[SPARCbook] PS for Ultrabook

[stephen price]

Hi Richard
I think, imho, that you may be setting yourself for a
failure.

>From what I remember, the U20 is strictly an 18v
machine & does bad things running under voltage.

Also - at power-up it uses just about every amp it can
find - and then curves down to about 5amps nominal.

So using undervoltage or trying to use less amps is a
bad idea - strictly my opinion - you understand...

As far as trying to repin the plug, the power supplies
I used, (something like the url I sent previously) are
all properly grounded 3 wire plugs, with the output
coming out 5 leads - so that matching the lemo
connector pins to the output wan't much of an issue.  

The caveat being that the guage of wire that the lemo
connector uses is very small compared to the guage of
wire coming out of the brick - so I pre-soldered the
lemo with small guage wire - then cut off the plug 
from the brick and mated the 5 wires from the brick to
the 5 wires I presoldered on the lemo connector.

Worked like a champ, even doing the battery charger
signal correctly (that's identified as one of the 5
pins on the lemo connector).

I hope that this helps...

regards
steve

--- Richard <richtom1 at excite.com> wrote:

>  Thanks for your reply Steve,  Well now that the
> holidays are over I can concentrate more on this.  I
> reconfigured my email header so this should come
> through ok. The Tadpoles I have are U20's (2) plus
> another one for parts.   The power requirements are
> actually 18V 6.5A which comes to 117W.  I did a
> search after Christmas but didn't find anything
> exact. I'll search again this week and think I
> should stay under 6.5A and 18V....maybe 17V and
> anything from 5.5A-6.5A will be safe? I have a quote
> and will order the lemo connectors in a week.   The
> 5 pin input diagram shows pin 1 (AC failure
> indicator); pins 2 & 3 (+18V); pins 4&5
> (return).  Does that mean pins 2&3 are the hot
> (18V) and pins 4&5 are the neutral?  If the PS
> cord only has a two prong  AC plug it can be plugged
> in backwards then the 18V will be going into the
> return side and vice versa.  All the different cords
> I have for AC adapters have just the two prongs.  I
> could cut the AC plug end off and wire 
> a polarized 2 prong plug end to it (the one with the
> larger hot  prong).  Will I have to split the
> positive wire in half (coming out of the AC adapter)
> to solder half onto pin 2 and half onto pin 3? 
> Likewise, will I have to split the negative
> (neutral) wire in half  (coming out of the AC
> adapter) and solder half onto pin 4 and half onto
> pin 5?  Pin 1 is AC failure indicator any idea of
> what I do with that one? I have been reading through
> all the posts (still not done) looking for info on
> how to reset the password on my other Sparcbook (a
> 3TX).   Any help would be appreciated.  Richard
> 
> _______________________________________________
> Join Excite! - http://www.excite.com
> The most personalized portal on the Web!
> _______________________________________________
> SPARCBook mailing list  -  SPARCBook at sunhelp.org
> http://www.sunhelp.org/mailman/listinfo/sparcbook
> 



      ____________________________________________________________________________________
Be a better friend, newshound, and 
know-it-all with Yahoo! Mobile.  Try it now.  http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ