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Author: Subject: Power Supplies
Xenos
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[*] posted on 4-1-2003 at 22:07
Power Supplies


I am trying to preform electrolysis of various compounds and need a sufficient power supply. From my understanding, high amps and low volts is the best. I tried rewiring a microwave transformer, but the results were not pleasing. I need a reletivly cheap high amp power supply. Anyone have any ideas? I did find this on ebay. Is that any good?
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rikkitikkitavi
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[*] posted on 5-1-2003 at 00:59


It is a very good powersupply for that price.
The main disadvantage is that it is difficult to pull 48 A @ 5V unless you use thick wires and a several parallell connected eletrolysis cells. So maybe it is a bit oversized, but that increases the possibility to run it continously for 24/7 duty.

A cheap alterative is old PC-AT power supplies. You can usually pull about 20 A from the 5V.
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trinitrotoluene
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[*] posted on 5-1-2003 at 23:23


Maybe a car battery recharger will do the trick. Its 12 volts and 7 amps DC power.



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rikkitikkitavi
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[*] posted on 6-1-2003 at 02:03


that depends on the size of the charger. I have seen everthing from 12V/4A to 24V/50A for forklift batteries (24V, 400 Ah) . The later cost considerably more than 75 US$.

I m using a 18V-22V.75A transformer with 4 100A recitifying diodes+ a Variac .
And big cooling on the diodes..

/rickard
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[*] posted on 20-1-2003 at 08:36
?


without a bench of capacitors it is no DC source at all. More some pulsed power supply.

Many reactions ask for a stable V or I as I remember and without the possibility for fixed I it is of reduced usability anyhow.
A solid state relay might be cheaper and much easier to control.

Just my 2 cents
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lucifer
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[*] posted on 20-1-2003 at 15:34


Use a big capacitor a coil and again a big capacitor and you will have a good dc current.


A computer supplies will still be the cheapest solution I think and if you need more than 5 V you can put two of them in series.
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[*] posted on 20-1-2003 at 16:52
PC power supplies


If you go for PC power supplies, make sure you get an older AT one and not one of the newer ATX models. I tried to modify an ATX supply for electrolysis with my meager knowledge of electronics a few weeks ago, and it was not successful. One problem is that you need to connect two pins to actually turn on the supply; just plugging it in or flipping on the power switch isn't sufficient. A more serious problem is that, according to a number of web pages that I consulted, the power supplies can easily be damaged or destroyed if they are run without a proper load attached to them.

I read one person's account who had gone through 6 PC power supplies in just a few months with electrolysis experiments. That is far too high a failure rate. I would use a battery charger or even invest in a nice professional, programmable DC power supply if you are going to do a lot of experimentation with it.

Maybe somebody who is handier with electronics than me could make the PC power supplies work well, but I would just scout garage sales and auctions until you find a power supply that can do the job.
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Organikum
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[*] posted on 22-1-2003 at 00:54


Putting two power supplies in series does not work. Pfft makes the fuse. If you are lucky. If you are unlucky you smell it.

Polverone: You have to shorten the green next to the blacks in the middle for a moment and you have to have a load on the main voltages aka 3,3V, 5V and 12V. A lightbulb is sufficient. Damage can occure when you have full load at 3,3V and nuthing else. Lightbulbs on 12V and 5V solve this problem.
But a battery loader with the capacitor - coil - capacitor attached as luzifer proposed will do better.
IMHO.
As parts are free or cheap just try a few ways. And tell.
Thats the real fun.

ORG
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lucifer
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[*] posted on 22-1-2003 at 14:28


Putting two power supplies in series will work, but only if the common (-) is not connected to the ground, or else one output will be shorted, but I guess you already new that.
If the ground is removed from the supplie that is in series and the casings of the supplies don’t touch each other it should also work.

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[*] posted on 8-2-2003 at 11:30
you are right lucifer


But it depends on some more factors. Having two identical power supplies and following the ways you described ok. If you don´t have two identical ones I wouldn´t advice to do so except you know enough on electrics. Somebody having this knowledge wouldn´t have to ask so......
And there is still the possibility of getting some serious oscillations, but it maybe worth a try as the parts are free.

The main trick is a large bench of big capacitors - this should enable you to (ab)use nearly everything. A truck or diesel automobil battery might be the the best choice for most applications if not of semi-industrial dimensions.
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raistlin
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[*] posted on 14-2-2003 at 16:18


The main problem with using a large number of capacitors in series is that they have a tendency to explode after a short period of time. I found this out in electronics after trying to connect 4 high uF capacitors in series. Ten minutes later there was a loud explosion, and part of the tabletop was on the floor....:D



\"To ignite, or not to ignite, that is the question.\"
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[*] posted on 19-2-2003 at 01:42
Did I say series?


No, puhhh
But I was sloppy in my last post, sorry. The big capacitor bench was thought for use with any transforming device which gives AC on the outlet,
the automobil battery was a own concept for a power source for electrochemistry - delivers best DC with lots of ampere. Two batteries with a loader should satisfy also higher demands.
Advantage is that often batteries and loader are available and costs zero.

Exploding capacitors are very valuable. I learned a lot on electrics after the first big one went the way of overload. The permanent high tone in my right ear for several weeks was nasty so.....

ORG
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[*] posted on 13-3-2005 at 07:51
Dc power supply


I was looking at this on ebay

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=5...

it is 0-100v but the problem in it is only
.75amp I am worried that while it may supply a steady volts it won't push enough amps
This would be my first attempt at electrolysis
One other thing I wanted to ask is if I understand this right does it take 10 ma to make 1 amp so 100ma would = 10amp???????

[Edited on 13-3-2005 by Taz]
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[*] posted on 13-3-2005 at 09:24


.75 A ... ?

I would not buy a power supply like that to do electrolysis as the actual productivity of the procedure is directly proportional to the amps. In most cases for me 15 A is not enough. Hence my recent aquisition of a PC power supply with 2 fans and a capacity of 28A @ 5 V.




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Taz
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[*] posted on 13-3-2005 at 09:30
Thanks


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[*] posted on 13-3-2005 at 11:21


You can solve the load problem with PSU's with either a light bulb or, if you are like me and are into computer parts, one of your old 2 gig HD's sitting around collecting dust.

I've found that a suitable PSU for electrolysis is easily realized with a variac, transformer, full wave rectifier, and a nice 30,000uF cap. Depending on the resistance of my cell it usually is capable of 3-4 amps at low voltages...
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[*] posted on 13-3-2005 at 14:05


Don't know if you still can or not but you used to be able to get a 12 volt 3 amp regulated and fused DC power supply from Radio Shack for around $50.
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[*] posted on 14-3-2005 at 18:42
Well its a little costly But what about this for a power supply


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=5...
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rift valley
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[*] posted on 14-3-2005 at 19:50


That looks like a nice power supply, a little too much for me though. I am also interested in starting experiments involving electroloysis of H2O . From one of my other projects I have a 120 volt power supply that is 5-15 amp variable, is this power supply too big to do small (or any) experiments with electroloysis of H2O? A while back I bought a car battery charger from walmart for 25 bucks to do electroloysis of NaOH When I tried to use it as a power source the "Battery is dead" light lit up and it would not send any voltage, so I returned it. Is there something I was missing?

Thanks,
Paul

P.S. Would labx be a good place to find a cheap power supply? I was browsing their inventory and it seems like it is difficult to locate a product unless you have a specific model number in mind, it seems like a very confusing website to me.

P.P.S. Radioshack has a battery charger that does 13.8 volts at up to 25 amps of current for 100 bucks I'll probably buy this right after i fiish my electroloysis cell (I orded strips of stainless steel today for it) anyway heres the like for the charger I was talking about
[Edited on 15-3-2005 by rift valley]http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&am...

[Edited on 16-3-2005 by rift valley]
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[*] posted on 11-7-2005 at 13:16


Dumb question:
How do you know if your PC power supply is AT or ATX?...I just removed one from an old computer of mine. I have read every word on the case and no AT or ATX anywhere to be found.




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[*] posted on 11-7-2005 at 13:58


Quote:
How do you know if your PC power supply is AT or ATX?...I just removed one from an old computer of mine. I have read every word on the case and no AT or ATX anywhere to be found.


ATX power supplies have an ATX connector. This site has the pinout of an ATX connector:

http://xtronics.com/reference/atx_pinout.htm

I assume AT power supplies don't have an ATX connector.
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[*] posted on 11-7-2005 at 14:15


Look at the plug that powers the motherboard. If it is two inline plugs that both go to a single socket (twice the length of a single plug) it is AT. If it is a dual row rectangular single plug, it is ATX. Just load the 5 volt side with an amp or so and the supply will run fine. This is how many of the newer Galaxy base radios use a computer supply to replace the old transformer supply, they use a 10 watt 5 ohm resistor that gives the 5 volt side a load of one amp. You can then use either the 12 or 5 volt output for your experiments, staying within the ratings. If you load it correctly the power good line can be ignored, but I have found a few supplies that will not start without the power good signal (they also failed after a while). Some supplies have both connectors. It really does not matter as either supply can be made to work within their ratings.
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[*] posted on 11-7-2005 at 17:15


Last one I was using, I took all the red wires and all the black wires on the mobo connector and joined them together for each electrode respectively. Better than just using just one wire at 30A! :o

Tim




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[*] posted on 11-7-2005 at 19:26


Well my power supply has a dual row single plug going into the motherboard(indicates ATX by IrC's definition), however each pin only has one wire going to it(indicates AT by Craig's definition). Strange....so which is it?



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[*] posted on 11-7-2005 at 21:00


Only one wire to each pin. Not sure where that applies anywhere, but there is no reason only one wire would have to go to any single pin connector within a socket. However, none of this makes any difference to the question, what you have is an ATX supply, which is also the socket in craig's link, a correct view of an ATX plug. I would post a pic of an AT connector but I still can't get the ftp into the site to work for me, and I don't know of a link to a pic of an AT plug out there. They are getting so outdated nobody talks about them anymore I guess. But they are a cheap source of supplies, seeing as how so many were made and now are unused.

As to the almost $190 power supply on ebay that is 20 amps, not a bad supply but if you ever did any real plating it really is not big enough, especially for the bucks they want. H&Y Electronics sells a 52 amp power supply with voltage and current meters, all you would have to do is go in and slightly redesign it to allow full adjustability rather than a small range around 13.8 volts. For 52 amps under 200 dollars this would be a very worthwhile project, and finding a schematic to the supply would not be hard. It may even come with one. If not and you choose to go that way I can dig one up and even show what changes to make to convert it to a fully adjustable zero to 25 volt source of 52 amps.

Found a picture of an AT plug(s): http://www.upgradefever.com/gallery/showphoto.php?photo=25

[Edited on 12-7-2005 by IrC]
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