Need help...replace two back-to-back polar caps with one bipolar?

[sweetbeats]

Am I correct that the two polar caps in the picture below can be replaced with a single bipolar cap? Both of those polar caps are 10uF/16V...a reasonably equivalent bipolar cap would be something like a 22uF/16V?

 

[sweetbeats]

Wait...those are in series in the diagram right? So the equivalent bipolar cap would be 10uF right?

BUT...these caps are an input coupling cap so it couldn't hurt to increase the value anyway right?

 

[evm1024]

Think of the gap between the plates. When you series 2 caps the space gets bigger and the value of the cap goes down.

With equal caps the value will be half. 5 uF

--Ethan

 

[sweetbeats]

But...an input coupling cap...it wouldn't hurt to increase the value would it? 10uF or 22uF? I'm planning on putting a bipolar MUSE cap in there...below is a bit more of the view...that's an input coupling cap right? This is all line level. It is the input section of one of my CRL SEP400A's...multiband dynamics processor...

And am I understanding correctly that I can replace those two back-to-back caps with a single bipolar cap?

 

[sweetbeats]

And furthermore...

Have a look at the PSU section...

I want to try bypassing the filter caps with a .01uF film cap...but...are both polar caps on each rail filter caps? Bypass both? Or just the 1000uF?

 

[sweetbeats]

Dang!

The guy is like a PHANTOM!

...glides out of the fog, says something brilliant and *poof* he's gone again!

The iron is hot...literally...I hadn't really checked out the schematic on that CRL unit in terms of prudent changes and I'm in the middle of pulling caps...

 

[GCalo]

Capacitance in parallel doubles- in series 1/2's.

See: http://www.allaboutcircuits.com/vol_1/chpt_13/4.html

So a 5mfd at 16V non-polar (bipolar) should work.

You can by-pass all the large lytics with a .01 film.

Do it on the foil side after you pass the cap through, and solder all at one time.

 

[stevieb]

My experience is that, anything having to do with BI-POLAR is best avoided...

Don't ask me how I learned this.

 

[GCalo]

Bi-polars AKA non-polars are used primarily in audio circuits and loudspeaker crossover networks.

Since they are non-polar they are primarily found in AC circuits.

 

[sweetbeats]

Okay...right...so as far as the circuit is concerned, a single non-polar 5uF cap is going appear the same as two back-to-back 10uF polar caps.

BUT...

I don't have any 5uF non-polar caps...would 10uF be okay or even desirable? 22uF? its an input coupling cap and I thought that going bigger might be an advantage. Its interesting...outside of the PSU filter caps, all the electrolytic caps are 10uF/16V...and outside of the input coupling caps there are NO electrolytic coupling caps in the entire circuit.

Must know...must finish it...must not let IT sit unfinished...

And, Greg, so putting something like a good quality 0.1uF metal film cap in parallel with each of the 470uF and 1000uF caps couldn't hurt right?

 

[GCalo]

I have some I can mail up to you but they are axial. Would those do?

I might even have a fer polypropylene 4.7 mfd caps I could send.

.01 metallized polyester or polypropylene 100V would do great.

I am doing that to every cap in the P/s's.

 

[sweetbeats]

I have these for bypass caps:

http://www.mouser.com/Search/ProductDetail.aspx?R=BQ014E0104K--virtualkey58110000virtualkey581-BQ014E0104K

Will they work?

Still wondering if I should keep the value of the input coupling cap(s) at about 5uF or can I go with 10uF or would higher be even "better"?

 

[GCalo]

This might be better:

http://www.mouser.com/ProductDetail...EpiMZZMvCt%2bwg%2braTuoTvd5PT1YKFYdph9INmQ/8=


Stick w/4.7 - 5.0.

 

[LDS]

Have a look at the PSU section...

I want to try bypassing the filter caps with a .01uF film cap...but...are both polar caps on each rail filter caps? Bypass both? Or just the 1000uF?

C33 and C36 should be your main filter caps. The 1000uF caps are for the plus and minus 15 volt supply sections.

 

[sweetbeats]

Ahhhh...THAT makes sense.

So the 1000uF caps are like a secondary filter cap?

Nothing wrong with bypassing all of them?