Question about Capacitors

K

K2LRV

Guest
OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
 
K2LRV <lou002@gmail.com> wrote in news:225bd33d-09e4-40fe-9ae2-
50ed535b96e9@t54g2000hsg.googlegroups.com:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
Click to expand...
There are lots of guidelines, but capacitors are very complicated. The
simplest approach is to use what's worked, so think about what you want to
do, find a board from a successful commercial device that uses the same kind
of functions you want to make, and use the capacitors they do. To do that
you'll have to reverse engineer the circuit thoroughly or get a circuit
diagram from the maker.

For specifics, as I know them (limited knowledge though) try these:

Tantalum for long life and stability, decoupling close to chips and other
sensitive parts, and limit inrush current if you want to be sure they don't
fail early.
Electrolytic for large values, cheap, where reliability isn't critical, and
no harm is done if they burst. (Sealed, cheap boxes, basically).
Ceramic. Variable specs, but the really low values usually have better
dielectrics than larger values, but avoid using them for critical timing
functions. People do use them for timing things, but best not to.
Metallised polyester, mylar, polypropylene, and many other rare ones are good
for timing, have low variance with temperature and humidity, generally good
for accurate timers.
Teflon, polystyrene, and other high-cost caps, good for radio frequency
timing, very accurate values and stability in a wide range of conditions.
Mylar, teflon, polypropylene and oil-filled types for high voltage.

There is so much to add to this, and probably some corrections. Maybe the
only really good way to know is to look at any circuit that is common, OLD,
and still working well, trusted by lots of people. See how they did it.
 
On Tue, 21 Oct 2008 07:35:48 -0700 (PDT), K2LRV <lou002@gmail.com>
wrote:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
Click to expand...
It depends. Here's a brief starting point
http://www.stanford.edu/class/ee133/handouts/general/capHO.pdf

--
Rich Webb Norfolk, VA
 
Lostgallifreyan <no-one@nowhere.net> wrote in
news:Xns9B3EA2831BE81zoodlewurdle@216.196.109.145:

There is so much to add to this, and probably some corrections. Maybe
the only really good way to know is to look at any circuit that is
common, OLD, and still working well, trusted by lots of people. See how
they did it.
Click to expand...
By 'old' I mean about ten years. No point in looking much further back that
that in most cases. Also look at new types that make use of better materials
that were known before but not cheap to exploit. New tantalums are good, and
most polymer dielectrics are improvements of old ideas. Probably true for
ceramics too.
 
Don't use ceramic with high ripple currents, if you want them to be
quiet. They can act like tiny piezo buzzers. I used a big
electrolytic with a smaller tantalum in that case, no noise at all.
 
On 2008-10-21, K2LRV <lou002@gmail.com> wrote:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
Click to expand...
http://www.musicsynthesizer.com/txt/caps2.txt
http://www.interq.or.jp/japan/se-inoue/e_capa.htm
http://my.execpc.com/~endlr/

I think there's also a section on the subject in Bob Pease's
_Troubleshooting analog circuits_.

--
André Majorel <URL:http://www.teaser.fr/~amajorel/>
You measure democracy by the freedom it gives its dissidents, not
the freedom it gives its assimilated conformists -- Abbie Hoffman.
 
K2LRV wrote:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
Click to expand...
Oh God !

Buy a book !

Graham
 
Andre Majorel wrote:

On 2008-10-21, K2LRV <lou002@gmail.com> wrote:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.

http://www.musicsynthesizer.com/txt/caps2.txt
http://www.interq.or.jp/japan/se-inoue/e_capa.htm
http://my.execpc.com/~endlr/

I think there's also a section on the subject in Bob Pease's
_Troubleshooting analog circuits_.
Click to expand...
If you need to troubleshoot a decent capacitor you probably aren't living in
the real world.

Correction. There's no 'probably' about it.

Graham
 
DJ Delorie wrote:

Don't use ceramic with high ripple currents
Click to expand...
Ceramics are NEVER used with high ripple currents you brain dead
defective.

Go away and die.

Graham
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> writes:
you brain dead defective.

Go away and die.
Click to expand...
Wow, someone's off his meds again.
 
Eeyore wrote:

DJ Delorie wrote:


Don't use ceramic with high ripple currents


Ceramics are NEVER used with high ripple currents you brain dead
defective.

Go away and die.

Graham

Oh really..
Click to expand...

Tell that to the military customers that required us to
test the ripple currents on ceramic caps back when I was at
Semco.
We didn't actually make the ceramic material there how ever, we did
complete the rest of the cap's structure.

The main line was mica epoxy dips with very high Q.

Think before you speak!, not every one makes only audio circuits.

http://webpages.charter.net/jamie_5"
 
On Tue, 21 Oct 2008 07:35:48 -0700 (PDT), K2LRV <lou002@gmail.com>
wrote:

OK here is a question that I have never seemed to find some at least
good guidelines on. What type of capacitor to use, i.e. electrolytic,
tantalum, ceramic, etc.
Click to expand...
As a first step, "electrolytic" usually means "aluminium
electrolytic", and "tantalum" means "tantalum electrolytic". Both
types of electrolytic capacitor have much larger capacitance than a
similar size non-electrolytic, so will be used where a large value
capacitance is required.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
DJ Delorie wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> writes:
you brain dead defective.

Go away and die.

Wow, someone's off his meds again.
Click to expand...
Provide an example of a ceramic caps with high ripple current before
talking out of your arse.

Graham
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> writes:
Provide an example of a ceramic caps with high ripple current
Click to expand...
That would go against my original recommendation.
 
DJ Delorie <dj@delorie.com> writes:
Eeyore <rabbitsfriendsandrelations@hotmail.com> writes:
Provide an example of a ceramic caps with high ripple current

That would go against my original recommendation.
Click to expand...
That is, providing an example of ceramics used in a
high-ripple-current situation would go against my original
recommendation.
 
On 2008-10-22, Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
DJ Delorie wrote:

Don't use ceramic with high ripple currents

Ceramics are NEVER used with high ripple currents you brain dead
defective.

Go away and die.
Click to expand...
Is that the real Graham Stevenson or a forgery ? The Path: looks
genuine to me.

--
André Majorel <URL:http://www.teaser.fr/~amajorel/>
You measure democracy by the freedom it gives its dissidents, not
the freedom it gives its assimilated conformists -- Abbie Hoffman.
 
Eeyore wrote:

Jamie wrote:


The main line was mica epoxy dips with very high Q.


Mica caps with very high ripple currents ?

Bwahahahahahahahahahhahah
Click to expand...

You absolutely do not know what you're talking about..

Stop embarrassing your self and move to a different subject.

By Eye-Sore.


http://webpages.charter.net/jamie_5"
 
Jamie wrote:

Eeyore wrote:
Jamie wrote:

The main line was mica epoxy dips with very high Q.

Mica caps with very high ripple currents ?

Bwahahahahahahahahahhahah

You absolutely do not know what you're talking about..

Stop embarrassing your self and move to a different subject.
Click to expand...
Please post ripple current ratings for mica caps.

I look forward to seeing one that can handle say 10A !

MORON

Graham
 
Andre Majorel wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
DJ Delorie wrote:

Don't use ceramic with high ripple currents

Ceramics are NEVER used with high ripple currents you brain dead
defective.

Go away and die.

Is that the real Graham Stevenson or a forgery ? The Path: looks
genuine to me.
Click to expand...
It's genuine.

Anyone who thinks you use ceramic caps as reservoir caps needs their
brain examined.

Graham
 
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