Frequency sensitive rheostat manual single phase starting circuit

The frequency-sensitive rheostat is a contactless electromagnetic component. During
the starting process of the motor, the frequency of the rotor current gradually decreases, and
the equivalent impedance of the frequency-sensitive rheostat automatically decreases as the frequency of the rotor current decreases. This characteristic of the frequency-sensitive rheostat
exactly meets the requirements for the series resistance during the motor's step-down starting process . Therefore, as long as a first-level frequency-sensitive rheostat is used, the speed of the wound asynchronous motor
can be continuously and smoothly increased.     Frequency-sensitive rheostat is often used for starting of large and medium-sized wound asynchronous motors .     The frequency-sensitive rheostat manual one-way starting circuit is shown in Figure 3-163.