Hardware hack - USB powered push from multiple USB ports

[nutterwithbutter]

just wanted to ask a question:

Is it possible to mod a cable that goes from multiple USB ports from my computer to a 12V DC 1.25

I know USB is 5V max output - what if i use 3 of my USB ports? Is it possible to create a custom cable that does this?

thanks!

[ObtuseMoose]

No. All the USB ports on one computer are ultimately powered by one 5 volt power supply. You would need independent, isolated power supplies for each port to do what you're suggesting.

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Moose

[Stromkraft]

Is it possible to mod a cable that goes from multiple USB ports from my computer to a 12V DC 1.25

Why would you want this if I may ask?

[fishmonkey]

No. All the USB ports on one computer are ultimately powered by one 5 volt power supply. You would need independent, isolated power supplies for each port to do what you're suggesting.

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Moose

that's not necessarily true. most computers have multiple internal USB hubs. USB Y-cables that combine the power output of two USB ports are not uncommon, however this is to boost the amperage, not the voltage.

Why would you want this if I may ask?

presumably to get full display and pad brightness without a mains adapter...

[Stromkraft]

Why would you want this if I may ask?

presumably to get full display and pad brightness without a mains adapter...

Sounds interesting.

[nutterwithbutter]

yep - it was to ditch the mains adapter but still have full display brightness

back to the drawing board!

[fishmonkey]

you could use a small 12 V lithium power brick...