DIY USB hub power cable

A friend had a USB hub with a power-uplink port and needed to power some high-current devices through it. So I gave him a spare mainsto USB-A adaptor and finagled a cruddy USB cable into a power cable.

Boring as heck, but it gave me an excuse to try-out iMovie08

Category:

Howto & Style

Tags:

• usb
• power
• hub
• iMovie08
• iMovie

[mgoodhew]

Eh? You have an external case you want to "make external"?! Seems like that's already been done for you.

Anyway, I'm guessing you have an external 3.5" USB drive chassis you've removed the casing and drive from and replaced with a 2.5" drive. Presumably this works "as-is" and you want to do-away with the separate "power brick" and see if you can power it off the USB port alone.

I'd just buy a new 2.5" USB carrier from eBay and be done with it.

[Hollrobb]

Always leave an inch or two of wire on the end you cut off thats not going to be used (on this project) and that way you can throw it in a box and maybe one day on another project you can use it without having to cut another cable/cord. When you cut it off up to the plug then it's worthless now, like this guy did. Just a tip.

[mgoodhew]

@Hollrobb True. Did something like that when I mangled some audio leads. Still, have a mountain of USB cables and little need to violate them.

[BriareosHX]

i have a question, how to make a usb cable to power a 12v external hdd that requires 12v power, becoz usb is only like 5v,

if anyone knows how to make this or where to buy such a cable please send me a messege on here. thnx

[mgoodhew]

By "12v external HDD" I presume you mean a 3.5" quarter-height ("Desktop") hard-drive.

It's possible to convert 5v to 12v with a matching drop in current.

The bad news is that these drives tend to suck about 0.5A to 1A on their 12v lines (6 to 12 W). USB ports are supposed to deliver a maximum of 500mA (2.5 W). You'd have to bundle-together min. 3++ mainboard USB ports to have a chance at powering a 12v drive (probably).

My advice: Give-up and use a much lower-power 2.5" ("laptop") HDD.

[shoebucket]

@mgoodhew Just a quick correction; according to pinouts.ru/Slots/USB_pinout.sh­tml you can actually push 1.8A through USB, but it requires that you short out the White & Green (Data - and Data +, respectively) in order to do so... 5V @ 1.8A should theoretically convert to 12V @ 750mA as long as you don't mind losing your data connectivity (making this example useless for the OP's request, yes, but still pushing more than 500mA)

[adambennett08330]

i have a question.i have an old seagate desktop external case i wanna make external.i trashed the plastic casing and left the board with connections intact...is it possible to connect a usb cable to the ac port and power by usb?..i dont wanna use the 500gb 3.5 drive that is in it i took that out and placed inside my desktop pc.what i wanna use is my 2.5 250gb laptop drive as an external and always having this plugged into a power outlet is not very portable at all and was wondering if can help

[TheEgg185]

i just cut off the end of a usb wire and want to power a small light bulb (flashlight) with my computer and put it behind my monitor. i think it would be better for my eyes to have behind my monitor lit up instead of looking at the harsh monitor brightness contrasted with the dark around it. id like it to turn on/off with the computer so i wont have to think to turn it on/off

[TheEgg185]

@mgoodhew thats good advice

[Hollrobb]

@mgoodhew ,Yes it dont take long to get a nice size pile of cables and such, now that everything you buy these days comes with a usb/data cable. My tip was for the people that havent been over-run with cables yet,lol Take care,Rob