What is a Universal Motor?

AIP shares with you the" What is a Universal Motor? ".

October 25, 2023

What is a Universal Motor?

Universal motors are versatile and widely used electromechanical devices that can operate on both alternating current (AC) and direct current (DC) power sources. These motors find applications in various household appliances, power tools, and small industrial machines, making them an essential component in today's modern world. In this article, we will explore the workings and applications of universal motors, shedding light on their unique characteristics and advantages.

Universal motor

Understanding Universal Motors

A universal motor is a type of electric motor that is capable of running on both AC and DC power supplies. Unlike many other types of motors that are designed to work specifically with either AC or DC, the universal motor is designed to adapt to either input. This unique feature is made possible by the motor's construction, which includes both a wound stator and a wound rotor.

Key Components of a Universal Motor:

Stator: The stator is the stationary part of the motor and consists of field windings that are connected to the power supply. In the case of AC power, the stator windings receive a sinusoidal voltage, while in the case of DC power, they receive a constant voltage.

Rotor: The rotor is the moving part of the motor and is connected to the armature, which contains windings. These windings are supplied with current from the power source. The rotor rotates in response to the magnetic field produced by the stator windings.

Key Components of a Universal Motor:

How Universal Motors Work

The operation of a universal motor is based on the principles of electromagnetism. When electric current flows through the stator windings, a magnetic field is created. This magnetic field interacts with the magnetic field generated by the rotor, causing the rotor to spin. The direction of rotation can be controlled by altering the polarity of the current supplied to the stator and rotor windings.

One of the distinctive characteristics of universal motors is their ability to provide high levels of torque and rotation speed, making them suitable for applications that require variable speed control. They are often used in devices where compact size and lightweight design are crucial, such as handheld power tools, kitchen appliances, vacuum cleaners, and blenders.

How Universal Motors Work

Applications of Universal Motors

Power Tools: Universal motors are commonly found in power tools like drills, grinders, and circular saws. Their ability to operate on both AC and DC power sources makes them ideal for these applications, as they can be used in different locations with varying power supplies.

Household Appliances: Many household appliances, such as blenders, vacuum cleaners, and food processors, rely on universal motors due to their ability to provide the necessary power and speed control for efficient operation.

Small Industrial Machines: Universal motors are used in small industrial machines where compact, versatile motor designs are needed. These include textile machines, sewing machines, and small conveyor systems.

Automotive Applications: Some older automotive designs also utilize universal motors, particularly in systems like windshield wipers and electric fans.


Universal motors are remarkable devices that exemplify versatility and adaptability. Their ability to work on both AC and DC power sources, coupled with their high torque and variable speed control, makes them a valuable component in various applications. As technology continues to evolve, universal motors remain a relevant and indispensable part of our everyday lives, powering tools and appliances that make our daily tasks more manageable and efficient.

For more information about the universal motor tester or another motor tester,  please feel free to contact AIP via Tel/Whatsapp: +86-13969776659, E-mail: international@aipuo.com.

AIP universal motor tester