transistors

[Winfield Hill]

Fred Bloggs wrote...

The deal was to get equal collector currents and halve the collector
resistor on the output transistor. The output transistor Vbe2
corresponds to the compensating transistor *emitter* current of
(Vcc-Ib1*Rb1-Vbe1)/Rc1-Ib2 so that the emitter current of the output
is the same making the output collector less by Ib2 or
(Vcc-Ib1*Rb1-Vbe1)/Rc1-2*Ib2, and therefore the output voltage is
Vcc-((Vcc-Ib1*Rb1-Vbe1)/Rc1-2*Ib2)*Rc2 then since Rc2/Rc1=0.5 and
Rb1=Rc2, this reduces to (Vcc+Vbe)/2+(0.5*Ib1+2*Ib2)*Rc2.
Yep- looks like you're right.

Right, Vout is about 10.35 volts, or 3.5% high. Of course, those
are presumed to be 5% resistors, commonplace for the 70s and 80s.

The goal is to get the maximum swing at Q2's output, while biasing
the output at 0.5 Vcc; we erred by not using 19.35k instead of 20k,
to account for 650mV of Vbe drop used in biasing on the ground side.

.. Vout = Vcc - [((Vcc - Ib1 Rb1 - Vbe1) / Rc1) - 2 Ib2] Rc2
.. = 20 - [((20 - 2.5uA * 10k - 0.65) / 19.35k) - 10uA] * 10k
.. = 20 - [((20 - 0.025 -0.65)/19.35k) -10uA] * 10k
.. = 20 - [( 19.325 / 19.35k ) - 10uA ] * 10k
.. = 20 - [ 998uA - 10uA ] * 10k
.. = 20 - 9.887
.. = 10.11 volts

which is within 1% of Vcc/2 for a beta of 200. And with a 19.1k
resistor (standard 1% value) we surreptitiously do better, now to
0.2%, more than good enough for the crude back-of-the-envelope
calculations we're illustrating. :>)

Figure 2.41B is preferred, with its two 180-ohm emitter resistors,
because the usual CE-stage distortion is reduced dramatically, and
the gain is pegged at about 49. The penalty is a modest 360mV of
output range. Surely that's a bit better use of some output-range
loss than twice that amount of loss for transistor diodes in series
with both collector resistors, and much higher distortion to boot.

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Winfield Hill]

Winfield Hill wrote...

Right, Vout is about 10.35 volts, or 3.5% high.

Actually more like 10.5 volts. I made a mental estimate
of 350mV and entered the value as a placeholder, intending
to check it before sending the post. Then my wife called
me away with something more urgent, so I clicked SEND to
be able close everything down. OK, here's the problem:

Does anyone out there have experience with a close relative
who had possibly-terminal congestive heart failure? Assume
an 85-year-old enlarged heart with bad valves, etc., and a
degraded life as a result. But now we're struggling with a
doctor's order that the discovery of infected valves should
not be treated with IV antibiotics, because after the region
is sterilized the infection will (may?) just come back again.
But we suspect that a severe rapid deterioration in the last
six months might have been due to this infection and therefore
perhaps could be partially reversed by removing the infection.
Meanwhile, we're not able to talk to or ask the cardiologist
who put forth the treatment opinion, because he was merely
analyzing the cardiac ultrasound exam data.

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Jim Thompson]

Winfield Hill wrote...

Actually more like 10.5 volts. I made a mental estimate
of 350mV and entered the value as a placeholder, intending
to check it before sending the post. Then my wife called
me away with something more urgent, so I clicked SEND to
be able close everything down. OK, here's the problem:

Does anyone out there have experience with a close relative
who had possibly-terminal congestive heart failure? Assume
an 85-year-old enlarged heart with bad valves, etc., and a
degraded life as a result. But now we're struggling with a
doctor's order that the discovery of infected valves should
not be treated with IV antibiotics, because after the region
is sterilized the infection will (may?) just come back again.
But we suspect that a severe rapid deterioration in the last
six months might have been due to this infection and therefore
perhaps could be partially reversed by removing the infection.
Meanwhile, we're not able to talk to or ask the cardiologist
who put forth the treatment opinion, because he was merely
analyzing the cardiac ultrasound exam data.

Thanks,
- Win

whill_at_picovolt-dot-com

Don't let them do surgery... it killed my mother :-(

...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 |

Will you still need me, will you still feed me, when I'm sixty-four?

 

[John Woodgate]

I read in sci.electronics.design that Winfield Hill

But we suspect that a severe rapid deterioration in the last
six months might have been due to this infection and therefore
perhaps could be partially reversed by removing the infection.
Meanwhile, we're not able to talk to or ask the cardiologist
who put forth the treatment opinion, because he was merely
analyzing the cardiac ultrasound exam data.

I don't have any *relevant experience*; it happened to my grandfather in
the days when the only antibiotic was penicillin, or soon after.

The question of intensive treatment of aged persons can only be answered
by taking quality of life into consideration. If the patient is mentally
alert and clearly wants to go on living (as my gf did), then treat. Even
if only a few weeks are gained.

Has the cardiologist actually MET your relative and assessed his/her
quality of life? If not, you are dealing with a robot doctor and had
best get a different one.

 

[John Crighton]

Don't let them do surgery... it killed my mother :-(

...Jim Thompson

I agree with Jim, surgery killed my dad too.
My dad, at age 78 took the bus to the Royal Adelaide hospital
on a Friday afternoon because his local doctor said something is
serious and should be checked out. It wasn't serious enough
for an ambulance. He hung around all afternoon for hours
and then on Friday night whoever was on duty decided to
open him up for a look around. They opened his chest twice
that night to inspect his heart and his stomach looking for a leak.
I am sure if my dad earlier on, had said "Stuff all this waiting
around I'm going home." he would have still been alive on the
following Monday.
I believe the cowboy surgeon that opened up my dad's chest
cavity twice and stitched him up twice with-in hours did him in.
Probably fixed the leak, therefore it was a successful operation
but with a "negative outcome." That is the term used
for died on the operating table.

I wish I could have got my dad to a few specialists rather
than trusting the local quack who just sent him off to the local
Adelaide hospital with a letter.

Win, this reply is of little help to you, but it got my thoughts,
about my dad's operation, off my chest.

Regards,
John Crighton
Sydney

 

[Winfield Hill]

Stefan Heinzmann wrote...

My posting was meant to be a "persiflage".

Yes, there's a lot of that jive going around. :>)


Word of the Day for Friday June 21, 2002
http://dictionary.reference.com/wordoftheday/archive/2002/06/21.html

persiflage \PUR-suh-flahzh\, noun:
Frivolous or bantering talk; a frivolous manner of
treating any subject, whether serious or otherwise;
light raillery.

"He was somber and wordless and utterly unresponsive
to my mother's charming persiflage."
-- Rosemary Mahoney, A Likely Story

Persiflage comes from French, from persifler,
"to banter," from per-, "thoroughly" (from Latin) +
siffler, "to hiss, to whistle," ultimately from Latin
sibilare, "to hiss (at), to whistle."


http://www.hyperdictionary.com/dictionary/persiflage

PERSIFLAGE: Dictionary Entry and Meaning
Pronunciation: 'pursu`flâzh
Definition: [n] light teasing

See Also: backchat, banter, give-and-take, raillery

Thesaurus - Related Terms:
aphorism, apothegm, backchat, badinage, banter, bon mot,
boutade, bright idea, bright thought, brilliant idea, chaff,
conceit, crack, cross, epigram, exchange, facetiae, flash of
wit, flight of wit, fooling, fooling around, gibe, give-and-
take, good-natured banter, happy thought, harmless teasing,
jape, jest, jive, joke, josh, kidding, kidding around, mot,
nasty crack, play of wit, pleasantry, quip, quips and cranks,
raillery, rallying, repartee, retort, ridicule, riposte,
sally, scintillation, smart crack, smart saying, snappy
comeback, sport, stroke of wit, turn of thought, twit,
wisecrack, witticism

Thanks,
- Win

whill_at_picovolt-dot-com

 

[Nico Coesel]

Winfield Hill wrote...

Actually more like 10.5 volts. I made a mental estimate
of 350mV and entered the value as a placeholder, intending
to check it before sending the post. Then my wife called
me away with something more urgent, so I clicked SEND to
be able close everything down. OK, here's the problem:

Does anyone out there have experience with a close relative
who had possibly-terminal congestive heart failure? Assume
an 85-year-old enlarged heart with bad valves, etc., and a
degraded life as a result. But now we're struggling with a
doctor's order that the discovery of infected valves should
not be treated with IV antibiotics, because after the region
is sterilized the infection will (may?) just come back again.

This doesn't make sense to me. I'm under the impression that
antibiotics _help_ the body to overcome an infection. Maybe you should
get a second opinion from another doctor.

 

[Frank Raffaeli]

Winfield Hill wrote... [snip]

Does anyone out there have experience with a close relative
who had possibly-terminal congestive heart failure? Assume
an 85-year-old enlarged heart with bad valves, etc., and a
degraded life as a result. But now we're struggling with a
doctor's order that the discovery of infected valves should
not be treated with IV antibiotics, because after the region
is sterilized the infection will (may?) just come back again.

[snip]

Both my mother and father-in-law have had heart problems. Luckily they
survived. Although their condition(s) do not seem so serious as your
relative.

I convinced my mom to go to the Cleveland Clinic. I hate hospitals;
however, in this situation, there was no alternative.

The cardiologist really knew what he was doing. Not only that, he took
a lot of time to answer my questions and explain what he planned and
what was going on. After the (successful) procedure, he followed up
with me daily. This hospital has a really good reputation in
cardiology. Still, there is no guarantee.

If the doctor will not take the time to talk with you, I would find
one who will. And when he talks, he should make sense. I hope
everything in your case works out for the best.

Regards,

Frank Raffaeli

 

[N. Thornton]

I read in sci.electronics.design that Winfield Hill


I don't have any *relevant experience*; it happened to my grandfather in
the days when the only antibiotic was penicillin, or soon after.

The question of intensive treatment of aged persons can only be answered
by taking quality of life into consideration. If the patient is mentally
alert and clearly wants to go on living (as my gf did), then treat. Even
if only a few weeks are gained.

Has the cardiologist actually MET your relative and assessed his/her
quality of life? If not, you are dealing with a robot doctor and had
best get a different one.

Untreated infection of heart valves is very serious, and steadily
destroys the heart. Antibiotic treatment is not traumatic, and may or
may not clear it. It is hard to see how withholding treatment is
justified... the reason quoted I dont find even a bit convincing. But
there might be various complications that might make it more
understandable. If it were me red flags would be lifting up, I would
want to know all the details and options. There arent many cases where
no treatment is best.

For antibiotic resistant infections there is a whole raft of treatment
options, I found something like 20 studied and successful approaches.
Yet here in UK hospitals seem to be choosing to remain ignorant in
most cases.

I can send you more details if you want and your email addy is right.
Mine is blocked.

For information only, go see a doctor.

Regards, NT

 

[N. Thornton]

I read in sci.electronics.design that Winfield Hill
about 'advice re congestive heart failure', on Sat, 6 Mar 2004:

I'd suggest also crossposting to sci.med, and reading there the thread
'septicaemia'. It'll be on google.

Regards, NT