6 Differences between AC & DC: AC vs DC Motors

When we speak of either AC or DC, we refer to the types of electric power used to run our machines and appliances. It’s also used for lights running in a domestic or industrial setup. We often mingle with ac and dc sources in our everyday lives. We seldom know the difference between them or how we utilize them in our daily lives.

Here we have looked at the methods of generating the power sources. It includes the different ways of utilizing them and where they are utilized. We’ll look at the differences between ac and dc systems and the differences between their motors. Their differences are as wide as normal chairs and zero gravity chairs.

circuit breaker

AC and DC power get their names from their nature of current flow as they transmit power to the devices that depend on them. The names are abbreviations for Alternating and Direct Current. They represent the current flow and the voltage flow.

What is ac & when is it used?

AC is electric power generated by the alternating current, which creates a sinusoidal waveform. A graph ranges from the negative to the positive side when represented in a graph. When it is in positive form, the graph is usually on the upper part of the wave. When in the negative, the curve is on the lower side of the graph.

It alternates between the negative and the positive sides 60 times a second for electricity consumed in North America. The same number is 50 times a second in Great Britain. The changing of sides happens so fast that the human eye never detects it. The completion of 50 to 60 rotations in a second is known as hertz.

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When is it Used?

AC is preferred where the power needs to be manipulated for activities, such as transporting it to consumers far away for use. When using AC, the electricity produced can be passed through transformers. It allows it to be stepped up to very high voltages for power distribution to be made possible.

AC is usually transmitted in high voltages over long distances to reduce the amount lost through heat. It’s done by minimizing the current in the lines since a lower current reduces the heat produced through resistance.

We should consider high-quality extension cords for our outdoor activities in our homes. Get a reliable circuit breaker based on your amp usage, and consider which amp wires to use based on your amp rating. Otherwise, the AC may become dangerous!

extension cord

What is DC?

DC stands for direct current. It is the most common electric power learned in schools for basic electricity classes. It is electricity generated from a constant current that flows in a single direction without changing its polarity.

If plotted in a graph, it gives a straight line showing no change over time for current or voltage against time.

How is it used?

DC is mainly used in applications of highly delicate components like motherboards. They require a low voltage supply. It’s also used where voltage storage is needed for later usage. Electronic devices are the main users of DC due to their reliable and constant voltage supply. It can come either from batteries or directly supplied from the mains but converted by inbuilt rectifiers.

DC is usually tapped from electricity storage points like batteries. They can be used later in portable generators or mobile phones. It’s also used in laptops or remote-control devices. Devices that utilize DC in our homes require much electric care.

Solar panels generate DC power, which is usually converted by inverters to AC power for usage in houses. Some people utilize solar energy without converting it.

Alternating versus direct current


The battle of currents has been in existence since the 1880s when the pioneers of both were still alive. Thomas Edison discovered DC, while Nikola Tesla discovered AC. Both worked day and night to support their currents.

However, Thomas Edison is recorded as having been more scheming of the two. He went to the extent of electrocuting live animals to show how dangerous Alternating Current was for consumption. He was afraid of losing royalties for the patents he had already sold.

At the 1893 Chicago World Fair, Nikola Tesla underbid to get the contract for powering the event. He won, and the world got the chance to experience AC. Later that year, it was also adopted by the Niagara Falls hydroelectric plant. It was to supply Buffalo with electricity.

While the battle might seem to have favored AC over DC, the use of DC is on the rise currently with computers and solar cells. You can also find it in electric vehicles and devices that depend on microchips. DC is now powering them! Direct current is preferred due to the constant stability necessary for the devices to work.

However, the war between the two is over. They now work to complement each other. For activities requiring high voltage like aluminum welding or flux core welding, AC is used.

You can use an SAE to Metric conversion chart on a different topic.

6 differences

Direction of flowStabilityAbility to modify current and voltage values
TransportStorageEffective value
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Direction of flow

The main difference between these two types of current is how they transmit electricity from one point to another. The appearance of the current when plotted on a graph is also different.

When AC transmits electricity, it changes its polarity from positive to negative. If plotted on a graph, it is an instantaneous change in the current value, which looks like a sinusoidal wave. When DC transmits a constant current value, it gives a straight line if plotted on a graph.


When looking at stability, we consider whether it fluctuates over time when transmitting electricity. DC transmits constant current with the same polarity. AC gives current that changes with time from one point to another and changes polarity.

Stability is mainly considered when looking for the best type of electronic device for optimal functionality. Without fail, you need something because circuit boards have chips that operate on a current that flows in a single direction. It does not change in value over time.

Ability to modify values

The ability to readily and cheaply modify the current or voltage is another major factor when looking for which to use.

The alternating current is easily manipulated. It can be changed, either step up or step down. The current or voltage supplied is favorable for you. DC cannot change the current supplied from one value to another. For instance, transmitting power is usually carried in high voltage lines. Once they reach our homes, they are reduced to values that can be consumed domestically. 110 to 120v are the most common values. In industries, you’ll find 208 to 240v.


For electricity to reach our homes from providers, it has to be supplied from the point of production to our houses’ point of consumption.  AC is easily transmissible over long distances. It’s due to its stepping up to increase the voltage and reduce the current. It means effectively relaying it over long distances with minimal energy loss.

For DC, it is harder to convey power over long distances. It’s due to its inability to be transformed to either higher or lower voltages.


DC power is easily tapped from storage facilities. An example is a battery. It can be utilized at any moment, while AC can’t be stored for use later on.

Effective value

The effective value is the constant or average amount of voltage or current you get when supplying a device. The practical value of DC is higher than that of AC due to the alternating nature of AC. It provides less voltage or current value for similar values with that of dc remaining constant. While using AC, you need to supply more current to attain a similar effective value with DC.

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AC Motor versus DC Motors


AC motors change alternating current to mechanical energy through magnetic induction. They are used by most of the appliances that we use. They need to be plugged into electric sockets to get the electrical supply to work. AC motors are machines as large as metal lathe machines that work on the metal of different sheet metal thicknesses.

While DC motors use direct current, AC motors use AC to produce mechanical power, just as their name states. Another distinct characteristic of AC motors is they don’t use brushes in their working mechanism.

Brushes drastically reduce the life expectancy of a motor with the parts that come into contact with them. It requires constant replacement due to their wearing out.

AC motor consists of two main parts that aid in its movement: Rotor and stator. The rotor is the rotating part of the motor usually connected to an external shaft to transmit the revolutionary movement needed.

The stator holds copper wires wound around it. It produces a magnetic field that leads to producing an electromotive force. It produces the turning effect needed to turn the rotor.

DC Motor

DC motors convert electric energy from direct current to mechanical energy, enabling the motor to turn. The motors work based on the principle that mechanical energy is produced once a magnetic field interacts with an electric field.

For the motor to work, it depends on two main components: The stator and armature. The stator is stationary and provides the constant magnetic field needed for the movement. At the same time, the armature is the rotating part connected to the dc source that provides the electric energy.


What are the three main differences between AC and DC?

Three significant differences between AC and DC are the following:
– The amount of electricity that it can be transported.
– Each type of electric current has a different frequency.
– The direction of the flow of each type of electric current.

Alternating current can carry more electricity over longer distances compared to DC.
The frequency of AC is between 50 Hz and 60 Hz, depending on the country we are talking about.

The frequency of DC is zero.

The direction of alternating current-type electricity is constantly reversed during the flow through an electrical circuit.
DC electric current flows in one direction continuously in an electrical circuit.

Are houses AC or DC?

Most homes use AC power to power all the appliances you use every day.
This predominant use of alternating current is due to the ease of generating and transporting it in electrical circuits.

AC can be transported over relatively long distances with ease.
An electric current transported at a higher voltage will suffer fewer electricity losses during the transport process.

Also, an electric current that can be transported at higher voltages will have lower resistance.
And the presence of lower resistance will lead to lower heating of the electrical cables during transport.

AC has all these advantages.
It can be easily converted into a high or low-voltage electric current with the help of transformers.

It can be easily deduced why this type of electricity is the predominant choice for powering homes.

Where is DC current used?

Any electronic device with a battery often uses DC as its primary source of electricity.
This type of electricity is also used to recharge the batteries inside electronic devices.

For example, mobile phones or laptops use DC to charge their batteries.
But all sources of electricity inside a house are AC type.

All mobile phones and laptops have an AC adapter inside their structure.
Its leading role is to take the alternating current-type electricity distributed by the power source and turn it into DC-type electricity.
Mobile phones and laptops can charge their batteries without any problems from an AC power source.

Why do we use AC instead of DC?

The main reason AC is used more than DC is because of the ease of transportation.
You can easily transport AC over long distances without suffering significant electricity losses during transport.

You can carry AC-type electric current through the electrical circuits at a very high voltage.
The higher the voltage of the transported electric current, the more quickly it will be transported.

This unique feature of AC is that you can change its voltage with only the help of a transformer.
On the other hand, DC requires a more complex circuit system to change its voltage.

Its voltage cannot be changed by a transformer alone.
This makes this type of electricity a more unfavorable choice.

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