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

摘要

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 E1 at which point the charging current jumps from zero to J1. 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.