GB379667A - Improvements in and connected with transformers of the static type - Google Patents

Abstract

379,667. Regulating transformers ; automatic regulation. NICHOLSON, H. G., Britannia Works, Colchester, Essex. Feb. 21, 1931, No. 5527. [Classes 38 (ii) and 38 (iv).] In a regulating transformer, the primary winding 3 or at least a part thereof is made to embrace an auxiliary magnetic circuit 1 on which is provided an opposing winding the current in which is caused to increase with load on the transformer thus causing the resultant flux linking the primary winding to decrease and tending to produce an increase in secondary voltage. In the arrangement shown, the opposing winding 7 is connected in series with a winding 9 on a second auxiliary core 8 to a source of constant voltage (e.g. the source to which the primary 3 is connected). The impedance of the winding 9 is caused to decrease with increasing load current by providing on the core 8 a coil 10 in series with the main secondary 4 so as to produce a flux opposed to that due to the winding 9. In a modification, Fig. 3 (not shown), the second auxiliary core 8 is dispensed with, and some of the turns of the main secondary 4 are made to embrace the auxiliary magnetic circuit 1 so as to produce directly therein a flux opposed to that produced by primary. An auxiliary saturating winding may be provided. In a further modification, Fig. 4, the two auxiliary cores of the first arrangement are combined in a single three-limbed magnetic circuit 13 having the primary turns and the winding 7 arranged on the outer limbs, and the winding 10 in series with the main secondary disposed on the centre limb. The flux opposing that produced by the primary turns in the auxiliary magnetic circuit may be additionally controlled bv manual or automatic variation of the magnitude or phase of the current in an additional coil provided on the auxiliary magnetic circuit.