I know this will sound stupid but...

ohh man -- I dont even want to think about that !! with that kinda current, we'd be talking double-ought, possibly quad

now just exactly how do you wind an inductor with wire as big around as your wrist ???

Buck converters are only capable of reducting voltage ... so if you started from a 12 v source -- you could get an output of 0-11v from the converter.

I only mentioned the buck converter because it would be the best way to get

150-200 volts from wall juice, but since wall juice isnt an option, neither is the buck converter !!

Well, actually, useful higher voltage won't happen across an individual cell. As another has pointed out, an electrolysis cell is kind of like a battery cell in that it has a characteristic voltage defined by the elements composing the molecule you want to split. Any voltage above that is wasted as heat. Above the characteristic voltage, the only thing that influences the amount of water electrolyzed is the current through the cell.

You can use higher voltages by putting cells in series, but they must be identical in electrode surface area and electrolyte composition (just like batteries). Then you get multiples of the characteristic voltage

-- 1.70V, according to

So, you have the choice of very large surface area cells at 1.70V plus huge amounts of wasted energy, or smaller area cells in series at multiples of 1.70V, with less waste. And, as John Barrett has pointed out, you need a current-mode controller to avoid losing control of the whole mess and blowing yourself up.

You really ought to learn to use Google. Try googling "water electrolysis voltage" (without the quotes).

John Perry

or how many cubic meters ??

(I presume we can convert -- assume gas at sea level pressure (14.7psi) ?? Homer -- figure that part out -- I did all the research on just exactly how much gas one battery might be able to produce)

Of course, if Rad is trying to fill a medium to largish balloon, he is still gonna have a problem -- I looked into large balloons using hydrogen for lift gas for the purpose of hauling up an antenna wire (I'm a ham radio operator).. and to get a decent amount of wire up --we needed 50-100 cubic feet of gas.. call it 10 cubic yards.. which wont be far off cubic meters..... call it 10 cubic meters just for grins -- woulda taken 40 batteries or more to generate the gas to lift just 15 or 20 pounds of wire !! Would have been a lot more efficient to use a gas generator -- my 10kw genny could produce 2.5 cubic meters per hour

Rad -- if you have mass production in mind -- better look into a rotary vane compressor and some welding tanks !! (the tall ones hold about 120 cubic feet of gas)

Ohh and last note: Rad -- if you still want to crank the voltage up because sulfuric acid isnt an option to reduce the resistance -- you can always put

10 batteries in series -- again -- much easier than a boost !!!! And once you figure how much gas you need, you may find that the extra batteries are needed to get enough gas, and to help keep the average discharge rate per batterry down to something reasonable so you dont cook the batteries !! (discharging batteries quickly causes them to heat up -- too quickly and they can be damaged, and if you short one out and leave it that way, its possible for them to explode !!)

so you have a real juggling act on your hands... production rate vs battery life vs load currents ... give us some more info about how much gas you need and how fast you need it from a cold start, and I'll be happy to recommend how you should set up your battery bank

Ohhh -- it would also help if I knew the resistance of the solution you were using -- and dont just say "tap water" -- your tap water and mine may have different additives and disolved solids which will make for different resistances... to give you an example -- I just tested my spit -- lotsa disolved solids and salts -- about 1 megohm resistance -- water will probably be higher resistance (which means less current for a given voltage) because it is more "pure"

Deionized water is as pure as it gets -- wont conduct a current at all -- which is why you have to add something like a salt or an acid to get it to conduct a current. (watch out for salts though -- especially table salt -- sodium CHLORIDE --- its possible for your electrolysis rig to produce chlorine gas if you use any chloride based salt)

Sorry for the long ramble here -- but I'm trying to get it all out at once before I head for bed --- seeya in about 8 hours or so !!

y'all have a good night !!

Welding cable!

--
.

Thanks John -- I didnt know that about excess voltage being wasted as heat -- That means I was wrong in one of my other posts -- it would be worth while to have the buck converter for a single conversion cell -- but if Rad is trying for higher production rates -- he is better off putting 7 cells in series to make best use of the available voltage..... and then more in parallel to suck more current :)

I guess you could build a crud load of cells pretty cheap using PVC Ts, "+"s, and pipe ... make a massive array :)

wrong, higher current = faster splitting.

Bye. Jasen

For all of those who want to know how much gas i need: I dont particularly care how much gas just that its at a moderate rate.

And I found this picture on

for the driver device on an negative ion generator. Will this setup get me more gas by producing higher voltage or is it just a big flop for what Im trying to do?

Picture not availible goto

and find the picture entitled "For Negative Ions Operating at 12VDC"

I guess the past posts about low voltage, higher current did not get past you.

Go ahead, try what ever you want. Just give us an idea which city/state your in so we can find cover.

Ever time you think about this project, read you own subject line.

donald

or is it just a big flop for what Im trying

quoted text -

You know there is a reason Im asking this question. I heard the low voltage high current and Im asking about this divice because I want to know if this is a viable way to electrolise water.

And if it isnt please could you tell me where to get a schematic/ instructions on how to make a current increaser.

There is no such thing as a high voltage electrolysis machine. Electrolysis cells are current driven, not voltage, per Faraday's Law.

Fundamentals of electrolysis are covered in an

tutorial.

But note that electrolysis from high value sources such as grid, solar, or pv is utterly and totally useless for bulk energy hydrogen production because of a thermodynamic fundamental called "exergy". Exergy instantly and permanently and irrecoverably destroys most of the quality and value of electrical energy.

It is exactly the same as 1:1 swapping two US dollars for one mexican peso.

Additional tutorial at

--
Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
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Please visit my GURU\'s LAIR web site at http://www.tinaja.com

OK -- recap of the essential results of this thread :)

to increase current lower resistance.. to lower resistance, put more resistors (electrolysis cells) in parallel

because voltages above the electrolysis threshold (~1.7v) are wasted as heat, and you are running 12 volt batteries, put 6 electrolysis cells in series to use up to ~10.2v of your battery (you could use 7 for 11.9v, but as the battery discharges, its voltage goes down, and you'll get below the threshold, and 10v is about as far as you want to discharge a gel-cell battery in any case)

make up a 6 cell series array and stick an amp meter in the line and hook up your battery.... for a 100 amp hour gel cell, you dont want to draw more than 5 amps or so.... if you are drawing less than 5, add more groups of 6 cells in parallel until you get to ~5 amps -- that will drain the battery down to ~10v in ~20 hours of use

more cell arrays in parallel = higher current = shorter battery life = more gas output :) but it all starts with that 6 cells in series to more effciently use the voltage

and make sure you have a volt meter on the battery -- because if you drain them down below 10v, you will damage the battery !!

I figure the easiest way to make these 6 cell series arrays is PVC pipes :) each "cell" would take 4 T connectors, a + connector, and 2 caps .. _ a few extras -- total of 24 Ts, 6 +, and 12 caps for the cells (and 3 extra caps as described below) -- hook them up like THIS:

at the bottom... the + connector is horizontal with a T connector on either side.. the T connectors have the crosspiece vertical... take a cap and drill a small hole in the center... install a 4" or longer machine screw with 2 washers on the outside (electrical connection) and a rubber washer + metal washer + nut on the inside (electrode).. insert and glue this into the bottom of the T section.. do the same for the other side.... on both sides -- place 6-12" of clear plastic tube into the T sticking straight up with a T on the top.. the crosspiece of the T should be horizontal and parallel to the open connections of the + connector.

join together 6 of these cells (connections are at the + and the 2 Ts on the top)... cap both of the upper strings of Ts at one end -- the other end is the gas output... cap one end of the string of + connectors.. the other end is your fill point (put and elbow with more clear pipe here with a funnel at the top). Place a wire diagonally from one connection on the 1st cell to the opposite connect on the 2nd cell... continue placing diagonal wires between each cell (5 wires).. the 2 connections left open are where you connect the battery.

Radium, is that you?

Tim

-- Deep Fryer: A very philosophical monk. Website @

Thanks for the info John Barrett And replying to Tim: Me?

Electrolysis is a voltage/current/diffusion driven process: each electrolysis reaction is characterized by an E0 value, below which no electrolysis takes place. As the impressed voltage increases from 0 to E0 volts, the current will increase linearly, like a resistor until E0 reached. Then the current will increase rapidly to a new current that is proportional to:

1) the particular ion involved 2) concentration of the ion 3) charge on the ion 4) the diffusion velocity of the ion.

Further increases in voltage will continue, at a slope equal to the original(resistive) portion of the process. During the process, heat is produced, much like a resistor. The rate of electrolysis is proportional to the baseline-corrected current(since this is the part of the current that is generated by electrolysis) Since we are dealing with H+ as the ion, about the only factor we have control over is (2), the concentration of H+. Pure water does not self-ionize very well. Has a specific conductivity of around 18 Meg ohm-cm. H+ concentration is about 1E-7 gms/L. Sulfuric Acid, on the other hand, is a very good liquid conductor. It self-ionized to about

98%, and produces about 3.6E+1 gm/L of H+. This is the reason to add H2SO4. A very small amount of H2SO4 to a very large amount of distilled water VASTLY increases the amount of H+ available for electrolysis, and the rate.

Other factors to check out(besides H2SO4 concentration): plate area distance between anode and cathode the effect of stirring the effect of purging cell with an inert gas

After you've got everything optimized, calculate the number of cells you'll need to satisfy the hydrogen rate you need. I think you'll find that after the E0 is exceeded, adding more acid will not increase H2 production rate, but only decrease cell resistance, which will waste some of the impressed voltage by producing more heat.

One other thing to consider. If you intend on producing any kind of power using this rig, you'll also need to produce(or buy) the power that is used on the front end for the impressed voltage. If you want to float balloons, you can buy hydrogen from compressed gas companies, or more safely use helium. Not quite as much lifting power, but a hell of a lot safer. Plus its also available from your local party store.

Lots of luck, and keep us informed on your progress. ____ "Sic hoc legere scis nimium eruditionis habes." (If you can read this, you're overeducated.) ____

Im not exactly trying to go all that in depth about this.

Im kind of just looking for a "simple solution" if you know what I mean

A simple solution for a simple mind.

Why can't you understand what everyone have been trying to tell you.

Please, do what you wanted from the begining.

Ignore what many have proposed.

Why did you bother to ask ??

What was the subject line again ??

donald

I thought we had pretty much wrapped this up with the series/parallel solution ?? reasonably simple, no electronics skill needed beyond using basic test equipment, resonably efficient given the conditions, and scalable for any production rate desired.