Are hybrid parameters useful for design?

[Jamie]

The other cool thing is LEDs. Kids love LEDs, which leads them into
Ohm's Law and so on.

I love LEDs.

Ok, no one answered me about my curiosity about using a laser diode as a
detector.. so, i will conduct some R&D of my own, since I have a few of
them here to play with.

I was just curious if the laser diode would have a PV/PR effect like
LEDS do and to what extent. Also, how would they hold up with a laser
looking straight at them?


Jamie

 

[rajibbandopadhyay]

It's also non-academic, in that a CS degree has almost
nothing to do with coding ability.

Perfectly said...

Hey, something like half of our Harvard and MIT graduates go into the
finance business.

Please do not argue on my behalf. I have learnt to ignore off-topic
arguments. It serves no purpose. BTW, I just posted my observation,
without putting my anguish and frustration behind it. Self-criticism is
an inner compass. It helps improve. It identifies what's ailing...

What sort of stuff do you do?

Don't ask! Another round of verbal abuse would ensue, and veer off-topic.
Regarding meritocracy:
http://dictionary.reference.com/browse/meritocracy?r=75&src=ref&ch=dic
1. an elite group of people whose progress is based on ability and talent
rather than on class privilege or wealth.
2. a system in which such persons are rewarded and advanced: The dean
believes the educational system should be a meritocracy.
3. a social system formed on such a basis
4. Cultural Dictionary: A government or society in which citizens who
display superior achievement are rewarded with positions of leadership.
In a meritocracy, all citizens have the opportunity to be recognized and
advanced in proportion to their abilities and accomplishments. The ideal
of meritocracy has become controversial because of its association with
the use of tests of intellectual ability, such as the Scholastic Aptitude
Test, to regulate admissions to elite colleges and universities. Many
contend that an individual's performance on these tests reflects his or
her social class and family environment more than ability.


Origin:
meritocracy Look up meritocracy at Dictionary.com
coined 1958 by British sociologist Michael Young (1915–2002) and used in
title of his book, "The Rise of the Meritocracy"; from merit (n.) + -
cracy. Related: Meritocratic.

Now the question is: Has any word remained true to its original meaning
much later than when it was coined?

 

[[email protected]]

Perfectly said...





Please do not argue on my behalf. I have learnt to ignore off-topic

arguments. It serves no purpose. BTW, I just posted my observation,

without putting my anguish and frustration behind it. Self-criticism is

an inner compass. It helps improve. It identifies what's ailing...




Don't ask! Another round of verbal abuse would ensue, and veer off-topic.

Regarding meritocracy:

http://dictionary.reference.com/browse/meritocracy?r=75&src=ref&ch=dic

1. an elite group of people whose progress is based on ability and talent

rather than on class privilege or wealth.

2. a system in which such persons are rewarded and advanced: The dean

believes the educational system should be a meritocracy.

3. a social system formed on such a basis

4. Cultural Dictionary: A government or society in which citizens who

display superior achievement are rewarded with positions of leadership.

In a meritocracy, all citizens have the opportunity to be recognized and

advanced in proportion to their abilities and accomplishments. The ideal

of meritocracy has become controversial because of its association with

the use of tests of intellectual ability, such as the Scholastic Aptitude

Test, to regulate admissions to elite colleges and universities. Many

contend that an individual's performance on these tests reflects his or

her social class and family environment more than ability.





Origin:

meritocracy Look up meritocracy at Dictionary.com

coined 1958 by British sociologist Michael Young (1915–2002) and used in

title of his book, "The Rise of the Meritocracy"; from merit (n.) + -

cracy. Related: Meritocratic.



Now the question is: Has any word remained true to its original meaning

much later than when it was coined?

You exemplify the semi-educated idiot for whom a little bit of knowledge isdangerous. The original use of the word by Young was satiric and critical of the coming social system in the UK. The problem is obviously with the self-perpetuating meritocratic ruling class and the relevance and consequences of their so-called measure of merit from a social science perspective. Here is an article written by Michael Young himself, but I doubt your readingcomprehension is up to it.
http://www.guardian.co.uk/politics/2001/jun/29/comment

 

[John Devereux]

On Sun, 14 Oct 2012 19:04:26 -0400, Phil Hobbs

[...]

The other cool thing is LEDs. Kids love LEDs, which leads them into
Ohm's Law and so on.

I love LEDs.

Ok, no one answered me about my curiosity about using a laser diode as a
detector.. so, i will conduct some R&D of my own, since I have a few
of them here to play with.

I was just curious if the laser diode would have a PV/PR effect like
LEDS do and to what extent. Also, how would they hold up with a laser
looking straight at them?

Hi Jamie,

Not been following thread, but you do know most of them have an actual
real photodiode built into them?

I think the LD bit will have a "PV" effect, since they work like LEDs
below the lasing threshold AFAIK. But Phil will know.

 

[rajibbandopadhyay]

Yes, that was precisely what I wanted to know. That then brings our
discussion to an end. Can I write to your email-Id., instead of posting
in open forum, if I have a query? I could then move away from this topic.
Thanks for your co-operation, JL, TW, PH, Miso, Bitrex, Jamie, JD & legg.
It felt nice reading your posts.
Regards

 

[rajibbandopadhyay]

Spice has an
important place, and so does prototyping. But for theoretical
pefornance calculations

Could you talk about your experience in Spice? By Prototyping do you mean
building the circuit physically in order to check its characteristics?

 

[rajibbandopadhyay]

Trying to restrict topic drift on SED? Completely doomed, sorry.

So it seems You could at least have added a smiley! The big jolt would
then have appeared relatively softer
Well, have to bear with the drift then

 

[Bill Palmer]

I know more about the meaning of meritocracy than he does, that's for sure. And claiming to know "more" than him is nearly vaccuous as he seems disturbed- if he's even Indian, or maybe just some f'ing troll from some Anglo waste dump somewhere.

If you're so fucking smart, how about you fix your fucking posts so
they're word-wrapped at a 72 characters and no double-spaced quoting, you
Google-groping monkey?

 

[rajibbandopadhyay]

But then I'm a physicist.

Great! Where had you been for so long?! Just promise to help me using
five of your precious minutes in a month, then.
Regards

 

[rajibbandopadhyay]

...

Do you have a working email-Id.? I tried to send you and email and it
bounced right back. I am sorry for the unsolicited email, but it's
important.
If you have no objection, just send an email to my Id. and I would reply
back.
Regards

 

[Fred Bartoli]

Phil Hobbs a écrit :

I do most of my circuit design in my head--you don't need to be a math genius
to figure resistor ratios and operating points, or even shot noise limited
SNRs on the fly--just a few rules of thumb, e.g. that a 60 ohm resistor has a
1-Hz Johnson noise of a nanovolt,

Hey, you're wrong by a bit lower than 1.5% (at room temp, which of
course I don't remind what it is

Another useful value is 1K = 4nV/rtHz


or that 3 uA of photocurrent has a 1-Hz

 

[rajibbandopadhyay]

On Mon, 15 Oct 2012 12:16:19 -0400, Phil Hobbs wrote:
A 2x2 matrix written out

with all sorts of algebra and stuff sort of defeats the point of the
exercise--it's far clearer just to write it out the usual way.

If it is a text-book curiosity why bother to write it at all! Of course,
Jim says he very occasionally uses it - which means he rarely uses it.
Indeed, why should he? Oh, God! We got our time wasted on this!

Guys, now we are really discussing issues!
Thanks!

 

[rajibbandopadhyay]

The 'benefit' is the ability to easily model things that don't yet have
models. Let the simulator cope with the Algebra.

I am so sorry, I was writing when JT was writing too. But do we require
these simplified models at all?

 

[rajibbandopadhyay]

... h-parameters are
introduced so that the student can use linear analysis to get a feel for
how circuits work.

Ah! That's the point. But when teachers don't supplement the text books,
you find yourself worse off than between the devil and the deep blue sea.
....

One of the conceptual models that I find useful is a pair of
back-to-back diodes, with a dependent current source around the B-C
junction, possibly with appropriate base spreading resistance if that's
going to matter...

Yes, I thought asymmetrical diodes represented the circuit better.

 

[Rajib Kumar Bandopadhyay]

The thing about matrix math is that, at least for me, it hides all the
causalities in one mathematical black box. I'd rather use step-by-step
analysis (Thevenin reductions, algebra, like that) so I can get a feel
for what's actually causing what.

Sorry I forgot to emphasise how important this comment is! So, it is
better that instead of remembering the formulae of h-parameters, we do
the analysis in the same way as h-parameters are reduced using simplistic
logic.
This at least sound logical

 

[Jeroen Belleman]

[snip]

It's not that hard. Remember orthogonality ?

Here's how S-parameters are handled in Spice...

http://www.analog-innovations.com/SED/S-Params.pdf

To get S11, I usually put the DUT in one side of a Wheatstone
bridge, which is exactly the way some VNAs do it in real life.
Apply 'AC 2' to the top of the bridge and get S11 as the voltage
across. It's very similar to the approach in your reference,
but it uses only one AC source. It's so simple I never bothered
to encapsulate it in subcircuits.

Jeroen Belleman

 

[o pere o]

Can I have the current picture in the developed countries on h-
parameters? I believe, with so much computing power at their hands,
people should not use h-parameters nowadays. They have no reason to. In
case of complex circuitry, you could do simulations, and in practice, you
use ICs in place of transistors. what is your experience with hybrid
parameters? Could you discuss this with people in the univ. laboratories?

I would mention an important aspect which intrigued me
while I was studying in Univ. The theory books put so much emphasis on
hybrid parameters, but to me, they are good for later analysis, i.e.,
not to invent something new, but when invented, they try to find how
the system work, not for learning electronics principles. And also, in the
practical world I did not come across specific cases of using
h-parameters. I thought - such wastage of time and effort!

(Today I realized that I answered this privately to the OP -and not to
the group. Here are my thoughts on this

Hybrid parameters are just one of several representations for two-ports.
Working with the conventional port variables V1, I1, V2, I2 there are 6
combinations of the independent variables, each one giving one specific
family. In practice, one family of parameters may be easier to measure,
or a given family may not exist.

So, your question should be rephrased as: is the two-port concept useful
for design? And the short response is yes.

Pere

 

[[email protected]]

Are you actually Sloman in disguise?





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John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com



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No, but you and the others around here are gullible suckers. The OP in thisthread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage the poser in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

 

[[email protected]]

He's been polite, and the question about h-params was reasonable.



I'm not a "sucker" because he hasn't cost me anything.

He's no Indian- and his conversation has been nothing but broad innuendo and generalities. His understanding of meritocracy is that of classic white trash American, that's the main giveaway, but you're the same so you didn't pick up on it.

 

[[email protected]]

On Monday, October 15, 2012 10:06:51 AM UTC-4, John Larkin wrote:
[snip]

Are you actually Sloman in disguise?





--



John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

[snip malarkey]

No, but you and the others around here are gullible suckers. The OP in this thread , with his obvious fake Indian name, is a racist troll posting through the eternal-september site. As best as I can determine, among his many previous aliases, he is "Charlie E.". So, go right ahead and engage theposer in email conflab about how things are in India from the perspective of some incapable rotting away in a braindead hell hole somewhere.

The OP is certainly NOT "Charlie E". How did you come to such a

braindead conclusion.



And why don't you learn to set line wrap properly?



...Jim Thompson

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

The 'Charlie E.' has used the same eternal-september header parameters- more than just the site.