Improved Method and Means for Eliminating or Reducing the Influence of Disturbing Currents on Telephone Circuits.

摘要

2030. Jacobs, C. M. Feb. 1. Telegraphs ; telephone systems.-Relates to methods of overcoming the disturbing influence of telegraphic and low-frequency currents on telephone receivers, particularly in the case of simultaneous telegraphy and telephony. In Fig. 1, a transmitter band receiver i are shown, the latter bridging across a Wheatstone bridge having non-inductive and inductive resistances h, h1 and g, g', respectively. These resistances may be balanced for steady currents so that the receiver will only be affected by high-frequency currents. Fig. 2 illustrates another method in which a condenser k is inserted. The receiver coils m are shunted by the low-resistance coil n, possessing a high inductance, the effect of which is to permit the passage of the low-frequency currents and compel the more rapidly vibrating currents to pass through the receiver. The condenser may be replaced by a " phonopore " coil ; in another modification, the telephone receiver may be wound with the phonopore coil with or without the shunting inductance coil n.