How to Choose the Right AC Adapter

#acadapter #adapter #charger #acdcadapter

If you have a drawer full of adapters, bricks, and cables, how do you know what fits a device? Here’s how to read the info on the adapter as well as the device you want to power.

Knowing which AC Adapter to use for each device can be confusing - but it doesn’t have to be. In this episode, DirtFarmer Jay shows you how to read the “code” on each device (both the adapter and the piece of equipment you want to power) so you can choose the right AC adapter for your gadget.

Once you understand the basic variables of the power supply and the device getting the power, AC Adapter symbols won’t be a mystery anymore.

Let’s start with the AC Adapter itself. Its name tells its function: to adapt/convert AC (Alternating Current) to DC (Direct Current) that most small electronics and electrical devices use.

So, your AC Adapter will generally have the info you need to make the right selection (or in the case of a jumble of cords in a “junk” drawer, match the adapter to the device it came paired with).

The three main pieces of data you need are 1.) the wall outlet power the adapter is designed to be plugged into, 2.) the output of the adapter in DC power (can be expressed in voltage, amps, or wattage), and, 3.), by use of a polarity diagram, what the polarity of the adapter’s charging tip is.

WARNING: Not all adapters give you all this information. Depending on how generous the manufacturer was with the information (or what they were required to provide by law), only some of the information may be on the device. It’s most common to see the polarity symbol, as well as output of the adapter, but not as common on the input. Many times, that can be deduced via where (such as what country) the product was marketed and sold, or the plug configuration (i.e., the plug is different for 110V and 220V outlets or European and North American plug ends).

What’s the worst that can happen if you use the wrong adapter for your device?

Well, the WORST that can happen is you “smoke” your electronic device, ruining it permanently, or making it in need of repair to replace a safety fuse installed to protect the main device from ruination when the wrong power or polarity is applied.

If you damaged your device, there are one of two things that happened. First, you could have supplied too much power to the device and heated circuits and components to the point they failed (this is a kind way of saying “melted”). Second, the polarity supplied may be wrong, which can create a “dead-short” situation. Some devices have a small fuse to protect the main circuitry when this happens, but not all. You may be able to get the device repaired, maybe not.

If the adapter you use supplies too little power, then the device may not work correctly either. You are calling on the device to complete tasks that adequate power is not being supplied for. So, getting it right solves the problem.

So, once you’ve chosen the right adapter for the wall outlet, you need to now see the power output of the adapter, as well as the polarity. If those match the power rating and polarity of the device that you are wanting to power, you should have no problems.

Here is a link for a universal adapter (not for use on computers!) that can be set to output different DC voltages, along with several adapter tips, and even a negative polarity adapter in case you need to switch from positive to negative polarity. This is a good starting place:

Sure, you can keep buying new adapters and devices instead of using what you already have, but that is a waste of money. With what you’ve learned in this episode, you can see if you have the right adapter on hand, and you can JUST DO IT YOURSELF.

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[TNtoolman]

I always kept my adapters that I no longer needed in a box in my shop... collected about 40 or so over all the years I accumulated them... about 2 weeks ago I threw them all out because I never needed one. You know in the next month I will probably need one... Murphy's Law.

[passionfly]

I have been looking for the video my entire life and with all the school and college I have NO ONE TAUGHT ME THIS! Our educational system sucks! Thank you Jay! +1 sub

[billhandymanbill]

Nice video. You can also double check the voltage and polarity by using an inexpensive multi volt meter (approx $10.00) on the output side of the AC adapter. You might want to further clarify and empathize the term “polarity” to mean what voltage direction is on the barrel and the insulated inner tip of the plug, example, negative DC voltage on the barrel and positive DC voltage on the insulated tip of the plug or vice versa if it is wired that way. Also, there are several different diameters of plugs and inner tips that manufacturers use too and therefore, sometimes the AC adapter will not fit the unit. The AC adapter you suggested comes with many different plug sizes and the unit can change the polarity on the plus too to accommodate this situation. I like your suggestion to label identify the AC plug when you buy an item that comes with the AC plug. Keep up the great videos!

[crystalchw]

Thank you! You saved me from frying my device, a fan. We are in the middle of a heatwave, so this is a lifesaver. Thx!!❤️🙏🏽❤️🙏🏽

[condor]

great video - some times they do not have marked DC or AC. The one you had does show AC and DC. I have one I was just checking on and it did not show either. It had the universal symbol for AC (~) and the universal symbol for DC which is a line with dotted lines under it just like you demo showed. Thanks!

[mikeplunkett]

I always learn something from watching your videos. Sometimes I learn stuff I didn’t know I needed to learn. Sometimes, I even learn about something I don’t even care about…but I still learn. Thank you and Dirt Farmer Maggie for all your hard work and for presenting your content in a friendly, simple and easy to understand way.

[mrdennischapman]

DANGER. I have been in electronics for the past 70 years (ham radio operator) and you forgot one IMPORTANT thing. If the device requires 3 amps and your power output is only 1.2 amps that could burn up the power adapter because it draws too much power. If the adapter is behind a couch there could be a fire that gets out of control. Please make sure that the power adapter can handle the power requirements of the device. It is always ok if the device uses less power than the adapter provides, but never more power than the adapter provides. Doing so is akin to plugging a bunch of heaters into an extension cord or plug that is only rated for a certain current draw. In a home you are protected by circuit breakers, but with these power adapters (many made in China) there might not be an internal fuse or safety cut off.

[TangibleTania]

Thank you....I learned quite a bit here! However I am in search of the type of adapter you shared a link for but I need 2A. The search continues...

[dreamingrightnow]

I've been searching for this for a while. Up until finding your video, all the nerds wanted to talk about was laptop chargers and that's an extra thing for my brain to decipher, lol. Thx.

[crabapple]

I really appreciate your clear and concise info packed video.
Thanks so much for your help.

[andyshap]

Hi Jay, as usual, great video. You didn't mention amperage though. You can have an adapter with the correct voltage, but If it doesn't provide the correct amperage, the unit won't power your device. A good rule of thumb is that it should provide the same OR MORE amperage to the unit you are powering, as the unit will only draw the amperage it requires.

[prettyromanticmusic]

This was actually very helpful, thank you.

[jchaney]

I'm curious why you didn't mention amperage output of the adapter.

[magicmantis]

Now I know how I fried an alarm clock. 😅 Thank you so much for this video. I aquire electronics that don't have a power adapter so I do a lot of mixing and matching. But ever since I fried an alarm clock maybe a year or so ago, I've been extra careful. Thanks again for this video. I feel much more informed.

[Rommy-]

Have an external hard drive that has no information such voltage and polarity on the device. How do you find that information? Thanks

[yadercalero]

Thanks for the explanation DFJ I had no idea, you just got a subscriber.

[peterbett]

Thanks Jay! You've been a great help to me. All the best from Sydney, Australia.

[sabadabigarage]

What about a 300 ma adapter to power a 800 ma device ??

[Ben-ttkk]

That universal adapter is clutch thank you

[josephpuchel]

Hey nice tutorial but I have a small shaver with a 2 prong connector. It’s horizontally oval with two prong plus has opening on one side to correctly fit two prong female charger cord
The thing is I’m missing the charging cord
Thank you