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The purpose of an electric motor is to produce mechanical energy from electrical energy, no matter the application of the electric motor. The various types of electric motors can be categorized into AC motors, or alternating current motors, and DC motors, or direct current motors.

How can you determine the best motor for you particular application? We’re breaking down the differences between AC and DC motors to help you choose the correct motor for your needs.


The difference is power between AC and DC motors is one of the main features that set them apart.

With AC motors, the direction of the current and the voltage alternates halfway through the cycle by changing the polarity located at the end of the wire. This cannot be done with DC motors. Instead, the current must remain in the same direction, flowing from positive to negative to keep the voltage steady.

AC Electricity

Electrons move inconsistently through wires that utilize AC electricity. Instead, they vibrate and impart energy. This type of electricity is used primarily in power distribution systems such as those within your home or business as they perform more efficiently when handling higher voltages.

AC transformers may be preferred over DC converters as they create electrical fields with higher voltages and lower currents. The benefit of lower currents translates into greater efficiency and less resistance within the wire.

If the application of your system does not need high levels of precision, such as maintaining home appliances, then an AC motor may be the right choice for you.

DC Electricity

DC motors are much more precise than AC motors. These motors perform at higher, constant voltages and provide high levels of stability. This performs well for applications that require steady energy supply, such as powering laptop computers.

Unlike AC electricity where the electrons move back and forth within a wire, DC electricity moves consistently in a one direction for a steady flow of energy.

AC to DC converters are available for use within the home as needed. With DC motors, the speed of your current can be easily controlled by increasing or decreasing the voltage needed for your application.


Differences between AC and DC motors may not be easily or initially noticed, but know that they are in fact very unique. This is due to their input and outputs. AC motors provide increased efficiency by utilizing alternating voltage intake as opposed to more stable DC motors that keep a constant voltage.

AC Motors

AC make use of an alternating current to generate a magnetic field. This field, created by passing a current through a non-moving casing around the shaft of the motor, makes the shaft rotate. Any interference in this magnetic field due to the way the motor is built can affect the speed of the motor.

These motors have long lifespans and a small margin of mechanical error, making them an efficient choice.

DC Motors

DC currents generate consistent magnetic fields. DC motors are designed to convert this constant voltage into mechanical energy by creating a rotating magnetic field. Coils at the core of the motor rotate and connect with the commutator which aids in alternating the flow of the current. This in turn rotates the shaft of the motor.

This function does not have the same level of efficiency as an AC motor. However, energy is very precisely converted with this type of motor.

What Should You Choose?

The choice of an AC motor or a DC motor depends on your particular application.

AC motors provide more efficiency, a longer lifespan, and function well for higher power appliances and applications without the need of a converter. These motors also produce less heat, lowering their chance of failing or overheating. However, AC motors can take up more space and do not work as well for portable needs.

DC motors are stable choices for applications that have sensitive electronic components as have lower electromagnetic interference. These motors can also run on battery power, making them great options for portability. They are more expensive motors and do not have the same level of efficiency or lifespan of AC motors, though their speed control and precision make them attractive choices, depending on their application.

If you need help determining the right motor choice for your particular application, contact us today!