How to make a charge pump, (doubling 9v to 18v)

[TKS]

Ok I saw a little enclosure that was used to change 9v to 18v.  How is this done?  Will it work the same as using a 18v power supply or does it change the mA?  Is it possible to get 9v up to 24v?  Thanks

[R.G.]

Read "circuit sweepings" at GEO for how to make -9V, +17V, +27V, +33V... from 9V.

Unless you specifically have some reason for rolling your own, use a purpose made charge pump like the Max1044, LT1044, LT1054, 7662, and many others.