GB463992A - Improvements in circuit arrangements for reducing the influence of fluctuations of mains potential and load on the potential supplied by a rectifier - Google Patents

Abstract

463,992. Converting automatic regulation ; charging and discharging batteries. SIEMENS-SCHUCKERTWERKE AKT.-GES. Dec. 3, 1935, Nos. 33508, 33509, and 33510. Convention dates, Dec. 4, 1934, March 23, 1935, and July 10, 1935. [Classes 38 (ii) and 38 (iv)] Fluctuation of potential of the D.C. circuit 4, Fig. 1, fed from an AC. circuit through a rectifier 3 due to variations in D.C. load and also variations in the A.C. potential, is prevented by means of two transformers 1 and 2 having different magnetic characteristics, their windings being in series on the primary side and in series on the secondary, and one of the transformers having a magnetic biassing winding fed with the rectified current. Preferably, the secondaries are in series opposition although series-additive connection may be used. When a battery 4 is used and the arrangement has a rising voltage characteristic as in Fig. 3, charging will cease at the point D and will not recommence until the battery voltage has fallen to the point E<1> at which point the charging current jumps from zero to J<1>. To cause the characteristic to drop beyond a particular load value, a resistance having a negative temperature coefficient is connected in parallel with the winding 5. In addition, the transformer 2 may be provided with a further biassing winding which is connected through a resistance across the rectifier. By adjustment of this resistance and also the resistance across the winding 5, the shape of the characteristic can be varied. To produce a characteristic having a very pronounced curvature, the biassing windings are connected to act in opposition. To compensate for variations in the rectifier impedance due to temperature changes, a resistance may be connected in parallel with the windings 5 having a similar temperature resistance characteristic to the rectifier. Fig. 10 shows a high voltage arrangement in which the load 20 is fed through a rectifier 3 from a step-up transformer 13, the primary of which is supplied from the series connected secondary windings of the transformers 1, 2, the saturating winding 5 is supplied from a rectifier bridge 14 in series with the primary of the transformer 13, and the saturating winding 7 is supplied through a rectifier 16. Resistances 15, 19 enable adjustments to be effected. The Specification as open to inspection under Sect. 91 also states that an A.C. load could be supplied by omitting -the rectifier and transformer 14. This subject-matter does not appear in the Specification as accepted.