Multiple Rasberry Pis to a Power Supply?

Hey Guys,

I am trying to work with as many as 10 different Rasberry Pis and I have a nice powerful Power Supply to work with, but I am unsure of how to connect multiple Raspberry Pis to the same power supply.

I attached an image of the power supply I have.

Any help would be awesome!

Thanks guys,
Jeff

EDIT: I found someone who accomplished this and have attached an image of his setup below, but I am not sure how he did it. An explanation of his set up or an alternative would be enormously appreciated!!!!!

Edited 1 time(s). Last edit at 08/08/2014 06:51PM by kfootball15.

That looks like a 12V power supply for powering LED strip lights. Do you know the specs of it (Volts / Watts)? This will dictate how to connect to it and how many pis you can connect.

The pi is powered by 5V via USB. To power it from a 12V supply, you could hack some 12V to USB cigarette lighters or (more reliably) some of these pololu step down voltage regulators. There are lots of options around.

You will need to be careful about the pi power demands, which you can read about here.

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[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Yes it is a 5V/300W- 60A Single Output power supply.

Rather then power it through USB I was hoping to save some money by powering them through the pins on the raspberry pi units, and then connecting those wires to the power supply. The problem I am having is connecting so many raspberry pis to the power supply. Someone else did something similar and I've attached an image, but I'm not quite sure what he did.

An help would be enormously appreciated!!!

Thanks so much

perhaps this will help
[www2.pmb.co.nz]
or
provide +5V to Pin 2 and 0V to Pin 6.

I have not done either so please verify my answers before attempting.

Edited 1 time(s). Last edit at 08/09/2014 09:34AM by cat.farmer.

Are there any instructions out there for a setup like the one he made? (pic in my 2nd post)

Starting at the power supply, it looks like he's run a red wire from a positive terminal to a power distribution block and run 6 or 7 from there to a chop block, which then connects to wires leading to the positive power supply pins of individual raspberry pi's (although the last part is a guess). Ditto for black / negative terminal, rinse and repeat for each available negative and positive terminal and you're running lots of pi's from your power supply. Red and black alternate along the chop block so you get a pair of wires next to each other providing positive / negative to each individual pi respectively.

Is that the info you're after?

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[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Quote
3dkarma
Starting at the power supply, it looks like he's run a red wire from a positive terminal to a power distribution block and run 6 or 7 from there to a chop block, which then connects to wires leading to the positive power supply pins of individual raspberry pi's (although the last part is a guess). Ditto for black / negative terminal, rinse and repeat for each available negative and positive terminal and you're running lots of pi's from your power supply. Red and black alternate along the chop block so you get a pair of wires next to each other providing positive / negative to each individual pi respectively.

Is that the info you're after?

This was very helpful!!!

Just for clarity can you show me some power distribution block and chop block examples that I can base my own design from? This would be incredibly helpful!!! Thank you!!

Depending on what you are doing with the raspberries, you might also consider using power filter capacitors to help smooth out sags or spikes on the rail that could cause reboots or more fatal surges. Are they the raspberry B..or the new B+ that has just come out? I know what I'm asking Mrs Santa for Xmas :-)

Edited 1 time(s). Last edit at 08/12/2014 03:17AM by ShaneH.

You can power the rpi via the GPIO header, but it's not recommended. You're bypassing the internal fuse, diode, voltage regulation, and capacitors for smoothing out the power. If you're careful, sure you might be able to get by with a decent power supply. But one oops and you've got a fried pi and not one of those tasty ones with the fruit filling. Just get some cheap usb cables from Monoprice of the length you need, cut off one end, and use the red and black wires to power the pi the proper way via the USB port and your power supply. Or you could get a bunch of usb connectors, solder them to a circuit board, and make a custom "outlet strip" of sorts.

Quote
cdru
You can power the rpi via the GPIO header, but it's not recommended. You're bypassing the internal fuse, diode, voltage regulation, and capacitors for smoothing out the power. If you're careful, sure you might be able to get by with a decent power supply. But one oops and you've got a fried pi and not one of those tasty ones with the fruit filling. Just get some cheap usb cables from Monoprice of the length you need, cut off one end, and use the red and black wires to power the pi the proper way via the USB port and your power supply. Or you could get a bunch of usb connectors, solder them to a circuit board, and make a custom "outlet strip" of sorts.

Hmmm this sounds very interesting and sounds like a more simple option.

I think I would run into a similar problem with connecting all the USB cables to the power supply. How do I go about connecting all of those red and black wires to the power supply at the same time?

Edited 1 time(s). Last edit at 08/12/2014 03:40PM by kfootball15.

Quote
kfootball15
I think I would run into a similar problem with connecting all the USB cables to the power supply. How do I go about connecting all of those red and black wires to the power supply at the same time?

As long as you won't need to quickly add and remove additional cables, strip off an inch or two from each cable, twist them together, solder them along with a pigtail that goes to the power supply. Wrap the soldered connector in electrical tape or shrink tubing. You may be able to just use a big enough wire nut since the wires are small, but with that many a soldered connection would be more reliable.

I actually build a 48 node cluster of Rasberry Pis for testing network equipment. I think I actually used the exact same powersupply you did. The way I connected the power was to use electrical bus bars meant for a electrical panel to connect them similar to this one:

[www.carltonbates.com]

I got two of them, one for the positive and one for the negative, which I mounted to the underside of my enclosure. I then ran the wires from the powersupply to the bus bar and then distributed the power to the Pi's from there. Worked great. Make sure the bus bar's screws can get tight enough to hold your wires.