One PSU for Pi, WebCam, Wifi and 12v Motor


13 posts
by aframe » Thu Jan 24, 2013 11:57 am
Hi all,

Got a little project that is nearly it's completion and just looking to plug in (literally) the final piece of the puzzle.

I want to be able to power my Pi, USB Camera, Wifi Dongle and a 12v dc gear motor, from one slim-as-possible wall plug power supply.

The way I have things at the moment is:

Pi plugged in using stock power supply. The wifi dongle and USB cam are plugged directly into the pi.

Motor connected to an L298N board powered by a 9v battery for testing.

As I said, I'd like to have one power supply that can provide the 12v ~2a required for the motor, and the 5v Xa required by the Pi.

Here's the motor I'm using: http://www.pololu.com/catalog/product/1591

Can anyone recommend a good power supply that's as small (and cheap) as possible, that will allow me to leave the motor and pi plugged in all day.

I'm from the UK so would only be looking to buy products available here.

Thanks for your help.
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by daveake » Thu Jan 24, 2013 12:27 pm
Many external hard drives have (or used to have - seems less common these days) dual-voltage power supplies. I just searched on ebay for "5V 12V PSU" and this was the first possible one that came up: http://www.ebay.co.uk/itm/6-PINS-HDD-HD ... 3f08712595
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by aframe » Thu Jan 24, 2013 12:44 pm
Thanks for the link. I was hoping for one that I wouldn't have to hack apart and mess about with too much.

Is there such a thing?
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by daveake » Thu Jan 24, 2013 2:06 pm
It wouldn't take long to knock up an adapter with a PS/2 socket at one end and a micro-USB at the other, plus whatever connector you need for your 12V motor. Personally I'd just grab a USB-micro USB lead, remove the USB end, and solder it to an inline PS/2 socket. If you're hoping to buy something with those connectors already in place I think you'll be out of luck.
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by aframe » Thu Jan 24, 2013 3:03 pm
I only need micro-usb and a 12v power and ground, will the above be ok with that?

If so, I'd better get searching for connectors...
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by daveake » Thu Jan 24, 2013 3:39 pm
Yes, it'll have 5V, 12V and GND in the PS/2 plug. Just be very very careful that you connect the right micro-USB wires to the right PS/2 pins to avoid having an ex-Pi on your desk :)
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by aframe » Thu Jan 24, 2013 4:52 pm
Fantastic.

Thanks for your help Dave!
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by paulie » Sat Feb 09, 2013 11:58 am
daveake wrote:Yes, it'll have 5V, 12V and GND in the PS/2 plug. Just be very very careful that you connect the right micro-USB wires to the right PS/2 pins to avoid having an ex-Pi on your desk :)


Yes, it will have ex-Pired....

Badum tish!
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by KenMacD » Wed Sep 04, 2013 4:40 pm
From the Cupieboard wiki they have a wiki page on using a molex power adapter to provide both 12v and 5v.

The page is http://linux-sunxi.org/Cubieboard/HDD.

Using a molex adapter with the linked usb splitter seems like it might do what you want.

(Disclaimer: I'm not an expert in power adapters, and I haven't tried this)
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by klricks » Fri Sep 06, 2013 3:58 am
The power supplies that come with these USB to IDE/SATA adapters have +12V and +5V outputs. The drive power cable would be easy to modify.

http://www.ebay.com/itm/USB-2-0-to-IDE- ... 2eb8170013
Go here for my RPi writeup. Basic config, Serial Port add-on etc:
http://home.budget.net/~klricks/Comp/RPi/Rpi.html
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by smstext » Sat Sep 07, 2013 6:43 pm
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by eduardosleal » Thu Sep 26, 2013 6:35 pm
Are those IDE/SATA dual-voltage power supplies stable when the raspberry or the peripherals consume current near 2A? Say the 12V motor will consume 2A, would the power supply still be able to supply 5V and 1A to the raspberry?

Has anyone tested it?
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by klricks » Fri Sep 27, 2013 1:08 am
eduardosleal wrote:Are those IDE/SATA dual-voltage power supplies stable when the raspberry or the peripherals consume current near 2A? Say the 12V motor will consume 2A, would the power supply still be able to supply 5V and 1A to the raspberry?

Has anyone tested it?


I have not tested it on a RPi but the PS for my SATA/IDE adapter is rated at 12V 2A and 5V 2A. The SATA drive I have connected is rated 12V 0.55A and 5V 0.7A
I would be careful trying to push any PS to the limit. Will the 12V motor be on constantly?
Go here for my RPi writeup. Basic config, Serial Port add-on etc:
http://home.budget.net/~klricks/Comp/RPi/Rpi.html
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