Power Supply and external drives question: Will they fry? at DVinfo.net

John Britt · January 27th, 2005, 02:43 PM

Just doing some almost-Spring cleaning in the office and have mixed up the power adaptors for two of my external hard drives. One is for my ADS USB 2.0 Hard Drive Kit and the other is for my Iomega 80GB external HDD. Upon closer inspection, I've noticed some slight differences:

One says:
Input: 100-240Vac, 0.6A, 50/60Hz
Output: +5V === 1.5A, +12V === 1.8A

Other says:
Input: 100-240Vac, 50-60Hz, .85A Max. 50VA-80VA
Output: 5Vdc === 1.5A, 12Vdc == 1.5A

Neither is branded ADS or Iomega. Strangely, the Iomega drive has an Input rating of 5V/1A and 12V/0.75A. But I know that one of these supplies came with the Iomega drive. Even more strange is that I have another, Iomega-branded, power adaptor for an older CD-R drive (same input ratings as the HDD) that has properly rated output for both Iomega drives (5V/1A and 12V/.75A).

Both "no-name" power supplies have the same type of output plug.

Can any electrical-minded members here tell me if the varying amperages make a diference, or will everything be OK since the output voltages are the same for both power supplies (5V and 12V)?

EDIT: By the way, yes I did try Iomega's support. It was fairly unhelpful and I ultimately got the response of, "Well, try one and see what happens." Great...

Greg Boston · January 27th, 2005, 03:05 PM

John,

The supplies need to be able to supply more current than the drive requires. Therefore, a 1.5A for a .75A load is normal. If the load was equal to the supply output, it wouldn't last long (kind of like running your car engine at redline rpm continuously). But you are ok voltage wise. Also, make sure that the plugs have the same polarity (ie same voltages going to same pins or sections of barrel)

I would use the 1.8a supply for the USB drive and the 1.5A for the Iomega drive.

=gb=

p.s. As long as you are spring cleaning, get a Brother label maker and label those suckers!

John Britt · January 27th, 2005, 03:19 PM

<<<-- Originally posted by Greg Boston :

p.s. As long as you are spring cleaning, get a Brother label maker and label those suckers! -->>>

Heh heh...

So, you would say that using the Iomega CD-R power supply (output rating 5V/1A and 12V/0.75A which is equal to the input ratings of both Iomega devices) on the Iomega HDD would be a bad idea, since the load is equal to the output?

Thanks for your help, Greg

Greg Boston · January 27th, 2005, 03:36 PM

One says:
Input: 100-240Vac, 0.6A, 50/60Hz
Output: +5V === 1.5A, +12V === 1.8A

Other says:
Input: 100-240Vac, 50-60Hz, .85A Max. 50VA-80VA
Output: 5Vdc === 1.5A, 12Vdc == 1.5A

John,

Your original message above said that one supply was 12v 1.5a and the other was 12v 1.8a. You stated the 'load' requirement of the Iomega as .75a. Not knowing what the load requirement of the usb drive is, I assumed you should go with the 1.8a adaptor on that one.

Must be some spring cleaning. You've gone and gotten yourself all confused! (just kidding, of course)

=gb=

John Britt · January 27th, 2005, 03:49 PM

Greg

In the OP, I also mentioned a third power supply:

"Even more strange is that I have another, Iomega-branded, power adaptor for an older CD-R drive (same input ratings as the HDD) that has properly rated output for both Iomega drives (5V/1A and 12V/.75A)."

This is the power supply I mentioned again in my second post. It has an output rating equal to the input of the Iomega HDD. It is from an older Iomega CD-R drive that has the same input ratings as the Iomege HDD. I pulled the CD-R drive and power supply from another room to see if it matched either of the power supplies I already had. Sorry for the confusion.

Greg Boston · January 27th, 2005, 04:02 PM

Sorry John, my bad. What I can unequivocally tell you is that after the voltages match up, the current suppying capability must be greater than the load requirement of the device it's attached to. Use this as your guide and you won't fry anything. If you can determine what the usb drive needs current wise, you should be able to make an informed decision on which on to hook up where.

=gb=

John Britt · January 27th, 2005, 05:36 PM

So, basically, the higher amperage doesn't matter? So the only reason to use the 1.8A supply with the USB drive enclosure is for the off-chance that it requires more than 1.5A? OK, so I think I've got a handle on this. Thank you very much, Greg, and sorry for the confusing descriptions above. You've been very helpful -- much moreso than Iomega's support and without the long-distance toll charges!

January 27th, 2005, 02:43 PM	#1
John Britt Major Player Join Date: Sep 2003 Location: Atlanta, GA Posts: 621	Power Supply and external drives question: Will they fry? Just doing some almost-Spring cleaning in the office and have mixed up the power adaptors for two of my external hard drives. One is for my ADS USB 2.0 Hard Drive Kit and the other is for my Iomega 80GB external HDD. Upon closer inspection, I've noticed some slight differences: One says: Input: 100-240Vac, 0.6A, 50/60Hz Output: +5V === 1.5A, +12V === 1.8A Other says: Input: 100-240Vac, 50-60Hz, .85A Max. 50VA-80VA Output: 5Vdc === 1.5A, 12Vdc == 1.5A Neither is branded ADS or Iomega. Strangely, the Iomega drive has an Input rating of 5V/1A and 12V/0.75A. But I know that one of these supplies came with the Iomega drive. Even more strange is that I have another, Iomega-branded, power adaptor for an older CD-R drive (same input ratings as the HDD) that has properly rated output for both Iomega drives (5V/1A and 12V/.75A). Both "no-name" power supplies have the same type of output plug. Can any electrical-minded members here tell me if the varying amperages make a diference, or will everything be OK since the output voltages are the same for both power supplies (5V and 12V)? EDIT: By the way, yes I did try Iomega's support. It was fairly unhelpful and I ultimately got the response of, "Well, try one and see what happens." Great...

January 27th, 2005, 03:05 PM	#2
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	John, The supplies need to be able to supply more current than the drive requires. Therefore, a 1.5A for a .75A load is normal. If the load was equal to the supply output, it wouldn't last long (kind of like running your car engine at redline rpm continuously). But you are ok voltage wise. Also, make sure that the plugs have the same polarity (ie same voltages going to same pins or sections of barrel) I would use the 1.8a supply for the USB drive and the 1.5A for the Iomega drive. =gb= p.s. As long as you are spring cleaning, get a Brother label maker and label those suckers!

January 27th, 2005, 03:19 PM	#3
John Britt Major Player Join Date: Sep 2003 Location: Atlanta, GA Posts: 621	<<<-- Originally posted by Greg Boston : p.s. As long as you are spring cleaning, get a Brother label maker and label those suckers! -->>> Heh heh... So, you would say that using the Iomega CD-R power supply (output rating 5V/1A and 12V/0.75A which is equal to the input ratings of both Iomega devices) on the Iomega HDD would be a bad idea, since the load is equal to the output? Thanks for your help, Greg

January 27th, 2005, 03:36 PM	#4
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	One says: Input: 100-240Vac, 0.6A, 50/60Hz Output: +5V === 1.5A, +12V === 1.8A Other says: Input: 100-240Vac, 50-60Hz, .85A Max. 50VA-80VA Output: 5Vdc === 1.5A, 12Vdc == 1.5A John, Your original message above said that one supply was 12v 1.5a and the other was 12v 1.8a. You stated the 'load' requirement of the Iomega as .75a. Not knowing what the load requirement of the usb drive is, I assumed you should go with the 1.8a adaptor on that one. Must be some spring cleaning. You've gone and gotten yourself all confused! (just kidding, of course) =gb=

January 27th, 2005, 03:49 PM	#5
John Britt Major Player Join Date: Sep 2003 Location: Atlanta, GA Posts: 621	Greg In the OP, I also mentioned a third power supply: "Even more strange is that I have another, Iomega-branded, power adaptor for an older CD-R drive (same input ratings as the HDD) that has properly rated output for both Iomega drives (5V/1A and 12V/.75A)." This is the power supply I mentioned again in my second post. It has an output rating equal to the input of the Iomega HDD. It is from an older Iomega CD-R drive that has the same input ratings as the Iomege HDD. I pulled the CD-R drive and power supply from another room to see if it matched either of the power supplies I already had. Sorry for the confusion.

January 27th, 2005, 04:02 PM	#6
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Sorry John, my bad. What I can unequivocally tell you is that after the voltages match up, the current suppying capability must be greater than the load requirement of the device it's attached to. Use this as your guide and you won't fry anything. If you can determine what the usb drive needs current wise, you should be able to make an informed decision on which on to hook up where. =gb=

January 27th, 2005, 05:36 PM	#7
John Britt Major Player Join Date: Sep 2003 Location: Atlanta, GA Posts: 621	So, basically, the higher amperage doesn't matter? So the only reason to use the 1.8A supply with the USB drive enclosure is for the off-chance that it requires more than 1.5A? OK, so I think I've got a handle on this. Thank you very much, Greg, and sorry for the confusing descriptions above. You've been very helpful -- much moreso than Iomega's support and without the long-distance toll charges!