I believe this is called a boost regulator.
look here:

http://www.national.com/parametric/0,1850,676,00.html




On Mon, 17 May 1999, list wrote:

> I need to generate 24VDC/150ma  from 11VDC/1a for a pic project. Anything
> out there to accomplish this.
> Tom
> Tom@comtronix.com
>