# high output dc square wave generator help

Woo-Woo Discussion in 'Twilight Zone' started by goffrobb, Apr 11, 2013.

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1. ### goffrobb

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Apr 11, 2013
hi
basically the project is a square wave generator to run a high current hydrogen generator (electrolysis)

hydrogen generator power requirements:
100-300 Amp current draw
automotive 12V system (12-14 average)(this is then cut down to approx 2V by neutral electrodes in the hydrogen generator)
to increase performance current should be square wave

So the part i need information/advice on is how to create a square wave generator that will take 0-14+V input at anything up to 300 amp current draw (not totally necessary but device should be able to handle high current to be sure it wont blow up if i ever tried)

variable frequency control and duty cycle control (not to worried about accuracy) would be helpful so i can test out different settings and see what happens

basically i do not have a huge understanding of how a square wave generator works so im looking for either something i can buy or a perfect circuit diagram for a circuit that will do what i want that i can make.

cheers for any input that anyone can put to this

Robb L

2. ### Harald KappModeratorModerator

11,517
2,651
Nov 17, 2011
Use a 555 timer to generate the square wave (_very_ little power. Or use a µC which may give you additional features, but needs programming.
Use a step-down converter that has programmable output voltage (or shut-down) use teh square wave from the 555 to control the step-down converter. This will result in a minimum of losses.

Although I may say taht at 300A this project sounds rather ambitious. With currrents this high you have to take into consideration the magentic attraction and repulsion of the wires leading this current.

3. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
That sounds awfully inefficient.

But I guess you're not going for efficiency with a 200 to 300 amp load.

4. ### goffrobb

7
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Apr 11, 2013
cheers
yea 300A is very ambitious really having that capability is mainly for test purposes and if it can handle that then the more realistic <100A will run continuously with ease and can peak over and above requirement.

5. ### goffrobb

7
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Apr 11, 2013
creating resistance through water bringing the voltage is the whole point. keeping the voltage at 12V creates too much heat 2 volts is enough to allow the high current to pass through the water/electrolite to the next plate having high current increases production of HHO(hydrogen and oxygen)
based on this the low voltage is actually more efficient. cheers for your input though

6. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
So, it is more efficient to waste more than 80% of the power.

It is probably a big hint that you'll get less power out than you put in.

693
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Mar 9, 2012
8. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,496
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Jan 21, 2010
I think he's be better off pulsing 12V to an inductor set to terminate the pulse when the current hits 20A (or thereabouts). If he's right about the voltage across his cell, he'll then get a 200A pulse.

Naturally, finding a 200A schottky diode might be a bit of a problem, but the frequency will probably be low, so a "normal" diode might suffice.

He'll be more than 500% more efficient and may get his energy efficiencies up to the teens or even more...

693
2
Mar 9, 2012

10. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
Don't be silly, everyone knows that the water molecules vibrate and if you pulse them at exactly 14.47513kHz (+/-20%) then you will gain an order of magnitude better efficiency that predicted by science!

But you're also aware that we're not allowed to mention sugh things in public so I'm making this a secret message that only you and I can see (definitely not for the OP's eyes).

We have to remain sceptical in public so that our funding from the oil companies continues.

11. ### goffrobb

7
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Apr 11, 2013
sorry i wasnt particularly clear the HHO generator has a number of plates +,- and nutral N in a configuration such as - N N N N N + N N N N N - (i think thats correct polarity cant remember) total voltage accross + - plates is 12V but voltage between individual plates is only about 2V so not losing voltage (in a way regulating V between plates by adding or removing nutral plates) also increasing surface area for HHO production.

12. ### goffrobb

7
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Apr 11, 2013
sorry i wasnt clear enough the HHO generator is made up of a number of staineless steel 316 plates size can vary but maybe 6"x 6" (cathode/anode) (positive +, negative - and nuetral N) in an arrangement of something like [ - N N N N N + N N N N N - ] (number of N plates may vary)
but could also be something like [ - N N N N N + N N N N N N - N N N N N + N N N N N - ] or more cell sets the voltage between the the +/- cathode and anode will be 12V (or whatever is being put in) but the voltage between each N plate (or +/- and N plate) will be approx 2V (i will add or remove N plates to achieve something near the 2V mark)

the number of plates in theory changes amount of surface area for HHO production and will also change the amount of current the device will draw
i will add plates untill i either achieve desired HHO per minute or untill i cant consistently provide the nessisary current requirements without over loading anything
hence why i want the electronics to be able to handle such high amperage

13. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
Let us know when you break the laws of thermodynamics.

14. ### goffrobb

7
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Apr 11, 2013
i know what Ive written is not perfect theres a lot more to it and it gets complicated when electrochemical subject is added into the equation however the science of separating bonds between hydrogen and oxygen atoms in water through electrolysis is proven though still not widely known
I do not claim to be any kind of expert in the matter but i have researched and understand most of the principals

anyway this forum isn't meant to be about the hydrogen device, more the control of current flowing to it

15. ### goffrobb

7
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Apr 11, 2013
unsure of frequency possibly farly low maybe something like 100-300Hz would probable surfice (if not variable) duty must be variable for experimentation also i may wish to decrease duty overtime say from 90%-30% over a couple of hours of continueous operation due to gradual increase on current draw (effectively capping current in a way)

16. ### BobK

7,682
1,688
Jan 5, 2010
ROFL

Yes, it is proven. And part of the proof, I hope you understand, is that the hydrogen produced contains less energy than you put in to produce it.

Bob

17. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
True, because we try to encourage scientific literacy.