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Asked: 2021-11-30T03:45:45+00:00 In:

Powering External DVD-RW Via USB Phone Charger

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Hey Everyone,

I have an odd question today:

I own an HP external DVD-RW drive. It has two USB cables, one for data and one for power. My question is, could I hook up the power USB to a USB phone charger, like this one:

http://www.bestbuy.com/site/htc-tc-…

The one I have is rated 4.8 V and 1 Amp. This brings up two questions:

1. I thought USB 2.0 could only deliver 500 mA of power…does it use the data terminals for extra power or something?

2. I don’t know how much power the drive draws…that being said, could it really damage the drive trying? I would assume that the drive draws the most power allowed by a USB cable, and a wall adapter shouldn’t be able to deliver more power than a computer…right? Or are there no voltage limits on USB cables?

In case you are wondering, I only want to do this so I could open/close the drive without the computer being on.

Thanks!

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    2 Answers

    1. I would be seriously disinclined to use a phone charger to power a usb drive – whatever style/type the drive might be. Many usb psu are often overrate in terms of what current they can safely deliver – without starting to run warm/hot… which might well shorten the life of the psu. Some of the bottom end/cheaper units have had problems in that regard… Check around for reviews of any psu you might consider using; typically Amazon sites various of course have reviews…
      That same psu would then be available for other usb devices too.

      Look for a decent make with at least 2-3amps – or more current rating.

      An overrated psu wouldn’t normally damage a drive; although the drive might well not run properly if the true current o/p available was inadequate… But if the psu decided to deliver the wrong DC volts (higher than 5Volts…) that “might” be a serious and troublesome issue for the drive…

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    2. The voltage will remain constant at 5 volts, it’s the current draw that will change. Tablets & iPads can draw upwards of 2 amps or 10 watts, I doubt your drive draws that much but if you’re concerned go to a computer or electronics store and get a power supply that works with tablets. You probably wouldn’t burn out the drive with a under rated power supply but the drive could give you data errors. You could fry the power supply if it doesn’t have decent protection and the drive wants to pull more current then the supply can deliver. Usually there is a sticker on the back or bottom of the drive with the specifications on it.

      No, the data terminals do not supply extra power.

      message edited by THX 1138

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