Hey,
I just bought the RPi B model and also got myself a 1A power supply.
When i try to acces my external hard disk (USB 500GB) it just crashes and comes back, every 5 seconds.
Now i think my power supply is too weak.
Thing i have plugged on to my RPi : HDMI, LAN, SD Card, Hard disk.
My hard disk uses 0,55 A.
Is my power supply too weak?
Greetings,
-
mahjongg
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Re: Power supply unit
its not possible to power that much stuff -through- the PI, the PI has an 1 A fuse built in, (its a kind of a fuse, but not like you are familiar with, this one repairs itself after a few days of rest) put too much current through it (more than say 900mA) and it will start acting funny and lower the voltage that it lets through, and the stuff connected to the PI (especially USB devices like WiFi adapters) cannot cope with the lower than 5V voltage! If you want to use stuff that is consuming that much current (including -any- kind of hard-disk, but even some power hungry wifi adapters) then you need to connect it to, and power it with the hub's power supply!
Some hubs will then also power the PI, (even without the micro-USB power cable attached) which is a BAD thing, as that way to power a PI (its called back feeding) bypasses the fuse, and thereby also removes the protection against shirts, and over-voltages so that these may now damage the PI when they happen!
The solution is to either use a hub that doesn't back-feed, or to cut the 5V wire in the cable from the PI to the hub (or otherwise block the 5V from going into the PI, for example by cellotaping the 5V pin of the USB connector), then power the PI with the micro-USB cable plugged into one of the USB ports of the hub.
Or you could just take the risk, then you don't need the micro-USB cable.
Some hubs will then also power the PI, (even without the micro-USB power cable attached) which is a BAD thing, as that way to power a PI (its called back feeding) bypasses the fuse, and thereby also removes the protection against shirts, and over-voltages so that these may now damage the PI when they happen!
The solution is to either use a hub that doesn't back-feed, or to cut the 5V wire in the cable from the PI to the hub (or otherwise block the 5V from going into the PI, for example by cellotaping the 5V pin of the USB connector), then power the PI with the micro-USB cable plugged into one of the USB ports of the hub.
Or you could just take the risk, then you don't need the micro-USB cable.
Re: Power supply unit
I was planning to go tonight to buy a USB hub. Any suggestions as to how I would find out if the hub does this?The solution is to either use a hub that doesn't back-feed