Powerbook power adapter pin-out

Does anybody know the pin-out of the white-brick power adapter
Uli Wienands wrote on :

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

Michael Black replied on :

Uli Wienands (wienands@redacted.invalid) 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