Tuesday, July 03, 2012

Raspberry Pi Power Supply


One of the features of the Pi is that it comes with nothing in the box other than the bare board. No power supply, no SD card, no no network cable, no nothin'. 


On the basic setup Pi forums there are a number of topics on the subject of what power supply to use. Well, I don't know about anybody else, but I found that the power supply that comes with an Amazon Kindle was just perfect. 


The specification and FAQ on the Model B Pi board (the one that is available just now) is that it requires a stable 5V supply of at least 0.7Amps. The Kindle charger is rated at 5V at 0.85A ... match. Of course, it's all very well having a charger with the right rating, but I suspect more people will struggle with the power connector - it's a micro-USB. Yes, 'micro'. Not a mini-USB like a Sony eReader, or my old Motorola phone, and not the weird slim, wide, pseudo USB that my newer Samsung phone uses. It's a about the same width as the mini-USB, but half the thickness. In the FAQ, the Raspberry Foundation claim that GSMA expect micro-USB will be the universal charging solution for mobile devices, but it's not there yet.


So, as I say, the Kindle charger works just fine, which is just as well because despite quite a collection of mobile phone chargers and other electronic devices connectors, the Kindle charger is the only one that works for me. 

3 comments:

  1. It's also important to get a good cable from the Adapter to the Pi, because over thin wires the Voltage will drop considerably when the Raspberry Pi is drawing more than idle power.Thanks:)
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    Ac Dc Power Adapter

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  2. The cable that comes with the Kindle charger seems to fit your criteria just fine. :)

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  3. Once you have decided where to buy your power supply, you need to check that it will supply enough power for the Raspberry Pi. See the picture to the left. Any charger you will find will have a data label like this one. The top line is the power it takes from the mains. You can ignore this, (so long as you are sure it was made for your country.). The bottom line is the power it provides (outputs) to the device it's charging. There are two numbers listed, and you can be fairly certain that the first one of them is going to be "5V" (V means volts). Occasionally a power supply might supply a bit more, and anything up to 5.25V is safe. The second number is the important one. thanks!
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