On Thu, 28 May 1998 21:04:55 -0400 NCS Products <ncs@WORLDNET.ATT.NET>
writes:
>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.

You need a boost converter as Harold said. Just a few addition. Consider how
your environment handling
switching noise and switching frequency changing according to the load.
If this is not a  problem I would go for NJM2360. Only a few additional
parts and ready to go.
One of our design work very well with 330uh/330uF and 1N5819 diode.(cheapest
solution)
One step up is NJM3524, fixed frequency, PWM drive but You need an external
switching device.
If You care about size for switching device we found ZETEX Super SOT's are
excellent choices.
I recommend to use JRC because their cost is a fraction compare to the big
guys and we use them over 200K annually
without any problem or defective out of spec. device. Their website is
<http://www.njr.com>
If You really care about noise, go for the big guys they have a plenty of
solution and high price.

Good luck,
Peter
schupet@dvp.com