GB600154A - Improved transformer tap-changing devices - Google Patents

Abstract

600,154. Transformers. GENERAL ELECTRIC CO., Ltd. Sept. 28, 1945, No. 25267. Convention date, Oct. 25, 1944. [Class 38 (ii)] A tap-changing device for a transformer, which can give both fine and coarse steps of adjustment and can make connections for bucking or boosting of voltage, has switches for feeding a fine-selector section of the trans-' former, selectively, at its centre or at either of its ends, for connecting a coarse-selector section to one end or the other of the fine-selector section so that the section voltages are additive, for feeding the coarse-selector section, selectively, at one end or the other, and for completing the circuit through the coarse-selector section alone. There may be two or more coarse-selector sections. The coarse-selector section CF has the same number of turns as the fine-selector section FS whereas the coarseselector section CS has half that number. This Figure shows the switches in the neutral position. Boosting is effected by turning controller A clockwise and bucking by turning it anti-clockwise. Switches B1, B2, D and E are driven in steps by the controller A, preferably through Geneva gears, so that the switch arms turn in the same direction as the controller. The latter has contact arms S1 and S2 movable over these contacts so that one arm remains on a contact until as soon as the other arm has come to rest on the next contact. The arms S1 and S2 may be connected together and to the outgoing lead Y through, for example, a separate impedance byepass. The contacts of one or more of the switches may be separated, or two or more of the switches may be combined.