It seems there might be a bit of confusion here. Hysteresis motors are not typically categorized as single-phase induction motors. Instead, they are a distinct type of motor known as synchronous motors. Single-phase induction motors are a different category of motors commonly used for various applications.
Let's clarify both concepts:
Single-Phase Induction Motors:
Single-phase induction motors are commonly used in household appliances, fans, pumps, and other low-power applications. They are simple and robust, but they require an additional mechanism (usually a capacitor) to create a rotating magnetic field necessary for their operation due to the absence of a true rotating magnetic field in single-phase power supply.
Here's a brief overview of their working:
When power is supplied to the motor, a single-phase AC current flows through the main winding.
Due to the phase difference between the main winding's current and voltage, a magnetic field is produced, which causes the rotor to attempt to follow the rotating field.
However, due to the motor's inherent design, the rotor doesn't start rotating initially but instead starts to vibrate and move back and forth.
To overcome this issue and create a rotating magnetic field, an auxiliary winding with a phase shift (usually obtained using a capacitor) is employed.
The combined effect of the main and auxiliary windings produces a rotating magnetic field, allowing the motor to start and continue rotating.
Hysteresis Synchronous Motors:
Hysteresis motors are a type of synchronous motor that doesn't require any starting torque mechanism like capacitors. They are used in applications where precise speed control and smooth operation are required, such as in clocks, recording devices, and precision instruments.
Here's a simplified explanation of their working:
Hysteresis motors consist of a rotor made of a material with high hysteresis loss (usually a magnetic alloy). This material exhibits a significant lag in magnetization with respect to the applied magnetic field.
When an AC current flows through the motor's stator windings, a rotating magnetic field is created.
The hysteresis effect in the rotor material causes it to resist changes in its magnetization. This results in the rotor attempting to follow the rotating field, aligning itself with it.
Due to this alignment process, the rotor slowly turns to synchronize with the rotating field, which is why these motors are called "synchronous" motors.
Hysteresis motors are known for their smooth and quiet operation but are limited in terms of power output and efficiency.
In summary, single-phase induction motors and hysteresis motors are different types of motors with distinct working principles and applications. Single-phase induction motors are widely used in various applications due to their simplicity, while hysteresis motors find use in applications where precise speed control and smooth operation are critical.