CurtPalme.com Home Theater Forum

[paw]

Which is worst, caps in new, old stock, never used equipment (like 5 - 10 years old) or equipment that's been in use for 5 - 10 years?

I've heard caps dry out and they need to be reformed. I don't understand the reformed bit.

[deronmoped]

Heat is bad for the caps, so it can depend. If the equipment has been in use but no real heat is degrading the caps they have a much greater chance of continuing to work. I still would prefer NOS stuff over used stuff though.

I think a greater factor is how well the cap is built, some come off the assembly line that are not as good as the others. This would explain why some caps fail before others do, under the same operating conditions.

Deron.

[Dave Lister]

A dried out capacitor has to be replaced, you cannot reform it.

Reforming is a way of restoring the plates in a capacitor using an electric charge to remove oxides, the plates in the capacitor are made from strips of aluminium foil which during manufacture is first treated with an acid to increase surface area, they then place a strip of paper soaked in an electrolyte between the 2 strips of foil and roll it up, it is then placed inside the can and the rubber bung is inserted.

When a capacitor dries out it is the electrolyte that dries out, it would be impractical to disassemble the capacitor and soak the paper in more electrolyte.

It is far easier and cheaper to replace old capacitors with new ones.

[JustGreg]

OT a bit...I hope the CRT hobby survives long enough to see the deployment of these puppies. I couldn't find any info relating to their noise properties but assume it would be lower overhead than current cap technology.

http://www.nedo.go.jp/english/activities/portal/gaiyou/p06028/p06028.html