GB477738A - Improvements in or relating to electrical impedance networks - Google Patents

Abstract

477,738. Impedance networks. SIEMENS & HALSKE AKT.-GES. Feb. 22, 1937, No. 5228. Convention date, Feb. 22, 1936. [Class 40 (iii)] Positive hot conductors (whose resistance increases with increasing temperature), negative hot conductors (whose resistance decreases with increasing temperature), and cold conductors (whose resistance is substantially independent of temperature) are combined to form high-pass or low-pass frequency filters or attenuation equalizers. When an alternating current is superimposed on a steady direct current, the resistance of a negative hot conductor increases asymptotically with frequency from zero towards a limiting value, and the admittance of a positive hot conductor has the same property. An L section, Fig. 5, therefore behaves as a high-pass filter if the series arm X and shunt arm Y are respectively a cold conductor and negative hot conductor, a positive hot conductor and cold conductor, or a positive hot conductor and negative hot conductor. Low-pass filters are formed by interchanging the positions of these elements. An attenuation equalizer is formed, Fig. 11, by arranging a cold conductor W<1> and negative hot conductor H- in shunt across a transmission line W. Specifications 366,920 and 466,241 are referred to. Reference has been directed by the. Comptroller to U.S.A. Specification 1,875,157.