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Use a notebook ac adapter as power supply for external usb hard drive?

  • Power Supplies
  • Notebooks
  • Hard Drives
  • External USB
  • Components
Last response: in Components
April 2, 2012 6:16:52 PM

Notebook power supply ac adapter:
input: 100-240v ~ 1.4A 50/60Hz
output 19V – 4.74A

Can the ac adapter be build into a power supply for an 3.5” external usb hard drive?
If so, can the ac adapter be used for both 3.5” and 2.5” external usb hard drives?

More about : notebook adapter power supply external usb hard drive

a b ) Power supply
April 2, 2012 9:44:31 PM


If you want to destroy your Hard Drive electronics go ahead.

Read voltage markings on external hard drive case or instructions. Use only correctly rated power supply

2.5" drive probably requires 5V regulated
3.5" drive probably requires 5V + 12V regulated unless hard drive case has its own built in regulator then probably 12V

also get polarity wrong and burn out hard drive electronics.
(if you are lucky only USB to ATA or USB to SATA electronics burnt out)


Mike Barnes
a b ) Power supply
April 2, 2012 10:42:16 PM

You could use a couple of regulator IC to reduce the voltage down to the required amounts (LM2940 for 12volts) and (LM7805 for 5volts), but it would be simpler and safer to get a pre-made hard drive psu with a 4 pin molex and sata power connecter.