GB708980A - Improvements in or relating to transformer arrangements - Google Patents

Abstract

708,980. Transformers; automatic regulation. SOLA ELECTRIC CO. March 3, 1952 [March 16, 1951], No. 5488/52. Classes 38(2) and 38(4) A transformer arrangement having a primary winding 36 and a secondary winding 38 loosely coupled on a magneto core 10, a condenser 11 in circuit with the secondary winding 38 of such a capacity that when the transformer is excited with a voltage of predetermined magnitude and frequency a condition of series resonance exists, and a load circuit connectible to a predetermined portion of the secondary winding, is characterized by a third winding 39 disposed on the core 10 in additive polarity to the secondary winding 38 and in such a position as to link with some of the secondary leakage flux but substantially free of linkage with the primary leakage flux, the secondary winding 38, the third winding 39 and the condenser 11 being serially connected. The loose coupling between windings 36, 38 is occasioned by the air-gapped shunts 22, 23 and the air gap 35 tends to isolate the winding 39 from the primary flux which will be substantially confined to the low reluctance shunts 24, 25. The resonant circuit 11, 38, 39 will keep the output voltage substantially constant, the winding 39 being instrumental in neutralizing any harmonics which appear in this voltage. Any slight variations from constancy in the output voltage may be eliminated by the provision of a bucking winding 37 tightly coupled with the primary winding 36 and connected in the output circuit 47, 48. Alternatively, the winding 37 may be dimensioned to give a rising or falling output voltage. Specification 529,420 is referred to.