Possible Duplicate:
Choosing power supply, how to get the voltage and current ratings?
Is it possible to set up a DC source of power for a laptop so that it mimics the specs of the adapter (basically set up something with the same voltage and amperage)?
The specs I am trying to mimic are 19V and 2.42A. I'm not sure exactly how to set up something with specs near that, but I do have a model train set that can output a variable voltage amount, and using batteries might also work. Any suggestions on this would be appreciated.
I also have other adapters lying around that can be cannibalized for spare parts.
Is is harmful to laptops to use slightly too much amperage or voltage? If not I may just hook it up to a different adapter that uses 20V (I don't know the amperage, but I'd imagine it is higher).