MOT's and overheating story:

My cousin (hate to admit blood lineage here) put a small roast in a microwave oven. In a conventional oven he was supposed to cook it for 45 minutes. He put it in the microwave for 45 minutes. Somewhere around 30 minutes the transformer burned out. Even with fans blowing on the MOT's, they still can be burned out.

Food for thought. (no pun intended)

 

I'm not an expert but I do like to have facts and I like to read base material rather than rely on partial info. So the first thing I do is some research.
The electrochemical cell voltage of an electrolysis reaction varies from about 1.2v to 2.2v, never higher.

I got into this years ago, and like you said do the research. And mine like yours said the same thing. Upping voltage and current is exactly the opposite of what normally works when doing this.

 

MOT's and overheating story:

My cousin (hate to admit blood lineage here) put a small roast in a microwave oven. In a conventional oven he was supposed to cook it for 45 minutes. He put it in the microwave for 45 minutes. Somewhere around 30 minutes the transformer burned out. Even with fans blowing on the MOT's, they still can be burned out.

Food for thought. (no pun intended)

Thereis a differents between intermittant service and continuous service. BUT if the transformer is for a thousand watt oven and the application here demands 210 watts, that may have an adequate margin. But your comment identifies the exact reason that I suggested watch it for a few hours. There is not enough information for me to give an exact analysis. For the industrial machines I always allowed at least a 20% margin. And not a single customer ever complained.

 

I see the answers to the following questions have been answered, but it seems reiteration is necessary.
No - I didn't. I was focusing only on rectification methods.
Whatever filtration you desire - that's up to you. Whether you listen to experienced advice or choose to go a different way - that's again, up to you.

As for seeing things on YouTube - I saw a guy with a small DC motor connected to a pigtail of copper wire with an additional pigtail supposedly making the motor run. He demonstrated that the motor ran vigorously when connected to a 9V battery and how it ran slow - but ran - on just the pigtail. What you DON'T see is the hidden hearing aid battery inside the motor. The pigtail simply completed the circuit. The demonstration went on to show that it wasn't being done via hidden magnetic coupling beneath a table because he lifted it into the air and walked around showing the device running. It was a cleaver hoax, but it was just that - a hoax. Also saw a guy use a motor to spin a generator then switch the generator to supplying power to the motor - and it ran. Then he added things like a drill press, a grinder and a band saw, and all supposedly ran on just the power being produced by the generator. But physics proves that can't be legitimately done. Beneath the table were secret connections the viewer could not see. Why do people manufacture these hoaxes? Because of advertising. They get paid when their video's are watched. They make money from advertisers by tricking you into seeing how they did it. Shame on them. And I've even watched some of these videos thinking "I'm going to do that too and get free energy." Well, actually I've never been that dumb. But I have watched some of them out of curiosity to see if I can figure out how they did their magic trick. Yes, "Trick".

You can try and replicate that video if you feel inclined to do so. But when asking skill and expertise (not referring to myself, I'm a noob too) LISTEN to what's being said. To keep asking the same question over and over in the hopes to get the answer you want isn't likely going to happen. I must admit some frustration with the lack of attention you've been paying to what's being said. For me to say "Use two diodes instead of four or six" and have you ask "So are you saying I should use just two diodes instead of four or six right?" is frustrating.

Bottom line, build it as you see fit. Then discover the results were either like the guy on YouTube or perhaps the experience of those of us on AAC were right all along. The choice is yours and yours alone.

Peace.

I’m trying to to sort through all of the differing opinions I apologize I missed that. I am not doing that because I am looking for a different answer. There is one person looking for info and getting back two people that agree and three people that disagree. You try and figure something out like that.

 

I’m trying to to sort through all of the differing opinions I apologize I missed that. I am not doing that because I am looking for a different answer. There is one person looking for info and getting back two people that agree and three people that disagree. You try and figure something out like that.

I will do it on my own because even the professionals can’t be humble enough to agree amongst themselves apparently. Thanks for the attempted input.

 

Thereis a differents between intermittant service and continuous service. BUT if the transformer is for a thousand watt oven and the application here demands 210 watts, that may have an adequate margin. But your comment identifies the exact reason that I suggested watch it for a few hours. There is not enough information for me to give an exact analysis. For the industrial machines I always allowed at least a 20% margin. And not a single customer ever complained.

Thanks for the help mr.bill keep on trying to assist people.

 

Long Post Warning, but I'm going to do this once, then I'm out of here. With the exception of a couple of posters (and they know who they are) there's a lot of misinfo on here based on little knowledge/experience. So here's my summary.

I'm not an expert but I do like to have facts and I like to read base material rather than rely on partial info. So the first thing I do is some research.

The electrochemical cell voltage of an electrolysis reaction varies from about 1.2v to 2.2v, never higher. Therefore, allowing for various losses at high current, apparently mainly in the interface between electrode and electrolyte due to gassing, and some cable losses, 5v is more than adequate. If you need to go much higher at the power supply output then you're losing 50W or more in the cabling which is crazy (2m of 10AWG = 6mOhm, at 25A this is ~4W) Conversion rate is roughly proportional to current but losses increase as the square of the current. The law of diminishing returns applies.

Commercial units use carefully regulated low voltage per cell, moderate current and stack cells in series, so total voltage on the stack is 100v or more to get close as possible to theoretical conversion rates of 60% as previously stated.

I may not have all the facts at 100% but I now have a better feel for it. What is needed is an efficient, regulated, low voltage, moderate current, variable supply with <5% ripple.

View attachment 211845
That picture is close to useless. It coud be looking at a 7v rail, theres no way to tell. lets give it the beneft of the doubt and say its ac coupled so only looking at the ac component. Again that could be 1v/division or 1mV/division, without that info it tells us nothing. (why are all these photos so out of focus you can't get useful info out of them?)


Which, sadly, just shows how little you know or understand - thats actually the least accurate and definitely the hardest way to go... but don't let me stop you trying.


The 5v supply was just by way of example, you can have other voltages by adjustment. Those $30 supplies are pretty reliable, but for even higher reliability go for a higher wattage supply. I've used 400W versions in a CNC machine that runs virtually 24 x 7. Or go for a branded supply, such as Meanwell, 5v @ 40A is ~$40.


ATX supplies are SMPS - they are 80% efficient or more, compared to the 50% you'll be lucky to get with alternator rectifiers. Once again, you have a lot to learn.

Their voltage regulation is better than 0.5%. SMPS is the way all power supplies have gone, you rarely see a linear supply these days for anything bigger than an amp or so. We are not maxing out the supply, its barely using 50% capacity of a typical 500W box; again, if it worries you go for a bigger ATX supply.


There is no flaw, this is common practice. I've built several high current supplies for battery chargers for LiPo packs this way.

An ATX supply of 500w designation or more will easily give 5v @ 40A which is more than enough. Bigger wattage supplies will give proportionately more. There's a wealth of videos on YouTube on how to make ATX supplies produce a variable output on the 5v rail from near 0 to about 8v. Personally that's the way I'd go on this. Its not a challenge to do this.

@Hutch2793 I'm not saying it can't be done your way. But sourcing very large electrolytic capacitors with low ESR to handle the ripple current in the capacitor (you can't just use any old capacitor or they'll overheat and can explode, you need a high ripple current rating) will be expensive. And that choke is going to be really hard to source, I've searched and the best I can find is over $130. Your best bet will be to wind your own on those discarded cores, but you'll need to experiment with the number of turns - more turns = lower ripple but more losses/heat. It just seems like a lot of effort and cost to provide a mediocre solution. As a learning exercise maybe it has some value, if you bother to go and learn how to run the math; I've tried to give you a flavour but I get the feeling you don't really want that, you want to be told do this, do that. If your interest is more in the electrolysis then go the other route.

You said you wanted to be a professional engineer. Kudos to you. But start by doing the research and getting the facts so you can make sense of what others say.

You are right I don’t know much, but this is akin to having four professors in calculus all tell you that they disagree with two of the other professors.

if you think that the paper you read means you know more about electrolysis then good for you. keep in mind that there are a vast amount of end products, as well as a vast number of electrodes that can be used. It is not as cut and dry as you are trying to make it by reading one published paper. I didn’t want to tell you what this supply was for because I know you don’t know why my requirements would be so obscure, or have any way of figuring that out without doing it for yourself and learning some things. I will follow my own advice and leave this forum. You need to work on how you help people. It seems more like a pissing match with you. I didn’t think you were wrong or didn’t know what you were talking about. It was just the way you said it. It turns people off to you when you try to prove others wrong. I’m sure you Know what I mean. Thanks for trying.

 

You need to work on how you help people. It seems more like a pissing match with you. I didn’t think you were wrong or didn’t know what you were talking about. It was just the way you said it. It turns people off to you when you try to prove others wrong. I’m sure you Know what I mean.

So you think that is worse than taking advice from some one who has a bad "help" record in this forum? He will agree with you and go along with what the original poster wants to hear, whether he knows the real answers or not(and most times that is the truth of the matter). He's like one of those "psychics", that advertise on TV, they pick up on what you want to hear and make you happy.

 

So you think that is worse than taking advice from some one who has a bad "help" record in this forum? He will agree with you and go along with what the original poster wants to hear, whether he knows the real answers or not(and most times that is the truth of the matter). He's like one of those "psychics", that advertise on TV, they pick up on what you want to hear and make you happy.

Alright guys, I don’t know enough about the forum, the people, or the subject at hand. I’m not sure where to go with it at this point.
I will reduce cell size and electrode size. Is it possible to produce 6.5 volts at 3 amps at least with the transformers I have. If not, tell me no, it can’t be done. I would appreciate a new way go accomplish this. I will run smaller scale and hopefully the choke, filter, and rectifier will be easier to access. If not tell me what you think should be looked into. Not, oh well if it was 5 volts, you could do this. It is 6-7 volts required with a minimum of 3 amps. The lower on these scale you are the longer it takes. You guys all warned me about the dangers and complications which is exactly why I’m hesitant to experiment on my own with it. trying different things sounds about the worst thing I could do. I was less scared before getting on this forum, but I had a healthy respect, now I don’t want to even mess with it. I hope that is not the objective of the people here. I know a lot of people at uni that try to make engineering seem impossible, so they can make themselves look smarter than they are.

The MOT power supply is a very standard practice here in the u.s for what I am trying to do. I do not personally know anyone anymore that does this, which is why I’m here. I have used regular power supplies before. It takes over 150 hours and the larger your cell and electrodes the more amperage needed to speed the process up.

 

I will continue to stick with power supply advice because what I know about electrolysis processes is only that caution and adequate venting are good choices.

One reason for the disagreement with those who advocate a switching power supply is that they are more efficient, and far more modern, and they often take up much less space and weigh a lot less. So a switcher does have a lot going for it. I often include a switcher supply from a known-good company in equipment that I design. That is quite a bit different from attempting to design a regulated switch-mode regulated power supply. THAT is a serious undertaking, although now there is available a whole lot of design help on a number of company websites. So there is more help now than ever. But still, given the currents and higher frequencies involved, creating the design of a well-working switch-mode power supply is still a serious task.
A transformer based supply is much simpler to create, but if you have to buy all of the parts it will cost more.

For a transformer type power supply feeding a filter I have an interesting concept taken straight from switching power supplies, which is the idea of one more diode added that would allow the collapsing magnetic field in the choke inductor coil to continue to supply current. That is sort of the concept of a choke input DC filter, I think. Perhaps somebody skilled in using a simulation program will want to run a simulation and see what happens.