Speed ​​regulating circuit without speed regulator

The general circuit of a capacitor-started motor is shown in Figure (a), which uses a capacitor to shift phase to generate starting torque. If the motor winding wiring is changed from parallel to series, as shown in Figure (b), then the voltage in the main winding LR and the secondary winding LA will be relatively lower than when connected in parallel, which is equivalent to connecting a motor in series in the circuit. reactor, the motor speed naturally drops. If you want to get two speeds, you can add a double-pole double-throw switch SA in the circuit, as shown in Figure (c), and use the switch conversion wiring method to become a two-speed motor. Ceiling fan motors often use this wiring method.