| 摘要 |
420,255. Impedance networks. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and FARREN, L. I., c/o General Electric Co., Wembley, Middlesex. Oct. 27, 1933, No. 29876. Drawings to Specification. [Classes 40 (iii) and 40 (v)] Relates to systems in which either the input terminals or the output terminals of a number of filters are connected in parallel, and comprises means for neutralizing the reactive component of the impedance presented by the group of filters as a whole. For instance, in a set of filters whose input terminals are connected in parallel for the purpose of separating the channels in a multiplex voice-frequency telegraph system, the impedance facing the amplifier which feeds the system should be a constant resistance. Each individual filter offers substantially this resistance within its pass range, but any given frequency lies outside the pass range of all but one of the filters. The remaining filters therefore produce at this frequency a reactive component in the total impedance. This is neutralized by connecting in parallel a reaction network whose impedance is substantially equal and opposite at all frequencies to the reactive component of the existing impedance, so as to produce an antiresonant effect. Two examples of a network suitable for use where twelve harmonic channels are used and comprising two inductances and a condenser are given in the Specification.
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