Non-Polar Capacitors

[Meat&Beer]

I'm putting together a power supply, and the caps I have for the bias are non polarized. The bias circuit is coming off the secondary pre-rectification, a la 'Wreck style if you want a visual. (No bias tap on this transformer.)

Question is, I have non-polar axials that I'd like to use. Is there any reason not to use them in this location? Or for any location, for that matter?

Thanks!

[Bob S]

I've used non-polarized without any problems. As long as you don't exceed the voltage rating, they work fine.
I don't remember checking for which lead is the outer layer, but that might be worth thinking about in a supply string.

[Meat&Beer]

Thanks Bob! They're 100v, all good there.

I did snoop around on the Google and with the site search, I didn't seem to find anything specific to the bias circuit with bipolars, though. Found out all kinds of things about them, but I have a suspicion it's not a good idea for this particular function...

[R.G.]

Bipolar caps are literally back-to-back (well, OK, + to + or - to - ) electrolytics inside. If you use them with only one polarity of voltage across them, one of the oxide layers stays unused, and may deteriorate faster - but that's OK, as it's never used.

The biggest issue is that a bipolar or non-polar of the same capacitance and voltage as a stock polar one is sometimes bigger and almost always more expensive for the same C*V product.

[rp]

So why aren't all e-caps non-polar? Cost?

BTW are those big value/high volatge caps like Solens non-polar?

[martin manning]

So why aren't all e-caps non-polar? Cost?
BTW are those big value/high volatge caps like Solens non-polar?

Yes and yes.

[Leo_Gnardo]

So why aren't all e-caps non-polar? Cost?

BTW are those big value/high volatge caps like Solens non-polar?

Solens I"ve seen are film caps. Non-polar all right, there is no polarized version.

[Cliff Schecht]

So why aren't all e-caps non-polar? Cost?
BTW are those big value/high volatge caps like Solens non-polar?

Yes and yes.

Cost, size and for ESR reasons. The cost goes up, the size goes up and the ESR doubles. Not good for switching/linear supplies but alright for what you're doing.