PWM question...experts please??

[mobman]

Hey guys,

I am a total noob to HHO and have bought a drycell kit which did not come with a PWM. Now while I understand the basics of PWM I am not really sure of its operation since PWM let you adjust (beside amps) voltage and frequency. I dont get what adjusting voltage and frequency does?? Can someone be so kind to explain exactly what a PWM does and what the proces of adjustment is?

Also I am seeing a lot of PWM being sold on ebay for HHO purposes with a amp rating of say "30 amps" does that mean that is the maximum amp draw one can achieve? or is that for something different? My drycell is rated at 7-10 LPH of HHO gas production and I do not want to go over 60 amps what PWM should I purchase?? Thanks!