recycling chargers

ismael schinca ischinca at plan.ceibal.edu.uy
Thu May 13 09:26:59 EDT 2010


We did this in Uruguay. It's difficult to ensure proper regulation on the
12V rail. You have to have a proper load to ensure stability. A good power
supply of course helps. To improve this you can put a resistor in the 5V
rail. Of course it wastes some power and the heat is a concern if it's
enclosed. But we tried it and it worked fine with only the power supply fan.

Ismael

2010/5/13 Sascha Silbe <sascha-ml-ui-sugar-olpc-devel at silbe.org>

> On Thu, May 13, 2010 at 06:44:34PM +1000, James Cameron wrote:
>
>  An ATX or AT switch-mode power supply attached to a set of nine laptop
>> charging cables.  The power supply is being used as a 12V DC regulated
>> source.  The original PC power harness cables have been removed.
>>
> FWIW, I've also used a ATX power supply to power an XO-1, but stopped doing
> so once I discovered why the XO-1.5 would run from it: Being a cheap model,
> it regulated only the 5V rail, so the 12V rail dropped down to 9V with a
> switched-on XO-1 connected to it. The XO-1 barely coped (the power light
> started flickering some time ago, probably due to the power supply aging and
> delivering an even lower voltage than before) and the XO-1.5 (without MPPT
> ECO) didn't like it at all (whining noise, LED off).
>
> Summary: If you're trying to replicate this setup, make sure your PC power
> supply regulates the 12V rail (just hook up some load and check the
> voltage).
>
> CU Sascha
>
> --
> http://sascha.silbe.org/
> http://www.infra-silbe.de/
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-- 
Ismael Schinca
Plan Ceibal - Depto. Técnico - I+D
Avda. Italia 6201
Montevideo - Uruguay.
Tel.: 601 57 73 Int. 2227
E-mail : ischinca at plan.ceibal.edu.uy
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