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Question on LT Spice equivalents...

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Chris Carlen

Jan 1, 1970
0
Frank said:
Chronic fatigue is one of the toughest to diagnose. I think
there are over 120 standard tests for your blood alone, and if
nothing is (seriously) wrong with that, you're in muddy waters.

Yes. That is the end conclusion to which I and my doctors reached. At
that point it is a question of what to do about it. I chose to fight it
by exercising, and doing everything as normal as possible. That goes
somewhat against the common knowledge amongst CFS sufferers, who usually
complain of debilitating fatigue after exertion, and few hold full time
jobs. For this reason, the doctor never could decide for certain
whether to diagnose CFGS or fibromyalgia. But it doesn't matter when
there is no treatment. I remain convinced that the only thing one can
do is at the mental and spiritual level, to fight against it.

But the point of all this was that I have decided not to pursue another
degree, since I feel I don't have enough energy to study more than about
1 course per semester, which just isn't enough for any degree program.
That I continue to study slowly on my own and learn new stuff at my job,
is pretty satisfying considering that I could easily take a "minimum
effort" approach, especially in a government lab. But that's not my
character.
Doctors have an obligation to always do what is in the patient's
interest. Sometimes that simply means quitting further diagnoses,
depending on the severeness of the patient's discomfort.

Actually, I was more afraid of having a false diagnosis, given just to
satisfy the need to have an answer. I think sometimes doctors just
diagnose what they are familiar with, like a psychiatrist probably
perceives many cases to be depression that really aren't. Thus, I was
pleased to find a doc toward the end that took a very scientific
approach, even administering treatments for some difficult to diagnose
conditions just to test the hypothesis.
A lot of problems are pretty much untreatable anyways. You once
mentioned you suffered tinnitus - if I'm not mistaken. That's
easy to diagnose - you tell the doctor you hear that tone, he
looks into your ear, sees nothing, and says 'yes, nothing we
can do about it'. Opening your skull for that is not an option.

Mild tinnitus, mostly proportional to fatigue. It's not too much of a
problem unless I get really bad insomnia for a few nights, which follows
taking my work too seriously at times.

Thanks for the comments.

Good day!

--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
[email protected]
 
C

Chris Carlen

Jan 1, 1970
0
Jim said:
Young whipper snapper ;-)

I think Chris just needs to get laid, he probably has that allergy to
semen build-up ;-)

...Jim Thompson

Heh, heh. Don't worry Jim, I *am* very happily married.


Good day!


--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
[email protected]
 
C

Chris Carlen

Jan 1, 1970
0
Winfield said:
Chris Carlen wrote...



You surely have a medical problem that hasn't yet been properly
diagnosed, perhaps one that can be fixed. Don't give up looking
for the answer. Most of the rest of us don't suffer with your
problem, and you shouldn't have to either. Certainly many of us
are affected by low blood sugar or lack of sleep, but not with a
chronic energy loss like you describe. Perhaps it's time to try
the medical establishment again, with new doctors, in new towns.

Thanks for the concern. I'll consider it. If you knew what I did to my
body when I was 12-21, you might understand a little better. I put way
too many miles on in a short span back then, and have to pay for that now.
Sheesh, I'm 60 and don't suffer your problem - stop such talk.

It's Buddhism, Win. Just a different perspective.


Have a good day!


--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
[email protected]
 
Y

YD

Jan 1, 1970
0
If so they're wasting their time.

Thanks, Stefan. I'm afraid once you read a bit more of what goes on
here you'll see that a lot of folks are just bitterly envious of my
overwhelming popularity. Hence the frequent digs aimed at me by those
who feel they don't get due veneration for what *they* post!

Sometimes the answers you get are of general interest, but I feel you
overdo it a bits. Not that it would be wrong or anything but you can't
get your whole education out of news groups. By education and
inclination I'm used to digging out my own answers before hollering
for help, so learning to use search engines is a good idea. You wanna
know something? I usually do find what I need, takes a bit more work
is all.

A little bit more humility might make you look better, I'm smarter,
richer and much better looking :)

- YD.
 
Y

YD

Jan 1, 1970
0
On Thu, 05 Feb 2004 11:14:21 -0800, Chris Carlen


....
I am certain it is a physiological problem, as if I can get a good night
sleep and feel refreshed, I am very happy. The swings in my mood
exactly follow whether it's been too long since I ate, or if I had
trouble sleeping. The doctors never suggested, after examining the
data, that I was depressed. I know this to be true since I have more
powerful means to deal with those sorts of things than does modern
psychology--meditation, which has also saved by butt.

....

When did you last have a vacation?

- YD.
 
B

Ban

Jan 1, 1970
0
Paul said:
Thanks, Stefan. I'm afraid once you read a bit more of what goes on
here you'll see that a lot of folks are just bitterly envious of my
overwhelming popularity. Hence the frequent digs aimed at me by those
who feel they don't get due veneration for what *they* post!

Paul,
you seem to measure popularity by the number of answers in a thread. Well,
congratulations! you come almost close to news2020

Ban (one of the bitterly envious folks)
 
I

Ian Buckner

Jan 1, 1970
0
John Woodgate said:
I read in sci.electronics.design that Jim Thompson
4ax.com>) about 'Question on LT Spice equivalents...', on Thu, 5 Feb
2004:

I said 'expected': I didn't give any guarantee of compliance. (;-)

"Expected to work" or "expected to charge for" ?

Regards
Ian

;-)
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Frank Bemelman
anadoo.nl>) about 'Question on LT Spice equivalents...', on Fri, 6 Feb
2004:
I have a friend who is a
doctor, and he says that everyone who claims being healthy, hasn't been
diagnosed thoroughly enough.

Yes, and a lawyer will eventually find that you do something illegal.
 
W

Winfield Hill

Jan 1, 1970
0
Paul Burridge wrote...
Well worth keeping in mind, I agree. Fortunately this application
(the active element in a c-mos oscillator) both seem to work
equally well, certainly when breadboarded.

Paul, <SIGH> When will you finally learn to listen to your
more experienced and knowledgeable elders? Just do not use
buffered cmos logic in crystal oscillators, even if they
"seem" to work OK in a spice model or breadboard. They can
have trouble starting up, or become flaky later in the field.

If you won't accept my own wisdom (and you certainly should,
haven't you learned that by now?), read the authoritative ON
Semi app note, "Unbuffered Gates for Crystal Oscillators,"
http://www.onsemi.com/pub/Collateral/AND8141-D.PDF There are
many other places with the same instruction (don't we say so
in AoE?) but you should take my word on this.

Thanks,
- Win

whill_at_picovolt-dot-com
 
R

Roy McCammon

Jan 1, 1970
0
Chris said:
I am certain it is a physiological problem, as if I can get a good night
sleep and feel refreshed, I am very happy. The swings in my mood
exactly follow whether it's been too long since I ate, or if I had
trouble sleeping. The doctors never suggested, after examining the
data, that I was depressed. I know this to be true since I have more
powerful means to deal with those sorts of things than does modern
psychology--meditation, which has also saved by butt.

It is the nature of the human body to slowly degrade then die....

Chris,
Even if the primary problem is physiological, its not unusual
for the stress of dealing with it to induce depression. I
would try an anti-depressent if I were in your situation.
 
R

Roy McCammon

Jan 1, 1970
0
Frank said:
Chronic fatigue is one of the toughest to diagnose. I think
there are over 120 standard tests for your blood alone, and if
nothing is (seriously) wrong with that, you're in muddy waters.

what do you suppose the odds are of getting a false positive
if you take all those tests?
 
P

Paul Burridge

Jan 1, 1970
0
I read in sci.electronics.design that Frank Bemelman
anadoo.nl>) about 'Question on LT Spice equivalents...', on Thu, 5 Feb
2004:


Many forms of tinnitus can't be cured, but some can, and most can be
alleviated.

Indeed. Solutions include the use of ear-plugs or turning up the
stereo. :)
 
P

Paul Burridge

Jan 1, 1970
0
Paul, <SIGH> When will you finally learn to listen to your
more experienced and knowledgeable elders?

Win, you must surely have notice by now that you're about the only
bloke on this forum that I don't *dare* argue with...
Just do not use
buffered cmos logic in crystal oscillators, even if they
"seem" to work OK in a spice model or breadboard. They can
have trouble starting up, or become flaky later in the field.

Fine. Noted. I'd just like to point out in my defence that all the
circuits I've seen on the Web for these cmos oscillators use the
74HC04 hex inverter as the active element, so I just followed the
circuits shown without question. This chip *is* unbuffered, right?
If you won't accept my own wisdom (and you certainly should,

I can assure you, I *do*!
haven't you learned that by now?), read the authoritative ON
Semi app note, "Unbuffered Gates for Crystal Oscillators,"
http://www.onsemi.com/pub/Collateral/AND8141-D.PDF There are
many other places with the same instruction (don't we say so
in AoE?) but you should take my word on this.

Logic (as in *reasoning* rather than ands, ors exors, nands and stuff)
leads me to suppose that *buffered* gates ought to work better -
certainly for starting-up purposes than unbuffered. So that's wrong
then? I just need a clarification on that sole point before following
up the pointer you've given.

Thanks,

p.
 
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Jim Thompson

Jan 1, 1970
0
Win, you must surely have notice by now that you're about the only
bloke on this forum that I don't *dare* argue with...


Fine. Noted. I'd just like to point out in my defence that all the
circuits I've seen on the Web for these cmos oscillators use the
74HC04 hex inverter as the active element, so I just followed the
circuits shown without question. This chip *is* unbuffered, right?

Wrong. 'HC04 *is* buffered, it has three inverters in series. Besides
over-driving the crystal it is prone to spurious oscillations plus
significant slowing of the oscillation frequency.

'HCU04 (Note the "U") is the *unbuffered device... a *single* inverter
stage.
I can assure you, I *do*!


Logic (as in *reasoning* rather than ands, ors exors, nands and stuff)
leads me to suppose that *buffered* gates ought to work better -
certainly for starting-up purposes than unbuffered. So that's wrong
then? I just need a clarification on that sole point before following
up the pointer you've given.

A single device is ANALOG!
Thanks,

p.


...Jim Thompson
 
S

Steve Kavanagh

Jan 1, 1970
0
Winfield Hill wrote
Just do not use
buffered cmos logic in crystal oscillators, even if they
"seem" to work OK in a spice model or breadboard. They can
have trouble starting up, or become flaky later in the field.

As one who has built a few 'HC04 oscillators that have worked fine
when an 'HCU04 wasn't at hand, but perhaps not enough to have hit on
one that was problematical, I would be interested to learn what
actually goes wrong with these things, what the symptoms are and what
are the mechanisms behind the problems. I can imagine that all that
gain could have interesting consequences, but what are they in
practice ?

Steve Kavanagh
 
C

Chris Carlen

Jan 1, 1970
0
Roy said:
Chris,
Even if the primary problem is physiological, its not unusual
for the stress of dealing with it to induce depression. I
would try an anti-depressent if I were in your situation.

Thanks for the input Roy. I have committed my life to never using
mind/mood altering drugs. Thus, I cannot do that. Even if I were
*really* depressed, as diagnosed by a doctor, I would likely choose not
to take such drugs. I believe that depression is a spiritual problem,
even if the psychiatry alchemists think that it is caused by a "chemical
imbalance". How do they know which came first, the bad thinking or the
chemical imbalance? When they are so intimately linked, how can anyone
know which is the cause, and which the effect?

For me to take drugs would be a failure to face life on life's terms.
Life is sometimes depressing, frightening, joyful, tragic, pleasant,
etc., and actually, more often than not, just neutral. Emotional
stability is to me not being emotionally constant and placid (or
compressed dynamic range, which is what the drugs basically do), but
being able to remain stable in core intentions and values in the face of
sometimes difficult emotional realities. Anything that stands in the
way of allowing me to face the realities as they are, is in effect both
absolving me of an important responsibility of dealing with my emotions
honestly, as well as removing the precious opportunity to do so and the
strength thus gained.

Thus you can see, I have a pretty strong view about psychiatric drug
usage. I think for folks who really cannot control themselves, then it
is Ok to prescribe such medications as a last resort. But even in the
case of someone who is depressed, and you might find this odd, I think
it is more ethical to encourage them to deal with it without medication
knowing there is a finite risk of their doing harm to themselves, rather
than drug them. If they do something foolish, then maybe resort to
drugs. But to deny them the right to take the risk is to impose our
probably incorrect ideals about how life "should be" on someone. There
is a spiritual opportunity in all suffering. Drugs take that away. I
would rather struggle and have a chance at true liberation from the
delusions of the mind, than live in an anesthesized state with no chance
to see this.

But you see, for someone with my experience, I have little choice but to
view the whole situation backwards from what most people think. That is
because the real reason for most of my troubles including the fatigue
and generally weaker constitution than might be considered normal for my
age, *is* drugs. I was once a rather serious addict, you may recall. I
am quite lucky to be alive actually, and extremely lucky to have most of
my mind left. For folks such as me, the *only* solution is total
abstinence from drugs of any mind/mood altering kind, except for
surgical operations or extreme physical pain.

If you could have seen my mental condition 14 years ago, with almost
weekly bouts of deep despair and suicidal contemplations, you would have
certainly concluded that I needed medication. Fortunately I had
guidance from folks with true faith in the potential of the human mind
to heal itself from within, and they insisted that I could be restored
to sanity without using any more drugs, ever. In time I came to believe
the same thing, through simply examining the reality of my daily ability
to live without the drugs I had once used. Life was quite bitter for a
few years, but eventually the clouds dissipated, and I could begin to
experiment with more subtle techniques of mental restoration such as
meditation. My life has steadily improved for 14 years due to this
policy of no drugs (including alcohol) and basic spiritual practice such
as personal introspection and meditation. It has improved in terms of
basic happiness even despite a couple of physical health downturns.

What would have happened to me had the doctors gotten their hands on me
then instead of my having chosen the path that I took? I could possibly
have been institutionalized, or more likely stuck on an endless flow of
chemical cocktails, probably to this day. I know this to be the case
because I have dealt personally with many folks who were under the spell
of the doctors while I was stabilizing into the lifestyle of abstinence.
I saw their lives remain still or regress back into addiction while
mine improved. It was really very sad. I think it very likely that I
would never have returned to college and revived my intellectual
faculties had the doctors gotten me. We probably would have never had
this opportunity to converse, and I wouldn't have collected a few really
great postings of yours that I will process bit by bit in the coming years.

Hmm, I was planning to sort my pile of parts from Digi-Key. I will
return to that task.

Have a good day!
 
S

Stefan Heinzmann

Jan 1, 1970
0
Jim said:
A single device is ANALOG!

Isn't that answer a bit *too* simple? So a single device is analog, but
three in a row are digital? That makes the typical OpAmp a digital
device, when going by the internal amplifying stages.

Clearly, the AC gain of a buffered gate is a lot higher than that of an
unbuffered gate. But how exactly that leads to startup problems and
other trouble is not obvious to me. The application note Win has
mentioned does just note that without explanation. Another source is
Linear Technology's AN-12. Jim Williams writes there that the problem is
"the inability to reliably identify the analog characteristics of the
gates used as gain elements". He proceeds to describe the symptoms, but
without a deeper analysis of the causes.

I have since accepted it as common knowledge that unbuffered gates make
better crystal oscillators, but I admit that I still don't quite know
why it is so.
 
P

Paul Burridge

Jan 1, 1970
0
Wrong. 'HC04 *is* buffered, it has three inverters in series. Besides
over-driving the crystal it is prone to spurious oscillations plus
significant slowing of the oscillation frequency.

'HCU04 (Note the "U") is the *unbuffered device... a *single* inverter
stage.

I can only assume that I'm misunderstanding the meaning of "buffered"
in this context, then. I assumed that "buffered" meant there was a
high degree of isolation between input and output of each inverter; a
high-impedance input and low-impedance output as in an emitter
follower stage for instance. Hence, an oscillator will typically be
followed by a buffer to prevent the load of subsequent stages
influencing the oscillator's stability. Are you saying that's not
right, then?
A single device is ANALOG!

Now I'm completely baffled. There was me thinking "analogue" referred
to smoothly variable as opposed to quantised. What has being single or
multiple got to do with it? I'm obviously missing something here. :-|
 
S

Stefan Heinzmann

Jan 1, 1970
0
Paul said:
I can only assume that I'm misunderstanding the meaning of "buffered"
in this context, then. I assumed that "buffered" meant there was a
high degree of isolation between input and output of each inverter; a
high-impedance input and low-impedance output as in an emitter
follower stage for instance. Hence, an oscillator will typically be
followed by a buffer to prevent the load of subsequent stages
influencing the oscillator's stability. Are you saying that's not
right, then?

Buffered gates have a buffer amplifier following the actual logic
function at the output. In CMOS that's the typical pair of MOSFETs.
Since that buffer happens to invert, you need yet another (internal)
inverter to undo this inversion. As a result, a buffered inverter gate
consists of a CMOS inverter (a MOSFET pair), followed by another
inverter to cancel the inverting effect of the output buffer, followed
by the actual output buffer. Three pairs of MOSFETs in total.

Unbuffered inverters have just the inverting buffer, that's a single
MOSFET pair.

The nomenclature is a bit dubious in my opinion, but you get used to it.
It makes a bit more sense in gates that are not just inverters. Have a
look into the data sheets for the MC14011B and the MC14011UB, for
example. Those are 2-input NAND gates. The former is buffered, the
latter is unbuffered. The data sheets contain the internal circuits
which I recommend you to compare.

As a CMOS gate has very high input impedance anyway, you can not get any
more isolation by adding buffer stages. The buffer adds more gain and
often allows higher output currents.
 
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