GB473281A - Electric converters - Google Patents

Abstract

473,281. Converting ; automatic regulation. SIEMENS BROS. & CO., Ltd., and DOUBLE, H. S. April 6, 1936, No. 10067. [Classes 38 (ii) and 38 (iv)] Relates to an arrangement for supplying a D.C. circuit TL from an A.C. circuit TA through a rectifier VA and transformer TRA and in which a saturable choke CAA, CHB is connected in the supply lead for effecting voltage regulation, a saturating winding being supplied through a rectifier AR, and consists in the provision of a tuned circuit CHX, CX which operates to cause fairly large changes in the supply to the saturating winding for small changes in the applied voltage. As shown, the rectifier is supplied partly from the secondary SW of the main transformer TRA and partly from the supply through an auxiliary transformer TRC, a bridge BB having ordinary resistances RX, RY and ballast resistances BRX, BRY, being included between the rectifier and the saturating winding. The choke CHX forming part of the resonant circuit has a saturated core so that small changes in voltage applied to the circuit cause large changes in current to the resistance bridge due to the circuit passing into and out of resonance. The saturable choke is also provided with a further saturating winding which is connected in series in the load circuit to give regulation in dependence on load. A delay action switch TH is provided to allow the valve filament to heat before the load is applied. A polyphase arrangement is described. The bridge BB may be replaced by the connection shown in Fig. 5 in which the saturating windings are in two opposing parts A and B, one part being in series with the ballast resistance BRX and the other in series with the resistance RX. In a modification of this, rectifiers may be included in series with the resistances BRX and RX instead of a separate rectifier bridge AR, Fig. 1, being used. A further modification is shown in Fig. 7 in which the saturating winding A is in series with a series-parallel connection of rectifiers RE1, RE2 and resistances BRX and RX. In a further modification of this, the winding A is connected between the points C, D and a further resistance is included in series in the supply leads. Specification 430,247 is referred to.