First and foremost, you need to understand what an AC adapter is, before choosing the right one for your device. So, basically, an AC adapter is a device that converts electric power, usually 110-240V AC, into a smaller amount that your device to operate efficiently. In most cases, AC adapters are used to charge or power battery operated devices. Now, when it comes to identifying the adapter your device needs, you have to figure out what it needs to operate, where you check all the labels and symbols indicating either the voltage or mAh/A on the device. Try to understand your device before deciding on the adapter to use to power it.
Also, when choosing an adapter, you need to ensure that the V matches the mAh, in the sense that the adapter output V matches the device’s input V. Also, that the plug has the correct polarity and it fits into the device.
You also need to check the (V)olts. Yes, most adapters converts AC to DC, but checking the output is still of vital importance. The adapter has to have the correct voltage given that the device only runs on the rated voltage. Of equal importance, you will need to check the (A)mps. The adapter of your choice should be able to supply enough current rating for your device to work. If you find out that the device has a higher rating, that shouldn’t worry you as the device only consumes the power it needs to operate. However, if your adapter has a lower mAh than the output device, then the device won’t work as it should, and if it works, the device might overheat which is very dangerous.
I know that this sounds difficult, and that you are thinking to yourself; ‘how on earth are you supposed know all this? Well, if you are one of these people, then just get a universal power adapter, as it allows you to have different polarities, voltages and connectors. With this one, you won’t have to worry about all these jargon of information.