I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+

The expresion of which takes up a couple of lines on notebook paper alone.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

On Tue, 22 Jul 2008 23:46:42 -0500, "Tim Williams"
wrote:

I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+

The expresion of which takes up a couple of lines on notebook paper alone.

Tim

I find it easier (and less error prone) to use jw = s (Laplace
notation) until the very end, when you need to split amplitude and
phase.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Democrats are so cute. Â*Stupid as bricks, but cute.

On Tue, 22 Jul 2008 23:46:42 -0500, "Tim Williams"
wrote:

I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+

The expresion of which takes up a couple of lines on notebook paper alone.

Tim

I spent the day programming, and programming has absolutely nothing to
do with math.

John

On Wed, 23 Jul 2008 14:04:16 -0700, John Larkin
wrote:

I spent the day programming, and programming has absolutely nothing to
do with math.

Curiously, I spent the day plumbing, which ended up involving the Law of
Sines for some strange reason.

"R.L. Horn" wrote in message
...
Curiously, I spent the day plumbing, which ended up involving the Law of
Sines for some strange reason.

That Chebyshev guy was working on turning linear (pistion) motion into
circular (wheel) motion when he came up with those functions of his.

Anyone have a reference for a more detailed explanation of what Chebyshev was
up to? My knowledge of him comes primarily from a couple of brief footnotes
in engineering texts. I asked our ME at work if he'd every heard of the guy,
and he said no.

---JOel

On Thu, 24 Jul 2008 05:32:10 +0000 (UTC), "R.L. Horn"
wrote:

On Wed, 23 Jul 2008 14:04:16 -0700, John Larkin
wrote:

I spent the day programming, and programming has absolutely nothing to
do with math.

Curiously, I spent the day plumbing, which ended up involving the Law of
Sines for some strange reason.

And a higher sense of accomplishment, no doubt.

John

John Larkin wrote:
On Thu, 24 Jul 2008 05:32:10 +0000 (UTC), "R.L. Horn"
wrote:

On Wed, 23 Jul 2008 14:04:16 -0700, John Larkin
wrote:

I spent the day programming, and programming has absolutely nothing to
do with math.
Curiously, I spent the day plumbing, which ended up involving the Law of
Sines for some strange reason.

And a higher sense of accomplishment, no doubt.

John

Higher math, higher sense of accomplishment. What's not to like? Beats
working for a living. I just finished a section showing that the SNR
of a focused-beam measurement is proportional to the square of the
Strehl ratio--thereby showing how optical aberrations affect the actual
data.

Cheers,

Phil Hobbs

On Fri, 25 Jul 2008 10:18:15 -0400, Phil Hobbs
wrote:

John Larkin wrote:
On Thu, 24 Jul 2008 05:32:10 +0000 (UTC), "R.L. Horn"
wrote:

On Wed, 23 Jul 2008 14:04:16 -0700, John Larkin
wrote:

I spent the day programming, and programming has absolutely nothing to
do with math.
Curiously, I spent the day plumbing, which ended up involving the Law of
Sines for some strange reason.

And a higher sense of accomplishment, no doubt.

John

Higher math, higher sense of accomplishment. What's not to like? Beats
working for a living. I just finished a section showing that the SNR
of a focused-beam measurement is proportional to the square of the
Strehl ratio--thereby showing how optical aberrations affect the actual
data.

Cheers,

Phil Hobbs

And I find that the more hairy electronics I design, the less real
math I do. Square roots now and then, logs rarely, calculus pretty
much never. Simulate and fiddle, now and then.

Electronic design is largely qualitative. Of course, one has to
understand Fourier transforms and correlations and physics and stuff,
but not actually have to do them much.

John

On Tue, 22 Jul 2008 23:46:42 -0500, "Tim Williams"
wrote:

I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+

The expresion of which takes up a couple of lines on notebook paper alone.

Tim

The circuit you analyze in the PDF looks like the same one you asked about
in sci.electronic.basics in November or 2005. Didn't that have something
to do with induction heating?

You've definitely improved your skills with complex algebra in the
meantime. However, in the PDF file, on the first page, around the middle
you show 5 algebraic manipulations. The third one is in error.

You have:


jwL + R
= -----------
1 + jwRC

but it should be:

R
= jwL + ----------
1 + jwRC

The circuit you show in this post at the beginning can be analyzed as shown
in the attachment.

"The Phantom" wrote in message
...
On Tue, 22 Jul 2008 23:46:42 -0500, "Tim Williams"
wrote:

I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+
^ ^ ^ ^ ^ ^ ^ ^ ^ ^

The circuit you analyze in the PDF looks like the same one you asked about
in sci.electronic.basics in November or 2005. Didn't that have something
to do with induction heating?

Excellent memory! In fact the one quoted above is specifically my induction
heater output network... the one in the PDF is a simpler network, notably
differing in that Lw -- infinity. If Lw cancels with most of C (which it
does at resonance, except for the amount that Lm takes for itself), then
what's in the PDF is an acceptable model. But that's limited to resonance
only, which is kind of boring.

On the other hand, it works for anywhere you want to look at a
series-resonant tank with R || C...

You've definitely improved your skills with complex algebra in the
meantime. However, in the PDF file, on the first page, around the middle
you show 5 algebraic manipulations. The third one is in error.

Yup, I noticed that just this evening. Transcription error. I had it right
on paper, and I believe correct in ASCII as well. So, blame it on LaTeX...
LaTeX made me do it. :^)

I believe I also have the correct form of the four-element network. I fixed
the error where I was getting a few hundred negative ohms on the complex
plane. :^)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Tim Williams" wrote in message
...
Yup, I noticed that just this evening. Transcription error. I had it right
on paper, and I believe correct in ASCII as well. So, blame it on LaTeX...
LaTeX made me do it. :^)

If you want to use LaTeX but not bang your head against the wall nearly as
much (at least until you become quite proficient at it), you might want to
look at Scientific Workplace by McKichan Software (www.mackichan.com) -- it's
a WYSIWYG editor that still keeps everything in TeX internally so you can keep
using (most) LaTeX packages with it, style files, etc.

Some other options are MathType, which lets you enter the equation via WYSIWYG
and then generates the LaTeX for you, or something like Ekee which previews
LaTeX equations graphically (http://rlehy.free.fr/).

LaTeX/TeX is slowly dying, which is sort of a mixed blessing: While rather
brittle and difficult to use (far more so than need be in this day and age),
it still has many good features and ideas that regular word processors don't
(or don't implement as well). The hard-core TeXer keep
supporting/revising/updating it, but I suspect that it's still going to die
out almost entirely within a decade. (Where I did my graduate work only a
couple of departments -- ECE, math, etc. -- were still recommending it for
theses, but other than individual professor's requirements, I don't think it
was ever *required* so long as you could generate a PDF for the library
meeting the formatting standards proscribed.)

The biggest problem with, e.g., Microsoft Office and OpenOffice is that they
tend to start becoming brittle themselves when working on large documents.

---Joel

"FatBytestard" wrote in message
...
ANY application that needs to deal with ANY overtly large file is going
to tax ANY system.

I've used both Word and LaTeX for large (100 pages), and I guarantee you that
LaTeX is much more stable in such situations.

LaTeX isn't exactly "user friendly" and has plenty of its own warts, but it's
very predictable, stable, and bug-free.

There was even an editorial back in the early 2000's in one of the IEEE
journals (I believe) where the editor lamented how Word was getting less and
less stable -- for large document usage -- with each subsequent release after
Office 2000. I've been told that Microsoft was making stability something of
a priority for Office 2007, though (but haven't used it myself).

Since spreadsheet and database apps are specifically meant to deal with
files so large, if opened on an appropriate system, one will experience
no problems.

Get a clue: Of all Word documents, how many do you think are 100 pages?
Maybe 0.01%? Guess how much priority fixing bugs related only to such
documents receives?

There's a good reason that very few books are published using Word as the
final typesetting program of choice.

---Joel

"FatBytestard" wrote in message
...
It sucks for DTP. THAT is the reason. Word is not designed for huge
documents

Agreed!

like excel, access, publisher, and powerpoint are.

Access is a toy compared to something like SQL Server. While Microsoft has
never attempted to position Access as a "high end" database, you see an
unfortunately large number of people trying to press it into service as one.
It's often the usual case of where companies would rather have an employee
spend some hundreds of hours per year fighting with Access to get the job done
rather than just ponying up the money for SQL Server (or some other heavy-duty
database) proper -- salaries are easier to budget for than software upgrades.

Excel seems to have some surprisingly low "maximums," like 64k rows, but it's
been suggested to me that this may be done on purpose because it's difficult
to argue that you shouldn't be using a real databse by the time you hit 64k
row. So I'll reserve judgement there...

I haven't used Publisher and only used PowerPoint a few times, so I'll refrain
from commenting on them as well.

Perhaps in the future, you should be more specific.

Fair point.

---Joel

"The Phantom" wrote in message
...
The circuit you show in this post at the beginning can be analyzed as
shown
in the attachment.

Bah, a triple-decker, with j's on all levels. Didn't your mother teach you
anything about math? ;-) (Probably not, mine isn't big on math...)

Here's the simplified version. It makes pretty plots that make sense, even
giving real-world values.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

On Thu, 24 Jul 2008 03:30:41 -0500, "Tim Williams"
wrote:

"The Phantom" wrote in message
.. .
The circuit you show in this post at the beginning can be analyzed as
shown
in the attachment.

Bah, a triple-decker, with j's on all levels.

What's wrong with j's on all levels? If you can deal with j's in the
numerator, you should be able to deal with them in the denominator too.
That way you have a very compact expression, and avoid the possibility of
making an error in deriving the cumbersome expression you get when you
rationalize it (multiply the numerator and denominator by the conjugate of
the denominator).

Didn't your mother teach you
anything about math? ;-) (Probably not, mine isn't big on math...)

Here's the simplified version.

My expression agrees with this. It's identical, except that I left mine in
factored form, which makes it a less cumbersome expression.

It makes pretty plots that make sense, even
giving real-world values.

Tim

"The Phantom" wrote in message
...
What's wrong with j's on all levels?

I was told to "simplify" expressions so that no radicals, imaginary factors,
fractions, etc. are on the bottom.

Too bad this leads to less than simple expressions, like for such purposes
as this!

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

On Fri, 25 Jul 2008 00:33:41 -0500, "Tim Williams"
wrote:

"The Phantom" wrote in message
.. .
What's wrong with j's on all levels?

I was told to "simplify" expressions so that no radicals, imaginary factors,
fractions, etc. are on the bottom.

Same here. Makes splitting into net real and imaginary parts rather
obvious.


Too bad this leads to less than simple expressions, like for such purposes
as this!

Tim

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Liberals are so cute. Â*Stupid as bricks, but cute.

On Fri, 25 Jul 2008 00:33:41 -0500, "Tim Williams"
wrote:

"The Phantom" wrote in message
.. .
What's wrong with j's on all levels?

I was told to "simplify" expressions so that no radicals, imaginary factors,
fractions, etc. are on the bottom.

Too bad this leads to less than simple expressions, like for such purposes
as this!

What software are you using for plotting these expressions?


Tim

On Fri, 25 Jul 2008 00:33:41 -0500, "Tim Williams"
wrote:

"The Phantom" wrote in message
.. .
What's wrong with j's on all levels?

I was told to "simplify" expressions so that no radicals, imaginary factors,
fractions, etc. are on the bottom.

If you go back and look at the thread from Nov 2005, you will see that at
one point you said:

"Ah, well then. Imaginary numbers are fine for imagining things, but I
need real numbers, that exist in the real world."

Apparently the plotting routine you were using at that time couldn't deal
with the complex constant j. But now you are able to deal with it in the
numerator. Whatever you're doing with j in the numerator, you can do the
same with j in the denominator.

When it comes to plotting functions, there's no need to '"simplify"
expressions so that no radicals, imaginary factors, fractions, etc. are on
the bottom.'

In fact, doing all the algebra to "simplify" increases the possibility of
making a mistake. If you just plot the simplest expression, such as the
first one in my attachment, the one with "j's on all levels", the plot
should be the same, and with no extra algebraic simplification necessary.


Too bad this leads to less than simple expressions, like for such purposes
as this!

Tim

The revised addition.

Typo fixed, plus a subtle typo nobody else noticed. ;-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Tim Williams" wrote in message
...
I did this. And the more difficult problem of:

Z o---Lm---+---C---+---GND
| |
+---R---+
| |
+---Lw--+

The expresion of which takes up a couple of lines on notebook paper alone.