thesmug
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Electrolysis power supply capacitors
Earlier today I modified an old atx power supply as an electroplating/electrolysis power supply. Everything works fine, but the two input capacitors
make a high pitched whine (the sound of a capacitor discharging, obviously) that pulses very rapidly. I have concerns I might damage the power supply
so has anyone else had this? If so, did it do any damage and/or did you find a way to fix it?
[Edited on 4/12/14 by thesmug]
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elementcollector1
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Capacitors do that sometimes - apparently it's supposed to happen? This can be smoothed out by simply adding more capacitors.
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thesmug
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Ok, good to know. It's a simple modification and adding more capacitors would be really hard, especially space wise.
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elementcollector1
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How is it set up? I've been using either 12V or 6V batteries, and these don't work at all (even when chromate is added in minute amounts), possibly
because they run out so quickly. Permanganate does nothing either...
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thesmug
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It's a modified ATX computer power supply made in almost exactly the same way as woelen's at http://woelen.homescience.net/science/chem/misc/psu.html
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Bert
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What are the type/ratings/physical sizeof those caps- Electrolytics?
Do you absolutely need to keep the circuitry in the manufacturer's chassis?
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Zyklon-A
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I hate using batteries, why not just buy a fixed PSU? Here, there are cheap PSU's of any voltage/amperage combination. You just have to find the one you need.
[Edited on 12-4-2014 by Zyklonb]
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thesmug
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@Zyklonb, my setup is essentially that. @Bert they are 470uF 200v electrolytics, about 4cm tall and 2cm wide. I think it's almost absolutely necessary
to keep the manufacturer's PCB intact since it's a very complex circuit.
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hyfalcon
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You can keep the circuitry intact, just take the circuit boards out of the metal housing they are mounted in. That will give you more room to add
bigger, taller caps if necessary.
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Bert
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If no room in original chassis?
Unsolder the leg wires of the electrolytics, solder in some lead wires in place of these.
Attach a pair of larger electrolytic caps to the leads, outside original chassis. Be careful to follow same polarity when hooking new caps up.
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thesmug
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I will try the above suggestions. Thank all of you very much.
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aga
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Sure it is the caps ?
Normally it is mechanical instability in the chopper transformer.
When the sound appears to be coming from another place, it can be a component resonating with the switching frequency at some sub-harmonic or other.
Easiest fix is hot melt glue all over the places where you think the sound comes from.
That usually dampens or stops the maddening high-pitched whining noise.
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The Volatile Chemist
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Quote: Originally posted by aga  |
Sure it is the caps ?
Normally it is mechanical instability in the chopper transformer.
When the sound appears to be coming from another place, it can be a component resonating with the switching frequency at some sub-harmonic or other.
Easiest fix is hot melt glue all over the places where you think the sound comes from.
That usually dampens or stops the maddening high-pitched whining noise. |
Yup  I use a Computer PSU, but sciplus.com has some awesome ones I'd like to get.
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Bert
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Cheap transformers ARE noisy-
In this regard it is important to notice that a noisy transformer means that: a) The transformer is badly constructed, or b) That the transformer is
forced to operate in a magnetic region close to or at core saturation.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
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2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Texium
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I was planning on putting together an electrolysis setup, and I was wondering what the proper voltage/amperage combination would be. I know very
little about electricity and just don't want to use batteries anymore. Would a simple AC/DC power converter from Radio Shack of the proper
voltage/amperage be suitable, or is that a really stupid and noobish idea?
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markx
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| Quote: Originally posted by zts16 | | I was planning on putting together an electrolysis setup, and I was wondering what the proper voltage/amperage combination would be. I know very
little about electricity and just don't want to use batteries anymore. Would a simple AC/DC power converter from Radio Shack of the proper
voltage/amperage be suitable, or is that a really stupid and noobish idea? |
Everything depends on the purpose of your experiment. But usually electrolysis power supplies are designed for low voltage (around 5V dc) and high
amperage (>10A). For example if you plan to perform electrodeposition of metals, you can probably make do with a rather simple and low amperage
power supply from just about any radio parts store or a salvaged power supply from an old machine (e.g PC power supply). Electrodeposition is usually
performed at low current desities and therefore the power supply is not working under a high load. The opposite case is with electrosynthesis like the
production of chlorates, perchlorates, permanganates, etc.....there the stress is high as usually strong currents are forced through the cell and one
needs a beefier supply. Also a means of controlling the current and monitoring the amperes and applied voltage is very beneficial. This can be
performed with a simple dc PWM module (pulse width modulation) and simple volt+ampermeters that operate on the same power supply. All of these can be
had for a very good price on Ebay or from your local electronics store.
If one needs a specific regime for the electrochemistry ( constant current, constant voltage or constant power) then also these modules can be bought
in a wide variety on ebay. LED drivers offer a pretty good solution in that case and are quite affordable.
The options are plentiful....but for us to offer more detailed suggestions, you have to first decide on what area of electrochemistry you wish to
explore and what will be the scale of the experiments ( a shot glass sized cell with a few square centimeters electrode area or a bucket cell with
plenty of electrode size).
Exact science is a figment of imagination.......
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arkoma
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I use a crappy old 250W PSU from an ancient e-Machines desktop, drawing so much current the fan kicks on high. No probs so far and been using it a
while
@AGA--excellent tip
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The Volatile Chemist
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If you use too little sized electrodes or too little soltn., or too little space btwn. electrodes, things heat up, but that's about it.
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Texium
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Thread Moved
21-11-2023 at 14:00 |
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