John
Is that really true?
I don't really work in the s plane usually, or in any practical way, but it
could be very useful when one has inadvertently introduced a zero to know
where it is. Also, being able to pinpoint poles would make no end of
difference - it would save lots of calculator time between screen shows.
It also strikes me as an advance in general. If what one saw could tempt
users to view things in a more basic way they would understand the working
'tant mieux'. It would advance the 'feeling' about a circuit. Many may not
agree, but I think 'feeling' is good in design. If something can put in
front of you all the toys that you are playing with, then how can that be
worse? And you often can't see on screen, in the tenths of a degree of
phase shift, if anything is going on whatever, when you are looking within
your bandwidth.
I have a delicious example of this. Why should an amplifier, driving well
designed speakers, sound better when it has a 0R22 resistor on its output?
It does, and there is a reason, and it has nothing to do with damping
factors. The resistor is nominally there to aid stability, but it in fact
characterises the whole amplifier.
Looking at the result of high pass and low pass sections of a speaker is the
way to find out what's happening here (both of which get better by the
way), but wouldn't it be lovely if LTS flagged the zero that had been
introduced. "Hoy mates, brand new zero. " Don't know what you've done, but
here it is right under my finger!"
That has to be worthwhile, doesn't it? I brace myself for Woodgate's
searing reply as he cauterises my ignorance.
CT
,
On 12 September 2011 08:53, John Woodgate <jmw@...> wrote:
**
In message <j4kc7c+m7e7@...>, dated Mon, 12 Sep 2011,
RobertTalty <rtalty@...> writes:
Not much point focusing on the WHY PZ analysis is not supported!
As I understand it, software PZ analysis as normally implemented doesn't
stop at realistic frequencies and pole or zero co-ordinates, because it
can't be told what they are. So you get as a result every pole and zero
from DC to light, some with extreme co-ordinates, and not all of the
irrelevant ones are outside the useful passband of the circuit.
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
When I point to a star, please look at the star, not my finger. The star
will
be more interesting.
[Non-text portions of this message have been removed]
