| 摘要 |
PURPOSE:To reduce the size of a transformer serving as both three-phase and single-phase transformers, by delta-connecting secondary windings, providing an intermediate tap on one of the secondary windings, and winding the secondary winding provided with the tap on one of the outer legs of a three-phase three- leg core. CONSTITUTION:Primary windings 11, 12, 13 of a three-phase transformer are star-connected, while secondary windings 11', 12', 13' are delta-connected. In addition, the secondary winding 11' is provided with an intermediate tap 21. Thus, it is possible to obtain a three-phase current (210V) from three-phase output terminals 14, 15 and 16, a single-phase current (105V) from single-phase output terminals 14', 17 and 15' 17, and single-phase current (210V) from the terminals 14', 15'. The secondary winding 11' used for both three-phase and single-phase currents is increased in shared capacity when three-phase and single- phase loads are simultaneously applied and therefore increases in heat generation amount. For this reason, the secondary winding 11' is wound on one of the outer legs of a three-phase three-leg core. |
