Testing Capacitor Leakage with nS setting on Multimeter

[@TrevorsBench]

I learned something new today, Thanks Tony

[@stevent1074]

Nice! Never thought of this. For higher voltage levels >50v I like to use a megger to apply voltage to the capacitor rated value. As you showed, a capacitor charged with DC no longer flows current and acts like an open circuit. Observe if the resistance is erratic or never stabilizes. This will indicate a leaky cap. Thanks for the tip

[@xraytonyb]

I've tried that as well. As long as the test voltage of the megger doesn't exceed the ratings of the cap, it works great. Mine only does low voltage, 500 volts and 1kV, so that's the only limit. Thanks for the comment!

[@poormanselectronicsbench2021]

I made a vid awhile back named "Conductance, Gigaohms and Easter Eggs", played around with the nS function on a few meters, and also found that some of the old Sprage TO-X series capacitor testers have a fairly accurate function that also tests with low voltage and out to 50G ( Marked on the meter as "50 Kilo Megaohms) . Some of the older Fluke bench DMM's as well as the side button 80XX models have it s a marked function, BUT, it it an unmarked 'Easter Egg" on some lower priced handhelds as well. I do use the nS function on a Fluke and Brymen if I ever want to make sure I have no sort of resistive fault on items I am testing.

[@karllangeveld6449]

A really good application of that nS feature. I was always wondering what it was for. Thanks again, Tony. You inspire.

[@anandarochisha]

My old Sprague tel-ohmike T04 tests to 20 gigohms. Good video.

[@nickk6109]

Very useful for testing soldering of caps when building tube amps (and SMD) to ensure they're not damaged. I have a Byrmen 869s that has the same mode so this is going to be useful addition to the pre-start checks!

[@scanman84]

It would appear that there is no absolute way to test old electrolytic caps. Checking the ESR and their rated capacity seems to help the most help. I'm considering purchasing a Capacitor Wizard. They are kinda pricy, but I've see several techs on KZbin using them. I have a lot of 70's gear to restore. I'm hoping not to replace every single cap in them. I built a Heathkit AR-1515 receiver back in 1976. I still have it and look forward to restoring it and many others. Thank you for all your videos. You are a master of your trade and hobby!!

[@xraytonyb]

My go-to is the ESR meter and a leakage meter that can apply working voltage to the capacitor.

[@scanman84]

@@xraytonyb Thanks! You are the best.

[@whatcouldgowrong7914]

I just do ESR tests and for leakage, use a lab power supply at its max rated voltage with a microamp capable multimeter in series to monitor once its charged…

[@oriole8789]

Great observation, makes perfect sense. I don't think you need a python script for this though haha. You were correct when you said that they have a simple reciprocal (inverse) relationship. NANO (1x10^-9) siemens maps to GIGA (1x10^9) ohms. The sign of the exponent simply flips. So you can just use any calculator to do 1/nS = Gohms, or the opposite, 1/Gohms = nS.

[@zulumax1]

Have you seen the Mr. Carlson low voltage capacitor leakage tester? I use the Heathkit IT-28 leakage tester, and sometimes put a 100 micro amp meter in series so I can watch the electrolytic capacitor forming.

[@DaveMcAnulty]

Yeah, pretty sure it works the same way, I know it uses gigaohm resistors.

[@zulumax1]

@@DaveMcAnulty I see you have a Commodore 64 video up. I will have to check it out later. Still have my original one I bought in 83, and a parts donor I stole the sid chip out of. New external power supply, and I checked the ESR on the mainboard PS caps, still low ESR, so I didn't change them.😙

[@JakePlisskin12]

This video just confirmed how little i actually understand about electricity. For the life of me how the stuff works.

[@xraytonyb]

That's OK. I prove on a daily basis how much I don't know or can't remember! :)

[@jdmccorful]

@@xraytonyb ditto!Thanks for your time.

[@zulumax1]

Micro Mhos, not to be confused with micro Larry’s or micro Curley’s.

[@JCHaywire]

Curcious? I like this video, and appreciate the knowledge. Cheers! W0XO

[@afnDavid]

5:53 That is why they taught us scientific notation in middle school ! For when you deal with very large and/or small numbers. MATHS! MATHS! Maths are an essential life skill like it or not. I was expected and required to learn and memorize dozens of formulas in my high school electronics courses. Nowayadays>>> "Hello Siri what is 2 plus two?"

[@xraytonyb]

I would love to say you're wrong, but unfortunately, then I would be wrong. ;)

[@wolfgangrichter6088]

Good you are immersing into Python Tony ! When will we see videos about TensorFlow and AI ?

[@harryshector]

I wonder about the effect of the voltage level at which the measurement is conducted. When one does a “real” leakage test - at voltages approaching or equal to the rated voltage of the device - As with an old Heathkit or Eico capacitance tester, the applied voltage clearly had an effect on the level of leakage observed. A capacitor might be ‘fine’ at 30 or 50 volts, but turn into a resistor at 200 or 300 volts. I know that Carlson claims his low voltage leakage tester is as valid as any higher voltage test, but is it really? Speculation says that current generation film capacitors are likely to outlast the equipment they are put in. Be great, if they did. What’s your take on the impact of test voltage upon the validity of test results?

[@jim9930]

Energy in Joules = 1/2 (CxV) sq'd. That energy is stored in dielectric 'twisting' of chemical bonds in the molecules. Once you exceed the bond strength... breakdown happens. Before that, there is nonlinearity in many different materials (elasticity). Mylars go nuts above 10-30 volts. Polypropylenes and polystyrenes are much more stable to much higher voltages. Ceramics can be ridiculously high before the bonds move in the crystal lattice {MLCC's are a cheap and different bypass solution}. Leakage is voltage dependent above some threshold of a given material. The voltages used in multimeters are NOT enough to excite those problems ( you'll entirely be looking at small signal models). It is possible to see the capacitance vary slightly vs voltage with just a handheld multimeter... bench supply and a little more sophisticated equipment is used to 'spec' different capacitor dielectric materials. READ the manufacturer data sheets... or have a chemist friend at Dupont

[@xraytonyb]

@jim9930 That is the best explanation I've heard so far about this subject. Thanks!!

[@jim9930]

@@xraytonyb Your welcome! Did you try isopropyl? I had some fun, thanks.

[@stevencraig]

Considering how easy it is these days to post videos on the internet, I have yet to see someone demonstrate a capacitor failing a high voltage leakage test while passing the test done by Carlson's device. I've only seen plenty of theory about it and plenty of mudslinging towards him for it.

[@LawpickingLocksmith]

My mate Harry with his Russian wife declared the end of the Flukes. So I use an Aneng that goes up to 200 Gigohms.

[@ronwade2206]

Looking up, Curcious... Nope, not there. 😊

[@stevewayne1480]

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.

[@xraytonyb]

I never tried one of those, but I did try using a megohm meter (A.K.A "megger"). It worked to some degree, but it was limited to only 9volts, 500 volts and 1kV test voltages, which didn't allow me to adjust for every capacitor's max voltage rating.

[@tveasy5172]

If you applie DC near 30 V through the film capacitor and measure the voltage in the serie, the voltage go down to the 0 V and the value above the 0 after charging time could indicates the leakage. The same way as the conductivity, but with the cheapest equipment.

[@xraytonyb]

Leakage is measured as current, not voltage. If you apply 30 volts across a capacitor, current will flow through the capacitor until it fully charges, at which point current will no longer flow. Any current measured through the capacitor at that point will be your leakage current. This will be the case regardless of how many volts you apply across the cap, provided you do not exceed the maximum rated voltage of that capacitor.

[@tveasy5172]

Thank you for answering. As I see in other channel, measuring voltage through the tested capacitor also will help. Normally, the voltage go down to zero after charging and quickly, but in faulty capacitor it go slow and stop at an considered level. The benefit of this method is possibility to use voltmeter that's easy to find to anybody.

[@frankgeeraerts6243]

Just like the transconductance of a tube ( GM) is defined in "Siemens"...........Mho... See a tube redplating, first check leakage on the signal coupling capacitor.

[@xraytonyb]

I still like mhos (along with Larry and Curley)

[@frankgeeraerts6243]

@@xraytonyb Indeed ...and.......thanks for the trick with the tester Tony

[@srtamplification]

Wouldn't this be measuring only conductance (inverse of resistance) in this case? Admittance (inverse of Z) would only apply to an AC test.

[@xraytonyb]

You are correct. Using the terms interchangeably (and incorrectly), just like saying resistance and impedance. A bit naughty.

[@srtamplification]

@@xraytonyb I don't know about naughty, 😂, but an admittance reading would change with frequency so that sort of test would not be static.

[@nickk6109]

@@srtamplification However the multi-meter is providing DC hence for DC leakage at low voltage (and here's the rub) it would work. For leakage occurring at higher voltage (ie 500Vdc) in tube amps that would still really need at an HV test. However if you've just soldered the cap in and overheated it.. its' a good starting pre-check test before switching up and running a voltage ramp up to test.

[@mikesradiorepair]

No need for Python script. The most basic scientific calculator can do exponents and reciprocals. Everyone does own a scientific calculator DON'T YOU? 🙂 In the case of the first cap you tested it would be 1 over .05 times 10 to -9 = 2 X 10 to 10 or 20 G Ohm.

[@xraytonyb]

The calculators work fine. I wanted something quicker and I didn't want to write a program into a calculator (I don't have one that can save a program). Excel doesn't like numbers with big negative exponents (not sure how many decimal places it can handle). The python program was easy, and will be handy when using nS mode in the future. Thanks for the comment!! (BTW, I really want to learn how to use an HP calculator with RPN. A few of my friends have them and I never took the time to learn from them.)

[@mikesradiorepair]

@@xraytonyb I flip back and forth between modern "textbook display" calculators and my RPN calculators about ever month or so. Some of them like my HP Prime and HP35S can do both so I just switch modes. Today to follow along in the video I was using a vintage HP 15C which is a RPN only one line display calculator. RPN is easy to do once you have the light bulb go off over your head and understand how it works.

[@xraytonyb]

My one friend is really into those RPN HP's. He has one that can store programs on these little magnetic tape strips that look like a stick of chewing gum. Really cool!

[@mikesradiorepair]

@@xraytonyb If it had the "stick of gum" memory sticks it was a HP 65, 67 or 97. I have each in my calculator collection. I'm lucky enough to have at least 1 if not several of every calculator HP has ever made. I even have 2 prototype HP calculators. I stumbled across them at a public auction in a whatnot junk box. It was a estate sale of a recently passed away HP engineer. Think I paid a whopping 50 cents for that box. One is a HP 15C prototype and is probably worth more than every other HP calculator I own.

[@BlankBrain]

@@xraytonyb I have an HP-45 that I bought for college in 1973. I never got used to arithmetic calculators. If I want to do calculations, I just throw the variables into a LibreOffice spreadsheet and build formulas. It lets me verify and save results too!

[@jim9930]

When you get up into the giga-ohms, clean the surfaces with alcohol. Your probably just measuring finger oils and contaminants on the outside body of the caps. Got any teflon capacitors? Thanks for wasting my day! Now I have to go check polystyrenes, micas, just bought an assortment of NPO/GOG ceramics... hours of electronics 'nerd' entertainment. 👍

[@xraytonyb]

How did I waste your day? The video was less than 15 minutes and you chose to watch it of your own free will. Quit being so uptight.

[@DaveMcAnulty]

@@xraytonyb Read the sentence after he says "wasting my day" , he is saying that tongue in cheek, you gave him something to go try on all his caps.

[@xraytonyb]

@jim9930 Sorry for the misunderstanding! My apologies!!

[@jim9930]

Ok, it's 5 hours later now... first the 'beauty rest' afternoon nap, then immediately upon arising; FEED the guinea pig (nothin' gets done around here till the fuzz bunny gets fed!) And now to my results with a Bryman 869s meter: My reference polypropylene 1.076uf measured around .06S until I wiped the sharpie off. YUP, confirmed, isopropyl alcohol brought that down to 00.00. Next just a bunch of standard old .01uf X7R .2" lead spacing purchased from Jameco - same game .09S until I wiped them, then 00.00. Also had a box of .015uf 'green' .25" lead spaced mylars. First couple I picked up had been fingered a bit grabbing other ones... so yep again, .33S until I picked one from the bottom... .01S wiped it with iso and 00.00. I have what seems to be an endless supply of 1, 1.2, 1.5, 2uf snipped from the rocket boneyard in Sharps, FL years ago (old aerospace consoles, etc) Same again, wiped off mylars read 00.00. So last but not least, a bunch of .01u, .039u, 470p, 100p polystyrene I have for various projects. Same result again - they read some number around high 10gigs until I wipe them down with isopropyl {91% bought at Rite-Aid}... then 00.00 My conclusion, I measured surface contaminants before wiping them. Let me know what ya'll find? Thanks again Tony, excellent adventure 👍👍 Here's another to try - wipe anything near the cap & meter and touch a lead - static charge is very evident... sometimes you don't need to touch anything, field coupling of tiniest static charge!

[@paul.alarner6410]

can the same be done with electrolytics?

[@jdmccorful]

An interesting idea.