Current supply of 1.5A is allowed?


4 posts
by monimi » Sun Nov 25, 2012 3:34 am
Hi, i just got a raspberry pi and i got a 5V 1.5A power supply, and i wanted to know if this power supply adapter is allowed for me to use with the board properly (mostly regarding to the current that the adapter provides), i wouldn't like to break my new raspberry pi. Thanks in advanced.
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by gstreeter » Sun Nov 25, 2012 10:26 am
That PSU will be satisfactory and safe for use with the Pi, I use the same rating unit myself. Problems only arise when there is too little current for the Pi and any attached USB devices for example.
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by psergiu » Mon Nov 26, 2012 9:35 am
Think of the Amps as of the quantity of electrical current.
RPi uses 750 mili-Amps so your power supply must be able to provide AT LEAST 750 mA.
If your power supply is able to provide more, that's okay, RPi will use only 750 mA.
I personally run my RPis off some 2 & 3A power supplies - with a more powerfull supply you have the advantage that you won't have significant voltage drops whe you connect more power-hungry peripherals.
Example:
3A PSU with no load: ~5.12V
3A PSU with only RPi: ~5.08V
3A PSU with RPi + 5400rpm USB HDD: ~5.03V at spinup then ~5.07V
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by redhawk » Mon Nov 26, 2012 11:13 am
The amp rating of a power supply simply refers to it's maximum current output capability the actual current usage varies depending on power demand of the equipment.
Since the PI has an F3 polyfuse for current limiting then you're really only able to use a maximum of about 750mA even if your PSU is rated at 30A.
A power supply that's capable of delivering 5v @ 750mA or higher current is more than adequate for the PI proving it can maintain a steady output voltage with respect to current usage.

Richard S.
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