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I am new to the PI. I am building a pi that will have cameras, sensors and all sorts connected to it. I am wondering even if I use an over powered power supply at 5.3v will it really be enough to run everything at full power? If not, then how do you provide more power to the entire system? Is there a regulated power supply for example?

  • I'm not allowed to comment. How much power does the kit you plan to connect to the Pi consume in total? (i.e. how many amps at 5V). – joan Apr 9 '14 at 19:48
  • that is yet to be determined. The entire unit has not been constructed yet, but I am certain it will require more than the 5.3v possible just to make sure that everything has enough power. – user14105 Apr 9 '14 at 19:55
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    You shouldn't be worried about volts. Really 5.25 is the top limit you should be feeding in there. Volts is like how fast the river flows and amp is how wide the river is. The Pi can only handle a river flowing at 5volts. The reason you can supply abnout 5.25 is because the 3.3,2.5 and 1.8 voltage regulators, REGULATE 5.25 down to 3.3 and that is thier MAX tolerance. All you need is a SWITCHING power supply. like the ones used in computers, not the cheap 1dollar USB things. Spend ~15 dollars on a 5v 2A switching power supply and everything will be fine. – Piotr Kula Apr 9 '14 at 20:04
  • makes absolute sense. Thank you very much for the help. – user14105 Apr 9 '14 at 21:05
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    You'll find that if the current draw is too high that the voltage will drop to compensate this will buy you a little leeway, but it really is best to get a supply that provides sufficient current. – Fred Apr 9 '14 at 22:45
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You need to learn a little bit more circuit theory!! (This also applies to many more on this site).

You need a good regulated supply (PSU) that will supply the rated 5v ±5% at 1A. There is no merit is using a PSU "rated" at more than 1A. (This should be proper supply - not a phone "charger" - many of which have poor regulation).

Internally the Pi regulates this down to 3.3v for most of its internal circuitry (as mentioned by @ppumkin). Supplying a higher input voltage will just overheat this regulator.

The excess current (1A less that used by the Pi) is used for HDMI, USB and GPIO power pins. This is limited to about 300mA (1A less ~700mA) by the on-board polyfuse. If you need more for externals, you can use a powered hub (USB) and/or provide a separate source to the externals (which only need a common ground).

There should be plenty of power for running the on-board peripherals, including the camera, although you should avoid drawing extra current via GPIO pin 1.

You can of course use a PSU rated at a higher current, provided you bypass the polyfuse, either by supplying 5V to GPIO pin 2 (although there are many other access points), bypassing the polyfuse, or simply feeding in through the full size USB ports.

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