Solar powered Sheeva Plug
From ComputingPlugs
This is courtesy of jmknapp, posted here with his permission. He experimented with a solar powered sheevaplug, here's what he has to say:
| If you remove the four plastic "feet" and remove the corresponding screws, the plug splits into two halves, one of which contains the main power supply and the other the main circuit boards. Here's the power supply side: |  |
| It's just a simple 5V supply with a 4-pin connector, the two red leads being 5V (actually 5.25V measured) and the two black leads being ground.
The circuit board side has the female power connector J3: |  |
| A closer view [of J3]: |  |
| The pins have a 0.1" (2.5mm) spacing.
So to run the plug on, say, a battery or solar panel just requires feeding 5V to J3. The schematic shows that the two power pins and the two ground pins are tied together: |  |
| Here's a proof of concept with an 18W solar panel and small battery (to bridge cloudy intervals): |  |
| The solar panel produces 18V @ 1A in full sunlight. That feeds into a 12V charging regulator which then goes into a 5V regulator and then to J3. The plug runs fine with this setup, including the USB hub (Targus Bend-A-Hub) which has an 802.11g USB adapter as well as a 16GB USB memory stick attached in the photo. The plug draws about 800ma @ 5V normally, up to 1000ma depending on cpu activity. The 802.11g dongle bumps the current up to about 1100ma.
Here's a laptop vnc'ed into the plug, showing the gnome desktop: |  |
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May 18 2009 2:29 pm
Please keep comments clean and constructive. Inappropriate comments will be removed. Thank you.
May 25 2009 7:33 pm
Wow, this is great!! congrats!
Jul 06 2009 3:23 pm
Thats great Info, I would like to do something similar to that, just to run a 24/7 downloads of the internet, would anyone contact me with ideas at chris.imo_(AT)_gmail_(DOT)_com
Jul 07 2009 11:39 am
what other ideas do you need? Just run rtorrent and you're good to go.
Jul 22 2009 12:11 pm
Can some please give an URL to making this same solar setup for the Sheeva Plug. There must eba charge controller in the hardware somewhere so that the battery gets charged, and then switches over to the solar pael etc etc
Jul 23 2009 9:19 am
When I talked with the person who build it, he told me that it was a solar kit from a while back. I did a quick search and found that sundancesolar.com have 5w solar kit that charges a 12v battery. I suppose you can get something like that and then rig a 12v to 5v converter to get the output to 5v.
Aug 23 2009 6:21 pm
I have a 12v solar power system that charges a bank of batteries. Right now I run a Linksys NSLU2 and all my networking equipment off of it. I built a 5v power supply with a very high efficiency switching regulator. I used the Murata Power Solutions 78SR 2 Amp Series - I bought mine from mouser.com. I takes the voltage from the battery (10-15v) and provides a stable 5v supply. I plan on using the same power supply for my Sheeva Plug. For more information see "How to make a battery powered slug" (http://www.nslu2-linux.org/wiki/HowTo/MakeABatteryPoweredSlug) and scroll down to the section titled "Powering a NSLU2 from a 12 Volt Battery." The same concepts apply to powering a Sheeva Plug from a 12v battery system.
Aug 31 2009 2:10 pm
Very cool, I'm surprise the NSLU2 draws about 3 watts during a file transfer.
Dec 15 2009 5:35 am
Wouldn't there be a significant power loss in the 12V > 5V transfer? Would that still be more efficient than AC>DC transfer? I run our entire house on DC, with AC through an inverter, and being able to run this 24/7 on DC would be great, if it actually took less power.
Dec 16 2009 4:49 am
The power loss depends on the type of 12 to 5 volt regulator / converter used. The 78SR series switching devices have high efficiency. Small DC-DC converters are typically quite efficient too. Ordinary 7805 style devices use an internal series pass transistor, with excess energy being dissipated as heat.
Dec 16 2009 3:41 pm
I suspect the reason he had to use a 12v regulator is because the output of the solar panel he had around the house outputs 12v. If you can find a panel or battery/charging unit that outputs 5v then you can plug it directly into the sheevaplug mainboard.
Mar 07 2010 10:46 am
Does anyone know that type of molex used by the J3 plug? Maybe a Digikey number?
Thanks.
Dick