. Electrical world. R. is the idea of the inventor, Mr. J. C. Barclay, of New York City, tobring these two devices into as small a space as practicable and yethave either removable for inspection without disturbing the other,and he has certainly succeeded admirably. SELECTIVE SYSTEM. Messrs. F. C. Penfield and O. Templin have recently patented aselective system adapted for independently ringing up to ten partiesupon a single line. The system depends upon the point use of bothsides of the line and the ground in various combinations with relaysand selective bells and several sources of current.
. Electrical world. R. is the idea of the inventor, Mr. J. C. Barclay, of New York City, tobring these two devices into as small a space as practicable and yethave either removable for inspection without disturbing the other,and he has certainly succeeded admirably. SELECTIVE SYSTEM. Messrs. F. C. Penfield and O. Templin have recently patented aselective system adapted for independently ringing up to ten partiesupon a single line. The system depends upon the point use of bothsides of the line and the ground in various combinations with relaysand selective bells and several sources of current. At two of thestations both rela)-s and bells are responsive to alternating currents,the selection of one of these stations being dependent upon the ap-plication of such current to one side of the line only. ,\t these sta-tions the relays are arranged to open the bell circuits when ener-gized, and each is wired through a condenser to ground from theside of the line other than that from which its bell is wired. There-. FIG. 2.—PENFIELD AND TEMPLIN SELECTIVE SIGNAL SYSTEM. fore, when the relay is operated the bell cannot be. For every otherstation the bells are normally upon open circuit, being groundedonly by the actuation of the corresponding relay. Both relays andbells at these stations are polarized and the latter are biased to respond to impulse currents of one sign only. For these stations therelay is normally grounded through a condenser, but it is found thatthe charging of this latter is sufficient to cause the relay armatureto respond sufficiently to automatically short-circuit the condenseras long as the actuating current is maintained. Fig. 2 shows diagram-matically the circuit of this system, the signs indicating clearly thecurrent combinations necessary for the different stations. AUTOMATIC SYSTEM. Several years since an automatic exchange system was patented byJ. C. Slater, of St. Louis, for which an improvement now system referred to requires the subsc
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
