Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: electrolysis basics
exodia
Harmless
*




Posts: 25
Registered: 3-10-2016
Member Is Offline


[*] posted on 24-12-2016 at 19:28
electrolysis basics


Hi there, I'm starting to get interested in proper electrolysis, and I'm not quite sure were to start from.

I have looked in the library for info (and in the forum) just to get into the basics, nothing experimental yet (like what do you want your volts for, or your amperes etc) trying to expand my electrical and technical knowledge, basically I know how the electrolysis works from a chemical point of view, but I'm lost when it comes to currents and set ups.

so basically id appreciate some input in:
links or write ups with the basics, and were do I start with the power supply (I have seen some people having really good results with the computer power supplies) but I have not got a clue how to convert this, I was looking more into something I can plug into the wall and will let me regulate Volts and Amperage.

Thank you very much.
View user's profile View All Posts By User
Tsjerk
National Hazard
****




Posts: 482
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 25-12-2016 at 00:25


Cool, I'm also not an expert but I'm also trying to learn. For the power supply I advise to look for a DC supplier with adjustable voltage and a upper limit amperage setting. There will be an internal resistance which will regulate the amperage as long as the resistance in the cell is lower.

Normally you never need more than five volts in electrolysis, I found a new 35 euro power supply with 0-30 volts, maximum upper limit of 5A on amazon. Make sure you can also adjust the voltage in the 0-2 volt range as many electrode materials depend on exact voltage in this range for there functionality.

PC power supplies are fine , but usually only give 5 or 12 volts and the amperage depends on the cell resistance (which can and will change during the experiment).

It will be important to regulate this amperage as electrodes have a maximum amperage output/cm2.




[Edited on 25-12-2016 by Tsjerk]

[Edited on 25-12-2016 by Tsjerk]
View user's profile View All Posts By User
violet sin
International Hazard
*****




Posts: 1044
Registered: 2-9-2012
Location: , Location, Location
Member Is Offline


[*] posted on 26-12-2016 at 00:32


Adjustable voltage controll PCB can be bought super cheap on ebay. 2$ea. I pick up all manner of little function "x" PCB boards, whenever one is needed grab 3. Beats spending another 3 weeks wait time. "X" being any maner of tricks, V adj up/boost, V adj down/buck, signal generator, temp probe, stepper motoe controll, PWM motor speed controll, ... You name it they make one cheap

Buck/boost controller
http://m.ebay.com/itm/Boost-Buck-DC-DC-adjustable-step-up-do...

one recently was nice; a buck/boost controller for a few A( think 3A max). You supply it with 5-32 V DC and adjust the potentiometer to get desired V. it went low 1.25v. But you can drop that with a diode.. Drop about o.6v across each diode in series with output. On the other side of things, it was supplied with 12v ac adaptor and straight from the seller was putting out 45 V. Impressive boost for such a little guy, wonder what the sagg would be under load though.

Digi meter
http://m.ebay.com/itm/Mini-DC-100V-10A-Digital-Voltmeter-Amm...

Outlet box
http://www.truevalue.com//catalog/product.jsp?productId=5052...

Terminal block
http://m.ebay.com/itm/OE-Wire-Connector-12-Position-Barrier-...

Also nice is little digi V/A meter for a few bucks. Throw it in a project box with a terminal block for wiring. It will NOT dump much in the way of amperage, I.e. things like chlorate cell might(will) be quite a bit slower than with a 20A ATX. But for beginners its cheap, adjustable, easy to solder and small. I like using thin style outlet boxes from hardware store, the kind for house wiring the receptacle sits in, 99ยข. Plexiglass cover.


On the amperage side of things.. this setup isn't awesome. You would have to controll the mess by spacing and/or depth each electrode was submerged along with varying your supply V to reign it it... Or get the V right and get what you get A wise. Though there are other controllers much more capable of controling A as well. The little digi V/A meters are great for minding this though.

AC adaptor DC out -> V adj pcb board-> digi meter -> electrolysis cell or other load.

Things like on/off switch, several A circuit interruptor cord ( from hair blow-drier) and a decent project box all lend them selves to safety and ease of use. It's nice to have something that packs away on a shelf nicely. Guaranteed you will be more likely to use it if it's not a twisted pile of wires and alligator clips humming away.

Projects like this deff have their limitations, but are great to get you learning and figuring out what you want from a device. It's easy to blindly assume you need some overkill device, or undershoot your expectations also. This give you a foot in the door, the parts can be redistributed to other projects later, and it's quite cheap. Have fun, play safe




Sauce
View user's profile View All Posts By User
ficolas
Hazard to Others
***




Posts: 110
Registered: 14-5-2016
Member Is Offline


[*] posted on 26-12-2016 at 07:12


I have some questions related to current density.
How do you know what max current density to use for certain electrode? For bought electrodes it usually says it somewhere it seems, but if im using for example a graphite electrode from a battery, Im lost. Any way I could meassure it?
And if my goal is to use the electrodes as a part of the reaction, I shouldnt care about current density? For example, making iron hydroxide.
View user's profile View All Posts By User
Tsjerk
National Hazard
****




Posts: 482
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 26-12-2016 at 07:43


I guess for battery obtained electrodes are used you should be able to find reference values on internet, but it will probably also be a trail and error process finding out the maximum you can run them on.

When sacrificing your electrodes you only have to consider the maximum voltage indeed, as to high of a voltage will favor side reactions as electrolysis of the solvent (water in the case of iron oxide).
View user's profile View All Posts By User

  Go To Top