Raspberry Pi Forums

Hello,

I have a rasperry pi with a 2 ampere power adapter.
I measured the power consumption with a current measuring device.

Running at 700Mhz, it consumes 2,5W with 0,025A.
Running at 1000Mhz, it consumes 3W with 0,028A

How can this be? I thought the raspberry needs at least ~700mA, going up to 1+A when devices are attached?

Why does my measuring device only show that low number?
The measuring device is this one:
KD 302
http://www.reichelt.de/Energiemessgerae ... &OFFSET=16&

Well, there seems to be something wrong with your math.

If it is drawing 2.5 W at 5v, that's 500 mA (= 0.5 A), right?

And that's about right. Basically, what I've heard is that the Pi itself takes about 500mA and the ethernet (on a model B) draws about 230 mA (when running full speed/full blast).

the low current numbers are on the mains 240V AC side of the power supply, not on the low voltage side!

Remember: Wattage is equal to voltage times amperage. When you step down the voltage, the amperage must raise to provide the same power to a device. 2.5 watts at 5v is about 0.5A, but 2.5 watts at 240v is a much lower number: 2.5w / 240v = 0.0104A

mahjongg wrote:the low current numbers are on the mains 240V AC side of the power supply, not on the low voltage side!

Well, yeah, that would explain it as well...

Thank you all for your answers, now I get it!