Reforming Electrolytic Capacitors

[Whoops]

Thank you so much for the great explanation JR

 

[Whoops]

I'm building a capacitor reform setup soon.
It's not only the phillips axial caps I need to reform now, I received the component drawers of a small repair Radio/Tv repair shop that closed some years ago. There's a lot of NOS unused electrolytic caps in the lot, some of them even in the original store bags. (should be from the 90's)
I'm not really into scavenging stuff and turn trash into gold, but it was offered and they're never used before so I don't feel good in trashing them.

After reading a lot on this topic I'm going to build this circuit:

http://www.vmarsmanuals.co.uk/newsletter_articles/big_bang.pdf

It's simple enough and seems to have all I need.
I think it could be an useful tool also to read the leakage of non-electrolytic capacitors. I will built it with and internal Voltmeter.

While I was reading on the subject I found this project, it's more complex but offers some really nice ideas.
I think it's cool and would like to share it with you:

http://archive.siliconchip.com.au/cms/A_112073/article.html

http://archive.siliconchip.com.au/cms/A_112110/article.html

 

[Whoops]

in this page there's some tables of the normal leakage expected for different values of electrolytic capacitors.
Do you think that there's some mistake in the numbers measurement?
It seems to me that those values reflect micro amps and not milliamp as it's written in the table.
Do you think it's a typo?

http://www.electrojumble.org/reforming.htm

 

[benb]

I think those leakage numbers are "real," the table says "typical" but they're probably much higher than what you would normally see.

1. it's from 1968, and electrolytics have steadily improved since then. But then, is this for the older ones you found that you want to reform?

2. The text above the tables says "...it is probable that these relate to a temperature of 70oC." That's way hotter than the "standard" room temperature of 25C (though it could be typical for a loaded PC switching supply or a not-well-ventilated device using vacuum tubes), and leakage should go down greatly with lower temperature.

If I saw a cap with that much leakage at room temperature, I'd lean toward throwing it out.

 

[Whoops]

I think those leakage numbers are "real," the table says "typical" but they're probably much higher than what you would normally see.

1. it's from 1968, and electrolytics have steadily improved since then.

There's two tables one for vintage caps and another one for modern caps.

Both tables (vintage or modern) show excessive high leakage measurements if it's in milliamps.

Guess it's better to check the manufacturers data sheets if available than to trust those tables:
http://www.vishay.com/docs/28325/021asm.pdf

is this for the older ones you found that you want to reform?

2. The text above the tables says "...it is probable that these relate to a temperature of 70oC." That's way hotter than the "standard" room temperature of 25C (though it could be typical for a loaded PC switching supply or a not-well-ventilated device using vacuum tubes), and leakage should go down greatly with lower temperature.

If I saw a cap with that much leakage at room temperature, I'd lean toward throwing it out.

Thanks,
yes it's for older NOS caps I got and also for the Philips caps I got some time ago.