FETs Vesus Bipolars, Why More Efficient?

[Active8]

On Sat, 04 Dec 2004 18:57:39 GMT, Ratch wrote:

Below is an exchange I had with a professor of EE.
http://ece-www.colorado.edu/~bart/

I recognize the /~bart directory. I've downloaded his lecture notes.

--
Best Regards,
Mike

 

[Kevin Aylward]

lemonjuice wrote:

On Sat, 04 Dec 2004 18:57:39 GMT, "Ratch" <Watchit@Comcast.net> wrote:



To all interested parties,
I once believed that transistors were current controlled devices,
for
the reasons some of you have you have enumerated. I even had an
argument
with Kevin a couple of years ago. I was and still am impressed by
his arrogant, know it all attitude. Since that time I have been
introduced
to
new explanations, both from external sources, and Kevin himself from
various
responses he has made to threads relating to this subject. I have
since
concluded that on this particular subject he is right, as painful as
it may
be to admit it.

There is nothing to fear except the persistent refusal to find out
the truth , the persistent refusal to analyze the cause of
happenings.
D. Thompson

I ageee. You have been presented with the truth, and refuse to see it.

I haven't seen anyone trying to find out or prove logically or
physically why a transistor is voltage controlled apart from simply
writing an equation with Vbe included.

There has been many arguments, you simply wont are cant understand them.

We need proof ... solid proof. But not from people who still believe
that electrons orbit the nucleus like the planets... they are 96
years backwards in Physics.

We gave a simplified, non mathematical proof.

1) Applying a voltage to a diode will cause a current through it.
2) A given voltage must produce a current dictated by the laws of
physics, however that voltage gets there, i.e. Id=Is.exp(Vd/KT).
3) The base terminal of a transistor is simply a method to place a
voltage at the above diode junction.
4) Whatever current exists in the base to set up such a voltage is,
essentially, irrelevant. Itt wont change the diode relation.

As prior noted, have a read of
http://www.mtmi.vu.lt/pfk/funkc_dariniai/transistor/bipolar_transistor.htm

Also, it has beep pointed out hat it is *electric* field that cause
charges to move. What more is there needed to actually say?

---------------------------------------------------------------------------


See also the following link.

http://amasci.com/amateur/transis2.html

Links don't mean much .

They do if the explanation actually makes sense from a basics physics
point of view. If they start with well known principles and logically
derive a result that can have value. Unfortunately, the real issue is
when the reader simply don't understand the basic, and worse, doesn't
know that they doesn't understand the basics.

Again, what I find incredible here is that you are continually being
presented with evidence that explains, from *basic* physics why the
transistor is voltage controlled, and you cant actually understand the
explanation. You then have the audacity to claim that some of us here
are not up to much, based on this obvious evidence that it is you that
are not qualified.

Here goes
Check on this .

A normal transistor is a small device that uses a current to control
or modulate another current.

In a very simplified sense, one may use this approximation, sometimes.

Look, again, with all due respect, you have only the most elementary
understanding of this. This debate is quite daft as no, and I mean *no*
semiconductor device physics takes the view you are mentioning. Any
degree course worth its salt gets these misconceptions dispensed with
from day one. Why you still don't understand this, I just dont know.
This is despite the basics physics being described to you.

In a bipolar-junction transistor, an electrical current fed into a
base modulates the current flow between two other terminals -- the
emitter and collector.

Ho hummmm..

You need to understand that there is much nonsense written about the
transistor. We are telling you what is the accepted, standard *academic*
texts, not comics, or bantam paperbacks. This description is not
debatable. It is the way it is. It is just unfortunate that you don't
know what the accepted physics take on this is. None of us our
presenting our own view, we are presenting that with the academic world
has no debate about.

Some of us have actually done formal solid state physic classes in their
degree you know. You need to learn how to read real clues as to who
actually knows what they're talking about.

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.

 

[Active8]

On Sun, 05 Dec 2004 14:18:19 GMT, Ratch wrote:

"Active8" <reply2group@ndbbm.net> wrote in message
news:36heqomgvh0k$.dlg@news.individual.net...
On Sat, 04 Dec 2004 18:57:39 GMT, Ratch wrote:


Below is an exchange I had with a professor of EE.
http://ece-www.colorado.edu/~bart/

I recognize the /~bart directory. I've downloaded his lecture notes.

Yeah. I see now that I've downloaded the whole EE 3320 web book.

Looking through it, it appears to cover the same stuff as the MIT
open courseware on EE 6.012. Either someone swiped that page that
dealt with Early voltage, or the link posted in this thread went
right to the web book.

--
Best Regards,
Mike

 

[Kevin Aylward]

lemonjuice wrote:

On Tue, 30 Nov 2004 18:38:42 -0500, Active8 <reply2group@ndbbm.net
wrote:

On 30 Nov 2004 12:41:09 -0800, lemonjuice wrote:

Hey Poindexter. Do you thing you can find Integral f(x) dx with
only one point? Even if one limit if integration is at infinity,
it's still a point, i.e. dx has two ends.

OK... man then ... In fact 1 of the many possible definitions of
Potential says its related to the work done in bringing a unit
charge from infinity to an electrical field.

So man you already got your second point defined. When I say
whats
the
potential you already know its related to infinity.

Look up equipotential surfaces. Like I said, my Rx antenna has a
voltage at the feed that's proportional to it's length and the
strength of the electric field in V/m.


WHy are you cutting
Electrical field strength = Potential ... Thats another new theory
(grin)

BTW equipotential surfaces have nothing to do with this.

Look up the definition of Electrostatic potential.

For a point (x,y,z) its mathematically its

V(x,y,z) = q/4 * pi * epsilonnought * r
As I said before the reference point is at infinity.

But the original equation used to arrive at that has variables for
two potentials - one gets set to zero at a distance of infinity -
and two points - one which gets set to infinity as one of two limits
of integration.

The original equation is dV/dx = E
How many constants are in the solution?
Only 1. Why?
Because its a 1st Order differential equation.
What is the value of the constant .
Zero.

Why?

So the answer is simply V= E*x

Very very simple.

I'm not talking about Potential difference which is the potentail
between 2 points ... but the Potential of a single point
If you ever heard that Potential difference = Potential ...(grin)
then you have another new theory unheard of to me. Anyone who knows
about this theory send me a post please. Sounds
like Kevins "electrons with a centripetal force" theory. (double
grin)

The grin of the court jester.

I note you had no argument against the fact that an electron cant stay
in an atom if it don't change its direction at some point, not unless
the electron is always motionless. Is that which you claim?

Look you examine a point P(x,y,z) in an electrical field. According
to your reasoning its wrong to talk about the potential of the single
point. Lets assume you're right.

Its not "wrong" in the sense that one can use an implied reference, but
potential on its own has no physical meaning. Absolute potential can not
be physically measured. (see below)

As Potential is Energy per unit charge you are claiming
that bringing a unit charge from far off to that point would involve
zero energy.

In your Mickey mouse mathematics, sure.

So you violate the law of conservation of energy because
you assume that the energy of all unit charges in an electrical field
are zero.

No it wouldnt.

This is just one of the many ways to show why your idea is wrong.

Nope. Your just clueless about physics.

There's no rule stating that one point must be at
infinity.

This is basic physics, dude.


Its what physicists use and there is a physical reason why infinity
is known to be >a point of zero potential.

No it is not so known. Look you just make this up as you go along. You
have no idea what physicists say. Its *defined* to be zero. The charge
at infinity could be 1.54328C without changing any measurable physical
effects. Look up "gauge invariance". Physicists chose any gauge that is
convenient for simplifying the calculations, not because it is any more
correct than any other gauge. It helps the numbers to arbitrarily say
the potential at infinity is zero. Please describe an experiment to
prove that it is not that potential due to a charge of 1.45328C.

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.

 

[Kevin Aylward]

John S. Dyson wrote:

In article <1d15af91.0412051502.5ece8a33@posting.google.com>,

of 'engineering support staff.'

Note that I very commonly disagree with both Kevin and Wilfred on
many subjects,

No you dont.

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.

 

[John Larkin]

On Mon, 6 Dec 2004 06:51:13 +0000 (UTC), toor@iquest.net (John S.
Dyson) wrote:

Except in the most trivial circuits, modeling a transistor as a current
controlled current source is almost useless. As a most simple example, try
to describe a good first order approximation of the dynamic (not static)
behavior of a transistor switch with a current controlled current source
(beta) model vs. the more useful and admittedly more nonlinear voltage
controlled current source first order approximation.

OK. The driving device pumps current into the base, and it's opposed
by the "Miller" current in the c-b feedback capacitance, per Im = Ccb
* DVc/dt.

Solve for a decent first-order approximation.


John

 

[John Woodgate]

I read in sci.electronics.design that Kevin Aylward
<salesEXTRACT@anasoft.co.uk> wrote (in <V1Wsd.89506$F7.52260@fe1.news.bl
ueyonder.co.uk&gt about 'FETs Vesus Bipolars, Why More Efficient?', on
Mon, 6 Dec 2004:

John S. Dyson wrote:
In article <1d15af91.0412051502.5ece8a33@posting.google.com>,

of 'engineering support staff.'

Note that I very commonly disagree with both Kevin and Wilfred on
many subjects,

No you dont.

You don't agree that he often disagrees with you. So you disagree with
him. Since the disagreement operator X is commutative, I think your case
is a bit weak! (%-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Winfield Hill]

Kevin Aylward wrote...

John S. Dyson wrote:

Note that I very commonly disagree with both Kevin and
Wilfred on many subjects,

No you dont.

Trying to prove the point? Is this the right room for
arguments, not for mere gainsaying?


--
Thanks,
- Win

 

[Winfield Hill]

John Larkin wrote...

OK. The driving device pumps current into the base, and it's opposed
by the "Miller" current in the c-b feedback capacitance, per Im = Ccb
* DVc/dt. Solve for a decent first-order approximation.

Perhaps you found one. Perhaps not. In this case the base is
a summing junction whose voltage is constant, controlled by Vbe.
For simplicity, we consider the Miller current going into the
Ccb capacitance to be "outside" the transistor... :&gt


--
Thanks,
- Win

 

[Rich Grise]

On Mon, 06 Dec 2004 15:27:01 -0800, Winfield Hill wrote:

Kevin Aylward wrote...

John S. Dyson wrote:

Note that I very commonly disagree with both Kevin and
Wilfred on many subjects,

No you dont.

Trying to prove the point? Is this the right room for
arguments, not for mere gainsaying?

I'm still trying to figure out who this "Wilfred" guy is. ;-)

Thanks!
Rich

 

[Paul Burke]

Winfield Hill wrote:

Kevin Aylward wrote...

John S. Dyson wrote:

Note that I very commonly disagree with both Kevin and
Wilfred on many subjects,

No you dont.


Trying to prove the point? Is this the right room for
arguments, not for mere gainsaying?

British irony I think. Kevin was trying to sound like my Mother.

Paul Burke

 

[John Larkin]

On 7 Dec 2004 04:10:06 -0800, "lemonjuice" <exskimos@anonymous.to>
wrote:

No change in Vbe => gm * change in Vbe = 0 <=> Transconductance model
is a totally invalid analysis without considering the small base
current flowing through the base emitter junction.

This is one of the many other ways of proving again that the BJT is a
CCCS.

This is all silly. If you're poking current into the base, it's
current controlled, and if you're applying voltage, it's voltage
controlled. And the collector current goes up exponentially on base
voltage except when it doesn't.

That's what an engineer believes, anyhow. Philosophers can design
circuits the hard way if they feel the need and don't have anything
else to do.

John

 

[Winfield Hill]

Don Pearce wrote...

Everything obeys Ohms law. Whatever the condition, V/I=R. OK, so
R changes - V and I change accordingly. Ohms law is still obeyed.

Another useless concept, as stated. Incrementally applied,
that's another matter.


--
Thanks,
- Win

 

[Kevin Aylward]

lemonjuice wrote:

On Tue, 7 Dec 2004 20:17:54 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that lemonjuice
exskimos@anonymous.to> wrote (in
1102421406.506495.104990@c13g2000cwb.googlegroups.com&gt about 'BJT
transistor beta, vs Ebers-Moll, Gummel-Poon, and the other tools God
has given us', on Tue, 7 Dec 2004:

I don't see why the gm system is actually better as the 2 are
interlinked by the relation.

gm = hfe* dIb/dVbe

so you aren't avoiding beta by using gm. Its quite an unpredictable
variable too.

O no it isn't! (This is pantomime season in Britain.) I'm surprised
you didn't use hie instead of writing it as dIb/dVbe. But that's
beside the point, which is that hfe and hie both depend on more
fundamental quantities, and depend *inversely*, so that gm has FAR
less variation between samples of the same device than hfe has.

Really. From what I can remember dIb/dVbe is constant for the most
important intervals of Vbe.

Yeah, so your memory capacity is around 5 Bytes, your point is?

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.

 

[Active8]

Are you aware of the fact that this is just Dr. Slick (check the
headers) f*cking with you?
--
Best Regards,
Mike

 

[lemonjuice]

Really. From what I can remember dIb/dVbe is constant for the most
important intervals of Vbe.

What ????

...Jim Thompson
Yup... just like gm (grin)

 

[Jim Thompson]

On Wed, 08 Dec 2004 15:32:09 GMT, "Kevin Aylward"
<salesEXTRACT@anasoft.co.uk> wrote:

[snip]

Your just trolling, now go away.

Kevin Aylward

Hey, Kev, Please try to use good English... you consistently use
"your" when it should be "you're" ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Paul Burke]

Kevin Aylward wrote:

Hey, Kev, Please try to use good English... you consistently use
"your" when it should be "you're" ;-)

Oh, does your and you're sound any different?

Don't take the bait Kevin. Having lost on transistors, people want to
beat you on grammar. If I were you I'd settle for being an electronics
engineer and let them be expert grammatical engineers.

Paul Burke

 

[Jonathan Kirwan]

On Thu, 09 Dec 2004 16:54:04 GMT, "Kevin Aylward" <salesEXTRACT@anasoft.co.uk>
wrote:

I think I'm getting credit here for something I aint done

hehe!

Jon

 

[Winfield Hill]

Kevin Aylward wrote...

Paul Burke wrote:
Kevin Aylward wrote:

Hey, Kev, Please try to use good English... you consistently
use "your" when it should be "you're" ;-)

Oh, does your and you're sound any different?

Don't take the bait Kevin. Having lost on transistors, people want
to beat you on grammar. If I were you I'd settle for being an
electronics engineer and let them be expert grammatical engineers.

Wait untill they hear me speak. I'm from London, mate.

We'll be able to understand you?


--
Thanks,
- Win