Single-phase shaded pole motor reactance speed regulating circuit

In the circuit shown in the figure, the reactor is connected in series with the stator winding of the motor. Adjust the speed switch SA. When it is set to "fast", the reactor L is not connected and the motor runs at full voltage, so the speed is the fastest; when it is set to "medium" , part of the inductance coil is connected in series, so the speed is in the middle gear; when SA is set to "slow", all L coils are connected to the stator winding circuit, so the motor speed is the slowest.