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5 volt power supply, 60 Amps (too much?)  


WhitneyDesignLabs
(@whitneydesignlabs)
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So I recently acquired from our local salvage yard, a power supply that can put out 5vdc. (adjustable, slightly, but nominal is 5). at sixty amps 60A. Which is super cool. I could power lots of USB devices for now, and decades to come, for an entire house.

So my thought is, fuse protect it at the output, run low voltage wiring throughout the house, at 5vdc, put a standard USB outlet anywhere needed. Heaps of 5v USB outlets as needed.

If I understand Ohm's law correctly, no device will draw more than it needs?

Old USB devices that pull 1amp at 5vdc, no problem. Newer phones request 2A, and whine when denied. My Raspberry Pi 4, flat out squeals-bloody-murder, if not given a full 3 amps.

As time goes on, USB-C devices that want to pull 3amps(+?)  at 5vdc...

Future proof? 5vdc, and heaps of amps available.

Question: flaws in designing house wiring with 5vdc, in every room, nook and crevice, and 60 AMPS total for the whole house? Can it kill a device never expecting to get a possible sixty amps?

Thoughts...

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RCC1
 RCC1
(@rcc1)
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Each device would be fine if connected.   You can't force the 60 amps into something that doesn't need it.

My concern I would have is the 60 amps would require a quite large wire for distribution, and if you ever have a short or failure of a device, you would have an instant heater.  Use ohms law.  A short anywhere which would pull the distribution wiring resistance down to a couple of ohms.

Try Amps squared times resistance using 60 amps and 2 ohms.     60 * 60 * 2 = 7,200 Watts

That a pretty big heater if you have a fault.  Most likely a fire.

RCC1


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DroneBot Workshop
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Posted by: @whitneydesignlabs

If I understand Ohm's law correctly, no device will draw more than it needs?

That's correct. Of course, a short-circuit will consume all 60 amps, until the wire melts. So fusing is probably a good idea.

In my youth (back when the dinosaurs still roamed the Earth and there were only 4 TV networks) I worked as a technician in a place that manufactured power supplies. One time one of our assemblers forgot to install a mica insulator on one of the power rectifiers in a 100-amp power supply. When I hooked it up for testing it was pretty spectacular, not only did we get a room full of "magic smoke", it also vaporized the wires on my multimeter! The test leads looked perfectly fine, but they were now just empty insulated tubes - the wire inside was completely gone.

That's a nice find, I envy you!

😎

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


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WhitneyDesignLabs
(@whitneydesignlabs)
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5Vpowersupply a
5Vpowersupply b

Thanks for the feedback, guys. I added a couple pics of the scrapyard score.

Good idea about fusing. I think an automotive 40A ATC blade fuse would do nicely. I could even fuse it at 10-15amps and use smaller wiring. That would be equivalent of about 4 or 5 high-demand cell phones all charging at full tilt, and/or a raspberry pi doing some heavy processing.  Don't know for sure, but the idea seems pretty future proof. It would be nice to do away with all the wall warts everywhere and USB seems to be a pretty good standard by now.  

Side note: the power supply also has a 12v output. That could be handy in the shop.

Like: Python, Adept: C++, Don't like: Java


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