[sdiy] capacitor voltage ratings

[Brett Maddaford]

Hey Rafael

I can tell you I used slighty higher voltage caps in my steiner filter
without any problems, I used 50v models instead of the 35v specified and
they worked fine so you should be cool. Obviously the higher the voltage
the larger they get too so size is an issue too. I seem to remember Ken
telling me up to 63v was cool for replacing these.

Johns response does have me asking though if I'm running 15v into the
steiner filter and kens design specifys 35v capacitors does that mean
they are not running at their specified capacitence as 15v is knowhere
near 75-80% of 35v.....just wondering.

Cya
Brett

-----Original Message-----
From: John Henson [mailto:synthnerd at eircom.net] 
Sent: Saturday, 21 May 2005 10:06 AM
To: synth-diy at dropmix.xs4all.nl; Rafael_Cohen at prusec.com
Subject: Re: [sdiy] capacitor voltage ratings


To an extent this is true.
You can (and probably should) replace 16V caps with 25V ones if your
voltage rails are + & - 12V or 15V. The downside is that the capacitance
of electrolytics is dependent on the voltage across them. If memory
serves, electrolytics only come close to their specified capacitance if
the voltage across them is within 75 or 80% of their specified voltage.
Thus, space considerations aside, putting 100V or higher Caps across
synth type power supplies is largely self defeating. This problem does
not occur with film type caps. Regards John Henson

----- Original Message ----- 
From: <Rafael_Cohen at prusec.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, May 20, 2005 8:20 PM
Subject: [sdiy] capacitor voltage ratings


>
> Hey everyone,
> Yet another newbie question here.
> I am curious about the voltage ratings on capacitors.  I was buying 
> some from www.Jameco.com earlier today and I was trying to figure out 
> the dirrefences in price and the differences between the different
products....
> If I have a previous circuit that I am trying to copy and the old one 
> uses 100uF caps at 16V can I substitute 25V?  50V?  Why are some 
> cheaper than others?
>
> Also, in the CGS parts lists (soon to build my Steiner VCF), some of 
> the modules list caps at a particular voltage.  If I am substituting, 
> is it irrelevant as long as it is a higher value than the given 
> specifications?
>
> Thanks for any info...
>
>
> Rafael
>
>
>