Check uot youtube______ run HHO, hydorgen fuel, myers, lawton, brown gas, etc...
The best sight I have found so far is
www.waterfuelcell.org go to the forums section and check out the hydoxy section____________
*I am not affiliated with any of the sites that I posted here! Just trying to share info with an interested board member_______---
I tried to attach a modified version of the DAVE LAWTON circuit, you can find it at aqaupulser.com once you get on the site look for d14 I think they list it in thier description of their PWM product.
You might also want to check out zeofossilfuel on youtube or go directly to his sight at alt-nrg.org He has his own design
There is a lot more out there or desin yuor own....personally if I knew electronics I might be looking at a SILc40 series from Emerson and build a stand alone circuit...BUT since I found this sight trying to learn circuits only to discover an ALT-Energy thread section...