[SPARCbook] Error Codes Sparcbook 3xs

[Ian Spray]

On 11 Apr, 2005, at 17:38, christer at a-son.net wrote:

> I don't seem to find this in the FAQ, maybe you removed it? I have an 
> S3
> that doesn't work with the almost dead battery I have got and the DC
> adapter connected. I have another one the does work this way. I guess
> there must be some kind or regulator envolved, so was thinking this is
> what has gone bad. I had the idea of using the external battery 
> connector,
> but was unsure which leads to use, and what voltage was allowed. I gave
> up the idea, but I guess this would be possible then?
>
Well, the last version Hugo did still appears to be up:

   http://hvdkooij.xs4all.nl/docs/SparcBook-FAQ.html

but it just has a very short line about it (item 1.25).  No, this 
wasn't an official Tadpole option :)

Basically, you need to use a DC jack of the correct diameter (sorry, I 
don't know what mm size it is off-hand: I just took a PSU plug from a 
pile of broken bits) and then put two spade terminals on it and made 
sure I triple-checked that the wire to the centre of the plug went to 
the + on the battery.  Any voltage source that is a stable 12v and 
centre positive ought to work just fine.

I used an old Yeasu (sp ?) 12v 7.2Ah sealed gel lead acid and it worked 
fine for the amount I time I wanted it for (around 5 hours in 3 runs, 
charging in between each run from mains).  Note that I did *not* charge 
the unit whilst running from the battery: this would mean that at least 
13.8v was going into the unit and I am unsure what the spec on the 
voltage regulator is.  I also did not do any runtime testing, or 
investigation of what happens as the voltage drops off.

So if you have the desire to run the unit for a few hours away from 
mains and weight isn't a problem, then this is fine.  If you want to 
turn the machine into a server with a whopping battery backup system, 
then you will need to add a voltage regulator between the battery and 
laptop so the trickle charge voltage doesn't fry anything.

Does that help ?

-- 
Ian Spray             | Software Engineer     | Tadpole Computer Ltd.
ian_spray at tadpole.com | http://hw.tadpole.com | +44 (0) 870 432 4161
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