GB462385A - Improvements in the grid control of ionic valves - Google Patents

Abstract

462,385. Converting. ALLMANNA SVENSKA ELEKTRISKAAKTIEBOLAGET. July 2, 1935, No. 18902. Convention date, May 18. [Class 38 (ii)] A discontinuous voltage characteristic is imparted to a grid-controlled rectifier 1 by an arrangement in which the phase of the grid potentials supplied by a transformer 75 is controlled by a phase shifting circuit comprising a resistance 74 and two series-connected inductances 71, 73, the values of which are controlled by saturating windings 70, 72. The latter are respectively energized in accordance with output voltage and load current of the rectifier, the arrangement being such that the phase of the grid potentials is advanced to maintain constant voltage with increase of load over the lower part of the load range and retarded to maintain constant current with a drooping voltage above a predetermined load. The windings 70 are connected to points 41 so as to be energized by the difference between a current proportional to the output voltage as derived from points 4, and a current proportional to a standard voltage derived from the primary side of the main transformer 2 through a transformer 6, stabilizing resistance 61, transformer 62, rectifier 64 and smoothing circuit 66, 67. The winding 72 is connected to points 51 so as to be energized by the difference between a current proportional to the load current as derived from a current transformer 5 and rectifier 50, and a current proportional to a standard voltage derived through transformer 6, stabilizing resistance 61, transformer 63, rectifier 65 and smoothing circuit 68, 69. Rectifiers 84, 85 are inserted in both saturating circuits, the rectifiers being bridged by condensers to permit of alternating components being introduced if desired. Specification 412,773 is referred to. The Specification as open to inspection under Sect. 91 comprises also an alternative arrangement, Fig. 2 (Cancelled, not shown), in which the phase shifting circuit comprises an inductance in series with two parallel resistances which are caused to vary in response to output voltage and load current in such a manner as to produce a level compound voltage characteristic up to a predetermined load and thereafter to regulate for constant power. This subjectmatter does not appear in the Specification as accepted.