Yanbian delta-shaped three-stage step-down starting circuit

The circuit is shown in Figure 3-62. The step-down starting circuit is manually controlled by a button. When starting, the motor windings are first connected in
Y shape, then successively transferred to Yanbian △ shape (2:1), Yanbian △ shape (1 t 2), and finally transferred to △ shape and put into normal operation,
which is a three-stage voltage reduction start.