A few minutes ago I was doing some self-study in my old GROB Basic Electronics text book on aluminum electrolytic capacitors. This video really helped me to grasp how these caps are constructed. Now I can go back to my reading. Thank you very much RimstarOrg!
I'm going to make sure I see it if it will be there! Jeez, the ideas you come up with are just perfect! Everything you do can be made at home, if the instructions are followed exactly, and it's not just fun to copy your work, but it also opens like this huge field of further own experiments! respect!!!
Hi! I was watching this and trying to understand how do these fail. I only found vids that make them explode for fun, no explanation, or explanations on this working like this but nothing about failures. Why does it have polarity? Why polarity is important? What happens if you connect this experiment reversed? And why that doesn't happen when connected the right way?
When you reverse polarity you can break down the oxide layer which is the insulating dielectric between the conductive electrolyte and the aluminum, also conductive. This causes a short circuit since the two conductive materials. With enough electrical current conducting through this short circuit, heat is produced. This heats up the electrolyte building up enough pressure for the capacitor to either leak or blow up.
I'm guessing you meant ceramic capacitors. I don't know off-hand. I did play around with making barium titanate capacitors for a while for high voltage purposes, but I had to add epoxy as a binder and that didn't work out as I'd hoped. All I can suggest is look into what material you want to make them out of. Then I'd guess you'll have to form it under pressure and possible high temperature too. But I don't know any specifics.
That's the equivalent of connecting multiple capacitors in series. The effect is that the result will be able to handle higher voltages than just one of the capacitors would be able to. But the overall capacitance will be less than any one of the capacitors has. If you're trying get a higher capacitance using multiple capacitors then connect them in parallel. That means to connect all their negative plates together and all their positive plates together.
Thanks, man. Yeah I've had some messages from people asking for alternatives to homemade power supplies, or easier solutions, so I figured I'd use something simpler this time.
Sure, as long as you can get a complete enough layer for good insulation then it should work. Aluminum quickly forms a layer of oxidation even just in air so before I'd even placed them in the electrolyte for the first time they already had some oxidation. But clearly it wasn't enough given that when I plugged in the power adapter it conducted current fairly well. It's worth a try. Make sure you make a video and let us know.
1) Yes. 2) 61 microfarads is medium. On low power circuit boards, they're usually picofarad or nanofarad. For higher power circuits (TVs, power supplies, ...) some are microfarad and millifarad. Ultracapacitors are in the farads but I don't know what they're used for. Farad is the unit for capacitance, a measure of the ability to store electrical charge. 3) It depends on how much charge is stored in the capacitor. If a microfarad range capacitor is fully charged then it can give a painful shock.
I honestly don't know if the oxide layer would be able to withstand 300V+ forming or even 250V. I haven't done any breakdown voltage tests. You're right, it's the oxide layer that acts as the insulator, the paper doesn't matter at all. If you try it, let us know how it goes.
Not to my knowledge, but I could be wrong. There's also nothing about using saltwater on the wikipedia page. Baking Soda and Borax are all pretty easy to find in the US and Canada. Most grocery stores have both.
thank you very much, about the third question, i ment the capacitor that you had in the video, or a smilar one with the same charge, what could happen if you touch it?
Good point. You'd think that since the dielectric is aluminum oxide, it would always have the same dielectric constant and the same thickness across all manufacturers. That leaves just area as the changeable variable. I couldn't say for sure though.
Thanks! I'm working on a follow-up this week - a large surface area, aluminum foil, spiral wound one with paper towel as separator. Should get some decent capacitance (millifarads?) if it conducts well enough through the soaked paper towel. Just made a mess on my first try and too late to try again today. If that's not this week's video then you'll know it didn't work! :)
Hmm... From some searching, a 9V battery stores around 500 milliamp hours. The forming I did in this video took very roughly an average of 1 milliamp constantly for an hour so that's 1 millamp hour. So it should be okay. I'd be interested in knowing how your 9V battery works out so please let us know.
Thank you. I made electrolyte spiral cap but after some time the electrolyte evaporates !! I trayed also to reconstruct commercial electrolyte cap by open one and reposition the plates but also electrolyte got dray. Any advice you can provide?
Yes, but the baking soda provides the conductivity. It's a bit of a puzzle to me too as to why tap water causes a problem. My guess is some impurity in it interferes with the aluminum oxide formation - but that's only a wild guess.
Oh... and regarding the Alum, sodium bicarbonate and sodium borax both facilitate the formation of the needed aluminum oxide layer. I didn't mention it in the video but they also cause self-repair of the oxide layer. So the question would be, does Alum?
Perhaps am I too late to ask, basically the formation process is like how regular aluminum is anodized? but on a thinner scale? how thick you think its compared to the natural oxide layer aluminum develops in contact with air?
This is the first I've looked up anodized aluminum so take it for what it's worth. But from en.wikipedia.org/wiki/Anodizing#Process, it sounds a little different. They seem to use higher voltages and an acid for/in the electrolyte. I don't know anything about the thickness of either.
the aluminum oxide layer acts as the dielectric correct? would you continue to put voltage to it to build up that layer? and do you have any suggestions on how to keep that layer?
+Adam Hoogeterp Yes, the aluminum oxide layer is the dielectric. No, you don't want the layer to build up anymore than it has to since the thinner it is, the higher the capacitance. It doesn't sounds trivial for making a way to keep the layer but search for a comment by Geo K on my other related video ua-cam.com/video/lmVVdV8wuB0/v-deo.html where he talks about it.
Video? You and MongrelShark are the experimenters. I just teach. Looking forward to the video ;) lol. Yeah, in the solar business we put baking soda gently on top of the batteries to neutral any acid on top and clean them, being very careful not to let any get inside.
I've been keeping old electronic devices from the early 90's and 2000's example snes console, ps2 slim and crt tvs will these devices have problems with aluminum electrolytic capacitors if stored for a long time?
what if instead of using your way og forming oxide layer, i just heat oneplate using my homemade bunsen burner, and let the aluminium oxydize in the air?
Hi, can you please explain to these points 1) did the lamp get the electricity from the capacter? 2) is 61 microfarads much? what does farad say? 3) is it dangerus to touch the capacter?
okej, then what is the meaning of having the capacitor here? when i watched the other video the the capacitor get discharged very fast when you conect it to the resistances, is there any way (FOR US) to make a capacitor that work as a power source that can last longer? like in inte the cellphones (if im right guessing that todays cellphones battery är capacitors)
Just seen you answered MongrelShark with similar questions/answers. There's definitely a healthy 'yeah but why? and what happens if?' at the moment with many things taken for granted.
The circuit came from a book and is copyrighted, otherwise I would have included a diagram in the video. But many circuits use electrolytic capacitors. All you have to do is find one that needs a capacitor that has around the same capacitance. I don't know what the voltage limit is on these homemade capacitors, but mine used a 9 volt battery and was fine.
OUTSTANDING!!! I just saw the electrolytic cap build (...must have missed it somehow). The chenical process was most impressive...and I was amazed at the high capacitance you got...I am curious about the voltage rating though. THANKS NUCH!
If you connect an electrolytic capacitor the wrong way around then the oxide layer, the insulating layer between the two plates, will break down and no longer act as an insulator or dielectric. You'll have a short circuit between the two plates and they'll start conducting electricity between them. This will result in high electrical current and then rapid heating which may then explode the capacitor.
Yeah, I've read that electrolytic capacitor manufacturers each have their own recipe for the electrolyte so across manufacturers I wouldn't be surprised if the oxide layer thickness varied. But for a single manufacturer, I don't see why it would.
First, make sure you're using Sodium Bicarbonate or Borax as I show in the video and not salt. Salt won't work. Did the current drop as the oxide layer formed. Mine was still conducting but it had dropped all the way to around 700 microamps after an hour when I stopped it. So it was still conducting electricity but very little.
Um, I don't know. But it doesn't sound like it's working. :) Maybe your aluminum was coated with something non-conductive and the forming is removing the coating, exposing more conductive aluminum surface area. But now you have all that junk from the coating in your fluid. Did you sand off the aluminum and then clean it thoroughly with soap and very hot water and then rinse it thoroughly with very hot water first? If not, I'd suggest starting over by doing that.
There are many uses for capacitors in a circuit. This isn't my circuit but I think it's being used to periodically build up power for turning one of the transistors on. I'm pretty sure cell phone batteries are lithium ion batteries, not capacitors at all. Currently I don't know of any way for us to easily make super high capacitance capacitors. One future possibility is a graphene capacitor, but I don't think anyone's managed to do it as a home project yet. Search for "graphene supercapacitor".
Excellent Farads! Wow! I'd love to know more about the chemistry here? Wondering how alum would go too?. What stops it from being a Galvanic battery? I'm thinking the bi-carb and Borax might be less corrosive than alum? I've used those two to make laundry soap, seems to have some kind of "oxy action". I know Alum is a flocculator. I wonder whats going on with the oxide layer, re battery vs capacitor? Battery seems to change it from plate to plate. I guess this doesn't?
Not parts of a circuit that are powered by a battery are completely steady DC. The circuit in this video has a portion that would be DC with a wave on top of it. If we block the DC portion using a capacitor then just the wave portion is left. In that case the current would repeatedly flow and then stop flowing and then flow again as you say. That's the wave portion. We've created AC from DC.
Yes, you can. It works out the same. In fact, you can see where I did that at the beginning of my other video "How to Make a High Capacitance Electrolytic Capacitor" which you can get to using the link in the description below this video or find it on my channel page.
Hello, after watching this video, im still confused on the electrolytes role in this capacitor. I know that im told it acts as a cathode, but in an electrolyte there are positive and negative ions, so do the positive ions become negative ions and therefore the electrolyte becomes negative and then these electrons are ripped back off when energy is released, or is there some reverse attraction thing going on where due to the electrodes beginning to form negative and positive charges the electrolyte becomes attracted to it and then that acts as some overall charge differential?
Would it work, if I charge it with current limit to 300V+ and hold over 250V? Or won't that work with that kind of electrolyte? I got very thin Paper aswell, would that work at high voltage, because the isolation is done from the oxide layer?
I got confused about which video this was. For the circuit in this video the answer to 1) is no, the electricity came from the battery (I was thinking about my "How to Make a High Capacitance Electrolytic Capacitor" video.) As for 3), it really depends on how much charge you pump into it, also meaning how much voltage you charge it up to. I don't know the voltage limit for this capacitor, but a few volts like in this video won't hurt. I think you'd need 50+ volts, at a guess, maybe even 100+.
I haven't tried tap water (not pure water) myself but someone else messaged me that they were having problems and it turned out to be that they were using tap water. When the switched to distilled water they had success.
Electrolytic capacitors mounted on electronic circuits of devices manufactured after 1990 can remain unused for as long as possible without this disuse causing failures and depolarization in the electrolytic capacitors?
@@RimstarOrg I read that electronic devices that use electrolytic capacitors cannot be stored very long without use and it is necessary to use 1x per month for the electronilitic capacitors to not fail and to depolarize caused by disuse is it true? I have electronic devices saved from 1990
That doesn't sound right. I've used electrolytic capacitors that I've had in storage for a few years at least. Some I've taken from old devices that hadn't been turned on for years.
LOL. I can't help being curious. I'll add it to the list. It's a long list. Might be a while. This week is clean up & make space week. Then I can clutter everything up again next week. Lead alum puts the oxide on the pos when charging, and shines the neg, but it reverses to some extent when discharging. I'd say this is a capacitor because it can reverse. Ie the oxide cant leave the pos and stick to the neg. Wonder if its the electrolyte or the plate material. Lots to test with this one. :)
Great HowTo video :D I'll bet Alum would work. It's all very similar to homemade batteries (especially lead). Re the power supply "which is very complicated and noone has one" lol, true enough.
Looking forward to the video ;) lol. Didn't know that about repair and it's more useful info. Baking Soda neutralizes very well if given a day or two to do so and is what I have used with lead when converting gel battery plates. Once got the Minto's and Coke flume when pouring Baking Soda straight into a car battery....goggles time !
Hey If I did the same thing with an enormous version of this with long plates of aluminum foil and used the shiny side sandwiched with wax paper in the middle (thin paper or something?) and did something similar could I make a more efficient capacitor? one that could possibly store thousands of uF? Could I use something else other than distilled water? like vegetable oil or canola oil or something? because I have plenty of that.
+realflow100 The longer the plates, the higher the capacitance. I use a spiral in this one to get up to around 500uF, so with even longer plates you should be in the thousands of uF. It's a spiral so off hand I don't know if the relationship is linear. I suspect it is pretty much the same as a flat plate for this design, so it's probably close to linear. As for the fluid, the chemistry has to be right. You need that aluminum oxide layer to form. I doubt an oil would work but if you search for how commercially made electrolytic capacitors are made then you might get some ideas.
RimstarOrg just an experiment. I was thinking.. If I had long sheets of aluminum foil with wax paper or something sandwiched between to seperate them and then adding the distilled water and baking soda/something (all I have) Could it possibly be sealed in a large tube or something solid to prevent escape of the fluid or evaporation and make a useable capacitor for low voltage but higher capacity? Could I get tens of thousands of uF that way?
+realflow100 Sealing it should help with the evaporation problem. Theoretically you could get tens of thousands of uF, but practically, it would be an awful lot of effort.
hey i have a really important question what is i did this method with multiple plates in a series of only positives and a series with only negative in between them like this positive=l negative=| |l|l|l
Great video, RimstarOrg, thanks for sharing. Now I am looking forward for the advance way from you, may be "How to make UltraCaps". If you did it, let me know. Thanks.
Official? It's as official as the baking soda. On the other hand, I didn't try it with the Borax -- I only read that it should work (a source en.wikipedia.org/wiki/Electrolytic_capacitor#"Wet"_aluminum_capacitor)
You can. Aluminum foil works fine. I just wanted something stiffer in this video. I use aluminum foil instead in my "How to Make a High Capacitance Electrolytic Capacitor" video. There's a link to it in the description below this video.
The NACL has one problem, to increase the conductivity of wate,r you must add more NACl but unlike the baking soda when you add more slat , once you want to coat the electrode with AL2O3 the NACL will breakup and release CL gas that etch the electrode that's why you cant add too much salt and should add just a little that doesn't have any effect on the capacity of capacitor but the internal resistance of your capacitor will be higher.
I like the video. Very good. Do you show how to make polarized caps somewhere? Is there some formula on the plate size and what you have here that we are to use once rolled up and we attempt to put into a real life circuit? I need some 20uF and some 30uF give or take. Given the plate sizes you have, what capacitance do you once rolled up? TY
I have a video where I show making a cylindrical polarized capacitor but I don't have any formulas for polarized capacitors. The best I can suggest is doing trial and error unless you can find another source online. Here's the video ua-cam.com/video/ml2TdQ2_2mk/v-deo.html
I remember That baking soda and water mix Being called " saturated mix" when you mix the maximum amount of powder to a room temp fluid. A super saturated mix was when you heated it up to add more powder than room temp,would allow. That was grade 7 in 1980 lol!
Hi, I created a capacitor using the method shown in your video, I want to calculate capacitance of the capacitor. In your video you mention that the electrolytic capacitor minimizes the distance between the "plates" by using the electrolyte as a plate itself. What value can I use for distance in the formula to calculate capacitance?
Could you build high voltage caps with this method? And is it possible to produce bipolar, electrolytic capacitors, by applying AC? Thanks for any help :)
helut kuno I don't know what the breakdown voltage is of this capacitor but I imagine it's the same, or not as much as commercially made electrolytic capacitors. I don't know of any way to make it higher. And I've never tried making bipolar ones this way, so I don't know if it's possible.
When building up the dielectric layer did you electrolysis any water? Also, I have the same set up as you do, but for some reason when I try to measure the amount of amperage going through the capacitor it keeps fluctuating from 0.1 - 2.0 on the 200 mA scale. Any ideas as to why?
I don't know if I electrolysed any water. Maybe at the higher current. As to why yours isn't working... make sure you use distilled water. Also, did you use baking soda or borax? Salt won't do.
I don't know why salt doesn't work. Something to do with the needed chemical reaction I guess but chemistry isn't my strong point. But when you think of it, if salt would work then every electrolyser for producing hydrogen and oxygen would work only for a short time until an oxidation layer formed, and that's not what happens.
That is true, but what's strange is that I built an electrolytic capacitor, let the water electrolyze over the course of about an hour, and I watched it and the electrolysis of the water slowed until it came to a stop. At that point I charged it and was able to produce a current of about 0.1 milliamps which slowly went down to zero over the course of about ten seconds. I guess I'll have to do a little research. But do you know why baking soda and borax are more suitable electrolytes?
What do you mean by you "charged it and was able to produce a current of about 0.1 milliamps which slowly went down to zero." Do you mean you charged it as an electrolytic capacitor and then discharged the capacitor over a period of ten seconds. That sounds like it worked.
I don't know exactly why it needs to be distilled. Probably because tap water contains impurities which might interfere with either the creation of the layer or the working of the capacitor. I don't know the chemistry involved for the role of the baking powder.
When the voltage is applied the oxide layer forms and then the capacitor should charge. I was under the impression electrolytic capacitors are the only capacitors that continue to hold charge when voltage is no longer applied. Is this true? And would this example hold charge or would it dissipate due to the nature of the dielectric?
Paul C Electrolytic capacitors aren't the only capacitors that continue to hold charge when voltage is no longer applied. That's normal for all capacitors I'm aware of. Though all capacitors have some leakage through the dielectric and elsewhere, so the charge slowly leaks away. Charge up any capacitor, wait a while, and then measure the voltage and you'll see it's there. Though if it's a low capacitance capacitor, just measuring the voltage will quickly short it out. In this homemade electrolytic capacitor there's a problem with the reaction between any aluminum that doesn't have oxide on it and the water, that causes the oxide layer to slowly be removed. So it loses voltage that way. In commercially made electrolytic capacitors they put some other liquid in to prevent that. It's usually a trade secret though so I don't know what it is.
Amazing! loved the video! so will you feel a shock if you were to stick your hand in the electrolytic capacitor? Also, was it the capacitor or the battery that gave power to your load that's blinking on/off?
Twelfthward Nolaswagyoungin I didn't check to see if the electrolytic capacitor would give me a shock, so I can't say. It was the battery that gave power for the load that's blinking. You'd still need a battery or some other power source to charge your cell phone. A capacitor isn't a power source by itself.
RimstarOrg Ha! Very Well Sir...Well I wouldn't advise anyone to test that out haha... wouldn't be very wise... Far as the power source, thanks for clearing that up
I know there are videos about them but I've never looked into crystal cells so I don't know if they're like electrolytic capacitors. Maybe someone else here knows?
RimstarOrg erm.. I believe the crystals are dielectric/piezoelectric having p/n junction properties that separates charge and I noticed the anode and cathode seem to get coated with an oxidization between the metal & crystals. Their voltage seems to get set in the chemical reaction that occurs when they are made.. strangely enough 1.2 v with mine. They seem to pulse charge quite fast so I wonder if they are more capacitor than battery?
Nice video! If I have understood correctly you used the same chemical that was used for forming oxide layer (i.e., water + baking soda) as electrolyte (i.e., the interface between dielectric (oxide layer) and cathode) as well. Am I right?
Thanks! And yes, everything you said was right. And to add to it, the electrolyte is also one plate of the capacitor, with the aluminum foil being the other plate.
The dielectric, the aluminum oxide which I talk about in this video, is much thinner in an electrolytic capacitor than it is in a normal capacitor. The thinner the dielectric, the higher the capacitance. So electrolytic capacitors have higher capacitances than normal capacitors. Often you want a high capacitance. Remember, in this video, the electrolyte counts as one of the plates of the capacitor -- it's an electrically conductive liquid.
you got a subscribe and a like, can you please explain what size of uF cap did you just made or how can i make one to suit my project? i see this one reads .61 uF tho im not sure if that supplies .61 uF or 61.uF sorry if i misunderstood something i guess im not sure if a cap's job is to provide more power, save power, get rid of some power or simply multiply the power and in respect of power im not sure if electricity or current amps/mA / watts volts i just took apart my first tv CRT big box one tho this one was a mid size but desolder alot of small and big Capacitors and i think ill reuse dem since they have a good body no belly on top or no acid leak tho im not sure if it says 200V means you can charge up to or under 200v or 220 uF im asking cuz i see the 220 and the 200 so im not sure if is the same thing just one reads volts and the other one reads uF/F so sorta saying mV or Voltage Ampere is the same as mA just on a smaller scale
Frank Lopez It's 61uF which is 61 microfarads. There are many uses for capacitors in circuits. For example, some are used near the input to a circuit where the power is coming in, in case there's a large spike in power. The capacitor will absorb and store that spike of power instead of it going to the circuit and damaging it. Then it releases that stored power slowly so no harm is done. Another example is to put one just after a full wave bridge rectifier. The output voltage of the rectifier is very lumpy and the capacitor smooths it out before sending it on. And there are more examples. There are usually two number written on a capacitor. One is the capacitance. The other is the breakdown voltage, which is the maximum voltage the capacitor can handle before the dielectric material inside breaks and the capacitor is no longer any good. Note that the capacitance is sometimes written in farads with an F (F, mF, uF, nF, pF, ...) but there are a whole bunch of other standards that also mean farads but other lettering is used (never V or A though since they mean Voltage and Amps.) Sometimes only the number is written and you're not even sure if it's the capacitance. Luckily my meter measures capacitance so I can always check it. Otherwise, I have to try searching online for what the letter means. See here en.wikipedia.org/wiki/Metric_prefix for what the m in mF or mV or mA means along with the other possibilities.
A few minutes ago I was doing some self-study in my old GROB Basic Electronics text book on aluminum electrolytic capacitors. This video really helped me to grasp how these caps are constructed. Now I can go back to my reading. Thank you very much RimstarOrg!
Walter B. I've got an old GROB Basic Electronics text in front of me on my shelf too. Definitely one of the best. Glad I could help!
After just watching 1:54 Minutes I understand it better, than I ever did. And I watched a whole bunch of other videos. Great!
I'm going to make sure I see it if it will be there! Jeez, the ideas you come up with are just perfect! Everything you do can be made at home, if the instructions are followed exactly, and it's not just fun to copy your work, but it also opens like this huge field of further own experiments! respect!!!
As a former electronics instructor I am impressed by the clarity of this demo.
Hi! I was watching this and trying to understand how do these fail. I only found vids that make them explode for fun, no explanation, or explanations on this working like this but nothing about failures.
Why does it have polarity? Why polarity is important? What happens if you connect this experiment reversed? And why that doesn't happen when connected the right way?
When you reverse polarity you can break down the oxide layer which is the insulating dielectric between the conductive electrolyte and the aluminum, also conductive. This causes a short circuit since the two conductive materials. With enough electrical current conducting through this short circuit, heat is produced. This heats up the electrolyte building up enough pressure for the capacitor to either leak or blow up.
LOL Yes, but hard to describe in words. If you place the plug from a lamp into it does the lamp light up?
I'm guessing you meant ceramic capacitors. I don't know off-hand. I did play around with making barium titanate capacitors for a while for high voltage purposes, but I had to add epoxy as a binder and that didn't work out as I'd hoped. All I can suggest is look into what material you want to make them out of. Then I'd guess you'll have to form it under pressure and possible high temperature too. But I don't know any specifics.
That's the equivalent of connecting multiple capacitors in series. The effect is that the result will be able to handle higher voltages than just one of the capacitors would be able to. But the overall capacitance will be less than any one of the capacitors has. If you're trying get a higher capacitance using multiple capacitors then connect them in parallel. That means to connect all their negative plates together and all their positive plates together.
Do you mean what meter am I using to measure the capacitance? It's a Fluke 187.
Thanks, man. Yeah I've had some messages from people asking for alternatives to homemade power supplies, or easier solutions, so I figured I'd use something simpler this time.
Iam learning all over again. Please keep them coming when you get the time.
You're welcome! Glad I could oblige. Thanks for the suggestion.
Sure, as long as you can get a complete enough layer for good insulation then it should work. Aluminum quickly forms a layer of oxidation even just in air so before I'd even placed them in the electrolyte for the first time they already had some oxidation. But clearly it wasn't enough given that when I plugged in the power adapter it conducted current fairly well. It's worth a try. Make sure you make a video and let us know.
Thanks. Yeah, I'm keeping my eye out for how to make ultracaps too. Hopefully someday.
1) Yes.
2) 61 microfarads is medium. On low power circuit boards, they're usually picofarad or nanofarad. For higher power circuits (TVs, power supplies, ...) some are microfarad and millifarad. Ultracapacitors are in the farads but I don't know what they're used for. Farad is the unit for capacitance, a measure of the ability to store electrical charge.
3) It depends on how much charge is stored in the capacitor. If a microfarad range capacitor is fully charged then it can give a painful shock.
I honestly don't know if the oxide layer would be able to withstand 300V+ forming or even 250V. I haven't done any breakdown voltage tests. You're right, it's the oxide layer that acts as the insulator, the paper doesn't matter at all. If you try it, let us know how it goes.
Not to my knowledge, but I could be wrong. There's also nothing about using saltwater on the wikipedia page. Baking Soda and Borax are all pretty easy to find in the US and Canada. Most grocery stores have both.
RimstarOrg can you do a video of making a vinage style paper and wax capacitor like old radios have?
thank you very much, about the third question, i ment the capacitor that you had in the video, or a smilar one with the same charge, what could happen if you touch it?
Thanks. I'm glad you liked it.
Thanks, I'm glad you think so! And you're welcome!
Good point. You'd think that since the dielectric is aluminum oxide, it would always have the same dielectric constant and the same thickness across all manufacturers. That leaves just area as the changeable variable. I couldn't say for sure though.
Thanks! I'm working on a follow-up this week - a large surface area, aluminum foil, spiral wound one with paper towel as separator. Should get some decent capacitance (millifarads?) if it conducts well enough through the soaked paper towel. Just made a mess on my first try and too late to try again today. If that's not this week's video then you'll know it didn't work! :)
Ohh, thanks. Well that would do it :). Great videos, I'd never have thought that practical capacitors were possible to make.
Easy to understand as normal, very good video. Great stuff for guys like me.
What happens is you form the oxide layer with a boltage of about 1kV?
Will you be able to use the cap up to 1kV?
My pleasure, I'm glad to help!
Hmm... From some searching, a 9V battery stores around 500 milliamp hours. The forming I did in this video took very roughly an average of 1 milliamp constantly for an hour so that's 1 millamp hour. So it should be okay. I'd be interested in knowing how your 9V battery works out so please let us know.
Can you use a 9 volt battery because I don't have a 9 volt battery adapter
Yes
Thank you. I made electrolyte spiral cap but after some time the electrolyte evaporates !!
I trayed also to reconstruct commercial electrolyte cap by open one and reposition the plates but also electrolyte got dray.
Any advice you can provide?
Yes, but the baking soda provides the conductivity. It's a bit of a puzzle to me too as to why tap water causes a problem. My guess is some impurity in it interferes with the aluminum oxide formation - but that's only a wild guess.
Oh... and regarding the Alum, sodium bicarbonate and sodium borax both facilitate the formation of the needed aluminum oxide layer. I didn't mention it in the video but they also cause self-repair of the oxide layer. So the question would be, does Alum?
Perhaps am I too late to ask, basically the formation process is like how regular aluminum is anodized? but on a thinner scale? how thick you think its compared to the natural oxide layer aluminum develops in contact with air?
This is the first I've looked up anodized aluminum so take it for what it's worth. But from en.wikipedia.org/wiki/Anodizing#Process, it sounds a little different. They seem to use higher voltages and an acid for/in the electrolyte. I don't know anything about the thickness of either.
the aluminum oxide layer acts as the dielectric correct? would you continue to put voltage to it to build up that layer? and do you have any suggestions on how to keep that layer?
+Adam Hoogeterp Yes, the aluminum oxide layer is the dielectric. No, you don't want the layer to build up anymore than it has to since the thinner it is, the higher the capacitance. It doesn't sounds trivial for making a way to keep the layer but search for a comment by Geo K on my other related video ua-cam.com/video/lmVVdV8wuB0/v-deo.html where he talks about it.
Video? You and MongrelShark are the experimenters. I just teach. Looking forward to the video ;) lol. Yeah, in the solar business we put baking soda gently on top of the batteries to neutral any acid on top and clean them, being very careful not to let any get inside.
I've been keeping old electronic devices from the early 90's and 2000's example snes console, ps2 slim and crt tvs will these devices have problems with aluminum electrolytic capacitors if stored for a long time?
what if instead of using your way og forming oxide layer, i just heat oneplate using my homemade bunsen burner, and let the aluminium oxydize in the air?
ok thanks a lot but i have another question can i use a 9 v dry cell as a source of charge???
Hi, can you please explain to these points
1) did the lamp get the electricity from the capacter?
2) is 61 microfarads much? what does farad say?
3) is it dangerus to touch the capacter?
what would it mean if the current increased during forming instead...
thank you again
can you please tell me why the electrolytic capacitor blows up when we reverse polarity?
okej, then what is the meaning of having the capacitor here? when i watched the other video the the capacitor get discharged very fast when you conect it to the resistances, is there any way (FOR US) to make a capacitor that work as a power source that can last longer? like in inte the cellphones (if im right guessing that todays cellphones battery är capacitors)
Just seen you answered MongrelShark with similar questions/answers. There's definitely a healthy 'yeah but why? and what happens if?' at the moment with many things taken for granted.
The circuit came from a book and is copyrighted, otherwise I would have included a diagram in the video. But many circuits use electrolytic capacitors. All you have to do is find one that needs a capacitor that has around the same capacitance. I don't know what the voltage limit is on these homemade capacitors, but mine used a 9 volt battery and was fine.
I did the same but the capacitor value was not stable?
You're welcome. Glad it helped.
for the electrolyte, could you use saltwater?
OUTSTANDING!!! I just saw the electrolytic cap build (...must have missed it somehow). The chenical process was most impressive...and I was amazed at the high capacitance you got...I am curious about the voltage rating though.
THANKS NUCH!
I didn't measure the breakdown voltage but I'm guessing it's probably the same as the charging voltage but with reverse polarity. And thanks!
If you connect an electrolytic capacitor the wrong way around then the oxide layer, the insulating layer between the two plates, will break down and no longer act as an insulator or dielectric. You'll have a short circuit between the two plates and they'll start conducting electricity between them. This will result in high electrical current and then rapid heating which may then explode the capacitor.
Yeah, I've read that electrolytic capacitor manufacturers each have their own recipe for the electrolyte so across manufacturers I wouldn't be surprised if the oxide layer thickness varied. But for a single manufacturer, I don't see why it would.
Yup, just pull it partially out of the electrolyte. The oxide layer does seem fairly delicate though, so you'd have to be awfully careful.
How do you fix my one just bubbles a lot but doesn’t do anything like make an oxide layer pls reply
After looking at it I saw it was forming an oxide layer but it was still conducting electricity how fix
First, make sure you're using Sodium Bicarbonate or Borax as I show in the video and not salt. Salt won't work. Did the current drop as the oxide layer formed. Mine was still conducting but it had dropped all the way to around 700 microamps after an hour when I stopped it. So it was still conducting electricity but very little.
Thanks! Glad you like it.
Borax is just another material you can add to water to make the electrolyte. In the video I use Baking Soda, but I could have use Borax instead.
How can you tell the negative or positive terminal if it is not marked on it at any place. i took one out of a a/c and it has no markings at all
Are you sure it's an electrolytic capacitor?
Um, I don't know. But it doesn't sound like it's working. :) Maybe your aluminum was coated with something non-conductive and the forming is removing the coating, exposing more conductive aluminum surface area. But now you have all that junk from the coating in your fluid. Did you sand off the aluminum and then clean it thoroughly with soap and very hot water and then rinse it thoroughly with very hot water first? If not, I'd suggest starting over by doing that.
There are many uses for capacitors in a circuit. This isn't my circuit but I think it's being used to periodically build up power for turning one of the transistors on. I'm pretty sure cell phone batteries are lithium ion batteries, not capacitors at all. Currently I don't know of any way for us to easily make super high capacitance capacitors. One future possibility is a graphene capacitor, but I don't think anyone's managed to do it as a home project yet. Search for "graphene supercapacitor".
Excellent Farads! Wow! I'd love to know more about the chemistry here? Wondering how alum would go too?. What stops it from being a Galvanic battery? I'm thinking the bi-carb and Borax might be less corrosive than alum? I've used those two to make laundry soap, seems to have some kind of "oxy action". I know Alum is a flocculator. I wonder whats going on with the oxide layer, re battery vs capacitor? Battery seems to change it from plate to plate. I guess this doesn't?
Why do they put capacitors in dc circuirts ?.isn't the current going to stop flowing once its charged?
Not parts of a circuit that are powered by a battery are completely steady DC. The circuit in this video has a portion that would be DC with a wave on top of it. If we block the DC portion using a capacitor then just the wave portion is left. In that case the current would repeatedly flow and then stop flowing and then flow again as you say. That's the wave portion. We've created AC from DC.
Yes, you can. It works out the same. In fact, you can see where I did that at the beginning of my other video "How to Make a High Capacitance Electrolytic Capacitor" which you can get to using the link in the description below this video or find it on my channel page.
Hello, after watching this video, im still confused on the electrolytes role in this capacitor. I know that im told it acts as a cathode, but in an electrolyte there are positive and negative ions, so do the positive ions become negative ions and therefore the electrolyte becomes negative and then these electrons are ripped back off when energy is released, or is there some reverse attraction thing going on where due to the electrodes beginning to form negative and positive charges the electrolyte becomes attracted to it and then that acts as some overall charge differential?
Would it work, if I charge it with current limit to 300V+ and hold over 250V? Or won't that work with that kind of electrolyte? I got very thin Paper aswell, would that work at high voltage, because the isolation is done from the oxide layer?
I got confused about which video this was. For the circuit in this video the answer to 1) is no, the electricity came from the battery (I was thinking about my "How to Make a High Capacitance Electrolytic Capacitor" video.) As for 3), it really depends on how much charge you pump into it, also meaning how much voltage you charge it up to. I don't know the voltage limit for this capacitor, but a few volts like in this video won't hurt. I think you'd need 50+ volts, at a guess, maybe even 100+.
Cool! Glad to hear you get your hands dirty - that's the real fun.
I haven't tried tap water (not pure water) myself but someone else messaged me that they were having problems and it turned out to be that they were using tap water. When the switched to distilled water they had success.
could you please tell me the breakdown voltage.the approximate value.
+clicknsee I don't know the breakdown voltage, even approximate. I didn't test for it.
Hey can we use water instead(not pure water)
Electrolytic capacitors mounted on electronic circuits of devices manufactured after 1990 can remain unused for as long as possible without this disuse causing failures and depolarization in the electrolytic capacitors?
Yes, they can. They have additives to the electrolyte that make them hold their charge longer.
@@RimstarOrg I read that electronic devices that use electrolytic capacitors cannot be stored very long without use and it is necessary to use 1x per month for the electronilitic capacitors to not fail and to depolarize caused by disuse is it true? I have electronic devices saved from 1990
That doesn't sound right. I've used electrolytic capacitors that I've had in storage for a few years at least. Some I've taken from old devices that hadn't been turned on for years.
@@RimstarOrg How long without use and without risk to electrolytic capacitances?
That I don't know.
LOL. I can't help being curious. I'll add it to the list. It's a long list. Might be a while. This week is clean up & make space week. Then I can clutter everything up again next week.
Lead alum puts the oxide on the pos when charging, and shines the neg, but it reverses to some extent when discharging. I'd say this is a capacitor because it can reverse. Ie the oxide cant leave the pos and stick to the neg. Wonder if its the electrolyte or the plate material. Lots to test with this one. :)
Great HowTo video :D
I'll bet Alum would work. It's all very similar to homemade batteries (especially lead).
Re the power supply "which is very complicated and noone has one" lol, true enough.
Looking forward to the video ;) lol. Didn't know that about repair and it's more useful info. Baking Soda neutralizes very well if given a day or two to do so and is what I have used with lead when converting gel battery plates. Once got the Minto's and Coke flume when pouring Baking Soda straight into a car battery....goggles time !
Hey If I did the same thing with an enormous version of this with long plates of aluminum foil and used the shiny side sandwiched with wax paper in the middle (thin paper or something?)
and did something similar could I make a more efficient capacitor? one that could possibly store thousands of uF?
Could I use something else other than distilled water? like vegetable oil or canola oil or something? because I have plenty of that.
+realflow100 The longer the plates, the higher the capacitance. I use a spiral in this one to get up to around 500uF, so with even longer plates you should be in the thousands of uF. It's a spiral so off hand I don't know if the relationship is linear. I suspect it is pretty much the same as a flat plate for this design, so it's probably close to linear.
As for the fluid, the chemistry has to be right. You need that aluminum oxide layer to form. I doubt an oil would work but if you search for how commercially made electrolytic capacitors are made then you might get some ideas.
RimstarOrg just an experiment. I was thinking..
If I had long sheets of aluminum foil with wax paper or something sandwiched between to seperate them
and then adding the distilled water and baking soda/something (all I have)
Could it possibly be sealed in a large tube or something solid to prevent escape of the fluid or evaporation and make a useable capacitor for low voltage but higher capacity?
Could I get tens of thousands of uF that way?
+realflow100 Sealing it should help with the evaporation problem. Theoretically you could get tens of thousands of uF, but practically, it would be an awful lot of effort.
RimstarOrg On a scale of meh to passing out.. how much effort? o.O
hey i have a really important question what is i did this method with multiple plates in a series of only positives and a series with only negative in between them like this positive=l negative=| |l|l|l
Great video, RimstarOrg, thanks for sharing.
Now I am looking forward for the advance way from you, may be "How to make UltraCaps".
If you did it, let me know. Thanks.
Can we use vinegar as electrolyte
Where did you used borax in this experiment?
I showed it as an alternative to the baking soda in case you didn't have baking soda but you had Borax instead.
@@RimstarOrg is it official electrolyte for aluminium cap " borax ?
Official? It's as official as the baking soda. On the other hand, I didn't try it with the Borax -- I only read that it should work (a source en.wikipedia.org/wiki/Electrolytic_capacitor#"Wet"_aluminum_capacitor)
You can. Aluminum foil works fine. I just wanted something stiffer in this video. I use aluminum foil instead in my "How to Make a High Capacitance Electrolytic Capacitor" video. There's a link to it in the description below this video.
The NACL has one problem, to increase the conductivity of wate,r you must add more NACl but unlike the baking soda when you add more slat , once you want to coat the electrode with AL2O3 the NACL will breakup and release CL gas that etch the electrode
that's why you cant add too much salt and should add just a little that doesn't have any effect on the capacity of capacitor but the internal resistance of your capacitor will be higher.
What voltage to be stored in your cap
I don't know the voltage rating. To measure it, I'd have to increase the voltage until it breaks down and I never did that.
It's probably in the normal range for electrolytic capacitors though, 1V to 50V, in case you''re hoping for really high voltages.
Example i want to make 1000uf 16v or 1000uf 25v,etc do you have diagram or design or measurement how can do that..thanks
Without testing the breakdown voltages, I don't have any design.
Hey, How could I make ceramic diodes?
Thanks in advance.
I like the video. Very good. Do you show how to make polarized caps somewhere? Is there some formula on the plate size and what you have here that we are to use once rolled up and we attempt to put into a real life circuit? I need some 20uF and some 30uF give or take. Given the plate sizes you have, what capacitance do you once rolled up? TY
I have a video where I show making a cylindrical polarized capacitor but I don't have any formulas for polarized capacitors. The best I can suggest is doing trial and error unless you can find another source online. Here's the video ua-cam.com/video/ml2TdQ2_2mk/v-deo.html
@@RimstarOrg TY
can you form the oxide layer more than once?
Yes, you can. It'll happen automatically when you go to use it.
I remember That baking soda and water mix Being called " saturated mix" when you mix the maximum amount of powder to a room temp fluid. A super saturated mix was when you heated it up to add more powder than room temp,would allow. That was grade 7 in 1980 lol!
Hi, I created a capacitor using the method shown in your video, I want to calculate capacitance of the capacitor. In your video you mention that the electrolytic capacitor minimizes the distance between the "plates" by using the electrolyte as a plate itself. What value can I use for distance in the formula to calculate capacitance?
Good question. Unfortunately, I don't know what the distance is.
@@RimstarOrg No worries! Thanks for the reply :)
good experiment :) , can i know what is the advantages for the experiment?
+zim smis Like you said, it's a good experiment. :) But that's about it.
Could you build high voltage caps with this method? And is it possible to produce bipolar, electrolytic capacitors, by applying AC? Thanks for any help :)
helut kuno I don't know what the breakdown voltage is of this capacitor but I imagine it's the same, or not as much as commercially made electrolytic capacitors. I don't know of any way to make it higher. And I've never tried making bipolar ones this way, so I don't know if it's possible.
Ok, thanks a lot for your comment.
When building up the dielectric layer did you electrolysis any water? Also, I have the same set up as you do, but for some reason when I try to measure the amount of amperage going through the capacitor it keeps fluctuating from 0.1 - 2.0 on the 200 mA scale. Any ideas as to why?
I don't know if I electrolysed any water. Maybe at the higher current. As to why yours isn't working... make sure you use distilled water. Also, did you use baking soda or borax? Salt won't do.
I used salt. Would that be the issue? Why won't salt be a suitable electrolyte?
I don't know why salt doesn't work. Something to do with the needed chemical reaction I guess but chemistry isn't my strong point. But when you think of it, if salt would work then every electrolyser for producing hydrogen and oxygen would work only for a short time until an oxidation layer formed, and that's not what happens.
That is true, but what's strange is that I built an electrolytic capacitor, let the water electrolyze over the course of about an hour, and I watched it and the electrolysis of the water slowed until it came to a stop. At that point I charged it and was able to produce a current of about 0.1 milliamps which slowly went down to zero over the course of about ten seconds. I guess I'll have to do a little research. But do you know why baking soda and borax are more suitable electrolytes?
What do you mean by you "charged it and was able to produce a current of about 0.1 milliamps which slowly went down to zero." Do you mean you charged it as an electrolytic capacitor and then discharged the capacitor over a period of ten seconds. That sounds like it worked.
does the water need to be distilled?
Yes, it has to be distilled water.
@@RimstarOrg Could you explain why it needs to be distilled and the role of the baking powder? Im curious about this
I don't know exactly why it needs to be distilled. Probably because tap water contains impurities which might interfere with either the creation of the layer or the working of the capacitor. I don't know the chemistry involved for the role of the baking powder.
you can also do litle mechanics and make plate with oxide pullable, and you would have an adjustable capacitor
A VERY high capacitance one
When the voltage is applied the oxide layer forms and then the capacitor should charge. I was under the impression electrolytic capacitors are the only capacitors that continue to hold charge when voltage is no longer applied. Is this true? And would this example hold charge or would it dissipate due to the nature of the dielectric?
Paul C Electrolytic capacitors aren't the only capacitors that continue to hold charge when voltage is no longer applied. That's normal for all capacitors I'm aware of. Though all capacitors have some leakage through the dielectric and elsewhere, so the charge slowly leaks away. Charge up any capacitor, wait a while, and then measure the voltage and you'll see it's there. Though if it's a low capacitance capacitor, just measuring the voltage will quickly short it out.
In this homemade electrolytic capacitor there's a problem with the reaction between any aluminum that doesn't have oxide on it and the water, that causes the oxide layer to slowly be removed. So it loses voltage that way. In commercially made electrolytic capacitors they put some other liquid in to prevent that. It's usually a trade secret though so I don't know what it is.
can we use aluminum foil
thank you for this very instructive video
Can we use aluminium foil
Yes, that's what I use in this video.
Amazing! loved the video! so will you feel a shock if you were to stick your hand in the electrolytic capacitor?
Also, was it the capacitor or the battery that gave power to your load that's blinking on/off?
Wondering if I can use it to charge my cell phone lol
Twelfthward Nolaswagyoungin I didn't check to see if the electrolytic capacitor would give me a shock, so I can't say. It was the battery that gave power for the load that's blinking. You'd still need a battery or some other power source to charge your cell phone. A capacitor isn't a power source by itself.
RimstarOrg Ha! Very Well Sir...Well I
wouldn't advise anyone to test that out haha...
wouldn't be very wise... Far as the power
source, thanks for clearing that up
so is this what happens with crystal cells.. Are they electrolytic capacitors?
I know there are videos about them but I've never looked into crystal cells so I don't know if they're like electrolytic capacitors. Maybe someone else here knows?
RimstarOrg erm.. I believe the crystals are dielectric/piezoelectric having p/n junction properties that separates charge and I noticed the anode and cathode seem to get coated with an oxidization between the metal & crystals. Their voltage seems to get set in the chemical reaction that occurs when they are made.. strangely enough 1.2 v with mine. They seem to pulse charge quite fast so I wonder if they are more capacitor than battery?
Thank you so much for your time - excellent video
Nice video!
If I have understood correctly you used the same chemical that was used for forming oxide layer (i.e., water + baking soda) as electrolyte (i.e., the interface between dielectric (oxide layer) and cathode) as well. Am I right?
Thanks! And yes, everything you said was right. And to add to it, the electrolyte is also one plate of the capacitor, with the aluminum foil being the other plate.
What's the difference between normal capacitor and electrolyte capacitor
The dielectric, the aluminum oxide which I talk about in this video, is much thinner in an electrolytic capacitor than it is in a normal capacitor. The thinner the dielectric, the higher the capacitance. So electrolytic capacitors have higher capacitances than normal capacitors. Often you want a high capacitance.
Remember, in this video, the electrolyte counts as one of the plates of the capacitor -- it's an electrically conductive liquid.
Tq sir...
What is the circuit at the end? :)
+Magyar András Tamás It's one I got from an old basic electronics book I bought a long time ago at Radio Shack. Sorry, I don't have an online copy.
you got a subscribe and a like, can you please explain what size of uF cap did you just made or how can i make one to suit my project? i see this one reads .61 uF tho im not sure if that supplies .61 uF or 61.uF sorry if i misunderstood something
i guess im not sure if a cap's job is to provide more power, save power, get rid of some power or simply multiply the power and in respect of power im not sure if electricity or current amps/mA / watts volts
i just took apart my first tv CRT big box one tho this one was a mid size but desolder alot of small and big Capacitors and i think ill reuse dem since they have a good body no belly on top or no acid leak tho im not sure if it says 200V means you can charge up to or under 200v or 220 uF im asking cuz i see the 220 and the 200 so im not sure if is the same thing just one reads volts and the other one reads uF/F so sorta saying mV or Voltage Ampere is the same as mA just on a smaller scale
Frank Lopez It's 61uF which is 61 microfarads.
There are many uses for capacitors in circuits. For example, some are used near the input to a circuit where the power is coming in, in case there's a large spike in power. The capacitor will absorb and store that spike of power instead of it going to the circuit and damaging it. Then it releases that stored power slowly so no harm is done. Another example is to put one just after a full wave bridge rectifier. The output voltage of the rectifier is very lumpy and the capacitor smooths it out before sending it on. And there are more examples.
There are usually two number written on a capacitor. One is the capacitance. The other is the breakdown voltage, which is the maximum voltage the capacitor can handle before the dielectric material inside breaks and the capacitor is no longer any good. Note that the capacitance is sometimes written in farads with an F (F, mF, uF, nF, pF, ...) but there are a whole bunch of other standards that also mean farads but other lettering is used (never V or A though since they mean Voltage and Amps.) Sometimes only the number is written and you're not even sure if it's the capacitance. Luckily my meter measures capacitance so I can always check it. Otherwise, I have to try searching online for what the letter means.
See here en.wikipedia.org/wiki/Metric_prefix for what the m in mF or mV or mA means along with the other possibilities.
thanks for the tip