I'm not an expert on this topic, but I've done similar voltage
doubling with a ICL7660 to double 5v to 10v, but with much
lower current (< 50ma).  Maybe the spec sheet for the 7660
would give you a starting point to think about as long as
it lists theory.

--Anil

> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of NCS Products
> Sent: Thursday, May 28, 1998 6:05 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [OT] Doubling 12 volts...maybe use a 8-pin PIC!
>
>
> I need to double a 12VDC input to get 24VDC at .5 - 1A.
>
> This can be done, I'm sure, but how?
> I think the basic concept is, you charge two capacitors in parallel,
> then discharge in series.
>
> What type of switches (MOSFETS?) do I need, and how many.
> Any pointers to analog info would be much appreciated.
>