I need a power supply! How do I choose the correct one for my device?
 
Article ID: 43
Created On: 17 Oct 2005
Author: Caroline Swords
Edited On: 07 Jan 2010
Edited By: Caroline Digidave

If you are not sure which power supply you should buy for your device, please click the link below and fill out our help form, letting us know the device's model name and manufacturer, and we'll advise exactly which power supply you should purchase!

Digidave power supply help form

When choosing a replacement power adaptor, you 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

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 positive).
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 link below and fill out our help form, letting us know the device's model name and manufacturer, and any other information that you have (such as a power supply part number), and we'll advise exactly which power supply you should purchase!

Digidave query form

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