500ma usb powered HDs 20GB+

[overclucker]

im trying to find one to that spec. i need something with at least 20gb. i need it to work with my headunit in my car.

http://www.kenwood.com/usb/english.html

 

[Murdochs_mad]

I think these might help, the usb to 3.5" drive bit needs the external power adapter, but I'm sure the usb to 2.5" part is self powered (from the usb) all you'd need is a laptop hd, and make your own funky case

USB to 2.5"/3.5" Adapter

 

[overclucker]

im really looking for a already made enclosure for it. not just an adapter.

 

[Murdochs_mad]

How about one of these, you can get them with hd's in them if you want, if your worried about the 500ma limit, anything that runs off the USB port itself should be 500ma or less as that is what standard pc ports pump out.

 

[FeuerFrei]

2.5" HDDs generally doesn't need external power supplies at all, because they only needs 5v, where 3.5" drives need 12v

 

[Bios24]

Most 2.5" notebook drives can be powered from a USB port. I bought an enclosure on eBay and put an 80gb drive in it. Works great.

 

[overclucker]

2.5" HDDs generally doesn't need external power supplies at all, because they only needs 5v, where 3.5" drives need 12v

they all seem to be a little over 500ma, but with the ide to usb it will throw it over my limit.... grr

 

[overclucker]

i found these 2

http://cgi.ebay.com/ws/eBayISAPI.dl...E:L:RTQ:US:1&viewitem=&item=330052605235&rd=1

http://cgi.ebay.com/ws/eBayISAPI.dl...E:L:RTQ:US:1&viewitem=&item=330052958109&rd=1

 

[Xaotic]

Most 2.5" HDDs pull around 800mA including the interface board. Technically, they are USB 2.0 compatable, but not USB 2.0 compliant. To my knowledge, you will not find one that will run on a true 500mA current. Most laptops are overengineered and have regulators between 1A and 1.8A per pair of ports. This should allow you to run a drive from a single cable. Some enclosures have a Y cable that may allow you to reach multiple ports on different USB busses as a workaround, but these will typically be located on differing areas of the laptops and will often not reach. Typically, if the USB ports are mounted together, they run on the same regulator. More modern laptops normally have higher regulated current as well.

 

[Murdochs_mad]

Just ripped the HD out me laptop, its a Seagate Momentus 20gb - ST92011A
its rated at +5v 0.47amps, I don't know what the interface board would draw on top of that.

 

[overclucker]

Most 2.5" HDDs pull around 800mA including the interface board. Technically, they are USB 2.0 compatable, but not USB 2.0 compliant. To my knowledge, you will not find one that will run on a true 500mA current. Most laptops are overengineered and have regulators between 1A and 1.8A per pair of ports. This should allow you to run a drive from a single cable. Some enclosures have a Y cable that may allow you to reach multiple ports on different USB busses as a workaround, but these will typically be located on differing areas of the laptops and will often not reach. Typically, if the USB ports are mounted together, they run on the same regulator. More modern laptops normally have higher regulated current as well.

what about the 1.8" also do you have any idea how many amps a interface board for ide to usb usually draws in milliamps?

 

[Xaotic]

It's significantly lower, but we didn't end up using a current probe on the samples we had due to cost. They simply didn't make the RFA due to the cost.

From the spec sheets on the C4K40, the drive should pull around 420mA on startup. By comparison, the 5K100(relatively power efficient) will pull around 1000A on start.

Interface boards can vary widely due to components and parasitic load. Most RoHs solutions tend to use more efficient chipsets. Expect loads in the 100-200mA range for most units.

Personally, I'd stay away from the 1.8" drives due to the extreme lack of performance in the first couple of generations that we looked at. STR and access times were simply abysmal and the costs were truely abhorrent.

Of the retail enclosures that we looked at, the Vantec Nexstar wasn't bad. The Sabrent seemed underengineered and occasionally had issues with power on a single cable with larger drives. Both were not the caliber we were accustomed to, but would do for occasional use.

 

[Murdochs_mad]

Just checked me other laptop, has a fujitsu drive - 20gb but draws 0.55a, also check another drive I have which is a seagate momentus 40gb and that also draws 0.47a

 

[Xaotic]

Those are continuous power draws. The startup draw is the limiting factor on USB HDDs. Overcurrent can cause either the planar or the OS to error and shut off the port. Power usage will be highest on startup, while the disk spins up. USB HDDs are not usually much trouble, but opticals can have both high startup and high continuous current.

 

[overclucker]

It's significantly lower, but we didn't end up using a current probe on the samples we had due to cost. They simply didn't make the RFA due to the cost.

From the spec sheets on the C4K40, the drive should pull around 420mA on startup. By comparison, the 5K100(relatively power efficient) will pull around 1000A on start.

Interface boards can vary widely due to components and parasitic load. Most RoHs solutions tend to use more efficient chipsets. Expect loads in the 100-200mA range for most units.

Personally, I'd stay away from the 1.8" drives due to the extreme lack of performance in the first couple of generations that we looked at. STR and access times were simply abysmal and the costs were truely abhorrent.

Of the retail enclosures that we looked at, the Vantec Nexstar wasn't bad. The Sabrent seemed underengineered and occasionally had issues with power on a single cable with larger drives. Both were not the caliber we were accustomed to, but would do for occasional use.

performance shouldnt be an issue as its for my mp3 player in my car, as long as it can read the mp3 fast enough to play it. it shouldnt be that big of an issue.

so do you think i can stay within my quota of 500ma with a 1.8" and a very simple enclosure?

 

[gangaskan]

I'm in the same situation i have a 20 gig Hitachi i want to try out, but I'm not sure if a 2.5 hdd will be capable of doing it. i'll buy a external enclosure this x mas i thinks

 

[Murdochs_mad]

Those are continuous power draws. The startup draw is the limiting factor on USB HDDs. Overcurrent can cause either the planar or the OS to error and shut off the port. Power usage will be highest on startup, while the disk spins up. USB HDDs are not usually much trouble, but opticals can have both high startup and high continuous current.

Ah, rite on. How about a solid state drive, one of those ide to CF converters and couple of CF carrds? prob to small?

 

[overclucker]

Ah, rite on. How about a solid state drive, one of those ide to CF converters and couple of CF carrds? prob to small?

they have 10+gb cards now but they are quite pricy. plus on the url on my first page says they are not compatible.

 

[Xaotic]

You'd be fine with that. If you needed lower power than that, a Microdrive would probably be the way to go. It would add complexity since it needs an adapter for either PCMCIA or a reader. Then again, a reader might accomplish what you need at a reasonable cost and can be easily integrated or concealed. As a test, I threw some files on a second gen 4GB and MP3s are no problem at all.

 

[overclucker]

i'd rather stick with a hard drive if thats possible.