[Soekris] Battery Power

[Joel Jaeggli]

On Tue, 2 Mar 2004, Joel Dare wrote:

> At 12:10 PM 3/2/2004, you wrote:
> >I never tried it, but you might draw on other experience.
> ...Snip...
> >4*AA is 6 volts?  Don't you need 12?
> ...Snip...
> >Please summarize.  I know that I have a soekris project that
> >sometimes needs battery power.
> >
> >Seth
> 
> The Soekris specs say 5V DC fixed or 7-20V DC.  I know nothing about 
> electronics, but imagine that it's listed this way because of some 
> convention rather than the actual allowable voltage.  I'll probably burn my 
> board up learning otherwise.
> 
> In any case, 5V DC fixed usually is something like +/- 5%.  At first 
> glance, the Soekris seems to have a much better range than that.  My 
> batteries started at 5.8V and the board gave me an error LED when they got 
> down to 5.5V.  So, if I start at a higher voltage, given the lower amperage 
> and allowable voltage drop, then it should work quite a bit 
> longer.  Unfortunately, NiMh D batteries are only a little better than NiMh 
> AA batteries.  In Alkaline's, there is a significant difference (speaking 
> of the mAh ratings), so D Alkaline's would probably last 5 times as long as 
> D NiMh's.  If I could run the board on 8 AA's (12V) for a couple of hours, 
> I would be happy.
> 
> I am NOT using the NIC ports in my application, but I do need keyboard and 
> sound support, which I haven't found yet.
> 
> What I'm trying to do is create a computer that I can take to locations 
> where I normally might not take a computer (because it's rude). 

the smallest laptop I have (sony vaio u3) is a bit smaller than a 4521 or 
4801 including the keyboard and display, the cost delta is quite a lot (I 
picked it up for around $1000 used). I find it fairly unitrusive to use 
since there's no huge display in front of you, but people allways want to 
look at it because it's so small. 

> The system 
> would need a keyboard (likely a one-handed or small keyboard), and I would 
> use it for taking notes.  I'm a good typist and don't need really need a 
> monitor, but sound feedback would also be a plus.  I plan to write all the 
> software myself, so I can choose any platform, and I'm kinda leaning toward 
> FreeDOS right now.

I'm looking at the frogpad, I already have a half-keyboard, which works 
ok, and the vaio has a complete if realtivly miniscule keyboard, it's far 
and away better than trying to use the chicklet keyboard on a zaurus or a 
handspring treo.

> 
> Joel 
> 
> 
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Joel Jaeggli  	       Unix Consulting 	       joelja at darkwing.uoregon.edu    
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