[sdiy] L, C, and sometimes R

[mark s]

thanks for this link. hearing things explained in a new way always helps.

BTW the exact link that worked for me is:

http://www.nzart.org.nz/nzart/examinat/amateur radio study guide/Course 
Files/Caps Inductors Resonance/STUDY NOTES - CAPACITORS INDUCTORS & 
RESONANCE.htm


cheers
mark


At 06:37 AM 9/11/2004, you wrote:
>One other easy way (without complex math) to look at (quite a number of)
>filters is as frequency depended voltage dividers.
>This makes also clear why the load on a RC or LC combination needs to be
>taken in account.
>And what the difference in effect of load on a RC LP stage or a CR HP stage
>is.
>You can even calculate frequency responses of filters with multiple stages
>this way.
>
>When in 2nd grade high school "designed" my first filters like this, a bit
>guesswork and even more trial and error, but it kind of works.
>
>Cheers,
>Theo
>
>
>
>
>----- Original Message -----
>From: jhno <ear at heldscala.com>
>To: <synth-diy at dropmix.xs4all.nl>
>Sent: Saturday, September 11, 2004 11:19 AM
>Subject: [sdiy] L, C, and sometimes R
>
>
> > i really like how this page explains the basics of inductors and
>capacitors:
> >
> >
>http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Cours
>e%20Files/Caps%20Inductors%20Resonance/STUDY%20NOTES%20-%20CAPACITORS%20INDU
>CTORS%20&%20RESONANCE.htm
> >
> > much clearer (to me) than everything else i have read.
> >
> > interestingly, it talks about e.g. capacitive and inductive reactances
> > combining to make a notch filter, by causing very little current to flow
>at
> > the resonant frequency.
> >
> > hmmm. i usually think of it like this:
> >
> >
> > - capacitors (C) pass high frequencies; inductors (L) pass low
>frequencies.
> > therefore, a series C is an HPF, and a series L is an LPF.
> >
> > - in parallel connection, those frequencies are shunted to ground instead
> > of passed on. hence a parallel C is an LPF, and a parallel L is an HPF.
> >
> >
> > so how incomplete or inaccurate is this over-simplified model? in what
> > practical aspect does it fail, when designing/analyzing high-quality audio
> > circuits?
> >
> >
> > i think the main problem is that i tend to think of circuits operating as
>a
> > state machine of voltages. it seems like if you know all R and V in a
> > circuit, you have all the information - since I can be derived from them.
> > hence I seems like extraneous information and really just a different way
> > of looking at the system. it is useful to use this point of view when
> > calculating the behaviour of a transistor or tube, but couldn't all that
> > information technically be represented, albeit awkwardly, in terms of R
>and
> > V?
> >
> > in any case, my lack of intuition for I and V mean that i do not easily
> > understand e.g. the effects of the opposite phase shifts imposed by L and
> > C, and the relationship or combination of capacitive and inductive
> > reactance.
> >
> > please reveal the crucial point that makes it all fall into place - !
> >
> > jhno
> >
> >
> >
> >
> >