The attached drawing has V3 as a 12volt to 0 volt square wave. I'll try to post the netlist.
I'd like to know if this is a bad idea, and if there's a problem with the polarity of the 4.7 uf cap
Thanks, Richard Brune

 

If you put a reverse polarity charge across a polarized electrolytic capacitor, you will most likely destroy it in very short order.

You can get non-polarized electrolytic capacitors.

You could also use two 10uF polarized caps back-to-back.

Or better, you could use a poly cap that is not polarized. Poly caps have lower leakage than electrolytics, along with very good frequency response.

 

The easy way out is to obtain a bipolar capacitor, or else to use two 10 uF electrolytics in series with two terminals of the same polarity in common.

 

So I am getting reverse polarity form this circuit?

 

Have you run the simulation on it? At least the DC analysis part?

 

Test Point V2 goes from 10volts to 0 volts, but I'm not good enough with these things to tell if the polarity at C2 is reversed

 

You could also use two 10uF polarized caps back-to-back.

I was wondering about that the other day, won't one or the other be distroyed?

 

Nope, it's a strange thing about back-to-back electrolytics. Hook 'em up with both + or - terminals connected, and they act like a non polar capacitor.

 

One also gets the bonus of doubling the working voltage. (Put high value resistors in parallel with the caps if taking advantage of this.)

Of course, one halves the capacitance.