Abstract: A transforming apparatus automatically adjusting the voltage of three-phase power supply comprising three input terminals, three output terminals, a Y-connection three-phase transformer, a switch group, and a switch switching circuit. The three input terminals are respectively connected to three main lines of the three-phase power supply, and the three output terminals are connected to a load installation. The Y-connection three-phase transformer comprises a core, an R-phase winding circuit, an S-phase winding circuit, and a T-phase winding circuit. In the R-phase winding circuit, an R-phase main winding, an R-phase first auxiliary winding, an R-phase first switch, an R-phase second auxiliary winding, and an R-phase third auxiliary winding are serially connected in that order between the input terminal Rin and a neutral point O, the output terminal Rout being connected to the other end of the R-phase main winding.

Abstract: A transforming apparatus automatically adjusting the voltage of three-phase power supply comprising three input terminals, three output terminals, a Y-connection three-phase transformer, a switch group, and a switch switching circuit. The three input terminals are respectively connected to three main lines of the three-phase power supply, and the three output terminals are connected to a load installation. The Y-connection three-phase transformer comprises a core, an R-phase winding circuit, an S-phase winding circuit, and a T-phase winding circuit. In the R-phase winding circuit, an R-phase main winding, an R-phase first auxiliary winding, an R-phase first switch, an R-phase second auxiliary winding, and an R-phase third auxiliary winding are serially connected in that order between the input terminal Rin and a neutral point O, the output terminal Rout being connected to the other end of the R-phase main winding.

Abstract: An electric power saving transformer for three-phase current with an automatic voltage transferring device, in an autotransformer of a three-phase three-wire system or a three-phase four-wire system, has phase-winding of one set or plural sets of main coils which are connected to input terminals on a three-phase core-type core; connecting plural sets of exciting coils mutually connected in series to wind the three-phase core-type core between the ends of the main coils by means of plural combinations of connection; connecting plural electric switches between the ends of the main coils and the exciting coils which are switched to ON/OFF based on a voltage value detected at the input or output terminals; and connecting and disconnecting between the ends of the main coils and the exciting coils, by switching ON/OFF of the electric switches stepwise on the same value of voltages or currents between the phases in order to automatically change output voltage correspondingly to input voltage onto voltage transferrin

Abstract: In an autotransformer of a single-phase three-wire system or a single-phase two-wire system, plural sets of main coils connected with input terminals are phase-wound on a single-phase core-type core, and further, between the ends of the main coils, plural sets of excitation coils mutually connected in series to wind on the single-phase core-type core are connected by plural combined connections. Further, plural sets of thyristors controlled ON/OFF by using the value measured by a voltage sensor connected to the aforementioned input terminals are provided between the aforementioned ends and the exciting coils. Therefore, the circuits are automatically changed in response to the increase and decrease of the input voltage, with a result that a load is not ill influenced so that the voltage value is always output within the predetermined range.