DC/DC Converters for HHO

Feb 27, 2013


I see there are a few vendors pushing DC/DC Converters claiming that they are able to get more gas from their cells than from a PWM alone and how their unit will produce the same amount of gas (or more) with less strain on the alternator. I’m not sure if they are outright lying or just don’t understand the properties of electricity and hydroxy generation or maybe a combination of the two. I feel it is necessary to shed some light on the subject and document how this is very misleading to many people, especially those who lack electric theory and principals so they don’t make costly mistakes.

This whole scheme started by someone claiming that current is what generates hydroxy; not voltage. More current going through each cell produces more hydroxy, but more current going to the generator itself does not necessarily mean more current going through each cell. Hydroxy generation through electrolysis is well documented and you will find in all studies and textbooks that it is power, the product of voltage and current that creates hydroxy; not just current like they claim. It is also common sense to anyone who understands electrical properties and theory. If you buy into this and believe that more current to the generator is what generates hydroxy, you will probably also be misled to believe that you are somehow gaining by using a converter instead of just a PWM or putting less strain on the alternator; both of which are nonsense which you soon will see.

After they demonstrate how it sends more current to the generator, they will then tell you how their converter will output twice the current than what it takes in which means (according to them) that you can lower the current input from the alternator 50% putting less draw on the alternator; this is a half truth. Yes, it does in fact output more current to the generator than it takes in, but the power that is fed to the cells is not any more than what it takes from the alternator; in fact it is LESS than what is supplied by the alternator due to the losses from the conversion process. More importantly, there is actually less current going through each cell in a converter based setup than in a PWM setup as will be clearly demonstrated regardless of your knowledge.

As an example we will assume a 7 plate 6 cell design and 14v power source (since automotive regulators keep the voltage at approximately 14v). Dc converters are connected to parallel cells and PWM’s are connected to series cells. If you connected a series cell to a converter, you would have very little current flow which would barely generate any hydroxy (if any at all) due to the substantially lower voltage and if you hooked a parallel cell to a PWM at 14v, you would have way too much current which would overheat the generator. Neither of those setups would be fruitful. If you don’t understand what any of this means, continue reading; if you do, skip the next paragraph.

Think of electric current as water flowing through pipes. A series cell would be one long pipe and a parallel cell would be a pipe that branches out to six pipes of equal length and diameter (in the case of a 6 cell design) and then rejoins to another pipe on the other side. When water flows through the first pipe, it gets divided between the six pipes connected to it and then finally rejoins. You do not get more water flowing out the other end, you get the same amount you put in through the first pipe and you get 1/6 of that amount going through each of the individual pipes (cells) which then combines into the final pipe. The series cell being one long pipe means that ALL the water (current) flowing into it passes through each of the cells.

If you have 30 amps going to a generator with parallel cells and there are six of them; it means that there are only 5 amps going through each of the cells as is documented in Kirchhoff’s Law. If you have 15 amps going to a series cell, the entire 15 amps is going through each of the cells. So the PWM is putting 3 times the current through each of the cells than what the converter is able to do; even though the converter is outputting twice the current as the PWM. Again, this fact alone does not mean that the cell with the PWM will generate more hydroxy, in order to mathematically figure that out you would have to also know the voltage across each cell. Multiply the current through each cell and the voltage across each cell and you get the power dissipated in that cell which determines the potential of hydroxy production; actual production is based on the characteristics of the generator itself (especially but not limited to the plate gap). So while the converter will put out twice the current to the generator than a PWM given the same input power, the PWM (series) setup means there will be more current going through each of the cells. This is a result of power distribution; it is not magic, but simple electrical theory which isn’t too hard to understand if you aren’t fooled by those who tell you otherwise.

If we assume that a PWM and a converter are 100% efficient, they would both have the potential to produce the same amount of hydroxy given the same input power as the output power in both instances would be equal to the input power. However, in the real world there are losses. In a PWM, depending on how efficiently designed the unit is, it can be above 99% efficient as the KZX1250 is or it can be much lower; because there are only resistance and switching losses. In a DC/DC converter, there are also resistive and switching losses, but in addition there is also conversion and filtering losses as well; not to mention that converter switching frequencies are much higher than PWM’s meaning bigger switching losses. So the converter will deliver somewhat less power to the generator than a PWM given the same input power and thus will have a lower production potential. Losses are quite big on a DC/DC Converter; big enough to easily see. If you have one, measure the voltage on the input of the converter and the current going to the converter. Multiply the two together and you get the total power dissipation of the converter with the load connected. Next, measure the voltage across the output of the converter and the amperage coming out as well. Multiply these two values and you have the power that is dissipated at the load (your cells). Take the power out and divided it by the power in and you get the efficiency of the converter. You'll probably read something like 70% or 80%, or maybe if you bought a real high end unit, 90%. This means that 30%, 20% and 10% of the power was wasted in the conversion process respectively. That is a huge loss to take!

The only advantage for lowering the voltage on a parallel plate configuration is to reduce leakage currents; but many people have been brainwashing the public into believing that there are other benefits such as putting less of a strain on the alternator. However, if your generator has higher losses due to leakage current than the losses associated with converting the voltage, I believe the generator you are using is very much poorly designed and you would be better off rethinking your generator design, rather than applying a band aid such as a converter.

Many people don’t understand this fact because they don’t get the right information. It is really easy to get confused once you see that the converter is actually sending more current to the generator and that is why I am clearing this up here. Once there is a batch of ill informed people crowding up on a YouTube discussion, you get a bunch of “experts” who make it very difficult for me to fight them off with the truth because they are so dead set on being right because they believe others who they believe told them the truth and with the puny maximum character limitation that YouTube allows, explaining this is practically impossible.

- Regards, FreeMindResearch

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