Sciencemadness Discussion Board

wall wart as power supply for electrolysis

BauArf56 - 11-5-2021 at 04:56

i'm wondering if those apple's battery chargers could be used as power supply. They have as output 5V and 2A. Are they in dc?

njl - 11-5-2021 at 05:04

While this isn't good practice I have to admit I've used them before, they will work for some reactions. Some things to keep in mind though. Newer, smarter power bricks might require some interfacing with the device before any power is drawn, in other words they won't work as a power supply without a phone on the other end. Second, the off-brand power bricks may have power regulation that's all over the place, 5V 2A is only reliable when the equipment is reliable.

Johnny Cappone - 11-5-2021 at 05:29

Yes, you can. It provide DC.
But note the points highlighted by njl. In fact, these chargers can be quite interesting in the absence of a suitable power supply. They are compact, readily available and usually have protection against overcurrent/short circuit, which is always useful when working with exposed electrodes.

I would not recommend draining the 2 amps that it could, in theory, provide. At least not for long periods of time. These things were not meant to work on the limit for hours on end and are likely to overheat. Do you have any specific electrolytic processes in mind? I made maybe a pound of chlorate from one of those several years ago. Just respect it limits and be patient.

[Edited on 11-5-2021 by Johnny Cappone]

njl - 11-5-2021 at 05:36

Actually, I think 2 amp phone chargers require feedback from the load in order to operate. You probably couldn't sustain 2 amps even if you wanted to.

BauArf56 - 11-5-2021 at 05:41

Quote: Originally posted by Johnny Cappone  
Yes, you can. It provide DC.
But note the points highlighted by njl. In fact, these chargers can be quite interesting in the absence of a suitable power supply. They are compact, readily available and usually have protection against overcurrent/short circuit, which is always useful when working with exposed electrodes.

I would not recommend draining the 2 amps that it could, in theory, provide. At least not for long periods of time. These things were not meant to work on the limit for hours on end and are likely to overheat. Do you have any specific electrolytic processes in mind? I made maybe a pound of chlorate from one of those several years ago. Just respect it limits and be patient.

[Edited on 11-5-2021 by Johnny Cappone]

i was looking for a cheap alternative to 9 volt batteries, which usually are quite expensive, for making potassium chlorate.

Triflic Acid - 11-5-2021 at 06:00

Maybe try shorturl.at/wGPT4, those look really promising for electrolysis.

Johnny Cappone - 11-5-2021 at 06:56

Quote: Originally posted by BauArf56  

i was looking for a cheap alternative to 9 volt batteries, which usually are quite expensive, for making potassium chlorate.


There are much better alternatives than a cell phone charger. I would say 9V battery is not even an alternative.
Have you taken a look at the old AT/ATX power supplies? You can usually get one for a few bucks. They are excellent for the price they cost and can supply up to 20A in the 5V line, in addition to having a 12v line useful for powering other equipment in the laboratory.

Or you can just buy a small dedicated 5V-10A power supply, I just saw one on Ebay for just over 12 US dollars.

@njl, I believe that the feedback requirement depends on the design of the charger. The most modern ones, in fact, seem to have some mechanism of this type. Therefore, they will only function as a power supply when inserted into the intended circuit (recharge the cell phone battery). But most of them, at least from what I've seen, can still be used as a standalone DC adapter.

Triflic Acid - 11-5-2021 at 07:03

The apple chargers I used to use to power arduinos in the past, so I know that they work as DC adapters.

hissingnoise - 11-5-2021 at 07:09

Gonna need a bigger wart...

Check this out?

https://www.screwfix.com/p/streetwize-swbcg12-7-12a-battery-...

Edit to fix link.


[Edited on 11-5-2021 by hissingnoise]

Vomaturge - 11-5-2021 at 18:38

I tried a very small cell on on a 2a 5v android charger whose usb cable had broken. I drew a a few hundred mA, for a few minutes before the whole room started smelling like chlorine. I was more just messing around, not trying to create useful amounts of chlorates or chlorine.

Edit: definitely don't use a 9v battery. They're expensive, take a lot of resources to manufacture, and they will probably make so little electrolysis products that you won't be able to extract them.

If I had to eletrolyze a large amount of material I'd use a rectifier and this little 50va toroidal 12v lighting transformer, that I wrapped with as much 12Awg copper as would fit through the middle. In my case that gives 8.4v. Of course if you emulate this make sure you know what you're doing, there's lots of ways to get electrocuted or start a fire when building a line volt

[Edited on 12-5-2021 by Vomaturge]

yobbo II - 14-5-2021 at 15:05

Quote: Originally posted by hissingnoise  


Gonna need a bigger wart...




[Edited on 11-5-2021 by hissingnoise]


MOTHER OF GOD Hiss.
Thats like something you would hear in the health and safety office of a brothel when a worker was looking for a week off work!



Some old wall warts are actually AC out (for toys and other things) so make sure they are DC

Yob

Twospoons - 14-5-2021 at 18:44

TBH you'd be better off investing in a proper variable bench power supply. It will (should) be more reliable, and way more versatile- with the ability to run constant voltage or constant current ( both will be adjustable) this should open up more avenues in electrochemistry. I have one that will do up to 5A @16V or 3A @27V or 2A@36V (selectable) - cost me 80NZD new ( thats circa 45USD).
I also have a secondhand beauty that will do up to 50A at 60V (yep thats 3kW!) - old HP bench unit I scored for $300. So keep an eye on ebay for bargains like that. Some sellers don't really understand what they're selling.

Fyndium - 14-5-2021 at 22:41

Car battery chargers are essentially a transformer with variable switches for different voltage between 5-24V and they can give from 5A to 400A depending on size. They provide DC current straight out of box and are not at all expensive. Were lazy, I'd just get one.

Also, welding transformers are an excellent source for electrolysis, although they may be a bit big for many. Smaller ones come from microwaves. Just re-wind them to get desired voltage(4-6V usually), and use a full-wave rectifier to get full power DC out from it.

draculic acid69 - 15-5-2021 at 01:03

99.9% of wall warts are DC. AC adaptors are rare super rare. I've only ever seen three.
In my whole life. And that's out of about 1000 of them. And it'll always clearly state
DC or AC and volts and amps. Also what model of phone requires 2A? Thats a lot for a phone. Maybe an iPad.

BauArf56 - 15-5-2021 at 04:16

thank you all for answering! Yes, the charger is for ipad. So i'll try, i just hope to do not get shocked!

Fyndium - 15-5-2021 at 05:50

Some phone charger models have rather high power, for example warp charge for OnePlus. Long battery life isn't that important anymore, when you can charge it full in 15 minutes.

macckone - 15-5-2021 at 21:55

there are all kinds of wall warts and laptop chargers that will supply a good amount of power.
Older battery chargers are perfect as they are usually switchable between 6 and 12V and can output upwards to 10A continuously, the newer smart chargers won't work.

https://www.amazon.com/Aiposen-Transformer-Security-Computer...

$10 and free prime, they have models up to 60 amps.
There are also 12v and 24v models available.

If you get a 24v model, you can get an adjustable buck converter (or 6) to provide various output voltages and currents.
It is also possible to make a simple mosfet/op amp current regulator.

Fantasma4500 - 19-9-2021 at 02:18

use a microwave transformer, they can output 70A with low voltage
i cant remember the modification but im sure you can find some data on it
actually it might just be 3 thick copper windings in place of the top coil
i made my own spot welder, and it puts out 100ish amps with less than 10V, thats 2 thick copper windings in place of the top
otherwise ebay sells cheap powersupplies, just type in 5V 40A

macckone - 22-9-2021 at 09:01

Some wall warts are better than others.
You can buy some really nice high amp (30a) 12v power supplies on amazon.
Then buy a drok buck converter or two or three.

12v 30a:
https://www.amazon.com/SUPERNIGHT-Universal-Transformer-Indu...

buck converter with voltage and current limit:
https://www.amazon.com/DROK-Converter-5-3V-32V-Regulator-Tra...

katyushaslab - 25-10-2021 at 23:08

I've used a mobile phone charger to drive small electrolysis cells for chlorates.

Pictures of a super tiny cell:

Cell: https://i.redd.it/whqcgaiu3ga71.jpg
Electrodes: https://i.redd.it/v9hldyv8mr971.jpg
Yield: https://i.redd.it/h8oyxydbmmd71.jpg

I scaled it up to 500ml of electrolyte and still got decent yields, ended up producing over a kilo of potassium chlorate that way. More than I actually needed.


Edit: fixed image links.
[Edited on 26-10-2021 by katyushaslab]

[Edited on 26-10-2021 by katyushaslab]

B(a)P - 26-10-2021 at 03:22

Quote: Originally posted by katyushaslab  
I've used a mobile phone charger to drive small electrolysis cells for chlorates.

Pictures of a super tiny cell:

Cell: https://i.redd.it/whqcgaiu3ga71.jpg
Electrodes: https://preview.redd.it/v9hldyv8mr971.jpg
Yield: https://preview.redd.it/h8oyxydbmmd71.jpg

I scaled it up to 500ml of electrolyte and still got decent yields, ended up producing over a kilo of potassium chlorate that way. More than I actually needed.

[Edited on 26-10-2021 by katyushaslab]


Thanks for sharing. I can only see your first link and no image of the power supply. Presumably it was less than 2 amps? How long did it take to produce that much perchlorate? I would have thought a phone charger wouldn't cope with powering an electrolysis cell, very interesting.

katyushaslab - 26-10-2021 at 04:50

Power supply was, specifically, the standard one that comes with an "OnePlus 8 Pro". It is capable of doing higher power delivery, but my measurements (taken in-line using one of those gadgets for testing phone chargers) showed amperage around 2A normally. It got up to 2.5A sometimes, and sometimes dipped below 2A, with voltage usually being 4.5-5.5V.

I basically ran the cells (various iterations) non stop from July 10th to 19th September, harvesting product once a week, refreshing electrolyte, etc. Mostly it was a test of the endurance of the little electrodes.

The electrodes were one of those USB powered "bleach maker" contraptions you find on Chinese websites.

I also fixed the links in the post, the images should load now!

I'll eventually scrape together all the notes and do a proper writeup, I mostly just chucked results on Reddit or Twitter as I went along.

[Edited on 26-10-2021 by katyushaslab]