Bubble bubble toil & trouble. Saw your question on Gary's post about the dimmer. Not sure if that is a good approach to your problem. If I am understanding correctly you are worried about the 170 volt level you get when the filter caps charge to the peak value of the ac in? Seems like if 120 is good 170 would be better. Do you need smooth DC??? Seems like I recall people running these things from PWM's. If you can stand the ripple just your big bridge would work. If not I would use 4 2700 ufd. 200 volt dc caps like the 272m2000a052 from Mouser Electronics. Let me know if the 170 volts is really to much. From the video you posted it didn't look like they used anything fancy. A real 20 amp regulator at your voltage is not real cheap. If you are worried about the 170 volts, how about a half wave rectifier at 85 volts? This might be the best with the 8 caps. Getting a little expensive. $80. Do these really work?
Thank you Ronv for the reply

I am looking at a few different ways to power my Hyd generators, I may not even need a capacitor because the current is going through water, that may be good enough

Yes the 170 volts may be to much voltage to use, as it only takes 1.2 to 1.5 volts per plate to release the hyd from the water, i am looking at hooking 3 hyd generators in series, with 21 plates each, and using a 12v to 120v converter to a bridge rectifier to power the hyd generator, I like the half wave rectifier idea too at 85 Volts

These Hydrogen generators work very very well, i am using 30 and 55 amp PWM @ 12 volts, with a 100 Hz frequency , the 55 amp PWM has an adjustable frequency to it, these can also be used with 24 volts too, a hyd generator that i built, worked great, at Cruise speeds it would double my fuel milage, thats where they really shine, also the motor oil stays super clean, because almost 100% of the fuel is being burnt and used, you will always loose some fuel to heat

I love the extra power that I am getting too, normally on most SUVs and pick up trucks, 15 amps is the most you want to use to generate hyd, because it does take power from the eng to make hyd, I dont think these hyd generators are over unity, they help to make extra power in a number of ways, the fuel is burnt 25% more effecient, the hyd burns turns to water then flashes to steam to drive the piston down longer under power, the fuel is burnt slower, its like getting 120 octane gas

the added oxy helps everything to burn better, the eng sees the extra hyd fuel with or with out a comp. and will adjust for it, fuel savings of 20 to 60% is commom, with some vehicles getting 100% fuel savings or doubling your fuel milage @ cruise speeds 65 to 70 mph, I will also be making some portable units so they can be used in a boat too, I am just doing my R&D right now on some larger hyd Generators for big rigs, I may stick with 12 or 24 volts, but i just want to experiment a little

the hyd or HHO gas is just a supplemental fuel, to aid in MPH, its not the entire fuel being used, a eng would need to be modified to run on pure HYD, like stainless steel valves, bronze valve bushings, ceramic coated piston tops, and ceramic coated combustion chambers, stainless steel exhaust system, high energy ignition system , ETC

to name a few, also you will need to use syntetic oil to make it last, Thats why I kind of like a rotory eng

Take care, Chellie