[Power] Power solutions for charging 150+ XOs1.0/1.5

[Richard Smith]

On Tue, May 28, 2013 at 4:52 AM, Xavier Carcelle
<xavier.carcelle at gmail.com> wrote:
>
> Can you recall us :
> -the max current needed during the charge (and probably higher at the
> beginning of the charge) ?

Are you talking @ 240Vac? or at DC?

> -the difference of current needed for 1.0 and 1.5 ?

For 240Vac see the numbers I gave for George's SF presentation.

https://docs.google.com/presentation/d/1HL2Ok_9E6VIzEh0G-d_iQ5RoSAtwMZ74pw_Nme84Dbg/edit#slide=id.g22073e4d_0_0

Basically if you allocate a peak of 30W per XO (all XOs) you should be
ok.  If you know it would only be XO-1 on the circuit then you could
plan for 21W/XO.   Then 30Wh of energy for the full charge. XO off. If
the XO is powered on then its a bit harder to come up with the energy
needed because it depends on workload but it would be at least 15Wh
more and probably closer to 20Wh.

> -what the recommandations regarding the diesel group for 50, 100, 150
> XOs to recharge at the same time during the XOs class ?

I'm not clear on what recommendations you want.  You want
recommendations for a Diesel generator or for a replacement of the
generator with another technology?

> PS : Of course you guys have seen the fast recharge process found by Eesha Khare
> http://www.policymic.com/articles/43337/supercapacitor-phone-charger-eesha-khare-s-invention-charges-phones-instantly

Not to be cynical but I would not hold your breath.  Various people
have sent me articles about this and none of them actually say what
this magic is.  Considering the only thing she has powered so far is
an LED its a long ways off from any sort of usable product even if it
really is some revolutionary device.  LEDs take mW and a device like a
cell phone or batteries deal in Watts.  Thats 3 orders of magnitude of
difference.

--
Richard A. Smith
One Laptop per Child