Different Ways of Using PWM's

[Bob]

So far I have herd of about 3 distinctly different ways of using a PWM.
Each of these methods have their own merits and drawbacks.
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the method I am Most fimilure with is the one that Bob Boyce and Stan Mayer used in their ground breaking work a few years back.
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the easiest way I know of explaining how its used is to explain how to set the unit up in operation. assuming all things are working properly.
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 this Method was to simply set the Electrolyte to Maximum concentration ( saturation point of water with KOH, 28~30% KOH to water by weight, yes that is a great deal of KOH!)
and then use the PWM to control the Amount of Amperage that the cell recieves...
sense the cell can typically recieve way more amps than a PWM can handle in that configuration ( Maximum concentration of Electrolyte)  Care must be taken not to over burden the PWM or you will burn it up !....
this method has a few distint advantages, the High concentration of the electrolyte makes the resistance in the water go way down, and therefore the heat made in the water will be much less, and therefore the entire cell will run much cooler.
Also there is a slight increase in Hydroxy gas production, I guess because of the lower resistance in the electrolyte.
and you will use Slightly less power ( not much but some) due to the fact that the power going to the cell is now Pulsed and not on 100% of the time....
although this last fact seams to take away some production when added to the slight increase of production of less resistance in the electrolyte the end results is a Slight drop in production over standard hookup without a PWM... but it is only a very slight decrease and the benifits outweigh the losses in this case by a long way.
some people to to a PWM just for the "Cooler running" alone. but be aware that you won't get the cooler Running unless you use a Maximum concentration in the electrolyte.
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Another method is Used More or less to Allow a more Consistant LPM output at cold and Hot tempitures.
the way I understand it , is that you set your Cells electrolyte to draw 35 amps when you want a normal operateing amperage of only 20 amps....(Assumeing that your PWM can handle 40 amps)
this way, when it is cold you can crank up the amps using the PWM and achieve nearly the same output as when its hot.... and as the cell warms up you cut the Amps back down to 20 amps
in effect getting 2LPM when the cell is cold and when the cell is hot.
this method has allot going for it when you only drive a short distance, and in fact it usually takes 30 min for a cell to warm up to good operating temperature, but by then your already at your destination, ! so allowing a fast warm up by hitting the cell with more amps than it normally gets  has its merits and keeps the HYdroxy gas level high enough to make a difference in your gas millage.
... Typically when My cell is cold it only puts out about 3/4LPM but when its hot almost 3LPM
and it takes about 15 to 30 minutes to get up to full operating temperature... so you can see the advantages in this method!
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I am sure there are other methods of Useing a PWM, but these are the two that I am most Fimilure with, if you have veriations or knowledge of other methods please feel free to broaden our Hurrizons by explaining what ya know !
Thanks !
Bob.........

[ic-738]

Hi Bob, and all,

     Long time no contact. I lost contact to all those on the hgi when fall came around, lot of overtime and the pc wigged out and I had to wipe the hard drive.  On top of that I had to remove all gen. parts from the truck for some warenty work, I don't think they would have appreciated the hookup, lol.  Thankfully Russel "hg2" contacted me and gave me ur link.  This may be old hat, I have not had a chance to roam the whole forum yet, but I will throw out some of the work I did do over the winter.  I built a true pwm that will handle up to 90 amps.  the frequency adjust (whitch I found made a big difference) goes from 1khz to 350 hz variable in two steps with a change of a cap.  Duty cycle 0 to 100%.  Current adjustment 0 to 100%. I also built a circuit to control the o2 sensor.  Being warmer weather I can start testing the new pwm on my truck, and feed some data back in here.  With my old set up I was able to get 2 lpm at ~ 20 amps, and at one point when it was fully heated I employed another cell and got ~ 4 lpm at 40+ amps.  I don't want to go on too much off tangent, I just wanted to give all a little background on my endeavors.  Thanks again hg2 for the link, and Bob for your dilligent work to keep us all conected!

                                                                                        Thanks,
                                                                                         Mike
                                                                                         AB2DF.

[hg2]

  Hey ya Mike,

  Good to see to made here and are still active with the HHO,sounds like you,ve made some breakthroughs with your heavy duty PWM and O2 efie.I guess like most folks up north you're still waiting for warmer weather to start using your generator again without all the winter headaches.

  Btw I lost you phone #(along with everybody else's) when I switched over phone service.I'd be interested in hearing about all you've done since we last spoke.Pm me with it when you have time.

[ROADKING]

The pwm I chose to use is a zero fossil version, it is called a constant current pwm.  At the present I set it at 21 amps, then set the duty cycle and on my trip it started at 21 amps cold and was at 21 amps at the end of the day and I like that.  I have not really figured out just how to set the frequency on it, so I had a lpm gauge (oxygen) on the test bench, when checking it, and when I set up the ccpwm, I turned the frequency till the ball reached it highest level.  I am buying a scope to experiment with and see what I can do then, if anyone has any advise on this I would appreciate it.  This ccpwm is rated at 75 amps.  It seems to make more hho with the ccpwm than with out,  and the reason I feel this way is that the torch I had hooked up to it seem to burn better thru the ccpwm rather than straight current to the cell,  I really like checking a cell with my torch, it seems to tell me a lot about the cells.

[Bob]

ic-738 !
good to see ya finally made it over here ! Fantastic ! glad to have ya with us !
...sounds like your PWM is a goodern'   
what cells are you running in the truck "Randy Cells" or something else ?
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I am just about to order my stainless steel for my big cell, and I might throw in some tube cell meterial as well and try my hand at Hydrotechs version ,really sounds like a good cell to me !
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I'm in the middle of moving all my junk to the Ranch ...and its a long drawn out hassel!

but at least there is a shop there of sorts... that will make it a bunch nicer!
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Keep after it Mike ! you'll get 75MPG out'a that truck yet !
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Bob........