Hello.
I would like to have some help with those capacitor in the pictures (negative side on the right).
Anybody knows what if the third pin is just for stability or is this a shield?
Also how can I test them. They are probably 20 years old and I would like to be certain I will not blow anything if I use them.
Thank you very much.
I would like to have some help with those capacitor in the pictures (negative side on the right).
Anybody knows what if the third pin is just for stability or is this a shield?
Also how can I test them. They are probably 20 years old and I would like to be certain I will not blow anything if I use them.
Thank you very much.
Attachments
Out of experience (having butchered many TV sets and radios in my youth…) I think they're much older, maybe 40 or even 50 years. And they're missing the pins' identifier marks. I'd rather not use them anymore.
Best regards!
Best regards!
I got about 50 of those caps. I would like to use at least some of them.
I found some methods of checking and reforming capacitors on google.
Not all of them seems to be good (put a screwdriver across the pins to discharge it ??).
I guess I should check them first and if only some of them check bad I will let them go and use the rest.
Thank you kindly for your answers.
Have a wonderfull day.
I found some methods of checking and reforming capacitors on google.
Not all of them seems to be good (put a screwdriver across the pins to discharge it ??).
I guess I should check them first and if only some of them check bad I will let them go and use the rest.
Thank you kindly for your answers.
Have a wonderfull day.
Forget them.
"Reforming" is unreliable at best, not worth risking the equipment using them.
Suppose they can be "reformed" , sort of.
A fresh capacitor may have between 2000 and 10000 hours left.
What if these "work" but only have 100 hours?
EDIT:
I´m feeling some chest pain, I will watch some videos on DIY heart surgery, might save a few bucks 🙄
"Reforming" is unreliable at best, not worth risking the equipment using them.
Suppose they can be "reformed" , sort of.
A fresh capacitor may have between 2000 and 10000 hours left.
What if these "work" but only have 100 hours?
EDIT:
Oh, the famous "You Tube University" 🙄
I´m feeling some chest pain, I will watch some videos on DIY heart surgery, might save a few bucks 🙄
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its more likely stability as only one capacitance value on top.
dual capacitors had two capacitances values on top.
dual capacitors had two capacitances values on top.
Probably.
Basic measurements would be continuity between pins, continuity to case, confirm that capacitance exists and to confirm +/- polarity, charging it both ways from a higher voltage supply, say 50/60V through, say, a 4k7 or 10k resistor.
proper polarity will charge to near 35 V; reverse will stop at a low value,say 3 to 5 V or so.
I bet ESR will be very poor.
Capacitance measured can not be trusted, leaks often count as *added* capacitance to meter. 😱
Use them if you wish, but on "stay at home" equipment, say an amp or spare power supply, in good conscience I would not use them in any *sold* equipment.
Basic measurements would be continuity between pins, continuity to case, confirm that capacitance exists and to confirm +/- polarity, charging it both ways from a higher voltage supply, say 50/60V through, say, a 4k7 or 10k resistor.
proper polarity will charge to near 35 V; reverse will stop at a low value,say 3 to 5 V or so.
I bet ESR will be very poor.
Capacitance measured can not be trusted, leaks often count as *added* capacitance to meter. 😱
Use them if you wish, but on "stay at home" equipment, say an amp or spare power supply, in good conscience I would not use them in any *sold* equipment.
I would like to tell you my reasoning here.
I am here to learn.
If I throw everything in the recycling bin I learn nothing.
If I learn to test capacitor and none of them are good I throw them in the recycle bin,
but I have learn something. It's not a waste of time (I got a lot of time).
If some of them are good (after all they are new) I could use them in my diy projects I didn't win the lottery yet.
1- I had to lookup for ''ESR''. It's a type of blood test. 🙂 It also mean Equivalent Serie Resistance.
If I understand this paper correctly:
http://www.ieca-inc.com/images/Equivalent_Series_Resistnace_ESR.pdf
it is important in a PSU for the capacitor to deliver the energy as fast as possible but I don't have the tools to test ESR (got only a digital and analog multimeter).
2- Leakage: If I discharge them first and charge them with a 9 volt batterie (9.36v.) and come back say an half an hour later and check the voltage. If they have lost the voltage they have leakage right? Not good but if they are suppose to give that voltage as fast as possible why it's not good? I need an explanation please.
I did this test on 20 of them and about half end up to 2 to 4 volts the other half was between 7.80 and 9.20 volts. Is it a good test to know if I can use them?
3- If they got leakage and I reforme them, are they good now? From what I saw on the web they would last as long as new if they have never been used before. I got doubts.
4- If the pin 3 is a shield it would have no resistance between that pin and the case. It got plenty of resistance on the meter so it must be for stability. If the pin + or - have no resistance with the case the cap is short and not good. Right? It should be the first test to perform. Basic like said JMFahey. But to charge them with 60 volts, isn't it dangerous (35v. rating)? I don't have a 60 v. psu. , only a 30v. Can I do the same test with 30 volts?
Thank you for your comments, it is really helpful.
I am here to learn.
If I throw everything in the recycling bin I learn nothing.
If I learn to test capacitor and none of them are good I throw them in the recycle bin,
but I have learn something. It's not a waste of time (I got a lot of time).
If some of them are good (after all they are new) I could use them in my diy projects I didn't win the lottery yet.
1- I had to lookup for ''ESR''. It's a type of blood test. 🙂 It also mean Equivalent Serie Resistance.
If I understand this paper correctly:
http://www.ieca-inc.com/images/Equivalent_Series_Resistnace_ESR.pdf
it is important in a PSU for the capacitor to deliver the energy as fast as possible but I don't have the tools to test ESR (got only a digital and analog multimeter).
2- Leakage: If I discharge them first and charge them with a 9 volt batterie (9.36v.) and come back say an half an hour later and check the voltage. If they have lost the voltage they have leakage right? Not good but if they are suppose to give that voltage as fast as possible why it's not good? I need an explanation please.
I did this test on 20 of them and about half end up to 2 to 4 volts the other half was between 7.80 and 9.20 volts. Is it a good test to know if I can use them?
3- If they got leakage and I reforme them, are they good now? From what I saw on the web they would last as long as new if they have never been used before. I got doubts.
4- If the pin 3 is a shield it would have no resistance between that pin and the case. It got plenty of resistance on the meter so it must be for stability. If the pin + or - have no resistance with the case the cap is short and not good. Right? It should be the first test to perform. Basic like said JMFahey. But to charge them with 60 volts, isn't it dangerous (35v. rating)? I don't have a 60 v. psu. , only a 30v. Can I do the same test with 30 volts?
Thank you for your comments, it is really helpful.
2- A capacitor should ideally only discharge when there is some external circuit drawing current from it. In reality they also discharge themselves (leakage), but the slower that happens, the closer they are to the ideal behaviour. Electrolytic capacitors are not very good in this sense, especially not when they haven't been used for many years, so I don't think it is necessarily a problem if they lose most of their charge in half an hour. If they do in two minutes, they need to be reformed.
3- Reforming only helps against excessive leakage after long storage. If there is something else wrong, for example capacitance loss due to a dried-up electrolytic, it won't help.
4- I wouldn't dare to go any higher than 35 V or to deliberately apply voltage in the wrong direction, even if it is via a resistor, but JMFahey usually knows what he writes about. Charging to nominal voltage via a large resistor is also a good way to reform the capacitors.
3- Reforming only helps against excessive leakage after long storage. If there is something else wrong, for example capacitance loss due to a dried-up electrolytic, it won't help.
4- I wouldn't dare to go any higher than 35 V or to deliberately apply voltage in the wrong direction, even if it is via a resistor, but JMFahey usually knows what he writes about. Charging to nominal voltage via a large resistor is also a good way to reform the capacitors.
Thank you very much Marcel.
So first I should check if they are short with the case.
Then test if they leak. If so (like the half of the bunch at 2 to 4v. I've tested) I could reforme them and test again if the electrolytic is still good they will test good.
What about ESR? If they got bad ESR is it dangerous if I use them.
And about the test of charging them at reverse, this is to know if they still block DC like when we use them in the output of an amplifier?
So first I should check if they are short with the case.
Then test if they leak. If so (like the half of the bunch at 2 to 4v. I've tested) I could reforme them and test again if the electrolytic is still good they will test good.
What about ESR? If they got bad ESR is it dangerous if I use them.
And about the test of charging them at reverse, this is to know if they still block DC like when we use them in the output of an amplifier?
1) after earlier safety/usability comments,post #8 was all about learning. 🙂
If you have an unused 1930 made Ford T roller bearing, covered in grease, wrapped in paraffin paper and inside an old, dusty cardboard box, it IS new, wear comes for rolling and metal surfaces wearing, for lack of a better term.
Never rolled, as good as new, 90 years later.
But Electrolytics *actual* dielectric/"barrier" creating capacitance is a chemical product, created and maintained by a strong nasty salt dissolved in water plus some additives.
And to cause that chemical reaction, that liquid, the elctrolyte, must attack, etch the Aluminum surface.
Everyday that liquid keeps attacking the metal *even if unused*, dries up a bit, etc. and loses quality, that´s why electrolytic capacitors self damage along time, even unused.
In fact, often "unused at all" is worse than being inside a circuit and receiving expected voltage now and then.
"Reforming" applies voltage gradually and *tries* to send that nasty process backwards.
In any case they will charge up to the voltage they can stand, whatever it is,
usually it should be 10% or more above printed rating.
30 volts or less does not really test them, although it´s a hint.
Since they are a large sample of a batch, I distrust the WHOLE batch.
And we didn´t test them with realistic voltages yet 😱
Theyv are worse than I expected , and I didn´t expect much anyway.
Is it a good test to know if I can use them?
Please say "zero/short" or "open"
Test them from the 30V supply, through 10k, disconnect them afterv5 minutes, wait extra 5 minutes and read stored voltage.
Since you have not subjected them even to rated voltage, they should hold at leastb20/25V
If not, only use I imagine is
At least they are already orange, like any good clay pigeon.
Not NEW but unused, not the same by far.
If you have an unused 1930 made Ford T roller bearing, covered in grease, wrapped in paraffin paper and inside an old, dusty cardboard box, it IS new, wear comes for rolling and metal surfaces wearing, for lack of a better term.
Never rolled, as good as new, 90 years later.
But Electrolytics *actual* dielectric/"barrier" creating capacitance is a chemical product, created and maintained by a strong nasty salt dissolved in water plus some additives.
And to cause that chemical reaction, that liquid, the elctrolyte, must attack, etch the Aluminum surface.
Everyday that liquid keeps attacking the metal *even if unused*, dries up a bit, etc. and loses quality, that´s why electrolytic capacitors self damage along time, even unused.
In fact, often "unused at all" is worse than being inside a circuit and receiving expected voltage now and then.
"Reforming" applies voltage gradually and *tries* to send that nasty process backwards.
All caps have *some* ESR but too much degrades capacitor filtering capacity.
You are charging them through a current limiting resistor so you´ll never damage them.
In any case they will charge up to the voltage they can stand, whatever it is,
usually it should be 10% or more above printed rating.
30 volts or less does not really test them, although it´s a hint.
The faster they discharge the leakier they are.
Those who can NOT hold even 9V (which might self discharge to, say, 8 or 8.5V but not lower in such a short time) arev in TERRIBLE condition.
Since they are a large sample of a batch, I distrust the WHOLE batch.
And we didn´t test them with realistic voltages yet 😱
Theyv are worse than I expected , and I didn´t expect much anyway.
Is it a good test to know if I can use them?
In my book, they are in bad condition, specially seeing they can barely hold 2 or 3 V.
Again, "not use" means nothing here.
Please, "no resistance" means nothing, since it may mean zero resistance (short) or infinite resistance (open) at the same time.
Please say "zero/short" or "open"
Test them from the 30V supply, through 10k, disconnect them afterv5 minutes, wait extra 5 minutes and read stored voltage.
Since you have not subjected them even to rated voltage, they should hold at leastb20/25V
If not, only use I imagine is
At least they are already orange, like any good clay pigeon.
I've got a couple of 15,000 uF 63V caps laying around.
Date code 1991 I think.
In February, I charged them to 50V DC, then set them aside on a shelf.
Today, they still show 30+ volts across them.
Date code 1991 I think.
In February, I charged them to 50V DC, then set them aside on a shelf.
Today, they still show 30+ volts across them.
I guess what I write have to be revise by a moderator, it's delay a bit.
Thanks a lot JMFahey. Useful informations. Now I can get to work.
When I wrote ''no resistance'' it was 0 ohm on the meter and ''plenty of resistance'' when the meter is blinking. I should use the good terms. You are right, it's a good color on a cloudy sky background.
Thanks a lot JMFahey. Useful informations. Now I can get to work.
When I wrote ''no resistance'' it was 0 ohm on the meter and ''plenty of resistance'' when the meter is blinking. I should use the good terms. You are right, it's a good color on a cloudy sky background.
I still think you have a fair chance they will work fine after reforming. People who restore historic equipment often try to use the original power supply electrolytic capacitors; they always reform them, and then there is about a 50-50 chance that they will work acceptably and about a 50-50 chance that they dried up and need to be replaced anyway. I'm talking about 70-year-old electrolytics, yours look much newer to me (1980's or even newer). I do agree with JMFahey that you shouldn't use them in new equipment that you want to sell, though.
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The two pins that are diametrically aligned are the active ones; they should be reflected on the marking on top.
The third pin will have a small capacitance wrt the other ones (a few nF), the same for the can, but larger (they are in contact with the electrolyte).
Since the seal looks in good condition, they have probably not dried out.
Other, invisible problems can also appear, but with post-1980 technology, they are exceptional.
You can reform them with a 2K2 resistor in series with a source of 35V, or slightly higher.
After a few hours, the voltage should reach 35V or more.
If after 24 hours the voltage remains stuck at a low value, discard it.
The esr is an indicator of the internal condition and quality of the cap.
You need a specific tester for that (not very expensive, and useful anyway).
Be sure to gently discharge the cap before you connect it to the esr-meter!.
In general, good quality vintage NOS caps are perfectly OK: I have posted a number of examples on the forum
Thank you Elvee for your informations. I'm in the process of testing them.
I discover more of them. 129 in total. I don't even remember how I got so many.
I will give an update later just to let you know how many I could save. Just for fun. 🙂
I discover more of them. 129 in total. I don't even remember how I got so many.
I will give an update later just to let you know how many I could save. Just for fun. 🙂
I often get old stuff, buying dead/failing companies old stock, even estate sales.
Usually after, say, tubes or sockets from an old TV repairman, or perfectly good "stable" stuff such as most components are, buy buying by whole lots means invariably electrolytics come in the mix.
Since price is "per lot" , not part by part, I bring them home.
But then they get tested, period, not ifs or buts.
As a side note, notice my "testing" and Elvee´s "reforming" are quite similar 😛
And in both cases, actual *measurement* rules 😎
Usually after, say, tubes or sockets from an old TV repairman, or perfectly good "stable" stuff such as most components are, buy buying by whole lots means invariably electrolytics come in the mix.
Since price is "per lot" , not part by part, I bring them home.
But then they get tested, period, not ifs or buts.
As a side note, notice my "testing" and Elvee´s "reforming" are quite similar 😛
And in both cases, actual *measurement* rules 😎
Update:
Looking if I had more capacitor to test, I found a transfo so I could do a power supply giving 46 volts DC with 2 resistors of 1K82 in series to check them the right way.
I had 135 capacitors all together but some are used and I want to check them later, I start with 115.
One had a leak of electrolyte and 3 had a bump on the case so I've discard those 4.
I have enough jumper wire to charge the rest by group of 8.
They went up to 35v. in about 15 min. and to 40v. in 30 to 45 more minutes.
Since it took an hour to charge a batch it gave me a kind of schedule to mesure them the next day.
I check them individually at one hour interval between each batch so each capacitor had 16 hours to loose some voltage.
Just out of curiosity I charge a batch on the opposite way like suggested. They stop at minus 5.58v. I don't know if this is useful, what does it tell us?
I made groups and the result is I got 3 under 26 volts, one just over 30v. and the majority between 26 and 30 volts.
So if I discard the 3 under 26v. it means 7 bad on 116.
94% good Ha! Elvee was right! Almost.
Now I got more questions for you guy... if you don't mind.
1- Do I need to perform other tests before I label them ''good for my numerous projects''?
2- I know we have to put a capacitor (electrolytic most of the time) at the output of a SE amplifier but are there some kind of capacitor better than others to do that job?
Be back after walking the dogs 🙂
Looking if I had more capacitor to test, I found a transfo so I could do a power supply giving 46 volts DC with 2 resistors of 1K82 in series to check them the right way.
I had 135 capacitors all together but some are used and I want to check them later, I start with 115.
One had a leak of electrolyte and 3 had a bump on the case so I've discard those 4.
I have enough jumper wire to charge the rest by group of 8.
They went up to 35v. in about 15 min. and to 40v. in 30 to 45 more minutes.
Since it took an hour to charge a batch it gave me a kind of schedule to mesure them the next day.
I check them individually at one hour interval between each batch so each capacitor had 16 hours to loose some voltage.
Just out of curiosity I charge a batch on the opposite way like suggested. They stop at minus 5.58v. I don't know if this is useful, what does it tell us?
I made groups and the result is I got 3 under 26 volts, one just over 30v. and the majority between 26 and 30 volts.
So if I discard the 3 under 26v. it means 7 bad on 116.
94% good Ha! Elvee was right! Almost.
Now I got more questions for you guy... if you don't mind.
1- Do I need to perform other tests before I label them ''good for my numerous projects''?
2- I know we have to put a capacitor (electrolytic most of the time) at the output of a SE amplifier but are there some kind of capacitor better than others to do that job?
Be back after walking the dogs 🙂
