In Fig. 260 is shown the actual working connections of this ar-rangement through the hook switch by means of which the bell or
Size: 2540px × 984px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1900, bookdecade1900, bookidamericantelepho00mill
