making a bipolar cap from two polarised electrolytics

[rob_gould]

I understand that if I twist together the positive leads or the negative leads from two polarised electrolytic caps and then wire the cap in circuit with the other leads, I'll get a bipolar electrolytic.

Thoughts on this anyone? Good idea? Bad idea? Any rhyme or reason about whether it is better to connect the caps on their anodes or their cathodes?

I have a project (LVL LOC 500) for which I've forgotten to order 2 x 10uF bipolar caps, so it'd be great to get it up and running with some creative use of four 22uF polarised, even if it is just an interim measure...

 

[ruffrecords]

I just had a look at the schematic dated February of this year and I cannot find any non-polarised electrolytics. Whereabouts are they in the schematic?

Cheers

Ian

 

[audiomixer]

right.

you might consider the body of the cap acting as a shield - so it may be better to connect negative terminals. but thats probably negligible.....
22u in series would indeed be appropriate.

cheers,

Michael

 

[rob_gould]

I just had a look at the schematic dated February of this year and I cannot find any non-polarised electrolytics. Whereabouts are they in the schematic?

Cheers

Ian

Hi Ian. It's C21 and C22 which are marked on the schematic as NP even though the symbol shows a polarised cap.

right.

you might consider the body of the cap acting as a shield - so it may be better to connect negative terminals. but thats probably negligible.....
22u in series would indeed be appropriate.

cheers,

Michael

Thanks for the confirmation Michael!

 

[ruffrecords]

I found them. They are attached to the DRV 134PA which need them if there are large dc voltage differences at the cable ends. This is probably one of the very few cases where a non-polarises capacitor is required. You could always use a film cap.

Cheers

Ian