AC vs DC Power & Motors –  Differences and Benefits

AC and DC power isn’t new and yet it has been two main types of power we are taking advantage of even in the modern age we live in.

But did you ever understand the difference between AC and DC power, did you know how we use it, and what is the preferred power type for electronics we use on a daily basis?

These are some of the questions we’ll be answering in this article. However, you’ll also be able to learn more about AC and DC motors, and even about slip rings and their use in the AC motors, so keep on reading!

What is an AC Power and What is an AC Motor?

Source: Wikipedia.com

The easiest way to understand the AC power is to remember it as an alternating current (hence the AC shortcut).

It is a type of power that inverts its direction at times and if you have a look at the example of an AC power, you would see the oscillating graph and it is actually the “standard” electricity we have in our outlets at home.

And the most interesting thing that not many people understand is that AC’s power comes from the flow of electrons. AC power comes with a frequency of 50 Hz which means that it can change its direction 50 times in only one second.

AC motor is known as a motor that uses alternating current to turn it into and produce mechanical power with the help of magnetism.

What is a DC Power and What is a DC Motor?

Source: Wikimedia.org

DC power stands for direct current which is very easy to remember as an electrical charge of electrons that flows in only one direction.

One of the best examples of DC power is the electrochemical cell which can hold a charge of direct current. The best real example of this is the batteries and electronics such as TV, computers, and others.

Not only can direct current flow through a conductor, for example a wire, but it can also flow through insulators, semiconductors or even through vacuum.

What’s also interesting is that DC power can be produced from an AC power but it can’t be done vice-versa.

A DC motor is a type of a motor that can easily convert electrical energy into mechanical energy, just like the AC motor.

However, since the current is only flowing in one direction, a DC motor works differently than an AC motor, but it provides the same output (result).

Related: Single-phase and Three-phase Power Systems

AC Power vs DC Power

Source: Wikipedia.org

DC power is more efficient than the AC power, since direct flow provides higher efficiency which leads to better power to size characteristics.

Therefore, since DC power has more energy and is more efficient as a form of energy, that’s why it is being used in appliances and equipment which require more power to size characteristics.

For example, DC power is far much more efficient in the use of LED lighting. Yet, we have AC power in the household outlets due to the fact that DC power has more voltage and is more lethal, as well as due to the electrolytic corrosion which can be an issue with direct current.

AC power is still very efficient so it made a better choice for our homes.

AC vs DC Motors

AC motors are far more efficient than DC motors as they can produce high torque levels and are therefore considered to be a more powerful motor type. However, DC motors are more efficient and they can make better use of the input energy.

On top of that, DC motors are well known for their great speed control and a versatile output range, while the AC motors require resistance to control their speed.

Therefore, both motor types have their advantages and disadvantages, and therefore, both of these types are still used to this day, depending on the purpose.

Why are Slip Rings Used in Certain Types of AC Motors?

Source: Moflon.com

Slip rings are a small device known for elimination of wire winding problems in machines that have a rotary aspect to it, but how do they fit in AC motors?

If you ever come across slip rings in the AC motors, it wasn’t a mistake. Compared to DC motors, AC motors are not as good at providing great speed control.

Therefore, certain types of AC motors such as induction motors require additional options to control the motor’s speed.

In this case, slip rings are used to add resistance since it’s one of their many possibilities.

Slip rings help add resistance to the motor’s windings. As the motor rotates, slip rings turn with the rotation and the inner brushes in the slip ring maintain a contact but also add the resistance which is transferred to the windings.

AC motors require slip rings for resistance because they are an ideal way to adjust and control the speed and torque. This way, speed and torque matches the characteristics of the motor, eliminating the hazard in case there was no resistance.

Moflon is one of the most reliable slip ring companies that produces slip ring types that fit almost any industry, from aerospace and radar, to medical and even food & beverage industry. Moflon also produces custom slip ring solutions for situations where slip rings can do more than one job.

Related: Electrical Motors

Conclusion

AC and DC power is very easy to understand as there’s a clear and main difference between them, bringing different advantages and disadvantages.

Since they’re both different, there’s no better or worse power type, yet each one of them fits different needs and scenarios better.

Even the downsides such as inability to control speed in AC motors is fixed with the use of slip rings, so both power types and both motor types are still being used to this day, helping us power our homes, power our cities, gain mechanical power, and take advantage of electricity in general.

What is your favorite power or motor type and why?