On Friday 30 August 2002 18:24, you wrote:
> >Worst case scenario is to use an off the shelf AC converter.
> >If you can keep the power requirements down to 100Watts
> >they are available for about $45.
>
> I am looking at this too for the oldish Dell Laptop that I have. Howeve=
r it
> requires 18V at 3.5A (at least that is what the power pack says it can
> deliver) and I have been thinking seriously of doing a converter to get=
 to
> this instead of going to 230V to drive the power pack.

Hi,

Similar laptop here, and 18V power adapter. However the internal battery =
is=20
only 10-ish or so volts. If the actual charging ciruit (which is tricky f=
or=20
laptop batteries) is inside the laptop, you can probably hook it up with=20
anything 11-18 volts and be happy. I doub the external charger has the=20
volt/current/temp/etc sensing circuits in it, it's most likely just a=20
wallwart thing.

The official 12 volt accessory for this laptop costs 150 euro's from Dell=
=2E=20
It's probably nothing more than over/under voltage protection and spike=20
supression (of course very important, but not 150 euro's worth).

I have friends with old laptops hooked directly to the car battery, grant=
ed=20
the internal batteries are dead anyway (as in, 5 minutes of charge) which=
 is=20
why they ended up there, but they together with the charging circuit insi=
de=20
the laptop keep the voltage very nicely at the intended voltage (=3D inte=
rnal=20
battery output).

Try to find some more info on the net about your model,
Goodluck
Dennis

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