Welcome to myVolts Crowd Forum...........Where power supply experts answer questions and people share ideas about our products and services

Do you have a power supply question ?

How do I choose the correct power supply for my device?

Solved 1 Answers 55 Views Power Supply & Chargers

1 Answer

Best answer

If you are not confident in which power supply you should buy for your device, please ask a question and tell us your device's model name and the manufacturer, and we will advise you exactly which power supply you should purchase!

When choosing a power supply adaptor, you will need to consider the power requirements of 

the device, and also the size of the tip adaptor needed;

1. Output Voltage and Current 

Voltage V and current A are printed on your original adaptor, and, most likely, also on the device 

you need to power. The voltage is usually written right by the power input on the device. 

Choose a power supply with voltage V equal to the original voltage and of the same type (AC or 

DC - usually DC). 

Choose a power supply with current A equal to or higher than the current on the original power 

supply or device. 

2. Output tip size 

Power Supply Adapter Tip

The power adaptor will need the right-sized tip for your device. 

There are 3 dimensions, usually measured in millimetres.

  For example - a tip size of 9.5/2.1/5.5mm means that the barrel length is 9.5mm, the internal 

diameter is 2.1mm and the outside diameter is 5.5mm. 

3. Output Polarity 

AC to DC adaptors will have a negative centre (inner negative) or a positive centre (inner 


Make sure the power adaptor has the correct polarity for your device. 

If a power supply has a number of interchangeable tips supplied with it, the polarity can easily be 

changed to negative or positive. 

If you're still not sure which power supply you should buy for your device, please click the ask question button and please let us know your device's model name and manufacturer, and any other 

information that you have (such as the power supply part number), and we will advise you exactly which 

power supply you should purchase!

answered Mar 3, 2016 by admin (3,010 points)
selected Mar 3, 2016 by C