Using polarized capacitors (electrolytics) instead of Bipolar capacitors.

Don Vollrath said on 26 August 2005 Subject: [soundtraxx] Re: Capacitors which type to use

Barry and others explained it very well.

You can use a non-polarized type as a substitute for a polarized capacitor, but it is likely to be in a larger case size. Must be of the same or larger voltage rating. However, you can also use 2 polarized capacitors connected back-back as a single non-polarized unit. Connect the two + ends or the two - ends together. It doesn't make any difference. Both caps must have the same full voltage rating for the circuit. Both caps must be of the same uF value and be 2X the desired uF for the application. Sometimes this arrangement ends up with a more manageable and flexible way to install the parts.

It is a peculiar quirk of electrical engineering that our circuit diagrams show polarized caps marked with a + sign at the positive end but the parts all arrive with the negative terminal marked.

Ditto for diodes that have the arrow-like symbol for 'conventional current flow' analysis, but all the electrons are flowing the other way.

DonV

Original message

Various Soundtraxx decoders come with either a bipolar or polarized capacitor. Can you substitute a bipolar on the ones that use polarized? It would be nice if I could just use bipolar ones and not worry about getting the wrong capacitor or orienting it the wrong way (capacitors are horribly marked).

Also does it mater which lead you put the capacitors on?

I am modifying a Loy’s Toys tester to have multiple speaker connections and a rotary switch to A-B compare speaker setups. I sure would like to not have to think hard when hooking up the speakers to the tester.

Ned Carey