What is the affect of increasing filter cap capacitance

[hesamadman]

I have been thinking of building my filter chain a bit different to save some money. The next build I am going to start will require 3 16uf/450v capacitors. I thought maybe I would use two 8uf/250v in parallel to achieve a 16uf/500v rating. I could do one filter cap half the price this way. But I can get 10uf/250v even cheaper but would  give me 20uf rather than 16. Just curious what this may do or if my idea of putting two 8's in parallel in itself is a bad idea to start with??

[VMS]

To get 500V rating caps would have to be in series.

[AZJimC]

To get 16uf at 500v, you would use 2 x 32uf/250v in series, or 2 x 8uf/500v parallel.

The difference from 16uf to 20uf won't be much at all on filter caps, a little bit better filtering, and slightly larger current draw while charging, when first turned on.

[hesamadman]

To get 500V rating caps would have to be in series.

Shoot. That's right. Affective voltage rating of paralleled caps are equal to lowest rated cap. 

[Willabe]

I've been using Panasonic radial e-caps and so far I really like them. (But I make my own eyelet/turret boards.)

Do a search at Mouser and Digikey they both stock them. Part # EEU-EE2W220, that's a 22uF at 450v. (If there's an S suffix it's a shorter/fatter cap than the standard cap, spec sheet is there to click on.)

Hi temp (105c) hi ripple, long life (8000 to 10,000 hours @ 105c, an e-caps life is extended at lower operating temps, so the example rating given is worst case/shortest life time) small size, under $2.00 each.

Pic attached below.


                    Brad   

[kagliostro]

Sometime happens to find electrolytic radial capacitors at a very good price

this is an idea as to use a pair of 68uF 250v radial capacitors as a single 34uF 500v axial capacitor

(to keep the two capacitors together you can use shrinking tube)



K

[tubeswell]

And the effect of increasing filter cap capacitance is that, all other things being equal, the voltage supply is steadier, because you lose less charge on the non-charging parts of the cycle (when the load is depleting the charge). Assuming the load remains the same, the charging current is increased. More capacitance is like having a bigger vat to have to fill up with 'positive charge'* in a given amount of time.


* and the positive charge results from pulling electrons out of the positive pole of the cap, which takes work. The more electrons you want to pull out, the more work you have to do.

[lego4040]

Thats a big difference in cap size there Willabe. I did some research for caps on my last build and found the panasonic and Nichichon quite interesting. I would only use those two on my pedal builds if possible

[Willabe]

I would only use those two on my pedal builds if possible

Why?   

[lego4040]

What I meant is that the Panosonics and Nichichon are my preference over the IC brand for electrolytic's in the pedal building. They have a much better selection to choose from, especially Nichichon's standard electro's to really high grade audiophille and in between. I used to take standard computer soundcards and recap them with BlackGate's or better and I would save money, rather then buying a higher grade sound card

[Willabe]

Ohh, got ya.