AC vs DC Motor: What’s the Difference Between the Two?

Did you know that the first electric motor capable of enough energy output to perform tasks was invented almost 200 years ago?

Direct current and alternating current motors have been around for centuries but they’ve come into mainstream use over the past decade. Look around you and you’re likely to find something that uses an electric motor.

Tesla automobiles run on alternating current to get you from Point A to Point B. Most operating machinery that you see uses the best direct current motors to conduct the tasks they’re needed for.

Continue reading to learn more about the differences between alternating current and direct current motors.

What Is Direct Current?

Direct current is an electric current that is always going in the same direction with consistent amperage.

Direct current motors come with a host of benefits. They have a higher starting torque than alternating current motors do. It is also better for start-stop applications and allows for faster reversing. This is a big reason why direct current is the choice for DC motor braking.

Another benefit of direct current motors is that the speeds are able to vary depending on the changes in the voltage used. They are easy to control and are a cost-effective motor option.

There are two different types of direct current motors to know about. They are the brushed direct current motor and the brushless direct current motor.

Brushed Direct Current Motor

A brushed direct current motor has four components that allow it to work. It’s made up of a stator, a rotor, brushes, and a commutator.

The stator works by creating a stationary magnetic field that surrounds the rotor. It generates the magnetic field by using either permanent magnets or electromagnetic windings.

The rotor is made up of one or more windings. The magnetic poles created by the windings are attracted to the opposite poles that the stator makes which leads to the rotation of the rotor.

As the motor works, the windings receive a constant flow of energy to ensure that the poles produced by the rotor don’t overrun the poles created by the stator.

The brushes prevent the need for a controller to switch the current in the windings of the electric motor. It works by using a copper sleeve on the motor’s axle. This sleeve comes into contact with the commutator to produce a dynamic electric field.

The last component is the commutator. It gets rubbed by the brushes which supply the charge to the winding and create power for the electric motor.

The drawback to using a direct current motor is that it produces friction and sparks. It is prone to overheating and needs maintenance in order to continue working smoothly.

Brushless Direct Current Motor

The brushless direct current motor has three segments: a stator, a rotor, and a position sensor.

The main difference between the brushless and brushed direct current motors is that the mechanical commutator is replaced with an electric switch circuit in brushless motors.

Brushless motors are synchronous. The magnetic field produced by the stator and the rotor rotates at the same speed and frequency.

The advantage of a brushless direct current motor is that there is less maintenance required. They are also able to be used in a wide variety of applications due to the ability to work with multiple voltage requirements.

Alternating Current Motors

Alternating current motors have become increasingly popular over time. They have some major advantages that come with using them. AC motors require minimal maintenance to keep them up and running. They also require little power in order to get them started.

Alternating current motors are efficient and durable as well as quiet to operate. This makes them a highly sought-after motor for many different applications.

There are two different types of alternating current motors. They are the synchronous motor and the induction motor.

The synchronous motor works by rotating at a consistent frequency based on the supplied current. It uses a stator and a rotor to create power for different applications.

The other type of alternating current motor is the induction motor. Induction alternating current electric motors are one of the most common types of electric motors available today.

They are widely used because they are simple to use and offer a high level of ruggedness. Induction motors use a wound stator and rotor to create power using electricity.

The stator winding creates electromagnetic induction which is used to turn the rotor and create the power needed to make the motor work.

Alternating current motors have the benefit of requiring less power to start them up and begin running. They offer the user a greater level of control over the motor’s acceleration and current levels.

They are also able to be customized to a much greater degree so that they can be used on a wide variety of applications. Best of all, they have a greater degree of longevity and durability than direct current motors do.

Applications of AC and DC Motors

Alternating current motors are used in a variety of different industrial capacities. They are commonly found on appliances, compressors, conveyors, and transportation equipment.

Because they produce more stable torque and speed than direct current motors and have quicker response times they are perfect for manufacturing equipment as well as elevators and vacuums.

Direct current motors are commonly found in manufacturing equipment that requires consistent low-speed torque. Conveyors and turntables are common applications that DC motors are used for.

Dynamic braking is another common industrial use for direct current motors.

Make Electric Motors Work for You

Electric motors are a valuable tool regardless of if you need direct current or alternating current motors. While they work in different ways, they both provide important functions from transportation to manufacturing.

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