How can I measure the power usage of peripherals?


5 posts
by recantha » Mon Jul 16, 2012 8:20 am
Hi.
I've love to do some kind of tests about power usage of various peripherals and how they affect the Pi but I have no clue where I'd start. Does anyone have any pointers? I assume I'll need some kind of meter to measure, but I'm a newbie when it comes to electronics.
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by stevepdp » Mon Jul 16, 2012 11:06 am
Moved your post to troubleshooting. It should receive more attention here ;-)
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by Beanz » Mon Jul 16, 2012 11:22 am
Something like this maybe
http://www.maplin.co.uk/plug-in-mains-p ... itor-38343
I'd imagine if you note down usage for the Pi alone then add peripherals you can see the difference and work out what each thing uses.
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by sdjf » Wed Dec 19, 2012 12:25 pm
I have the same question. I have just bought a digital multimeter, and it can measure volts but not milliamps over 200mA. Can the question be answered by testing the voltage at TP1-TP2 with different devices plugged in?
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by efflandt » Wed Dec 19, 2012 2:01 pm
Something similar to what Beanz posted is available in USA called KILL A WATT, but that only tells you power used at the wall outlet to the nearest watt, which is only about 3-4 watts. With AC current you cannot directly calculate watts from amps x volts like for DC current because AC volts and amps can be slightly out of phase with each other resulting in less watts than VA.

You would need a multimeter that reads amps and rig up some way to put that in series with the 5 VDC. 0.1 A = 100 mA.
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