is USB power constant? can I use a USB wall charger to power my USB drives?

[Cathpah]

as the title suggests, I'm trying to use a wall charger for my ipod that uses a USB connection, to also be able to power my Lacie external "portable rugged" hard drive...that needs to be powered by a usb power connection when I connect it to my p-5000. (a cable with regular/large usb connection on one side to plug into wall charger and a power pin on the other side to plug into power outlet of hard drive)

sorry, not sure if i described this well at all, but i would love to be able to use that charger for my ipod as the power for my hd so i can transfer shots from my p-5000 to it, without having to sit in an internet cafe attached to their usb.

anyone know definitively? sure don't want to blow up my backup drive.

[PacAce]

How does the drive connect to the P-5000? Via the USB port? If so, how are you going to connect the drive to the wall charger? Or does the drive have two USB ports?

To answer your question, the power pins on the USB plugs/ports should follow a standard. I know I tried charging my Lazr phone with the iPod wall charger but I don't remember whether it worked or not. I think it did but I won't swear by it.

[Cathpah]

Originally Posted by PacAce

How does the drive connect to the P-5000? Via the USB port? If so, how are you going to connect the drive to the wall charger? Or does the drive have two USB ports?

To answer your question, the power pins on the USB plugs/ports should follow a standard. I know I tried charging my Lazr phone with the iPod wall charger but I don't remember whether it worked or not. I think it did but I won't swear by it.

the drive itself connects via a usb port to my p-5000 with a standard usb cable with big ends on both sides. This USB port can power the drive if plugged into a computer, but the p-5000 can't power this on it's own.

the other usb cord that i talked about, is usb on one side, and a power pin on the other which goes into a separate power hole/port in the drive.

so far, i've been going to internet cafes, using the usb on the computer to power the drive, and the other usb cord to attach the drive to the p-5000. just hoping i could do this in my room instead of tracking down internet cafes all the time.

is that clearer this time? sorry, kind of difficult to explain.

anyone else have any input?

[Jon]

Voltage is steady. The amperage may, or may not, be adequate for reasonable charge times and/or to run the drive from.

[20droger]

I'm not sure I quite understand what you're asking...

If you are refering to a USB port on a computer or other device, the port provides a "constant" voltage at a specified, but relatively low, amperage. The voltage is constant as long as the amperage is within range. Exceeding the amperage will cause the voltage to drop, and the plugged-in device will usually not work.

If you are referring to a USB hub, they come in two varieties: unpowered and powered. A USB hubs is itself connected to a USB port on a computer or another USB hub (the source port).

An unpowered USB hub derives its power from the source port. The total current of all the ports on the hub cannot exceed the current capabilities of the source port.

A powered USB hub derives its power from a separate power supply (usually a wall-wart). Power is independent of the source port. Therefore, powered hubs can usually provide much more current than unpowered hubs.

[Cathpah]

Originally Posted by 20droger

I'm not sure I quite understand what you're asking...

If you are refering to a USB port on a computer or other device, the port provides a "constant" voltage at a specified, but relatively low, amperage. The voltage is constant as long as the amperage is within range. Exceeding the amperage will cause the voltage to drop, and the plugged-in device will usually not work.

If you are referring to a USB hub, they come in two varieties: unpowered and powered. A USB hubs is itself connected to a USB port on a computer or another USB hub (the source port).

An unpowered USB hub derives its power from the source port. The total current of all the ports on the hub cannot exceed the current capabilities of the source port.

A powered USB hub derives its power from a separate power supply (usually a wall-wart). Power is independent of the source port. Therefore, powered hubs can usually provide much more current than unpowered hubs.

i'm not asking about any usb hub or anything like that.

what i'm wondering is if i can use my ipod wall charger and a usb cable that came with the lacie drive (http://www.lacie.com/products/product.htm?pid=10821) to power it.

i'm not trying to power the p-5000 or anything like that....just trying to power the lacie drive with the ipod usb wall charger (http://www.amazon.com/Apple-M9837LL-.../dp/B0002ZAIMI), something that the p-5000 just can't do on it's own.

all i'm wondering is if i plug the drive into the ipod wall charger (that accepts a usb cable) will it hurt the hard drive? if it doesn't power it enough, then i'll learn that in trying it out...but i don't want to try it unless i'm sure i won't kill the drive by using the ipod wall charger to power it.

[PacAce]

Originally Posted by Cathpah

i'm not asking about any usb hub or anything like that.

what i'm wondering is if i can use my ipod wall charger and a usb cable that came with the lacie drive (http://www.lacie.com/products/product.htm?pid=10821) to power it.

i'm not trying to power the p-5000 or anything like that....just trying to power the lacie drive with the ipod usb wall charger (http://www.amazon.com/Apple-M9837LL-.../dp/B0002ZAIMI), something that the p-5000 just can't do on it's own.

all i'm wondering is if i plug the drive into the ipod wall charger (that accepts a usb cable) will it hurt the hard drive? if it doesn't power it enough, then i'll learn that in trying it out...but i don't want to try it unless i'm sure i won't kill the drive by using the ipod wall charger to power it.

The iPod wall charger supplies power to the iPod the same way a computer does using the same pins. And since the pin designations on a USB port or cable are standardized, any USB device would be getting it's power from the same power pin.

That said, however, what I don't know is whether the Lacie drive is using a dedicated port just for the power and if so, is it using the standard USB pin configuration to get power to the hard drive. If you're saying that you can connect the Lacie to a computer through that USB port to power the drive, then I don't see why you can't do the same with the iPod power supply. But, of course, there's always a disclaimer. I've only ever plugged a cellphone to my iPod charger (besides the iPod, that is) so I don't really have first hand experience with a Lacie drive.

[anshu]

it should work. standard usb power is 500ma's at 5v. the voltage will be steady. If it can charge your ipod you should be good to give it a test run!
I would double check and look on the drive to see its power ratings and check those against the wall charger though.
In my experiences everything that runs off usb power is universal, I have 3-4 devices that run off usb power and leave chargers everywhere I could need them, no matter the brand or anything and it always works

[Cathpah]

just to update....took a deep breath and plugged in my hard drive to the ipod wall plug and it worked just fine. no smoke, no fire, no explosion.

all is fine and well in hard drive land.

[pocket sheep]

Excellent, i am sure that was a heart in the mouth moment. Sure hope everything was backed up somewhere else just in case

I had been wondering about whether this would work. I could never figure out how you would connect the Epson to the Hard disk if you are already using the plug on the hard disk to power it. I am having trouble picturing how you have managed to get it to work.... any chances of a pic or a diagram or something of the set up.

Cheers