Autotransformer for reduced-voltage starting

The utility model relates to the technical field of transformers, in particular to an autotransformer for reduced-voltage starting. The autotransformer at least comprises an iron core and coils, the coils are wound in the middle of the iron core, and a cross-over block is added in the middle of the contacting portion of each coil and the iron core. The autotransformer is characterized in that the iron core is made of silicon steel sheets by means of stacking, a seven-stage stepping seam is a 45-degree bias seam, a core-penetrating screw is arranged between an upper iron yoke and a lower iron yoke, and by-pass screws are arranged on two sides. Each coil is of a four-section cylindrical structure and integrally made of epoxy resin by means of vacuum casting, a radiating air path is formed at the center of each coil, and each coil is wound between the upper iron yoke and the lower iron yoke of the iron core. The autotransformer for reduced-voltage starting is applied to starting and running of motors, and has th