Random Comments - 9 - 2020 - Capacitor Leakage & Electrolytic vs Film
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- Опубликовано: 15 дек 2024
- I started this out as a quick video, but due to the number of questions & comments, I decided to try to answer some of them. I shot this video in about an hour and edited it in about an hour - two hours total! Not very well edited, but hopefully it will be helpful to a few of you. Best wishes!
4:00 - Description of cap leakage
7:20 - Film vs Electrolytic capacitor description
12:45 - Demonstrating leakage in a capacitor with test jig
24:07 - Testing leakage with VTVM
29:53 - Checking leakage in electrolytics at working voltage with EICO 950 tester
34:40 - Testing leakage with Sencore LC53
38:30 - Closing remarks
The tester that I built is for electrolytics. Designed by M Caldeira, he has a good channel as well that I've managed to learn quite a bit from. I made some minor adjustments to the design (for my uses) but its a cool device. Adjustable voltage up to nearly 400v so you can test at voltage and you can view the leakage through the amp gauge. It's a pretty handy device. This also shows capacitors reforming when you watch the movement.
Tony, thanks for producing content like this. Electronics has been one of the hobbies that I've delving into over the past 5 years or so and channels like yours provide me with many snippets of information that I just don't have the time to learn in a "conventional" manner. I just wanted to express my appreciation for folks like you putting content like this out there in an easy to digest manner. My hats off to you.
Rule of thumb: I always use high quality film caps (Vishay/Kemet/Wima) to replace old electros if the cap value is 4.7uf or less. When the cap value gets above 4.7uf it gets a bit dicey. Panasonic makes a line "audio-grade" low-voltgae electros in the 4.7 - 47uf range. (available at Digikey) They are made of silk (instead of paper). I've used them in discrete audio pre-amp circuit. Do NOT use any "generic" caps (film or electro) for output coupling. Many of them are non-linear at sub-sonic frequencies. (30hz or less) I found that out the hard way. For many op-amp audio outputs (where the DC is less than 100mv) you can use non-polarized 50v electros if you need values above 4.7 (4.7-22uf). Great video-lecture.
That's one of the best explanations I've heard.
This is one of the best video's about capacitors ive seen by far !
"What do you expect? It's me!" - I expected exactly what you delivered. Learning AND beeing entertained for an amount of time, as always. So thanks one more time for a fantastic video, sharing your expertise and experience. BTW: Meters like the Sencore or the Eico are hard to get and very expensive. Leakage seems to be the measurement all the cheap testers can not do at all. Maybe a leakage tester would be a good project? Greetings from Germany!
Cool video! I'm a bit of a leakage snob lol. I have so many testers from all eras with either a CRT Eye-Tube, a Neon Bulb, and a new Mr. Carlson's Lab Ultra-Sensitive tester I've built. I have a running joke where when some people would confusingly call a Bumble Bee Capacitor a Resistor because it looks like one... but now I don't correct them. Bumble Bee Capacitors ARE Bumble Bee Resistors because they ALL leak! Yet people still spend tons of money on the for the "mojo" 😂.
Once again you knocked it out of the ball park. Awesome informative vidio on caps thanks Tony
Thank you Tony. Really enjoy your sharing these experiences and knowledge. Please be well family and friends.
Excellent job of explaining the different types and the most effective test to use for each capacitor.
ESR is not a physical series resistance. It is the quality of the capacitor to charge and discharge recovery time rapidly , aka ( power factor) without overheating. It was never a concern until the advent of switching power supplies in computer power supplies. ESR is the result of material used to make the part. Leakage is a real resistance. It can be measured with a Simpson 260 VOM. Simple leakage can be measured with an ammeter in series with the cap as it is connected to a voltage source.
Excellent explanations, thank you for the time and trouble you put in to this.
Everything you wanted to know about capacitors but were gun shy about asking . Don't be afraid of asking dumb questions in electronics because there is no such thing!
Great video Tony especially for the physics/ chemistry behind what these components do.
My Father was an ETN on an SSBN in the 60's. He used to tell me all the time ,there is no such thing as a dumb question. Good to here it again!
@@Curtislow2 A electronics teacher told us students that at IIT in Chicago years ago!
*** Long time fan of your personality and the way you make video's seem like a conversation among friends ***
Tony... (also sent an email for married couple conversation)
I would like to ask this question again as it fits solidly in the scope of your video.
Because of a surplus, I have been using and hearing a small voice in my head saying, "this might not be a good idea." I am using:
- Nichicon FG Electrolytic Audio Capacitors - "Fine Gold" (ideally suited for first-class audio equipment)
So I have four quick questions I trust you can answer... after all this time as one of your trusted viewer:
Question 1: What 'film capacitor' manufacturers would you recommend using?
Question 2: Your personal recommended Nichicon 'power supply' capacitors to use?
Question 3: Your personal recommended Nichicon 'general purpose, not within the signal path' capacitors to use?1
Question 4: When and where do you use 105 degree blue Nichicon capacitors?
--- Off Topic Conversation -----------
As a side conversation off topic... And would make another 'old married pair,' successful video.
I have a Sansui AU-9900 and TU-9900 stereo pair that will sometime in the future be restored. I trust my work with Pioneer amps... but that is all. Please let me know what the costs range for both of these would be approximately and your schedule. I realize shipping will be very expensive for me yet I really want to pass my system down to my daughter.
I appreciate your insight,
Excellent video Tony 👍
This is one difficult topic to cover because when it comes to capacitors, there seems no limit to how much you can talk about them!
For the begginer there really isn't a quick and simple solution to testing them! I myself have multiple ways of testing capacitors and yet it's never as simple as pulling out your favourite piece of test gear and getting the results fast! The capacitor is only one device but can be used for many different things so that automatically gives you many different tests that you have to remember to perform depending on the job it has to do!
I have found that you really need to spend a lot of time testing capacitors in order to learn how a particular capacitor behaves with what you are testing it with! As you have demonstrated in the video, waiting for a 470uf capacitor to deflect the needle, good luck! How many capacitors would you throw out before you realize that something isn't right with the test circuit lol.
The trouble that I have is testing capacitors 470uf all the way up to 10,000uf, most of the shelf testers can't measure them! Heathkit and EICO are unobtainium in Australia! Not sure about the Sencor's availability down under but it doesn't look like it would be cheap!
I have been thinking about making something simple that shows voltage and current with adjustable voltage and switchable preset current to test capacitors but I haven't thought of a way to make an adjustable 150V to 200V power supply! My lab power supply only goes up to 30V, there's a 60V version from memory but at that price range there's probably something else that I haven't thought of yet.. I just want to test them at their rated voltage but also to have the ability to see what they do as the voltage climb's up from nothing, sitting and waiting for something to happen is not my idea of fun. So until the perfect tester comes along, I will have to keep searching!
Thank you Tony for your dedication and teachings
thank you very nice explanation. I finally understand the difference between esr and leakage. thank you.
Quite informative, Tony. BTW Great Camera set-up at your newly designed bench set-up since relocating it.
Very vellum made video. Thank you for this information. Your explanation was the best I have seen by far.
Thanks for saying. Not that type of acid. Was gonna eat one
Thank you for clearing up this subject, helps a great deal.
That was a great understanding electronics video. Thank you Tony.
The resister, said a different way, is a buffer that limits the action of discharge from a capacitor.
Excellent video! Thanks Tony.
Learned something really useful. Thanks for sharing your knowledge.
I learned something today: An electrolytic cap in a high-impedance circuit is as useless as teats on a bull! 😁
I have an electronic flash that has 2000mfd @ 450 VDC Capacitors. I bought a tester that does ESR, Capacitande and Vloss. Is that enough to test these electrolytics?
No. In my experience I have seen many capacitors leaking but showing acceptable ESR reading. Look for a video that says cheapest capacitor tester witch shows how to test with a multimeter in Micro Amps funtion.
Not to mention film sound so much better
Tony, hi! You mentioned that electrolytic capacitors are no good for AC and I understand since it's polarized. But what about those cases when a coupling electrolytic capacitor is used between two amp stages for coupling audio signal? This is the question I always had why those caps don't go bad and I still don't fully understand.... may it be because of the DC offset from the tube/transistor polarization to actual audio signal that makes the signal actually DC variant instead of AC?
I actually answered this question in the video about class A amplifiers. It's a bit much to type into a comment, but I may cover it again in a Random comments video. In short, the coupling capacitor never changes polarity. One side is always more positive than the other. The speaker "sees" the more positive and less positive signal as AC, because the capacitor is either charging up from the bias voltage or discharging down from the bias voltage through the speaker. The concept of offset can be a bit confusing sometimes. More about that in a later video. Thanks for the comment!
xraytonyb Thank you!
You can indeed buy non-polar (or bipolar, whichever term you prefer) *electrolytic* capacitors, or you can make them yourself, by putting two identical-value polarized electrolytic caps in series with the two + terminals (OR the two - terminals) tied together. If you do so, note that total capacitance is halved (and the voltage rating is doubled). Aside from speaker crossovers, the other place where it is particularly important to use a non-polar capacitor is in the feedback circuit of the differential amplifier in a hifi amp. Cheapskate amplifier manufacturers often use a polarized electrolytic for the feedback circuit, and they will often leak DC (possibly causing sufficient DC offset to damage a speaker or hopefully activate the amplifiers' protection circuitry first), or overheat and bulge and eventually fail, sometimes short-circuiting and causing other damage.
We need a new video update. What about those green ones I find all over the preamps of Reel to Reel tape players and some tests gear. Can they be replaced with those WIMA?
thank you for sharing your knowledge...
Great Video, Great Content as usual, Thanks Tony!!!
I see a lot of questions on reforming, I usually bring recapped equipment up to operating voltage slowly using a Vari-AC...depends on what the unit is as to the time. Ex: a recording console may take several hours, where a transistor radio my be reformed in minutes.
there are also polystyrene ans polypropylene
Excellent video, question, so the high value electrolytics say 47mf at 600v should be tested by the actual voltage. However, Mr Carlson recommends his low voltage tester for big value electrolytics. Is Mr Carlson wrong ?
I'm not familiar with his device, but low-voltage high-sensitivity testers have been around for a long time. They work very well in some cases, and not so well in others. Like any other piece of test equipment, it will have its useful purpose, but will also have its limitations.
@@xraytonyb it seems reasonable that the capacitor should be tested at least at it's working voltage. Problems with leakage my not become manifested until the cap is stressed.
Dear Tony, thank you so much for a great video, very educational! My question: what would be a good way to check the high capacity electrolytics, let's say over 10.000uF (as in PS filters) without breaking the bank? They cost quite a lot and replacing them blindly is not an economical option. Thanks so much beforehand!
Check out Paul Carlson's videos. He has produced many DIY kits that you can use to test caps of various kinds.
Excellent video.
@ 6:45 "... as this is limiting the current..."
A common mistake, resistors in series do not limit the current, they create a voltage drop...
And if you measure that voltage, use Ohm's law (V=IR) and divide by the R you already know, you get the current going thru the resistor and hence the whole circuit. Same difference, no?
Lysergic capacitors! Cooooolll!
I have one of those all in one testers that applies a high frequency square wave. Can you explain exactly what Vloss is mathematically on those units. I feel like when I don’t think about it too much that it’s obvious, but when I dig deeper it’s hard to get an official explanation of what it exactly is? And for low frequency power supplies like you see in stereos. What’s more important for filter capacitors? Vloss or ESR?
is foil the other word you were trying to think of?
Hmmm. I don't remember you replacing polarized electrolytics with film caps. I must have missed that.
I did as recent as the last video (SAE Mark 9 preamp). I replaced the 4.7 uF electrolytics with film.
Great video Tony!
Tony,, or anyone on here ever try leakage testing capacitors with one of those "Withstand Voltage Testers" used for IGBTs & .. ??
They're capable of high voltage (50~500V+ +) with up to 5mA output.
glad you did not turn that into a big huge segment,like you said;
(how long would that take you if you did?)
Hi Tony,
What do you think of the XJ01 meters that are advertised on Ebay for $50-$70 ?
Or would you have any recommendation for someone who cannot afford the going rate of the Sencore but wants to experiment on the subject?
Thank you
Cheers
Mark
I looked at it online and it looks very interesting. I may order one to try out in the future. Thanks for sharing!
Hello Tony I love your show learned a lot, I have a question I have an Onkyo Grand Integra m-510 power amplifier there is a call for a thyristor at location D037 witch is a TT202-50 there is no information anywhere on the part it looks like many have tried to find a replacement but with no luck. the schematic service manual is on hifiengine you are so great at figuring these things out hope you can help thanks
21:00 I believe I learned something today... An electrolytic capacitor in a high-impedance circuit is as useless as teats on a boar 😁
The difference between a capacitor and a battery is that there is no chemical process going on in a cap during charge/discharge, it is purely physics. In a battery charge/discharge is a chemical process (which takes a long time, whereas in a cap charge/discharge happens very fast)
Well sure, I guess you could say that is true for just about anything; it's not [insert real-world effect here] "but really it's just physics". I think both of you are sort of saying the same thing (as far as I can tell).
I do see where someone could get confused after hearing "electrolytic capacitors work on a chemical process". However what I think our boi Tony is trying to stay here is that electrolytic capacitors use a wet type of dielectric. This allows for more intimate contact with the capacitor's plates and more desirable characteristics that are very difficult or costly to achieve with solid composites.
I think I remember hearing something about how early electrolytic capacitors had some kind of borax solution or an alcohol-based electrolyte but I could be wrong.
So in short, electrolytic capacitors work just like any other capacitor in that they don't ever convert their energy to chemical energy (like a battery) but they are able to take advantage of some property of the electrolyte that I'm not completely confident in my understanding of yet.
@@finnsuchara1992 A strip of paper soaked in electrolyte makes the cathode of the cap. The electrolyte chemically creates an extremely thin non-conductive layer of oxide on the surface of the aluminium anode, which has been made "rough" to increase it's actual surface (up to 100 times). The initial "forming" of the capacitor is done by putting a voltage on it, so the oxide layer is created. Once this forming is done, the paper/electrolyte acts as a conductor (cathode) . As you know, capacitance is inversely proportional to the distance of the plates. The thinnest dialectricum can be achieved by an non-conductive oxidation layer. The electrolyte also is capable of "repairing" leaky spots when that layer is damaged, for instance because of long shelf life or a short excessive current burst. This process is called "reforming". Obviously, this will not work when the liquid in an old cap has dried out.
@@1959BerreVery cool, the more ya know.
can programmable hipot ac/dc/ir tester. be used to test capacitors?
Oh, This Old Tony, it was you all along. Never knew ur name was Tony. congratulations!
In all seriousness I do have an actual question and that is: is it appropriate to replace electrolytics with film (non-polarized caps) in most all circuits even outside of the audio world. As they're most likely used in a power supply if they're made within the last ~50 years? Furthermore, are there any specific circuits in which film replacements will not work (Ignoring size requirements)?
And what about tantalums, or silver mica, when in your opinion, (Tony) is it appropriate to use those.
I was sort of hoping for a little bit more detailed explanation about polarization and can't seem to find a whole lot of information elsewhere.
-If you made it this far through this book of a comment you should probably Subscribe to This Old Tony and Physics Anonymous if you haven't already.
And there are old tantalum bead capacitors, the devils creation :-D
13:05 Mouser... thought that packaging looked familiar... :-)
So Tony, does the lifetime of electrolytics have any real effect on your stock of replacements? You are recapping electronics that are at least 20 years old. Should I replace my unused store of electrolytics after 10-15 years, or what?
My answer would be maybe. Most of the new stock caps I have are less than 5 years old and they are just fine. Sometimes when you apply power to them for the first time, they will have some leakage until they re-form, then they are fine. I also have purchased bulk NOS capacitors and had problems. I purchased lot of about 100 capacitors (all 4.7 uF) from Olson's electronics when they went out of business. Almost all of them were leaky and would not re-form. They were brand new, but old stock. I ended up throwing them all away. I also had some high voltage sprague capacitors from work that were NOS. They are also leaky and out of tolerance. You really have to be careful buying NOS caps that are more than 10 years old!
I read Tony's reply to your question. As he says, older electrolytic capacitors need "reforming", and this is done by charging them, the right way round, + to +, THROUGH A RESISTOR. The value of resistor varies with capacitance, ie use lower resistance on larger capacitors. It's best to monitor the resulting charging process, usually right up to the cap's rated voltage. If it reforms OK it should be useable.
More info on reforming at: ruclips.net/video/IMWVNcgOKA4/видео.html
DONT try and blast them up without a limiting resistor or they can explode.
What would be the effect on the sound of an amp, when you replace an electrolytic cap with a film cap? Must have some effect.
Had a bunch of old Siemens electros, 1984 made, in my old stereo, was going to replace then, after slow changing and let then alone for 1 month they yet kept the charge, and specs better than new ones, the problem: the size, almost 6 times the volume of a new one, not a problem for my stereo, put then back :-)
Great video!
AAAAAwesome video!!! Can i request another video about caps but this time with sound tests? Like how poly caps compare to electrolytic when used as cathod bypass caps, coupling caps, etc? I cant find a video like that on youtube :/ Thanks!
Seen your work on the Pioneer Tuner and was wondering, what is your address and what do you charge to work on an old Pioneer stereo / receiver SX-780 with a bad AM tuner. Also, a checkup to make sure all is good.
(@9:48) - You little rascal! Polarized capacitors can most certainly pass an AC current; they’re often found as DC blocking capacitors at the output of cheap, audio amplifiers (such as inside powered computer speakers) and a speaker. The trick is to make sure the AC waveform is riding on a DC offset so that the signal excursion never reverse-biases the electrolytic cap! They’re also found as cathode (resistor) bypass caps in old tube equipment to shunt off unwanted AC from the tube cathode. It’ll be a cold day in hell when capacitors don’t pass AC (or the cap goes open-circuit)! 🤓
When I refer to alternating current, I am talking about when the signal crosses through zero volts and alternates polarity. In an amplifier, the voltage at the blocking cap is offset above zero. It never crosses the zero volt line and never changes polarity. Try connecting an electrolytic capacitor to the AC mains or to unrectified AC and see what happens. If the voltage varies, but doesn't change polarity, then the one terminal is still more positive than the other. This is what I am talking about. I understand about the concept of offset waveforms, but this can confuse those who do not understand the difference. If the negative side of an electrolytic capacitor becomes more positive than the positive terminal, it will be a very unhappy capacitor! Thanks for the comment!
@@xraytonyb I got a charge out this exchange.
I hope it was non-polarizing ;)
Sorry, I should have been more specific: It should probably state that “a polarized capacitor will pass a voltage waveform that varies w/respect to time. i.e. V(t) is not constant.” As long as V(t) on the (+) lead is > V(t) on the (-) lead for all ‘t’, and Vc (voltage across the cap) < Vmax, you’re in good shape. 😜
@@xraytonyb That's actually really helpful, if I was told that with a quick oscilloscope drawing when I started repairing test equipment I feel like that would have helped a lot. I do appreciate the effort put into trying to simplify concepts as much as possible, there's a lot of unnecessary* concepts (mostly unnecessary acronyms) In many of the videos I've watched. So thank-ya Tony.
*(No concept shaming)
Like the video
I'd like to know why guitarists pay so much for leaky black beauties and bumble bee's? I never tested one of these that didn't leak at some small fraction of their rated voltage. Did they leak that bad when they were new? Are they looking for a cap that charges slowly?
What is the best way to reform multi-section caps (new) that I could not use at the time of purchase but would like to install in a couple Ampeg restorations that I am now able to complete, they are a couple of years old.
I can share the two ways I do it, but there are other methods as well.
1) If you have one of those vintage capacitor checkers with leakage test, you can place the tester in leakage test mode and connect the capacitor. Dial up the voltage until the tester shows leakage (be sure to stay below the maximum rated voltage of the capacitor). As the capacitor "forms", the leakage will drop to minimum. At that point, increase the voltage until it shows leakage. Continue this process until you reach the rated voltage of the capacitor. If it shows minimum/no leakage at maximum rated voltage, it is properly formed. This process can take a while, if the cap is really old and some of them won't fully form or may even get worse. In those cases, you will need to replace the capacitor.
2) If you have a variac and one of those kill-a-watt line voltage monitors, you can try to form the capacitor in the circuit itself. Start by removing all except the rectifier tubes. Plug the Kill-a-watt into the mains, plug the variac into the kill-a-watt and plug the amplifier into the variac. begin by bringing up the voltage slowly. Watch the current on the kill-a-watt. When the rectifier tube starts conducting, you will see the current begin to go up. Raise the voltage until the current goes up to 20-50 milliamps or so (maybe a bit higher, because of the filament of the rectifier tube). If it goes up rapidly, lower the voltage until the current drops to that level. After a while, the current should drop. When it drops, increase the voltage until the current goes back up to 20-50 MA or so. Check the cap periodically to make sure it isn't getting hot. It may get a little bit warm, but shouldn't get hot. Continue this process until you have full line voltage at the amplifier. If the current drops to minimum, the cap is formed. At this point, it should no longer be getting warm. If the current won't settle down at full line voltage, the cap is bad.
You can also use a current limited variable voltage power supply to do the same process as above.
Hope that helps.
Thank you Tony for this excellent explanation. Why didn't I have that in school?
Which brands of capacitors do you prefer? Everyone has their favorites (Rubycon, Nichicon, Panasonic, United Chemicon, Sprague, Cornell Dublier, Elna, Jamicon, Samwha, Wincap, etc)? I am curious which brand(s) are good in your opinion.
Most of the above brands are generally good (at the audio repair shop we mostly use Panasonic) except that Elna are junk, garbage, failure-prone caps. Another brand that commonly fail are Shoei. I probably wouldn't trust Samwha either. I've never encountered Wincap capacitors. And one last comment, Tony mentions here that you can get miniature electrolytics that are even smaller than the ones he is holding in his hand, but I do not recommend them unless you absolutely have to have a capacitor that's small in order to fit it into the circuit when you are doing repairs and upgrades. Miniature electrolytic capacitors are far more likely to leak and corrode everything around them, or soak the board with conductive electrolyte (very very bad!), and far more likely to develop high ESR. Avoid them! Another warning sign of corrosive, conductive capacitor electrolyte having leaked out is when soldering and desoldering gives off a fishy smell. Scrub the board with alcohol and change those caps!
What I would like know is can you replace the electrolytic capacitors with film capacitors bridged together in parallel to make up the capacitance ?
Yes, you can. Usually, you will see a smaller value film capacitor connected as a bypass cap across the large electrolytic filter cap. This gives the benefit of better response when the amplifier is reproducing higher frequencies. I've also read that film caps, when used exclusively, don't have as good of performance with lower frequencies, but I never tested this for myself. In addition, it would take a lot of film caps to equal the tens of thousands of microfarads typical of the large electrolytics. This would be very large in size, and I imagine (not sure) it could add an inductive reactance component to the power supply as well. Thanks for the comment!
Can any film capacitor substitute for any electrolytic? Why is it primarily low value caps?
Thank you for the comment! The short answer to your first question would be yes. To answer your second question, I suggest using film caps in place of low value electrolytics (4.7uF and below) because film capacitors get physically large as capacitance value increases. Film caps above 4.7uF are fairly large, when compared to an electrolytic cap of equal value and they won't fit in the same physical space. There are other differences between film and electrolytic, including dissipation factor, ESR, and dielectric absorption, just to name a few. Film caps outperform electrolytic caps in all of those categories and some say that it affects the the sound characteristics in audio gear. That's a big subject that would take too long to discuss in a comment. Hope that helps.
About the time your face clears up, your mind goes fuzzy.
No, I had to grow a beard and have it start to grow gray first!
You don't need a special box... Now, go get a special box to test electrolytic caps.. hehe
Ya, I'll keep my box =P
Sorry Tony had to rib you a bit, even if I am only amusing myself. Real question though, what do you have to say about stability for oscillator circuits? Can't recall if you have mentioned this before, if you have, feel free to just post a link.
Cheers.
Great video. I kept waiting on you to grab a roll of toilet paper and some cut down aluminum foil and roll one up to test.
Thanks even a dummy like me can understand some of this I am just a guitar player who wants to do some easy fix on vintage amps
That circuit is a lot like Mr Carlson’s leakage tester
This one is better.
A perfect vacuum has the highest dielectric constant, rated at 1×1012 MV/m, higher than any known material. A perfect vacuum contains no material to breakdown and is, therefore, the perfect electrical insulator for a capacitor. I am surprised they haven't made a capacitor with no dielectric material and just put it into a small vacuum tube. Theoretically that would be the best replacement for troublesome Electrolytic capacitors with very extremely high capacitance and unlimited life.
A perfect vacuum has the LOWEST dielectric constant of any insulator, with a dielectric constant of 1.0. All insulating materials have a higher dielectric constant. Vacuum insulation strength is also poor if you consider narrow widths rather than a metre, without discussing how to incorporate a vacuum into a reasonably small capacitor..
Note that you have quoted insulation strength, not dielectric constant. And yes, they are entirely different.
Have fun and keep learning.
Hey 'genius', they make SMALL incandescent bulbs with all air removed, that's vacuum FYI. Take a film capacitor, ex. Mylar, and place it into a sealed vacuum tube. It is very PRACTICAL and economical, millions of vacuum bulbs of all sizes are made every year. Pull your head out of your backside and think before responding mindlessly.
Great session!
Thanks for sharing your knowledge