The Touchstone uses a lot of current compaired to plugging into the side port!  
Most USB ports will not supply enough power to charge the PRE with the 
Touchstone but will sucessfully charge with the side port.

There may also be a problem that some USB cords will not carry enough current 
to to use with a Touchstone.


The Touchstone must take the 5 Volts from the USB plug, convert the DC to AC 
and raise the voltage level well above the 5 Volts.  This AC Voltage is induced 
from the Touchstone to the PRE with a coil in the Touchstone and the special 
back for the PRE.  This is a loosely coupled transformer.  

The PRE has to take the AC and convert it back to DC and regulate the voltage 
to properly charge the battery! Lots of loss in the conversion processes and 
the inductive coupling requires a larger current supply for the Touchstone to 
work!


Leland Cox


--- In [email protected], Don Pomplun <bluefl...@...> wrote:
>
> I just picked up a plug-in Lenmar charging pack with 4 USB ports to 
> take on a trip.  Checking it out before the trip, I find some strange 
> things that seem related to Palm cords  --  I have the one that came 
> with the Pre and a similar(shorter) one from the Palm car 
> charger.  Either cord used with a Touchstone, plugged into my PC's 
> USB port won't charge., but plugged directly into the side USB port 
> on the Pre works as expected.
> Either cord used with the Palm Wall wart works OK on Touchstone or 
> side port.  But plugged into the (2 amp) Lenmar only works on the 
> side port, not the TS.
> Strangely the Palm cords work with the TS using my Kindle charger.  wazzup?
> 
> Don (CA) 
> 
> [Non-text portions of this message have been removed]
>


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