Does anybody know the pin-out of the white-brick power adapter (the 
one for Powerbooks and iBooks). I can see it has a 3-contact mini plug 
plus the shield around it (which I assume does not carry any current).
Per the label on the brick it is a 24 V unit.

I want to rig up a back-up battery so I can change the battery on my Pb 
while it sleeps without having to reboot.

Uli

Uli Wienands (wienands@gmail.com) writes:
>    Does anybody know the pin-out of the white-brick power adapter (the 
> one for Powerbooks and iBooks). I can see it has a 3-contact mini plug 
> plus the shield around it (which I assume does not carry any current).
> Per the label on the brick it is a 24 V unit.
> 
> I want to rig up a back-up battery so I can change the battery on my Pb 
> while it sleeps without having to reboot.
> 
> Uli
Search the newsgroup archives at google for it.  I've posted it a number
of times since I tracked it down and verified it myself some years back.

The shield does not seem to serve a purpose, though I've never had an
adaptor to check.  It's otherwise a standard mini stereo plug, and
one key thing is that what is normally ground (when the plugs 
are used for audio) is not).

  Michael