ext HD enclosure w no power adapt?

[crucialcolin]

Hello everyone looking at external hard drive options for enclosures to use as a backup storage drive.

Anyways I was wondering if there were any 3.5" sized enclosures that provided power over USB 2.0 similar to how the smaller 2.5"(laptop drive) enclosures do? might be able to do eSATA as well(cant remember if pc has those ports).

The reason I ask is because I'm thinking a full size drive may be a bit more reliable with drives of about 1TB of storage space. It also nicer to have the added portability from not have to carry a power adapter around all the time or buy spares. I'm planing to use it to backup data at the office every so often(probably once a week).

 

[Old Hippie]

I was wondering if there were any 3.5" sized enclosures that provided power over USB 2.0 similar to how the smaller 2.5"(laptop drive) enclosures do?

No, 3.5" drives can't be powered by USB.

 

[corkyg]

Correct! 3.5-in HDDs require 12 vdc for the drive motor, and 5vdc for the logic circuits. USB can only provide 5 vdc.

 

[crucialcolin]

ah yeah that explains it. I somehow forgot that the larger 3.5" still require 12v. Doh! Thanks for the responses anyways

 

[lamedude]

Would Firewire work?

 

[corkyg]

Same situation. Firewire provides 9 vdc. An excternal Firewire 3.5 drive still needs a power source.

 

[alaricljs]

1394: Voltage is specified as unregulated and should nominally be about 25 volts (range 24 to 30). Apple's implementation on laptops is typically related to battery power and can be as low as 9 V.

 

[dave_the_nerd]

Same situation. Firewire provides 9 vdc. An excternal Firewire 3.5 drive still needs a power source.

Not exactly.

Don't ask me how, but some firewire enclosures offered bus power options for 3.5" HDs. Fuzzy memory from when Firewire actually mattered (10 years ago... to Mac users...) but I think it was only really reliable on 5400 rpm drives. It provided enough power for a lot of drives, but not all of them.

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Ooh, Google is my friend. More info:

http://www.wiebetech.com/whitepapers/buspower.pdf

 

[alaricljs]

The spec indicates ~8 watts available. Voltage spec is even fuzzier.