Driver to drive?

[Jens Tingleff]

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Jumbaliah wrote:

I'm trying to come up with some component values for a pi-network low
pass filter for my future DDS project.

There are loads of books with schematics and tables of component values for
filters.

I arranged eq1 and eq3 to solve for I2. I solved for I1 in eq2 and
sub'd that into eq1 and 3. I factored and cancelled and flipped the
equation till I got Z3/(Z2+Z3). It doesn't seem right that Z1 isn't
involved. I must have missed something here.

What you might have overlooked is that Z1 is loading a perfect voltage
source, and so there is no effect on voltage V1 from Z1. Simple

You could put a current I1 into node 1, that would make Z1 a part of the
trans-resistance transfer function.


Best Regards

Jens


- --
Key ID 0x09723C12, jensting@tingleff.org
Analogue filtering / 5GHz RLAN / Mdk Linux / odds and ends
http://www.tingleff.org/jensting/ +44 1223 211 585
"I lost my heel" "Oh, don't worry about him!" 'Bringing up Baby'
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[Allan Herriman]

On 1 Nov 2004 22:27:59 -0800, burnboy1000@hotmail.com (Jumbaliah)
wrote:

I'm trying to come up with some component values for a pi-network low
pass filter for my future DDS project. I started to try and figure
out the basic transfer function for a 3rd order pi-network (two caps
and one inductor). It doesn't look right to me so I wanted a second
opinion.

Vi-+--Z2--+--Vo
| |
Z1 Z3
| |
Gnd Gnd

What I have is Vo/Vi = Z3/(Z2+Z3).

The equations I used to reach this was the following:
I2 is a current loop from Vi -> Z1 -> Gnd -> back to Vi
I1 is a current loop from Gnd -> Z1 -> Z2 -> Z3 -> Gnd

eq1 Vi = I2*(Z1) - I1*(Z1)
eq2 Vo = I1*(Z3)
eq3 0 = -I2*(Z1) + [Z1 + Z2 + Z3]*I1

I arranged eq1 and eq3 to solve for I2. I solved for I1 in eq2 and
sub'd that into eq1 and 3. I factored and cancelled and flipped the
equation till I got Z3/(Z2+Z3). It doesn't seem right that Z1 isn't
involved. I must have missed something here.

Would anyone have the general transfer function for a nth degree
pi-network?

You seem to be missing something, namely the input and output
impedances.


Vi--Za--+--Z2--+----+--Vo
| | |
Z1 Z3 Zb
| | |
Gnd Gnd Gnd


Za is the source impedance, and Zb is the load impedance. Vi
represents the potential of the Thevenin source, rather than the
actual voltage across the output terminals of the driver.

In a typical RF system, Za and Zb will both be 50 ohm, and (close to)
resistive.

Regards,
Allan

 

[Kevin Aylward]

Jumbaliah wrote:

I'm trying to come up with some component values for a pi-network low
pass filter for my future DDS project. I started to try and figure
out the basic transfer function for a 3rd order pi-network (two caps
and one inductor). It doesn't look right to me so I wanted a second
opinion.

Vi-+--Z2--+--Vo
| |
Z1 Z3
| |
Gnd Gnd

What I have is Vo/Vi = Z3/(Z2+Z3).

The equations I used to reach this was the following:
I2 is a current loop from Vi -> Z1 -> Gnd -> back to Vi
I1 is a current loop from Gnd -> Z1 -> Z2 -> Z3 -> Gnd

eq1 Vi = I2*(Z1) - I1*(Z1)
eq2 Vo = I1*(Z3)
eq3 0 = -I2*(Z1) + [Z1 + Z2 + Z3]*I1

I arranged eq1 and eq3 to solve for I2. I solved for I1 in eq2 and
sub'd that into eq1 and 3. I factored and cancelled and flipped the
equation till I got Z3/(Z2+Z3). It doesn't seem right that Z1 isn't
involved. I must have missed something here.

Would anyone have the general transfer function for a nth degree
pi-network?

Thanks.
Burnboy

This is called "filter design". There are no *useful* completely general
formulas for general filters. However, this is a subject extensively
studied such that there are loads of programs out there that will
calculate suitable values for specific filters, e.g. SuperSpice, and
other general filter design programs. I suggest a web search.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Winfield Hill]

Robert Monsen wrote...

John S. Dyson wrote:

It is interesting that Holbrooke doesn't seem to agree with Kerry's
claims. Holbrooke (sp), Kerry's foreign policy advisor, seems not
to be sure about the status of the so-called 300+tons of high explosives
in Iraq, but Kerry is making cocky and absolute claims. In this case,
Holbrooke seems more realistic than Kerry's obvious lies.

Here is what he really said:

http://www.newshounds.us/2004/10/27/richard_holbrooke_taken_out_of_context.php

On yesterday’s Big Story with John Gibson, Ambassador Richard Holbrooke
discussed the missing explosives situation. During the interview he made
a statement that the Bush surrogates have taken out of context and are
now repeating ad nauseam to every newsperson who sticks a microphone in
their face. Here are some excerpts from that interview:

In response to Gibson’s statement that the NBC crew didn’t see any UN
seals on any explosives when they traveled near the Al Qaqaa munitions
site, Holbrooke says “That’s not accurate” and goes on to say that the
NBC reporter noted that “they didn’t look very hard and then they moved
on and she didn’t see anything. And that was three weeks later. You and
I don’t know what happened...I do know one thing. In most
administrations the buck stops in the Oval Office. The White House press
spokesman, Scott McClellan, says that President Bush was only aware of
this ten days ago and I’m a little troubled by that..” Later he said:
“You don’t know the truth. I don’t know the truth....If this stuff’s
missing, it’s a direct threat to Americans.”

Later still:

HOLBROOKE: “...But, the President said in the first debate that “Senator
Kerry had the same intelligence that I had.” Do you believe that, John?
I worked in the White House. I worked in the government for 40 years...

GIBSON (interrupts): You’re saying the President knew more than Kerry
learned at the UN, when he went to meet the Security Council?

HOLBROOKE: Of course. The President of the United States - our
commander-in-chief - has

GIBSON (Interrupts again): You’re saying he knew there were no WMD?

(FOX starts playing its “get that guest off in a hurry” music.)

HOLBROOKE (patiently, as if explaining to a particular dense child): No.
I’m saying that when George Bush says that John Kerry had the same
intelligence he - the President of the United States - had, that’s
completely untrue. The fact is that Presidents have intelligence in a
way that no one else has. (Gestures to Gibson) Wait a second - I’m gonna
finish - and secondly that it’s his intelligence. You didn’t have it. I
believed there was WMD. You believed. John Kerry. John Edwards believed
it, but it was the administration’s intelligence.

Comment

On today's Big Story White House spokesman Dan Bartlett jumped all over
Holbrooke's one statement "I don't know the truth" to impugn John Kerry
for attacking the President.

To his credit Gibson did read back the quote and offered his own
explanation for what Holbrooke meant, i.e., that the ultimate
resonsibility for knowing about this lay with the President.

I'm troubled by the progress of these conversations. Bush supporters
rattle off a quick lying damning accusation against Kerry, turn it
into a sound bite and repeat it ad nauseam. Someone, News Hounds and
then Robert in this case, researches and carefully presents the truth,
which is generally the total opposite of the Bush camp's sound bite.
Although this truth completely refutes the Bush follower's lies, it's
barely noticed, and the sound bite lives on, growing louder and louder.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Rich Grise]

On Sat, 30 Oct 2004 09:17:36 +0000, Robert Monsen wrote:

Clarence wrote:
"Robert Monsen" <rcsurname@comcast.net> wrote in message

Well, point out some actual lies, and we'll see. Use well documented,
non-partisan sources.

Everything he says!
Besides you believe him, so you can't recognize facts. You a poor
judge, in fact your no a judge at all.

I haven't said anything one way or another about Moore, except that I
don't believe he is 'the epitome of dishonesty'. I've asked for an example
of a single lie from him that is documented by non-partisan sources.
Neither you nor Yanik seems to be able to come up with one.

You sound surprised. ;-)

Cheers!
Rich

 

[Rich Grise]

On Sat, 30 Oct 2004 13:59:58 +0000, Jonathan Kirwan wrote:

It quite simply takes work to read facts and to assimilate them. Most
folks aren't willing to put in the work to be comprehensive (too willing
to take the lazy way out.) All of us have to fight that impulse, though
with practice it gets easier to do so. But if you bank on laziness,
you'll win every time.

By the way, this could get everyone back into the idea of whether or not
there is "free will." But I won't go there.

Well, I will, imagine your surprise. ;-)

It's quite simple. Since the will is the intuitive, feeling-sense, its
denial leads the person wide open to fall for any scheme that puts on
a pretty face - you have to sense what's under the pretty face to know
the difference. Evil simply feels wrong, which makes the objections
of those of us who _do_ know the difference, easy for the faithful to
dismiss, since they don't acknowledge the validity of their own will,
let alone anyone else's.

In other words, the Will is the part of you that tells you when the
authorities are full of shit. Minds are, in general, quite stupid in
that respect.

Thanks!
Rich

 

[Frank Bemelman]

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> schreef in bericht
news:gb18o051janqs9e9gs078am0fgs6quf3rc@4ax.com...

On Sat, 30 Oct 2004 19:24:13 GMT, the renowned Fred Bloggs
nospam@nospam.com> wrote:



Paul Burridge wrote:
On Sat, 30 Oct 2004 02:55:02 GMT, Fred Bloggs <nospam@nospam.com
wrote:


Osama Bin Laden is only confirming what the prescient George Soros
stated yesterday to the National Press Club, he will escalate any
amount
of violence which then induces more violence from us and thus the
proverbial vicious circle. Americans would be wise to read the
philosophy at http://georgesoros.com/index.cfm?Fuseaction=Book before
casting their vote, and then do the reasonable thing which is to vote
for John Kerry.


Ah! So you've finally declared you favor Kerry! I was beginning to
wonder if you were one of these 'floating voters.'
Seriously, only part of the message from OBL has been released for
transmission by our wonderful obfuscatory media. I would urge anyone
who GaS to read the *entire* message, in English translation, from a
suitable Arabic web site. They may then get the full picture for once,
as opposed to the heavily cut rubbish that's invariably fobbed off on
us by the likes of the BBC, ABC, CNN, etc.

You can read the transcript of the OBL video here:
http://english.aljazeera.net/HomePage

Note that this is a* transcript of the approximately 5 minutes that al
Jazeera aired. It is *not* the entire 18 minutes- that's apparently
been censored.

In the actual al Jazeera broadcast, they provided an overview of his
other points (they had the full tape), which may or may not be
accurate as covered by drudge:

http://worldnetdaily.com/news/article.asp?ARTICLE_ID=41181

* They do not say whether it's the English language
translation/transcript that ObL provided along with the tape or an
independent translation.

I like that last paragraph:

"Your security is not in the hands of Kerry or Bush or al-Qaida. Your
security is in your hands. Each state that doesn't mess with our
security has automatically secured their security."

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[Paul Burke]

Carl D. Smith wrote:

This reminded me of a web page I found once that had quite a few
interesting measurements based on combining huge units of
measurement with very small prefixes or vice versa.

The one I remember was the attoParsec. It's about 1.2 inches.

Then of course there are the other units, like the milliHelen: that
quantity of female facial beauty required to launch one ship. Or the
kiloWhale, or the attoBoldon.

Paul Burke

 

[Robert Baer]

Pedro wrote:

Could a common Fluorescent ballast from a domestic light fitting be
used as a LF or audio or smoothing choke? I believe the core has an
air gap to prevent saturation, any idea of the typical inductance?

Thanks
Pedro

Measure it.

 

[Daniel Haude]

On 1 Nov 2004 04:40:57 -0800,
Winfield Hill <Winfield_member@newsguy.com> wrote
in Msg. <cm5asp01gb0@drn.newsguy.com>

As one small example of our country's mood, I offer the plight of our
airlines. It's now clear that we are not collectively afraid of flying.
Yet even though tickets are dirt cheap, our flying miles as a society are
way down in the last few years.

At least one bit of good news.

--Daniel

 

[Daniel Haude]

On Mon, 01 Nov 2004 11:29:15 -0700,
Jim Thompson <thegreatone@example.com> wrote
in Msg. <ejvco0ddt6pthr17s1jovtmco16bjph58u@4ax.com>

And my suspenders set off the metal detector every time, as well as my
Ecco shoes... so here I am shoe-less, with my pants about to fall off,
when I go thru the detector ;-)

So that was YOU I saw at the airport! ;-)

--Daniel

 

[Winfield Hill]

cablespec@3web.net wrote...

I'm looking an easy way to design a dual complementaty SPST switch
with a single control line in order to replace an obsolete Tesas
Instrument IC: TL604CP

You checked with Rochester Electronics? http://www.rocelec.com

Could it be possible to design a such switch using a CMOS CD4066
or by using a couple of fets?

The TL604 is a DPST switch, with a single control line, in an 8-pin
package. It has the feature that when one switch is on, the other
is off. There are a number of DPST switches on the market with this
feature, but none of them are in 8-pin packages (even if they were,
it's unlikely they'd have the same unusual TI pinout). However many
of these switches are available in small soic packages suitable for
making a mini-DIP sized substitute PCB. There are also some 8-pin
SPDT switches available. It's possible your TL604 application has
its two DPST sections wired in common to make a SPDT. In that case
you can consider one of these switches. Yes, the pinout is wrong,
but hey! Sorry about that.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Fred Bloggs]

JeffM wrote:

The President's overall approval is 49%
Fred Bloggs


It seems to me that the polls are all skewed:
Folks who are home to answer the phone are a specific demographic.
Only 10% of folks don't hang up the phone.
Pollsters don't call cell phones; many folks only have cells these days.

Andrew Tanenbaum's animated map of the changing Electoral balance
(May 24, 2004 - present) consolidating the polls:
http://electoral-vote.caida.org

Exactly- that is just one of many factors. The real and final poll is
today- and we shall see.

 

[Winfield Hill]

Daniel Haude wrote...

Winfield Hill wrote

As one small example of our country's mood, I offer the plight of our
airlines. It's now clear that we are not collectively afraid of flying.
Yet even though tickets are dirt cheap, our flying miles as a society
are way down in the last few years.

At least one bit of good news.

What, that tickets are dirt cheap, or that we don't fly much anymore?


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Fred Bloggs]

Julie wrote:

Fred Bloggs wrote:

Julie wrote:
Fred Bloggs wrote:

Julie wrote:

Fred Bloggs wrote:


The Bush criminals in collaboration with Matt Drudge are
starting to make their move to disrupt the national
elections. It is now clear they *will be* voted OUT OF
OFFICE, and the time to act is upon them. This tape is a
total fabrication. Apparently it was too much for the
zealots to forego discussion of "same sex marriage" in this
supposed Al-Qaeda terror production, and this will be the
last straw.


The origins of this tape will be traced back to the Bush
administration, and they will be removed from office:


Do you have any evidence of this that you can provide, or are
you just stating your personal unsubstantiated opinion?

CIA cannot confirm the authenticity of the tape- headline
today. This means it is a fake because there is very little
chance they could not confirm a tape with authentic Al-Qaeda
origin.


Very interesting take on logic: if can't be proved authentic,
*must* be fake.

Did I say that, poser. I said "very little chance".


Poser? whatever.

Your quote: "This means it is a fake..."

I'll equate this to my quote of "*must* be fake" -- variations in
interpretation are minimal, at best.

"Minimal, at best"? You're missing the point.

Your "very little chance" quote was with respect to the ability of
the CIA to confirm.

No- very little chance of being authentic when CIA cannot confirm os
what it means.

And infering from your original post, if fake, it *must* come
from Bush.

If it is fake then it would almost certainly be connected with the
Bush campaign- that campaign was clearly based on a fear platform-
the VP candidate outright warned America *will* be attacked if they
lose.


Regardless of the Bush platform, a connection can't be assumed unless
proven. You merely have jumped to what appears to be a personal
supposition supporting your beliefs/ideas, and in actuality, has
absolutely no relevance to the situation, until proven otherwise.
When that proof comes, please let me/us know.

Real life is not a mathematical proof, beliefs are formed on a
preponderance of reason. You are in fact a Bush supporter posing as an
undecided.

I now understand how you arrive at your conclusions.

I don't really think you do, poser.


Poser? Why does a discussion have to get personal?

Fred -- answer me one thing: do you really think that your messages
are clear, concise, and free from an unbiased opinion? I'm trying to
be *rational* here, I don't always succeed, but I'm trying.

I am not interested in your idea of how to interpret anything- it is
clear you are worthlessly ignorant. It is also clear you lack the
intelligence to read even the simplest news stories, and those are
adjusted for something like a 6th grade education level, so I will not
waste my time going any lower with you.

 

[Winfield Hill]

Paul Burke wrote...

... or the attoBoldon.

Yes?


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Jim Yanik]

toor@iquest.net (John S. Dyson) wrote in
news:cm6scj$1tl6$2@news.iquest.net:

In article <cm6j68$1qr$3@blue.rahul.net>,
kensmith@green.rahul.net (Ken Smith) writes:
In article <6c71b322.0411011526.7e518017@posting.google.com>,
Tom Seim <soar2morrow@yahoo.com> wrote:
There have been claims on SED that Kerry has never admitted to
committing atrocities in Vietnam.

I don't think I ever said that. I said he never said that he
committed war crimes. There is a huge difference, because the word
atrocities covers a lot of things that are not war crimes, doubly so
when it is being used in common language and not in a legal sense.

Mostly, those atrocities that Kerry lied about (or committed) were/are
unacceptable acts, or Kerry told unacceptable lies. Frankly, Kerry's
admission appears to have been partially coached by a lawyer,

I suspect Kerry was coached by the North Vietnamese.
His "testimony" came after he met with the enemy.



--
Jim Yanik
jyanik-at-kua.net

 

[Kevin Aylward]

Winfield Hill wrote:

Jim Thompson wrote...

Right there in front of your eyes. I use it daily... the typical
capacitance of an oxide capacitor on a CMOS process is around
1fF/um^2

For what gate-voltage rating?

The typical voltage rating of typical cmos processes

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Jim Yanik]

toor@iquest.net (John S. Dyson) wrote in
news:cm6v4a$1uoi$2@news.iquest.net:

In article <cm6nek$632$1@blue.rahul.net>,
kensmith@green.rahul.net (Ken Smith) writes:
In article <6c71b322.0411011521.14809f4e@posting.google.com>,
Tom Seim <soar2morrow@yahoo.com> wrote:
[...]
Gee, I thought the president's job was to lead the country.

.. and there is where you are so terribly wrong. The president like
all the others are elected to represent the people.

Actually, you have it confused. It is the legislature (most
specifically, the House of Representatives) that represents the
people. Most accurately, the Senate more represents the states, and
the President is supposed to be the head of state and to be
essentially the President/CEO of the government. The president is
also the civilian leader of the armed forces.

It is very inaccurate to make the claim that the purpose of the 'head
of state' is to represent the people!!!


It is not their job to
try to bend the people to their will.

That seems to be the media's goal(old media,at least).
Evidence is now emerging about the old meida's bias towards Kerry.


--
Jim Yanik
jyanik-at-kua.net

 

[John Fields]

On Tue, 2 Nov 2004 12:12:51 +0100, "Frank Bemelman"
<f.bemelmanx@xs4all.invalid.nl> wrote:

That's exactly how it is. It's not a matter of Kerry being the
solution to everything, which he is not, and nobody is, but what
counts is to get that disgusting piece of shit named Bush out of
office and preferably behind bars. Or cut into pieces and fed
to the dogs.

---
Is that you, Lee Harvey Bemelman?

--
John Fields