Inexpensive Electrolytic Capacitors

[Aurora]

What's driving them, you ask..??
Remember - in some areas 30-40$ is a good weeks pay for honest work........

[67plexi]

Just for kicks I tested some electrolytic capacitors today.

All new Capacitors.Tested with a capacitance-compatator bridge tester.

Sprague atom TVA1906 20uf @ 500vdc not made in USA
1st 20uf tested 45uf
2nd 20uf tested 50uf
F&T 22uf@ 500vdc
1st 22uf tested 45uf
2nd 22uf tested 37uf
3rd 22uf tested 40uf
4th 22uf tested 42uf
Mallory tc-75 20uf @ 450vdc
1st 20uf tested 20uf
2nd 20uf tested 20uf
Mallory tc-77 40uv @ 450vdc
1st 40uf tested 40uf
2nd 40uf tested 40uf
Mallory tc-79 50uf @ 450vdc
1st 50uf tested 50uf
2nd 50uf tested 50uf
Philips 22uf @ 450vdc
1st 22uf tested 30uf
2nd 22uf tested 33uf
philips 4.7uf @ 250vdc
1st 4.7uf tested 6uf
2nd 4.7uf tested 7uf
Sprague atom USA TVA-1406 10uf @ 150vdc
1st 10uf tested 13uf
2nd 10uf tested 12uf

All capacitors passed a ESR test. I also tested SBE sprague film caps
you don't want to know. Tested Mallory PVC film caps 100% top notch.
This just makes me sick

[dartanion]

I got my own source for non-bullshit signal caps. Catalog sales are only so good, you have got to measure everything. Trust no one! If you haven't learned that yet, do so soon.

It sucks to have spent good money on fake parts. We all have been victims of this crime I would have to believe. If components don't measure right on my bench, they are tossed. Or returned to the vendor. Whatever they want done, I don't care. Just give me what I paid for in parts. It pains me that resellers don't care enough to do minimal QA/QC on parts. You have to hold them to task, or move on to another source. There are enough fakes out there the we will all be affected by it and it will require replacement of said parts.

[Chappy]

Scary topic. Time to check the caps in all of my previous projects.

Can anyone recommend a fairly good quality new capacitance testor that won't break the bank? I don't need a full blown multimeter with all the bells and whistles as I already have a Fluke DVM that works beautifully.

Any suggestions greatly appreciated.

Cheers
Chappy

[Cliff Schecht]

Your Fluke doesn't do capacitance?

[67plexi]

Just to add insult to injury in the electrolytic world.

Xicon is no more obsolete at Mouser, A bit of good news I tested 22 each CDM 33uf @ 450vdc
All CDM tested 100% @ 33uf but the CDM are Radial.
Unfortunately I put stock in the F&T capacitors I tested over 40 F&T’s and all are out of spec.
F&T are the oats that have been run through the horse. Sprague is worse.
Cornell-Dubilier is the only capacitors I trust at this point the USA made ones.

Take care, Steve.

[Aurora]

There are several well known brands marketed in Europe, that seems to have little Us distribution , - Rifa and BC (ex Philips) to name a few.
There shouldn't be a problem when ordering from the larger industrial suppliers, as their reputation totally relies on customer feedback, with a much larger potential impact than to the small niche vendor.
F&T is one of the old "cliffs" in audio and HV capacitors, - seems strange that they should be out of spec....? How much in relation to spec'ed tolerance?

[flood]

all this is a bit scary...

i think i'm going to stick to a local manufacturer called keltron - http://www.keltroncomp.com/kccl/products.html - instead of importing a brand that i can trust.

a lot cheaper than anything i could import, and if i have a bad one, it's cheap enough to trash. if i have a few bad ones, i can take them right back to the dealer.

the payoff is the security in knowing that they're current production, not too expensive... also, from what i know, they do mil-spec production for the MoD as well. or have done it in the past...

either way, i think i'll check those too, just to be sure. :/

[Chappy]

Your Fluke doesn't do capacitance?

It's an older model from 1977 or 1978.



67 Plexi.

What type of tester do you use?

Chappy

[dynaman]

Huh. I've hundreds of 'lytics I've bought on the cheap through store closeouts, overstocks, etc. Mostly branded Nichicon, Rubycon, etc. Haven't had a failure yet so I'm not gonna worry.

There are other alternatives if you're willing to put in the work of searching. I've a nice stash of photo-flash caps that I purchased for pennies per piece. They're usually found in higher values in excess of 100uf. Voltages are typically around 300VDC. I run these in series and parallel to get the values I need. They're my fave caps for using at voltages over 500VDC. Their radial bodies save space and I've had no failures, even at +600VDC. New, they cost a fortune, but they can be scoured from those disposable film cameras for next to nothing.

Lots of hifi nerds prefer to use motor-run (NOT "MOTOR-START") caps for their performance. I think they're just big film caps. Often oil-filled. Usually seen in electric motor applications like AC units. Their size is prohibitive but they take high voltages well. I'll use these when I have the room. Cheesy, I know, but their canisters will take on a high shine when buffed. New, they're expensive, but can be had dirt cheap from certain aftermarket distributors. I'll bet your local heating and cooling shop throws out dozens of these every week. From what I was told, they don't degrade like electrolytics. Beats me.

Check out the pic. Shown are motor-run caps in 33uf, 50uf, 100uf and a multi-section cap that can be configured from 2.5uf - 67.5uf. These are all good up to about 600VDC.

[Gtr_Tech]

I discovered the fake Ebay axials some time ago. The picture of the cut open ones on the purple background (ebay review) is mine that someone from alt.guitar.amps used when I posted it there ranting about the whole deal. The ebay seller never did make good on the deal....acted like he didn't know what I was talking about when I asked for either good parts or credit for the junk ones. AFAIK they are still selling them. The guy that did the ebay review should've used the other pic...the one that shows the 400v rated radial inside the added shrink.

http://www.flickr.com/photos/62937081@N00/2931954597/

That was what was inside the fake axial housing....which was said to be 33u/450v.

I guess the moral to the story is....only buy from reputable sellers. Mouser, Digi-key, Allied, and Newark are all fine. Watch MCM....I've been burned by them (fake TO-3 case transistors), but they did credit me. Places that let the bean counters run the show end up with the fake stuff because they price is better. Be wary of *everything*....STK chips are be'n faked as well as other ICs and lots of transistors types that are in demand and out of production.

I've had good luck with surplus vendors for lytics. They usually come straight from an OEM mfgr who got them from the cap mfgr. Just watch the date codes and check them for value, leakage, ESR, and dielectric absorbtion before use.

[67plexi]

Chappy,
I use an old EICO Model 950 Resistance-Capacitance-Comparator-Bridge.
RCP Model 123 Flybacker it’s an AC ohm meter. Works for the ESR test.
Hewlett-Packard 3312A Function Generator @ 100hz.
Tektronix 2336 100mhz Oscilloscope.

I just received a new order of electrolytic capacitors all tested good, non china caps.

[ChrisM]

Opened up a Weber Eleon (is that how you say it?) cap that I got in 2008. It was rated at 16mF 450V.

Inside was another Eleon cap, much smaller and radial.
It was rated at 20mF 500V.

So I guess the trickery was in some ways good. Better voltage rating, but the capatence was slightly higher. Not enough to make a big difference but still some false advertising.


I think its crazy though that these caps inside caps scam has been going on for so long. I bought that cap in 2008, I bet it was manufactured in 2007 though and had been sitting on a shelf. Crazy!

[ChrisM]

Opened up a Weber Eleon (is that how you say it?) cap that I got in 2008. It was rated at 16mF 450V.

Inside was another Eleon cap, much smaller and radial.
It was rated at 20mF 500V.

So I guess the trickery was in some ways good. Better voltage rating, but the capatence was slightly higher. Not enough to make a big difference but still some false advertising.


I think its crazy though that these caps inside caps scam has been going on for so long. I bought that cap in 2008, I bet it was manufactured in 2007 though and had been sitting on a shelf. Crazy!

I spoke too soon.

Inside that 500V 20mF cap was a Samsung 400V 22mF cap. Had the leads cut very short than had this much thicker wire soldered on to it. Made it appear from the outer cap that the leads were very robust. When in fact the leads were actually quite thin and wimpy.

[Chappy]

Chappy,
I use an old EICO Model 950 Resistance-Capacitance-Comparator-Bridge.
RCP Model 123 Flybacker it’s an AC ohm meter. Works for the ESR test.
Hewlett-Packard 3312A Function Generator @ 100hz.
Tektronix 2336 100mhz Oscilloscope.

I just received a new order of electrolytic capacitors all tested good, non china caps.

67plexi

Thats nice to hear. Here I was thinking that I would have to shell out a few hundred bucks for a good quality new digital cap tester. I did some research on the net and came across that Eico tester. I just watched some go on the bay for $35. I think I can build my own just like it for much less. I think I will go that route and save my money for amp parts.


Thanks
Chappy