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Thread: Just asking, DOES A PWM REALLY DO ANYTHING?

  1. #31
    Join Date
    Nov 2009
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    1,418
    So I strongly suspect it is down to the very high concentrations of very corrosive electrolytes (KOH and NaOH) that most people here tend to use. These poor electrodes are basically immersed in extremely strong acids or alkalines, which are then made more active by continuous ion current flow. Stainless steel is good, but its corrosion resistance has its limits! Not to mention the fact that if the metal is reacting like that, then the gas output will be reduced by non-productive chemical reactions.

    To me this is just one more good reason to minimise the concentration of such electrolytic compounds.
    Farra, there is lots to learn from these plates. Here are some. First, this is what happens to someone who does not know what they are doing. If you look carefully at the plates you can tell exactly what happened. I was told the electrolyte was 8% NaOH that is less than 50% max and ran at reasonable temps (just between 38º C to 40º C) drawing 8 to 12 amps. Now on a 2500 mile trip you would think one would consider adding water well in this case not until the amps moved up to 15 amps did this enter into his mind duh... This happened more than one time during the trip. You can see the electrolyte level was right at the high damage line so obviously it ran like that for some time. With the water being used up level goes down and concentration goes up causing increased amps in a very small area and the results are just what you see. This is a good time to recommend a PWM for people like this. I see a PWM as something to use in Winter when you are trying to keep the electrolyte from freezing 0º C or below and when it is linked to RPM/MAP/TPS to increase and decrease the amount of HHO being injected instead of just one amount all the time. Now this does not take into consideration pulsing etc to help separate the water into it's components which is still under investigation and not clear cut in the practical world anyway.
    "Democracy is two wolves and a lamb deciding what to have for dinner. Liberty is a well-armed lamb."

    ONE Liter per minute per 10 amps which just isn't possible Ha Ha .

  2. #32
    Join Date
    Dec 2010
    Location
    England
    Posts
    81
    I see. So basically the water was being used up and not replaced, which thereby concentrated the electrolyte to far above the initial 8%.
    Farrah

    It's what you learn after you think you know it all that really counts!

  3. #33
    Join Date
    Nov 2009
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    This of course is an extreme case but shows that the plates can and do get eaten up under the right conditions. Two many amps per square inch is damaging even though you might not see it in the short term in most cases. When the over amperage is not excessive, it would take 1000s of hours of run time to show up.
    "Democracy is two wolves and a lamb deciding what to have for dinner. Liberty is a well-armed lamb."

    ONE Liter per minute per 10 amps which just isn't possible Ha Ha .

  4. #34
    Join Date
    May 2011
    Posts
    3
    Quote Originally Posted by SmartScarecrow View Post
    100% HHO .. runs fine ... been doing it since late last year ... so far, no damage to the cheap Chinese engine ... I am still not doing it well ... my delivery system needs much improvement ... and there are modifications to the piston engine I need to try to see what works best ... so far, have tried a milled down head to increase compression ratio to 13:1 and various timing and ignition mods ... I have also documented the volumes of HHO required to run the engine under various loads ... its all just pure research and data acquisition ... the understanding is goal enough for me ...

    EDIT: duh, should have said late in 2007, not last year ... its already next year ... and actually, I was running a little B&S 2.5 hp engine on HHO 5 years ago ... so this is nothing that new or exciting ... folks been tinkering with this for quite a while ... a lot of people are doing it now ...
    hello i did this and had success at first it ran but not so good then put engine tdc and mod the flyweel so magneto is dead on tryed it and runs great its work but fun also mod the carb

  5. #35
    Join Date
    Aug 2014
    Location
    Planet Earth
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    51
    Quote Originally Posted by Gary Diamond View Post
    I can't understand why anyone uses them, if you want to cut down current add more cells. i can't possible see how adj the freq. and pluse width duty cycle does anything Please prove me wrong.
    Gary diamond
    Concerning the PWM technology itself, it's a more efficient way of reducing the applied power without wasting power by using a dropping resistor.
    PWM is also adjustable, in case you want to adjust the power due to certain conditions.

    General rule of thumb, you want 2 volts per cell so you don't waste power generating heat instead of HHO.

    If you were really serious, you might just mount a 2nd alternator to power the cells, and after removing the regulator, you could adjust the field to get the voltage you want under circumstances where you want more HHO.

  6. #36
    You don't need a PWM. I did the math and realized it only takes a little under 2 hp to generate 15 amps minimal so I'm guessing the alternator needs the make 20 amps nominal to separate the H2 O2 from the water. Again, an educated guess of 3 hp nominal. I would need to see a 6 hp increase on a dyno after leaning out the mix to believe that this works.

    It's a simple concept and a simple test so why are there no youtube videos and other documentation to prove this simple fact? If anyone knows where I can see some dyno results, I'd be willing to try one of these contraptions. Otherwise, refer what David Hannum said to PT Barnum.

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