I have an USB-SATA/IDE adapter, such as this one: adapter Since it was a cheap product from China, the power supply that was included in the packaging no longer provides enough power to spin up a disk. I remember that back in the day, the 2.5" drives only needed the mini-IDE to work, so one did not have to connect the power supply. Since I do not really need to connect any 3.5" disks to my computer and the power supply is most likely a fire hazard even if I manage to fix it (I suspect the caps, though they are looking OK), I'm wondering if it's possible to power the disks from the USB port, old-school style.

Here's what I found on eBay though. It appears to be an adapter which might solve my problem.enter image description here

It seems to provide the power as well, so this would be perfect. However, there does not appear to be much going on on the board, so I am skeptical about the product. So here are my questions:

  1. Should this even work?
  2. Will it provide all three voltages (3.3V, 5V, 12V) required by the SATA spec or is it just some kind of a 5V-only hack that works on a small subset of disks?

I know the questions are not very specific, but neither is the product description. I can try to expand on the question somehow if you let me know in the comments.

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  • @TomCarpenter I thought hard about this, but in the end I've chosen this site because I'm interested in the electrical side of things rather than just connecting peripheries. – JohnEye Nov 28 '17 at 0:05
  • You should not need to stoop to a PATA connector to get this working. If you find an old external USB 2.5" drive, you can rip it apart and use the connector in that - provided your motherboard provides 2 amps at 5 volts (some don't, hence Y connectors). I won't vouch for them, but you can pick up similar cables from ebay et-el - eg ebay.com/itm/… – davidgo Nov 28 '17 at 9:52
  • ebay.com/itm/… ebay.com/itm/… – davidgo Nov 28 '17 at 9:53

These sorts of adapters, those without an external power supply, are typically designed only for 2.5" drives and smaller. The smaller drives require much less power, and typically run off a single 5V supply.

The reason that the adapter you picture doesn't have a supply is that it has a 44pin mini-IDE connector which includes +5V/GND on the extra 4 pins (on top of normal 40pin IDE). A 2.5" drive would be happily powered from such a converter because it wouldn't require the extra rails you question about (*).

The power requirements are much higher for 3.5" drives than these and similar adapters are designed for. Additionally the 3.5" drives will require 12V for the much large motors that are used, and these adapters will not produce that voltage rail. This is why your USB adapter can't spin up the drive (nor would the IDE/SATA pictured).

As you are interested in only 2.5" drives, such adapters will be workable, they will provide the necessary voltage rails.

For 3.5" drives (and any drive in fact) I would suggest getting a module to add an eSATAp connector to your computer. You can get drive bay modules and PCIe modules that allow you to connect an external drive via this port. The nice thing about the eSATAp variety is that it also provides 12V and 5V power rails, so you can get an passive cable to convert eSATAp to SATA+Power. It also doubles as a USB port when not needed for SATA.

(*) Having said that the adapter appears to have a linear regulator for regulating a 3.3V rail. But this still wouldn't get a 12V rail so wouldn't help connect a 3.5" HDD for those who need such a use case.

  • Thank you. The eSATAp note is especially valuable since I have not considered that. Cool. Right now, I'm trying to salvage the adapter because without the power supply, I cannot use it at all and a replacement power source is about as expensive as a new adapter with another power supply included. The IDE to SATA adapter, though, costs about 2 USD, shipping included :-) – JohnEye Nov 28 '17 at 0:00

BTW - just so everyone knows: there are a lot of 2.5" SATA drives that are intended for use in professional applications (NAS and RAID storage solutions). These look just like notebook drives and use the same connectors but they MUST also have the same 12vdc rail as their big brothers. They will not work with most 2.5" to 3.5" adapters and they certainly will NOT work with a USB adapter (unless it was made for a 3.5" disk).

I use these drives myself and they are also pretty cheap, very quiet and usually run cooler (and should use less power - but I have found that statement to be rather questionable).

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