GB250564A - Improvements in electrical apparatus for the elimination of aperiodic disturbances - Google Patents

Abstract

250,564. Regnauld de Bellescize, H. J. J. M. de. April 8, 1925, [Convention date]. Addition to 226,784. Eliminating effects of disturbing currents.-In the method of eliminating disturbances from a sinusoidal current described in the parent Specification, both parts of the differential apparatus now include a resonant circuit each comprising a constant resistance. The transformer T2, Figs. 3 and 5, which transmits both signals and disturbances alike, has a comparatively large metal section carrying a small number of turns, whilst the transformer T1, in which the hysteresis effect is utilized ta eliminate the relatively-feeble sinusoidal impulses, comprises a section S2 in series with a relatively small section S1 carrying a large number of turns. The combined output it applied to the grid of the valve L3 through an adjustable tapping P, so that the disturbing voltages are balanced out. Condensers C1, C2 enable the phases of the currents to be more effectively opposed, whilst the condenser C3 ensures the symmetry of the secondary circuit. The valves L1 and L3 may be replaced by two pairs of valves arranged in parallel. Fig. 6 shows a supersonic receiver comprising differential stages L1, L2 adjusted so as to suppress disturbances of different intensities. Specification 237,547 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a resistancecoupled amplifier, Fig. 7 (Cancelled), in which the amplification is such that sinusoidal currents in the input circuit I swing the plate current of the last valve between the upper and lower limits of the characteristic curve. This produces a counter-electromotive force across an adjustable resistance V, which can be arranged to counterbalance the sinusoidal component. This subjectmatter does not appear in the Specification as accepted.