Greetings from Townsville
I am very new to this group but am experienced with industrial electronics and been playing with hho for some time.
I doubted the PWM that came with the kit purchased and so looked for an alternative unit.
The jaycar unit is perfect and cheap takes not time to build and you can very the pulse withs with ease.
Check out the link belowhttp://www.jaycar.com.au/productView.asp?ID=KC5502
I have this kit working and highly recommend it for HHO generators, plus at $39.95 you cant go wrong