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Author: Subject: Problem in Chlorate
greenlight
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[*] posted on 20-5-2015 at 05:34


I have been gathering the materials for a Potassium chlorate electrolysis cell and have finally got everything together.
One last thing I am confused about is where the wires from my power cable i took from an old fan go and where the anode and cathode connect to on my 5v 20A power supply as it is from a Chinese company.
I have uploaded a picture of the symbols on the side of the power supply terminals.
There is L and N instead of positive and negative and am thinking the circle with three lines in it is the earth/ground.
Then there is two labelled COM and two labelled +V. I am guessing the anode and cathode connect to one of these on each side?
Any help if anyone uses a similar power supply would be much appreciated.

[Edited on 20-5-2015 by greenlight]

20150520_212227.jpg - 2.9MB

[Edited on 20-5-2015 by greenlight]
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elementcollector1
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[*] posted on 20-5-2015 at 08:45


Cathode connects to ground, anode connects to either of the +V (assuming the voltage is something like 5V?).



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[*] posted on 20-5-2015 at 09:01


Yes it is 5 volt 20 amp.
Is the ground the circle with 3 lines in it or the one marked N?
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[*] posted on 20-5-2015 at 09:35


Quote: Originally posted by greenlight  
Yes it is 5 volt 20 amp.
Is the ground the circle with 3 lines in it or the one marked N?


It's the circle one, I don't know what the 'N' stands for. "New Jersey"?




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Pumukli
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[*] posted on 20-5-2015 at 10:38


L is Line, N is Neutral, then comes the circle pictogram of Ground. These three lines are for the AC parts, you must connect a proper AC cable with a connector here. Don't mix the wiring!


COM COM and V+ V+ are the outputs, COM is the low voltage reference point (0 V), and V+ is the 5V output. So you use these outputs for the electrolysis. COM goes for the cathode and V+ for the anode. Don't mix the AC ground with the COM output, which is also a sort of "ground" though!
The first three bolts/connectors are for the AC connections, the last four (COMs and V+s) are the 5V outputs (and returns), and you must use these for the cell!

It is advisable to connect COM to COM and V+ to V+ too because it may be needed to use both pairs in order to be able to pull those 20 Amperes from the supply.

[Edited on 20-5-2015 by Pumukli]

V+ is of course +V in the photo...

[Edited on 20-5-2015 by Pumukli]
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greenlight
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[*] posted on 20-5-2015 at 19:45


Thankyou very much, so the anode goes to the V+ and the cathode to the COM terminals.
I am still slightly confused about the AC input. I have a power cord with plug which I cut off an old fridge with positive, negative and ground wires which i have stripped back. Can I use this cord or do I have to go to an electronics shop and buy a special AC power cord with connector?

If I can use this cord would the positive go in the L terminal, negative in the N and ground in the circle symbol terminal?
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violet sin
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[*] posted on 20-5-2015 at 22:30




wiki: http://en.wikipedia.org/wiki/Mains_electricity

" In most countries, household power is single-phase electric power, with two or three wired contacts at each outlet. Neutral and line wires carry current and are defined as live parts.[1][2]

--The line wire (also known as phase, hot or active contact, and commonly, but technically incorrectly, as live), carries alternating current between the power grid and the household.

--The neutral wire completes the electrical circuit by also carrying alternating current between the power grid and the household. The neutral is connected to the ground, and therefore has nearly the same electrical potential as the earth. This prevents the power circuits from increasing beyond earth voltage, such as when they are struck by lightning or become otherwise charged.

--The earth wire or ground connects the chassis of equipment to earth ground as a protection against faults (electric shock), such as if the insulation on a "hot" wire becomes damaged and the bare wire comes into contact with the metal chassis or case of the equipment. "

black white bare/green, or brown blue green are two common color codes. both referenced below

http://a.files.bbci.co.uk/bam/live/content/zbxb87h/small
wires from utility cords for plug in devices, brown = hot, blue = neutral, green = ground

http://cnx.org/resources/ac626fc261531714691887184e7f6df7cd2...
or black = live( hot), white = neutral, green/bare = ground


strip the wires, attach correctly, should be fine. if you don't feel this helps enough, add pictures of what you have. you don't want to wire it backwards or risk zapping your self. also for reference, I live in the US, and am most familiar with the 110V, 115V, 120V( what ever) kind. I have wired garages etc, for 110V outlets on jobs, also moved 220V receptacles for dryers/ranges/heaters in other construction jobs with permanent wires. also wired many projects using cords removed from other devices like you are doing. but I can't say I have worked on European mains receptacles/wires. which is what wiki says you may have there in Australia.

[Edited on 21-5-2015 by violet sin]

[Edited on 21-5-2015 by violet sin]
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Pumukli
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[*] posted on 21-5-2015 at 03:24


Yes, you can use that salvaged 3 wire cable, connect it as you wrote.

COM is the "negative" electrode of the 5V output, so it should be connected to the cathode. +V is the "positive" electrode, it should go with the anode.
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[*] posted on 21-5-2015 at 07:43


Thanks guys, that helped heaps.
I just finished wiring it up minus the anode and cathode wires which I will install when I am about to run the cell.
I have attached a photo just to make sure it is correct before I turn it on. I have brown in L, blue in N and green/yellow in ground.

[Edited on 21-5-2015 by greenlight]

20150521_233506.jpg - 2.9MB
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[*] posted on 21-5-2015 at 08:35


It seems right. (From half a globe away :-))

Anyways, as far as I know you can't be sure regarding the N and L wires because although there are conventions on how the wiring in the walls should be routed to the wall connectors, but sometimes the cables are mixed up. A "phase pen" or how it is called in English can help at a given connector, but one simply can't be sure the next connector will be the same. Fortunately mixing up the L and N wires doesn't do harm to the equipment. (Minor problems can arise in some special cases, but nothing serious.)

The other connections seems right.

If you have a hand held multimeter you can check the output voltage.
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violet sin
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[*] posted on 21-5-2015 at 11:53


AC input looks perfect :) Good job.
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[*] posted on 21-5-2015 at 23:41


Jumping com to com and V+ to V- really works?
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[*] posted on 22-5-2015 at 00:06


There is no V- !!!
The supply has double COM and +V outputs. I suggested connecting the individual COMs and +Vs because it MIGHT be needed to avoid an overcurrent situation on either of these rails. I don't know that particular power supply, never seen its schematic or actual output stage but doing as I suggested may be needed if someone wants continuously pulling the rated 20 Amps.

On the other hand connecting COM to +V would be a mistake! It would short the supply and may lead to various things from a faint clicking noise from the supply to a loud bang and property and/or user damage!
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[*] posted on 22-5-2015 at 00:17


Oh now I see there are 2 V+
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[*] posted on 22-5-2015 at 11:12


Thanks heaps for the help guys I have the power supply all wired up now ready to attach to the cell and start making chlorate from KCI.
I have one other question though, I would like to run a setup similar to the one on Woelens site. It is a small scale 100ml cell made from a Duran bottle. I would like to use a 1000ml container instead of the small bottle as my anode and cathode are larger being 2" by 6" in size.
He operates his small 100ml cell for 26 hours all up so do I have to times his run-time by 10 for a 1000ml cell and make it 260 hours before I turn it off?

Anyone have any experience with a 1000ml cell and can help with operating time and is 1000ml cell adequate capacity for these size electrodes?

And do I have to have the titanium strip spot welded to each electrode because mine came without them so is it okay to have some of the anode/cathode out of the solution through the container top with the alligator clip attached straight on to it or do they have to be completely submerged and this will ruin them?
Many thanks and sorry, but this is my first time doing this.

[Edited on 22-5-2015 by greenlight]

[Edited on 22-5-2015 by greenlight]
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[*] posted on 22-5-2015 at 12:22


"He operates his small 100ml cell for 26 hours all up so do I have to times his run-time by 10 for a 1000ml cell and make it 260 hours before I turn it off?"

It depends on how much current you can pass through the solution. If you scale up everything 10x then the time required to finish a batch remains the same, say 26 hours, in case the 10x multiplication is true for the electrolyzing current as well!
If you scale up everything but use the same current as Woelen had used, then yes, you must be more patient and let it run for 260 hours. :-)

(There are other factors as well, e.g. different current density on the electrodes may have (unexpected) effects, so it might be wise to calculate the (approximate) surface area of your anode and compare it with Woelen's and adjust the cell current accordingly. I would not aim for an exact match but would try to be somewhere in the +- 20% range.)

Take into account that higher current (voltage) means not only faster electrolysis but more dissipated heat in the cell as well! 10 times the current means 100 times more heat generated (roughly) and if Woelen's cell run warm then yours may run hot or worse! :-) So don't be greedy and try to make too much chlorate too fast with too high the current!
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[*] posted on 22-5-2015 at 13:27


pumukli: "Take into account that higher current (voltage) means not only faster electrolysis"... usually, current = amperage, potential difference = voltage.

the higher "current"(amperage) is representative of the number of electrons passing through at the given potential(voltage). this results in more work getting done at the same time. the voltage affects what is being worked on often (solution, product or electrodes). some times you raise the voltage, and it will punch holes in things or reduce your product. the current density of electrodes is not easy to nail down. 1) your solution's ability to pass the current at that voltage, 2) electrode size( surface area)/surface characteristics(like smooth/rough) can determine the interaction with the solution, and 3) the power supply's ability deliver the power given the other constraints.

electrode spacing, bubbles generated, solution polarization on electrodes, solution mobility(convection/pumped/none) can all affect what is happening. sounds super complex, and it can be at times. but a lot of that isn't super important with things like a chlorate cell. also I am no high paid electrical engineer/material sciences guy. I just read a lot, and have noticed first hand that if you are trying to nail down a specific current density, its kinda hard. so in the simple plug and play chlorate cell, just try to get it close.

you don't want TINY electrodes with dozens of amps running through it. it will surely self destruct. but HUGE electrodes with small currents may not have the charge confined enough to actually interact the way you want. though as you have seen on youtube, pictures here, and all over the net: smaller strips to nice big ones seem to work just fine with things like hacked ATX power supplies to nice bench-top power supplies.

the things I mentioned above, will affect metal plating setups a *LOT* more than chlorate.
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[*] posted on 22-5-2015 at 19:05


Again thanks for the help!!
Woelens setup for power supply is 5 volt 5 amperes.
I have read that for every 100ml of electrolyte solution you must have at least 2 amperes current to it.
My power supply is 5 volt 20 amperes and I'm still not sure what size cell to use between 500 to 1000ml.
I will probably choose 500ml and if I use 500ml cell size I will have a current of 4 amperes to each 100ml of electrolyte solution and if I'm on the right path it would be similar to Woelens 5 amp to 100ml so would take about 26 hours per 100ml like his?
So something around 130 hrs run-time?:)

The other thing is my electrode didn't come with a titanium strips attached to go through the lid of the cell and attach the alligator clips from the power supply to like Woelen and most other cells have. Is it okay to just attach the alligator clips straight to the electrodes and have them 3/4 submerged?



[Edited on 23-5-2015 by greenlight]
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[*] posted on 22-5-2015 at 19:53


I built my own spotwelder from a microwave oven transformer to tack on Ti wire leads to the MMO and Ti plate I had. it wasn't the easiest, but not super advanced either. a lot of busy work. did it like this guy: https://youtu.be/jydUZ5OUWAk

https://www.sciencemadness.org/whisper/viewthread.php?tid=50...
6th post from the bottom of the page, with several pictures. works great, though I have/did not made a handle for it yet. no time, ever. gotta use quick bursts, or it blows out the spot. Ti shoots some great sparks, and leaves some interesting craters when it reaches a certain temp in air :)
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[*] posted on 22-5-2015 at 20:57


So is the titanium strip essential and it will not work if I attach the alligator clips straight onto the small part of the electrodes that protrudes through the lid of the cell?

Also, I think I will use 500ml cell volume with a 5 volt 20 ampere power supply with 130 hours run-time, does this sound correct?


[Edited on 23-5-2015 by greenlight]
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[*] posted on 22-5-2015 at 22:36


Current = amperage, voltage = potential difference, not just usually but always. (Should be...)
I wrote "higher current (voltage)" because I don't know the actual power supply and don't know if it is variable or not. If it is variable then what can be varied? Probably voltage, so the operator can have more direct influence on voltage than on current, but of course variable voltage means variable current on a (roughly) fixed resistance... (cell with fixed electrodes)

You can connect the clips to the protruding parts of the electrodes, they don't need to be fully submerged. If I remember well Woelen's electrodes weren't fully submerged either, but I should check his website to confirm this.

On a quick glance your calculation is a bit off with that 130 hours. You intend to use approx. 80% of the current for the same volume (moles) of solution (100 ml) so you must increase the time by about 25%. So instead of 26 hours you will need 32 hours for the reaction.
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[*] posted on 23-5-2015 at 00:52


should be always,.. if I were speaking in a strictly scientific tone. but in conversation with the average person, you might say it as I did to not try sounding like an ass. overshooting your voltage, though increasing overall amperage, won't provide the same effect. pretty sure you will be spending a lot of your time splitting water at too high a voltage = no good any way... also makes more bubbles and higher resistance or current density from lower available surface area. you're kinda stuck with making due with the amperage passed at the voltage you desire, based on the conductivity, surface area, etc. unless you change spacing or something else. I have a 30V 5A variable bench top power supply from ebay, it works great, and ya, if you adjust one the other value changes also. though you can get it where you want it, you can't set the two individually like 5v at full 5a.. also noticed in the little adjustable power supply I made from cheap parts (https://www.sciencemadness.org/whisper/viewthread.php?tid=26... , 9th post down with pics)

the strips are not needed, but you will notice erosion to the clips and springs if they are in the container, some times leading to failure of the clips and a dropped electrode. the mist that evolves in the chamber isn't kind to working parts. if the strips extend out of the container, sealing is an issue, and greatly shortens the working area. though both will be fine if you accept their short comings.

Pumukli is right in that if you scale everything approximately, the hours don't stack up for additional solution. they remain similar. whether or not you get the same efficiency or not remains to be seen. you don't want to get it all DONE to a finished product in one go, best to convert a nice percentage, crystallize product, and add more salt, keep going. otherwise it's too hard on the electrodes. this has been noted several times in the older threads. some one posted a nice solubility chart a while back, don't have time to look for it now. g'night
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[*] posted on 23-5-2015 at 04:29


I am going to purchase one of these variable 30v 5 amp variable benchtop power supplys next but for now I am stuck with the 5 volt 20 amp unit so I will give it a shot with this first and see what happens.

I will construct a 500 ml cell and space the two electrodes a bit further apart like you stated may help Violet sin. The Potassium chlorate that should precipitate is insoluble so I will be able to tell whether it is working.

The reason I brought the 5 volt 20 amp power supply is because of this video (https://www.youtube.com/watch?v=9FyGP-zSpZo) on youtube and that's the current he has passing through his chlorate cell; I should have done a bit more research because he is doing a 3000ml run and his electrodes are spaced further apart I see now.

Thanks again for your help guys, much appreciated.

[Edited on 23-5-2015 by greenlight]
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[*] posted on 23-5-2015 at 10:10


I love that vid! one of the first things I saw on youtube when getting back into chem, that really oooohh-ahhhh'd me into saving for my own equipment. funny though, now that I have some good materials/equipment, I prefer electroplating experiments. more of a "what's next" guy, go figure. half the fun is making equipment 50%, 40% learning something new, 10% getting a product. unless you need the product for more learning in another subject that is, then the numbers are skewed differently. not to say there isn't pride to be taken in a job well done, I just don't make a living of the hobby, so learning is the pay off :)

greenlight: U2U sent, I'll try and provide some good links SM/external, find the sweet solubility chart posted some where here, general do's/don't with electrochem etc. as time permits.
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