What is an AC adapter?

The likelihood is that if you’re sorting out the electronics in your home, you’re going to come across an AC adapter at some point. But, many of us aren’t exactly sure what an AC adapter is, or how they work.

People often mistake an AC adapter for a charger, and it can be confusing to know which is which. In some cases, they may actually be within the same charging device, but it is important to know exactly what an AC adapter is.

Fortunately, it’s pretty easy to understand and differentiate an AC adapter from the other parts of your accessories, like the charging cable or the ports that you’re using with it. So, let’s look closer at AC adapters and how they work.

What is an AC adapter?

An AC adapter is simply a type of power converter that we can use to power electrical devices around our homes. They can be used to deliver charge into these devices that don’t have the ability to recharge themselves, and they’re typically best charged by your mains power, though they don’t have to be.

One of the most common misunderstandings about an AC adapter is likely because of its name – people think that the “adapter” means that it’s used for connecting two different style devices together. Sort of like a HDMI adapter, which could connect a HDMI port with another type of port.

But an AC adapter is called such because it literally adapts the type of current that’s used to charge your laptop or device. It converts the current from an AC (alternating current) to a DC (direct current).

We can use an AC adapter to charge many different devices, from a laptop power bank to charging the laptop directly itself.

AC vs DC

Many people wonder about what the actual difference between AC and DC even is in the first place, and why it needs to be adapted.

In an AC setup, the direction that the current is flowing can change periodically, which is down to the construction of the generator that’s used with it. However, DC is only flowing in one direction.


Essentially, your home is going to use AC running through it. But, the majority of tech devices that we use around the house are actually going to need to use DC instead. So, how can we get the AC “adapted” over to DC? Yep – a good AC adapter should be able to do the trick.

An AC DC power adapter is one of the most necessary pieces of equipment that we use with our electronic devices. We still need a power source to use them, though.

Why are AC adapters used?


If you’re still wondering why AC adapters are even used, then there are several reasons for using them. Here’s just a few of the main reasons why we stick with using AC adapters;

Low heat – One of the reasons why we use AC adapters is because they’re very good at staying low heat. This means that they’re unlikely to cause any problems when it comes to overheating and fires.
Safety – Probably the main reason why they’re so commonly used is that they’re one of the safest ways to convert this energy over. Generally, our mains electric voltage can be considered as dangerous, so the safe conversion over to our devices is essential.
Simplicity – The good thing about AC adapters is that once they’re designed, they’re relatively straightforward to replace too. You can easily get a new AC adapter, but it’s not as easy to replace a whole power supply.
Noise – Generally, AC adapters tend to be almost silent, though on occasion you can find some that might make a slight noise or whirring sound.

AC Adapters vs Chargers

Generally, we can definitively separate chargers and AC adapters from one another, even though you might have both of them combined into one plug or device.

Whilst an AC adapter specifically refers to the part of the charger that’s going to convert the energy current over, the charger is actually the parts that’s doing the.. well, charging!

A good example of this is with a power bank, which we typically think of as a charger. However, really a power bank is converting the charge from the lithium batteries in the device, so a power bank is also made up of an adapter as well as the batteries, which are the charge.

Are AC adapters universal?

Another very common question about AC adapters is whether they’re universal, and whether they can be used interchangeably on a variety of different devices.

The truth is that with this, it really depends on the adapter and charger that you’re using. This will come down to the voltage and amperage that’s listed on your adapter as well. Ideally, you want to use as close to the original as possible in this case if you want to use a different adapter with your device.

So, if you can make sure that the voltage is the same on both, then you can use a different AC adapter with a different device that its original companion. If you try and charge your device with a lower voltage, then it’ll probably charge pretty slowly.

If you use a voltage that’s higher than your normal charger, then it shouldn’t make your device charge any faster than it usually does either.


All in all, AC adapters provide a pretty essential function that most of us need on a day to day basis. The ability to switch or convert the current of our electricity is a necessity, and a good AC adapter is the perfect way to do this.

You’ll also need to think about the output voltage of your charger too. You don’t want to use a charger with a higher output voltage, as you could end up doing damage to your home electrics. So, the right adapter is an important part of your home setup.

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About Jon

Hey, I'm Jon. I'm an engineer by trade, so it makes sense that I'm obsessed with anything technology related! On the weekends, you can find me playing around with my computers or fixing something around the house. Feel free to leave a comment if you want to get in touch.

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