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PWM & high current

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  1. #1
    electrookie electrookie is offline

    PWM & high current

    Newbie here. I am building a HHO system, fracturing water into the gaseous components and am using a constant current PWM to control the electrolysis cell. The circuit works fine at low currents, but I am shooting for 80 to 100 amps. I have doubled the mosfets and that part seems ok. The problem I have is the capacitor on the output & to the +12v terminal is overheating, melting wires, blowing the cap up. There is a diode across the terminals as well that is getting very hot too. Without getting into the design to heavy, can anyone answer me why there is so much heat build up in this part of the circuit. I will be happy to provide full schematics if need be. I don't want to write a long story here and waste anyone's time. Just wondering if any gurus out there may have a quick answer for such a problem.

    Here are a couple ideas I am playing with. For the cap, can 2 caps be used in parallel? This would make it a 20,000uf cap right? And in general, with a diode, if I put 2 of those in parallel too, would this help? I'm willing to try anything suggested as I am a rookie when it comes to electronics.

    This is a relatively new movement in alternative fuels, even though HHO has been known for over 100 years. The HHO gas is used to ad to the fossil fuel, doubling mpgs, if not even more. Good thing to explore, but I need to figure out why the cap gets so hot. Its a 10,000uf 63 volt, and only used on 12 volt car systems, so the larger voltage rating hasn't helped. Any suggestions would be greatly appreciated.

    Thank you

  2. #2
    tcmtech tcmtech is offline
    We need a schematic to understand what you have built.

    And for what its worth being a deliberate HHO research concept this thread will likely get locked or deleted soon any way.

    Sorry but thats how open minded the powers that be are here. Spam, swearing, direct name calling, and HHO get threads deleted.
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    "Sometimes genius is simply having the ability to see and understand the obvious. " -- tcmtech

    "I didn't get to the point of knowing all that I do know by believing that I already know everything." -- tcmtech

  3. #3
    electrookie electrookie is offline
    Can do for the schematic. I'll get back here with it soon. But real quick, are you telling me deliberate HHO research is banned for some reason? HHO is Hydrogen Hydrogen Oxygen, are you saying HHO is somehow in the same class as Spam, swearing, direct name calling?

    Color this rookie confused?!?!?!?!
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  4. #4
    tcmtech tcmtech is offline
    The so called para science electronics get very frowned upon here.
    It may not get this thread locked or deleted but expect a good deal of pokes and rough treatment because of it. Especially if you cant give accurate reasons as to how or why something is done in a particular way.
    We all enthusiastically want to learn about new things but we cant just blindly believe without confirmable proof.

    I personally do agree with people trying to develop alternative fuels and fuel saving devices however every one that has shown up here that has claimed to have a working device or system has yet to put up the real facts, figures, and honest provable and scientifically confirmable data plus related information to how they are supposedly doing it.

    You may very well be one has a system than can stand up to scientific scrutiny but so far HHO and like devices have been the scam artists and liars paradise.
    The problem is those who claim to be able to do it and want to change the world for the better from it also want big money and never seem to be able to actually prove their devices work when put into real world testing conditions.

    Give us real working data and we will happily work with you! Give us specifications that need secret chemicals or trade secret circuitry or mystery devices and we get rough real fast.
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    "Sometimes genius is simply having the ability to see and understand the obvious. " -- tcmtech

    "I didn't get to the point of knowing all that I do know by believing that I already know everything." -- tcmtech

  5. #5
    electrookie electrookie is offline

    HHO Hoax or fact?

    I understand what your saying about scammers and such. I have spent too much money on them over the past 2 years or so. I'm very careful where I spend money now.

    It is a proven technology in the fact that the D.O.D. uses such technology in the Navy, on subs, and the Army is investigating it for use as well as NASA and other such agencies. Pseudo Science? To some, and many who think it will never amount to anything. If the nay Sayer's will take a close look at the products now offered in the market that use this technology to assist the fuel burn, you will be surprised.

    Yes, some people are claiming unity and even over unity. And every time I have pressed any of them to give us the details, we quickly find they do not really have a clue what they are talking about, or they claim to have "secret" technology. Of course the red flags go up. I'm not from Missouri, but you'll have to prove your claims before I will spend a penny on it.

    I believe over unity will one day be archived, but that's another brains quest, not mine. I simply want to put this on my cars and improve my mpg's. That's it. No mystery, nothing secret about it at all.

    The schematic is freely given to the world by a guy who calls himself Zero Fossil Fuels. His site is Alternative Energy research by Zero Fossil Fuel - Hydrogen, Solar, Wind. His constant current PWM is a device that works fine at low currents. I have asked him about jumping to the 100 amp range and told him the problems I have. No answer.........still no answer..........yet again, no answer. So this is why I am asking here.

    I can not find any help in these forums as to how to post a .bmp or .jpg or whatever. The schematic at ZFF's site is exactly what I have been working with except I put 2 130 amp mosfets in parallel. So there it can be found. No secret's, nothing hidden. Just guys trying to get something working right. ZFF is apparently a busy fellow so I can't slight him because his circuit DID fix a lot of problems to date.

    thank you again
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  6. #6
    Mr RB Mr RB is offline
    Well the quick answer is that you are exceeding the ripple current spec for the output cap. Generally you can fix this by adding enough caps in parallel and/or using larger caps that generally have a higher ripple current spec. A general rule of thumb is to use 1000uF for each amp, just as a starter point.

    If you are doing legitimate electrloysis research that I'm sure at least some people here (like me) are interested in what you are doing and will try to help. Just keep your posts to your actual measured facts and your personal hydrogen setup, as making wild claims or posting links to HHO website which make wild claims will annoy people. As an example saying "doubling mpgs" is one of the things that will start people arguing (based on previous threads) and mpg talk should probably be avoided.

    Back to the electronics side, what frequency are you running your PWM at and can you post the schematic or any more details?
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  7. #7
    tcmtech tcmtech is offline
    I took a look at it and the ripple currents are to high for the capacitors is why they heat up. Most likely the circuit has to small of wire and poor connector choices. Big heavy wire with good solid copper lugs should used. Preferably 4 gauge for the power handling lines. How ever that will likely burn out the switching devices since the present current limiting PWM circuit may be fairly slow at responding. You many need to go to much higher current capacity switching devices.
    Using multiple smaller capacitors with the same combined value as one big capacitor will help handle the high ripple current as well.

    The whole circuit could easily be replaced with a standard LM3525 or similar IC and likely give you a much better and simpler control system too.

    Negative RF spectrum?
    Reference to known and proven crackpot Myers?
    Sounds like a scam site to me still.
    Want some unobtainium bolts to hold everything together?

    Its things like this that are why people like me are skeptical of the HHO stuff. Yes the government does use electrolysis of water to get oxygen in subs and other under water vessels and so does NASA for rocket fuel and countless other commercial and industrial applications as well. They however do it with real proven systems.

    My question is if these agencies with countless billions of dollars already spent over the last 100 years didn't find that PWM or any other real electrical manipulation of the system produced a real provable and justifiable increase in gaseous output Vs electrical energy input why do so many countless others with little to no knowledge of electrical and chemical sciences believe they can?

    Just asking.
    0
    "Sometimes genius is simply having the ability to see and understand the obvious. " -- tcmtech

    "I didn't get to the point of knowing all that I do know by believing that I already know everything." -- tcmtech

  8. #8
    electrookie electrookie is offline

    Thanks for the help & advice....

    Thank you both, tcmtech & Mr RB, for your replies. I was guessing that the cap values were too low, but wasn’t quite sure. You both removed any doubts and I appreciate it much.

    I will take a close look at the LM3525 as you recommend tcmtech, thanks for the advice on that as well.

    I do not wish to start any controversy because of HHO, so I will adhere to your advice as given and keep it strictly to the facts and documented results. I am all too aware of the thieves taking advantage of people out there and can cite one major case that was shut down by the feds at beginning of this year, an outfit called Dutchman Enterprises. Although I do not think they were shut down because of the technology, only the dealership practices they were doing were very unethical. And if one is to search eBay for HHO, they will find plenty of bogus HHO equipment there that make outrageous claims. I know these people have no clue what they are claiming for the most part, but they sell their junk anyway. Buyer beware as the saying goes.

    The government has been using HHO for some time, and trying to get a hold of anything that the government has on HHO has been fruitless to date. I held top secret clearances when I was in the Navy and then Civil Service for the Air Force. Trying to use that as a “way” to get into the information I seek has been to no avail. Such clearances are 1) very old now & 2) the primary information is always on a “need to know”, which apparently I don’t need to know… I would love to have the results of those billions of $ spent on HHO research, and by all rights, any American should have access to such info, we pay for it. But my theory is simply that it is good enough for the D.O.D. to use, but not for the general public due to the fact that the single largest τλχ our government, at all levels, enjoys from us is the τλχ from gasoline & oil sales. HHO is a major threat to that income. And till they figure out how to τλχ us for water, they don’t want this technology out there.

    Then again, I may just be a conspiracy theorist, but I do know who shot JFK!!! It was Onasis who contracted with a hit man from the “mob”, CIA involvement not likely. In hind sight, Jackie was married to Onasis fairly quick don’t you think? There are few reasons for murder, thin out the choices, apply the facts after the event, what is left? Just my theory though, no facts to back it up other than history. They say hind sight is 20/20, I say it is x-ray vision if you look closely.

    Thank you guys again for your input, I value it much, and appreciate it just as much. And again, your advice on HHO in this forum is taken to heart & I will be very careful what I say.

    Have great days…
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  9. #9
    bryan1 bryan1 is offline
    OK guys the OP does seem to have a valid claim to ask about HHO here. So please keep the skeptic quotes and over unity scam quotes out of this thread. If further posts just try and throw this thread into disarray it will leave me with no choice to delete it, but I would prefer to see the OP's questions answered and lets help where we can.

    Regards Bryan
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  10. #10
    mneary mneary is offline
    Since the OP has told us he knows that the Government has solved the HHO problem and the D.O.D. is already using it, all we have to do is find out where the information is being kept.
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