Tantalum caps

[Rodgre]

Here's probably the most ridiculous question, but I'm sure some newbies might want to know this as well.

I haven't used Tantalum caps in years, and I recall using them in place of polarized electrolytics back in the day.

Now, I rarely see a mention of them being "polarized" or I never see them lumped-in with standard electrolytics in catalogs. The one or two that I have left in my component cabinet have a barely visible + sign on one leg.

Are they in fact polarized, or can they be non-polarized as well?

While I'm at it.... I always wondered why polarized caps are always noted on schematics where the + end is, yet every electrolytic cap is marked where the - leg is.

I think we need some standardization around here!!!!

Roger

[Peter Snowberg]

Are they in fact polarized, or can they be non-polarized as well?

They are in fact, "rabidly" polarized.

Unlike aluminum electrolytics, you can't put two in inverse series to make a non-polarized unit.

[J. Luja]

tantalums are almost always polarized -I've never seen a non-polar, but they do make them. if the + sign is worn off look at the legs, usually one is longer  to denote the anode "+" side

some electrolytics have "+" markings -there's a standard, it's just manufacturer specific :wink:

-Jeremy