[Thinkpad] Auto adapter for A-series

[Stuart F. Biggar]

At 03:20 PM 12/26/2007, you wrote:
>Hi,
>
>Can anyone point me to a good source for an auto power adapter that will
>work with the A21p?  This is the older, round-style plug.
>
>If I'd be better off getting a small DC-to-AC inverter and using the
>normal power brick I can do that too.  How many watts does it need to
>supply?
>
>Thanks,
>Rob

Rob,

I have an IBM auto/airline adapter that I've used with an A21p.
However, it is at work and I'm at home (holiday closure).

If I remember correctly it is a 72 Watt device and I've also used
it with a T43p (same tip).  Looking around with Google I find:

http://www-307.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-62330

Which lists two possibilities a ways down the page.  You might be able
to find one or the other on some site.

A different page shows the A21p using a 72 Watt device:

http://www-307.ibm.com/pc/support/site.wss/MIGR-4PJRRG.html

As for using an inverter, they aren't that efficient and the generally
produce a fair amount of electrical noise which may or may not be a problem
depending on the application.  I would guess an efficiency of about 80%
(could be better or worse) so a 100 Watt device should power the 72 watt
brick that came with my A21p allowing the TP to charge and operate.  I
think I'd rather use the IBM device that directly converts 12 VDC to the
16 the TP uses rather than the two stage conversion.

Stuart