External enclosure

[iontrap]

Is there an external enclosure, internal IDE and external USB 2.0, without an extenal power supply?

 

[morpheus6d9]

2.5 or 3.5 drive ?

 

[perplex]

All 3.5 external enclosures need a power supply I think.

 

[iontrap]

2.5 or 3.5 drive ?

3.5" drive

 

[Joni Nitro]

Are you asking if the there are enclosures with built in psu's or if it can be USB powererd? I am sure there are some enclosures with internal psu's or you could use a 5.25 enclosure with brackets for a HD. It you want USB powered drive then you will need a 2.5 laptop HDD.

 

[iontrap]

Are you asking if the there are enclosures with built in psu's or if it can be USB powererd? I am sure there are some enclosures with internal psu's or you could use a 5.25 enclosure with brackets for a HD. It you want USB powered drive then you will need a 2.5 laptop HDD.

I'm wanting a USB powered 3.5" drive, sounds like this doesn't exist.

 

[unhappy_mage]

3.5" drives take about 6 times the power of 2.5" drives - 12 watts versus 2 - so it's a lot less likely that your USB controller could supply adequate power to a 3.5" drive.

 

[cambre]

Another main problem is that 3.5" drives require 12 volts which USB can't provide.

 

[unhappy_mage]

Another main problem is that 3.5" drives require 12 volts which USB can't provide.

This problem can be solved with a dc-dc converter built into the enclosure. The problem is more one of current - at 5 volts, 12 watts means 2.4A (assuming lossless conversion to 12V). The USB spec says the maximum per-port current allowed is 500 mA (see page 206); this is about a fifth what you'd need to run a hard drive. A 2.5" drive takes 2 watts, or 400 mA on 5V, so it's within the spec. But I'd stay away from unpowered hubs with more than one drive, for the obvious reason.

Edit: I take it back, 2.5" drives draw 5 volts as stated. The rest of it stands, though.