Voltage Regulation
James Rollins
Derived from a capacitor multiplier with voltage attenuation
capabilities. It is simply several capacitor multipliers in series
with the voltage drop distributed across the bjt's. R4 controls the
load voltage while R1=R2=R3 causes the voltage drops across the
transistors to be evenly distributed.
Theoretically this allows one to use large voltages with the capacitor
voltage decreasing for each stage. The kth capacitor from the bottom
has a voltage of k/n*V while each resistor and transistor has V/n.
Tests show that this has significantly better ripple reduction than
one stage alone for the cases I've tested. A factor of almost 100x.
What seems nice about this circuit is the reduced voltage requirements
of the transistors which also allows for higher beta. The power
dissipation for each is also reduced but the same as using one
transistor. Overall this seems to be a much better circuit than using
one stage and using linear regulation alone.
The real question is how this would work out in practice?
Phil Hobbs
You don't have to do waste voltage like that--just split the base
resistor into N sections and use N capacitors (actually N-1 capacitors,
since you want one at the end for short circuit protection of the
transistor). You can get 140 dB in one stage in the tens to hundreds of
kilohertz.
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
James Rollins
<pcdhSpamMeSensel...@electrooptical.net> wrote:
> James Rollins wrote:
> >http://i41.tinypic.com/scv19i.gif
>
> > Derived from a capacitor multiplier with voltage attenuation
> > capabilities. It is simply several capacitor multipliers in series
> > with the voltage drop distributed across the bjt's. R4 controls the
> > load voltage while R1=R2=R3 causes the voltage drops across the
> > transistors to be evenly distributed.
>
> > Theoretically this allows one to use large voltages with the capacitor
> > voltage decreasing for each stage. The kth capacitor from the bottom
> > has a voltage of k/n*V while each resistor and transistor has V/n.
> > Tests show that this has significantly better ripple reduction than
> > one stage alone for the cases I've tested. A factor of almost 100x.
>
> > What seems nice about this circuit is the reduced voltage requirements
> > of the transistors which also allows for higher beta. The power
> > dissipation for each is also reduced but the same as using one
> > transistor. Overall this seems to be a much better circuit than using
> > one stage and using linear regulation alone.
>
> > The real question is how this would work out in practice?
>
> You don't have to do waste voltage like that--just split the base
> resistor into N sections and use N capacitors (actually N-1 capacitors,
> since you want one at the end for short circuit protection of the
> transistor). You can get 140 dB in one stage in the tens to hundreds of
> kilohertz.
>
I don't know what you are talking about. I don't believe you
understand the circuit. The transistor is used for voltage regulation
and capacitance multiplication. It has to waste voltage so that one
can also attenuate the voltage as it is meant for variable supply.
Even without it one still needs the transistor for capacitor
multiplication.
The capacitor multiplication is used to lower the capacitance
requirements and hence whatever capacitance you are using to get your
140dB I can do the same using a much lower capacitance which
essentially gets multiplied by the beta of the bjt's. With your method
I do not see any need to use resistors and extra capacitors and one
could just use one large filter capacitor. The problem is then how do
you get the voltage attenuation/variable supply?
Phil Allison
"James Rollins"
** It wouldn't.
At the moment of applying Vcc, Q1 cops the entire voltage as C1 is
uncharged.
Pffffttt....
..... Phil
James Rollins
Your point? C1 will charge up... duh! Every schoolboy knows this.
James Rollins
Your right that Q1 in the circuit will start with Vcc across it but it
is an easy fix and because in general in a real circuit the supply
voltage will not instantly be at Vcc but ramp up to Vcc it is not
necessarily an issue. It is an easy fix by adding a soft starting
feature. In fact the circuit I plan on using this with will have such
a feature since the supply will charge up a bank of large capacitors
which will supply another circuit. Alternatively one could use a
higher VCEO for the the first Q1. Similarly for Q2 being higher than
Q3. It allows one to use progressively lower voltage rated stages and
increase the regulation by another factor which I guess is beta^n for
n identical and ideal stages. Hence the capacitance is C*beta^n which
is significant improvement over one stage.
By implementing some safety circuitry and soft start the problem you
described should be eliminated.
legg
This used to be a ripple regulator, before the term was misapplied to
hysteritic switching regulators. In any event a capacitive multiplier
is used where regulation is not inherently intended, simply to reduce
ripple actively. The normal circuit simply establishes bias for the
pass element with sufficient headroom to absorb the ripple.
Linear regulation requires a reference and controlled gain. Your
circuit has neither, so it will only regulate as effectively as the
input voltage is regulated. The use of multiple series elementsdefeats
the simplicity of the original without providing the benefit of
regulation.
Check out p12 +13 of the LM10 data sheet as an example of the basic
concept of a floating adjustible regulator.
http://www.national.com/ds/LM/LM10.pdf
The capacitor being multiplied is C1 in these drawings.
RL
Phil Hobbs
Perhaps I was unclear. (I'm assuming that your circuit is intended for
a practical use, not just to learn SPICE or keep transistors warm.)
Your circuit wastes a lot of power to solve a nonexistent problem,
namely feedthrough due to the CB and CE capacitances of the transistors.
There's no point in doing filtering at the collector of the
capacitance multiplier, since this feedthrough is never the issue--it's
always the tradeoff of voltage drop vs RC time constant. If you take
your circuit, delete all but the bottom transistor, and short its
collector to the positive supply, you'll get equivalent performance with
a far smaller voltage drop. The bottom resistor can usually be very
big--it needs to pull just enough current so that the voltage drop is a
bit more than the worst case ripple.
I do this sort of thing all the time, usually with Darlingtons, e.g.
MPSA14s, so that I don't have to use such big caps. The CB and CE
capacitances (a few pF each) get swamped out by the bypass caps on the
base and emitter, yielding easily 120 dB and sometimes 140 dB rejection
at tens to hundreds of kilohertz in a single stage. I didn't invent
it--it's a standard technique in low noise circuitry, especially in
places like photodiode preamps, where noise on the bias supply looks
exactly like TIA voltage noise and so has to be down around 1 nV/sqrt(Hz).
If you really want to use something like this as a voltage regulator,
you're way better off using a DC-DC converter feeding a single cap
multiplier stage. If the switching frequency is in the sweet spot of
the cap multiplier, and you keep the jiggly power supply plane and stray
flux away from your front end circuitry, you'll never know the switcher
was there.
If you're really interested in reducing the voltage rating of the caps,
then you must be intending to waste most of the supply voltage at all
times--because otherwise, when the output is at its upper limit, all the
caps would see nearly the same voltage.
So I'm puzzled as to why you'd want to do this in a real circuit.
Cheers
Phil Hobbs
MooseFET
Q1 might find its self as a Colpitts common base oscillator. This
assumes that you don't exceed its SOA at start up.
Have you considered:
--+--- ------+------+------+---+-
! \ e/ ! ! ! !
! ----- ! \ \ ===
! ! ! / / !
-/\/-+ ! \ \ !
! \! ! ! !
=== !-----+ +---
! e/! ! !
! ! \! !
--------+ !----+
! e/! !
\ ! \
/ \ /
\ / \
! \ !
GND GND GND
It needs only one large transistor.
gghe...@gmail.com
>
> - Show quoted text -
"> The bottom resistor can usually be very
> big--it needs to pull just enough current so that the voltage drop is a
> bit more than the worst case ripple."
I love this circuit fragment (with one transistor), but have never
used the resistor at the bottom. (R4 in the original post.) What is
it's purpose? Is it only needed if the supply voltage is small? (a
few volts or so.)
BTW I find that adding a second RC pole helps, but adding a third is
not worth the extra bother.
George Herold
Phil Hobbs
A BJT saturates when the collector goes more than, say, 200-300 mV below
the base. (It depends on the device--small signal devices are better
than power devices.)
For 60-Hz high voltage supplies, you can sometimes have 10 volts or more
of ripple, so the cap multiplier will saturate hard on every cycle. If
you use the bottom resistor to drop the base voltage by 11 volts, that
10V ripple won't cause the transistor to saturate.
James Rollins
Gain is a misnomer. Amplifiers to not amplify but attenuate or
modulate. In any case the circuit I gave does have "gain". it is
simply R4/(R1 + R2 + R3 + R4).
The reference is R4 in this case. The capacitors hold the gate current
steady. Just because there is no zener does not mean there isn't a
reference. Of course there are better methods and ultimately I would
be using a precision reference because I would be replacing R4 with
more circuitry that allows for programmability.
In fact the precision regulator in the LM10 datasheet is very
similar.
As far as regulation is conserved I believe you are confused. Linear
regulators do no supply power but only attenuate it. Hence why all
linear regulators need some headroom. In fact the circuit I gave is
not much different than your standard linear regulator(See AOE for the
basics of regulation) except a zener is not used for a reference.
I believe you are not looking at the circuit closely enough because it
is a simple regulating circuit that accomplishes all the goals for
basic regulation. What it doesn't have of course are the more advanced
features found in modern regulators such as current limiting, over
voltage, etc. The circuit given of course is not meant to be the
final result but the basis of a practical circuit.
> Check out p12 +13 of the LM10 data sheet as an example of the basic
> concept of a floating adjustible regulator.
>
> http://www.national.com/ds/LM/LM10.pdf
How does the regulator handle the high voltage? The precision
regulator on page 12 still has to handle Vcc across it unless it
cannot adjust the full supply. Hence I would need a regulator that can
handle approximately 1000V. This is quite easy to see since gate of
Q3 is ~ 3 diode drops above the output voltage which needs to swing
approximately the full supply and hence the op amp would need to
handle approximately the full supply. Unfortunately this circuit
won't work. Simulation also
James Rollins
I do not understand what you mean "wastes" a lot of power. The circuit
wastes not much more than using just one transistor. The capacitors
and resistor network waste virtually no power. Only the transistors
waste power. Yet they have too since this is a linear regulating
circuit. It wastes no more power than one transistor except for the
additional voltage drops and potentially extra gate current... yet in
reality this is not necessarily true since HV BJT's tend to have very
low hFE than lower voltage BJT's.
The bottom resistor is used to program the output voltage. This is not
just regulating but stepping down the voltage. You are not
understanding the purpose of the circuit. You think the extra
transistors are useless but they are there to reduce the voltage drop
across just using one so that lower rated transistors can be used.
Also I am not trying to achieve a low dropout regulator but a
programmable one. A few volts below Vcc is not important.
The wasted power is maximum when The transistors drop half the supply
voltage which is required since the circuit is linear. A switching
circuit would be more optimal but because of the low power
requirements this requires a huge inductor in a buck configuration.
This circuit, at least in simulation, gives about 100x more ripple
rejection than one stage alone and the power dissipation is almost the
same as a single stage and in fact might be better.
Phil Hobbs
*sigh*
Jim Thompson
Observe the source (googlegroups), apply filter, sip a cold one ;-)
(Reminds me, Monday evening I found the solution to jaw pain after a
root canal... one bottle of Claret ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine Sometimes I even put it in the food
Phil Hobbs
> On Thu, 21 May 2009 17:55:45 -0400, Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
>> James Rollins wrote:
>>> This circuit, at least in simulation, gives about 100x more ripple
>>> rejection than one stage alone and the power dissipation is almost the
>>> same as a single stage and in fact might be better.
>> *sigh*
>
> Observe the source (googlegroups), apply filter, sip a cold one ;-)
>
> (Reminds me, Monday evening I found the solution to jaw pain after a
> root canal... one bottle of Claret ;-)
>
I keep hoping...such a cockeyed optimist I am, to be sure. I really
like helping people learn stuff, but it's a great deal easier with some
than with others.
How does Google maintain such a monopoly on these folks? (I mean, I
should probably be grateful as you say, but I really don't get it.)
They all want everyone to listen to their latest half-baked idea, but
won't listen in return, and won't accept any response other than oohs
and ahhs--anybody who doesn't bow in homage is obviously incompetent,
regardless of evidence to the contrary. Accepting the fact that their
brainstorm is an inferior derivative of a long-known technique is fatal
to their self-image, of course, and so must be resisted at all costs.
That must be very unpleasant.
My local school has a program where everyone gets to invent the city of
the future--and all get oohs and ahhs regardless of whether their idea
makes any sense whatever. We need another Sputnik scare, right away.
Cheers
Phil Hobbs
Jim Thompson
<pcdhSpamM...@electrooptical.net> wrote:
>Jim Thompson wrote:
>> On Thu, 21 May 2009 17:55:45 -0400, Phil Hobbs
>> <pcdhSpamM...@electrooptical.net> wrote:
>>
>>> James Rollins wrote:
><snip>
>>>> This circuit, at least in simulation, gives about 100x more ripple
>>>> rejection than one stage alone and the power dissipation is almost the
>>>> same as a single stage and in fact might be better.
>
>>> *sigh*
>>
>> Observe the source (googlegroups), apply filter, sip a cold one ;-)
>>
>> (Reminds me, Monday evening I found the solution to jaw pain after a
>> root canal... one bottle of Claret ;-)
>>
>
>I keep hoping...such a cockeyed optimist I am, to be sure. I really
>like helping people learn stuff, but it's a great deal easier with some
>than with others.
>
>How does Google maintain such a monopoly on these folks?
I haven't figured that out, either. For some reason googlegroups
seems to draw mostly nutcases :-(
>(I mean, I
>should probably be grateful as you say, but I really don't get it.)
>They all want everyone to listen to their latest half-baked idea, but
>won't listen in return, and won't accept any response other than oohs
>and ahhs--anybody who doesn't bow in homage is obviously incompetent,
>regardless of evidence to the contrary. Accepting the fact that their
>brainstorm is an inferior derivative of a long-known technique is fatal
>to their self-image, of course, and so must be resisted at all costs.
>That must be very unpleasant.
>
>My local school has a program where everyone gets to invent the city of
>the future--and all get oohs and ahhs regardless of whether their idea
>makes any sense whatever. We need another Sputnik scare, right away.
>
>
>Cheers
>
>Phil Hobbs
Unfortunately I think we're going get far more than a Sputnik (that
happened in the Fall of my senior year in high school).
What I'm afraid of is an atomic hit by one of the nutcase nations we
now kiss-up-to rather than tell them, "Knock it off, or else".
Pretty hard to deliver "else" when your president is a pansy :-(
The only fortunate thing is that the most likely target cities are
full of leftist weenies who voted for the pansy ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Diplomacy: Kissing ass when we should be kicking ass.
Joel Koltner
news:Z7mdnXrXnYBlQIjX...@supernews.com...
> Accepting the fact that their brainstorm is an inferior derivative of a
> long-known technique is fatal to their self-image, of course, and so must be
> resisted at all costs. That must be very unpleasant.
You know how many of the Jewish laws regarding what's acceptable to eat
(Kashrut) just so happen to line up with what was reasonably *safe* to eat
given the technology available a couple thousand years ago (e.g., lack of
refrigeration and an understanding of microbiology)? I think something
similar could be said about the admonishments regarding being overly
prideful... ignoring such admonishments is just setting oneself up for even
greater unpleasantness as you describe.
I've mentioned before that there is an odd facet of younger peoples' culture
today that saying "I don't know" is apparently considered worse than just
making up an answer and hoping that no one can decisively demonstrate your
error.
> My local school has a program where everyone gets to invent the city of the
> future--and all get oohs and ahhs regardless of whether their idea makes any
> sense whatever.
Your kids apparently didn't play much no-score soccer, eh? :-)
Hey, now that you're independent, and given that you like to teach... you
might think of putting up a "premium" web site similar to Doug Smith's here:
http://emcesd-p.com/ . At $50/year, it's dirt cheap for companies and even
most U.S.-based individual engineers, yet I suspect he makes enough from it to
make it more than worth his time adding content (also note that he has a *lot*
of 100% free information on his regular web site). You could even start off
just going through your book, similar to how it would be used in a
college-level course. This could tie in nicely with the upcoming release of
the 2nd edition...
> We need another Sputnik scare, right away.
Unless they're extraterrestrial, I don't think there'll be one... all
countries today have the technology to kill one another quite effectively;
it's just politics, the threat of retaliation, and on rare occasion some
clear-headed thinking that keeps us -- relatively -- safe.
---Joel
Phil Hobbs
> On Thu, 21 May 2009 19:04:21 -0400, Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>> My local school has a program where everyone gets to invent the city of
>> the future--and all get oohs and ahhs regardless of whether their idea
>> makes any sense whatever. We need another Sputnik scare, right away.
>>
>
> Unfortunately I think we're going get far more than a Sputnik (that
> happened in the Fall of my senior year in high school).
>
> What I'm afraid of is an atomic hit by one of the nutcase nations we
> now kiss-up-to rather than tell them, "Knock it off, or else".
>
> Pretty hard to deliver "else" when your president is a pansy :-(
>
> The only fortunate thing is that the most likely target cities are
> full of leftist weenies who voted for the pansy ;-)
>
> ...Jim Thompson
Nice. Like my town, for instance. :(
You really need to go to Compassionate Conservative school for a
refresher. Or find a kindergarten where they serve claret.
Cheers,
Phil Hobbs
Joel Koltner
message news:mjob1550d681fpal6...@4ax.com...
> Unfortunately I think we're going get far more than a Sputnik (that
> happened in the Fall of my senior year in high school).
Was it visible from... Massachusetts, was it (where you were living at the
time)?
> Pretty hard to deliver "else" when your president is a pansy :-(
Well, since you set up the context here with our being nuked by some nutcase,
I suppose you're right... those guys don't understand that even if Obama
wouldn't personally retaliate in kind, he'd rapidly lose control to those who
would. I fully expect Jim Yanik's going to be heading on up to D.C. to
personally wrestle the red button out of Obama's hands as soon as he hears
that the nutcases have launched... :-)
In the end, everyone loses -- plenty of needless death.
Hey, did you read that book, "The Idea Factory: Learning to Think at MIT" that
someone here (John L.?) recommended? I read it on a trip back to Wisconsin
this past week and enjoyed it, and I figure you might, even though it is set
in the early '80s (well after you graduated!).
---Joel
Jim Thompson
<pcdhSpamM...@electrooptical.net> wrote:
I never bought into that "compassionate conservative" BS.
As for your town... you could move. You know full well, if DPRK or
Iran go "ballistic", NYC will get it, again.
That is, if the Islamic extremists don't get there first ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Seeing Obama voters laid off gives me an orgasmic Schadenfreude
Phil Hobbs
pretty well on that sort of site, but my primary interest is still in
doing stuff, more than teaching about it.
I sent the index off a week or two ago, and the cover design has
converged on something more or less acceptable. I still think that
blurbs and so on belong on a dust jacket, so you can decently toss it
when you get the book home, but oh well--as an example of the breed this
isn't that bad.
http://electrooptical.net/www/beos2e/beos2e_cover.pdf
They tell me that the typesetters will have the index sorted out soon,
so that the book will come out in July. (If so, I'd like to shake the
typesetters' hands--the proofs had completely different pagination.
I'll go over it carefully before it gets printed.)
Jim Thompson
<zapwireD...@yahoo.com> wrote:
>"Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
>message news:mjob1550d681fpal6...@4ax.com...
>> Unfortunately I think we're going get far more than a Sputnik (that
>> happened in the Fall of my senior year in high school).
>
>Was it visible from... Massachusetts, was it (where you were living at the
>time)?
I grew up in Huntington, WV. Was only in Massachusetts for my 4 years
at MIT>
>
>> Pretty hard to deliver "else" when your president is a pansy :-(
>
>Well, since you set up the context here with our being nuked by some nutcase,
>I suppose you're right... those guys don't understand that even if Obama
>wouldn't personally retaliate in kind, he'd rapidly lose control to those who
>would. I fully expect Jim Yanik's going to be heading on up to D.C. to
>personally wrestle the red button out of Obama's hands as soon as he hears
>that the nutcases have launched... :-)
>
>In the end, everyone loses -- plenty of needless death.
People who voted for Obama deserve the results that derive from their
electoral idiocy. It's called "adjustment" ;-)
>
>Hey, did you read that book, "The Idea Factory: Learning to Think at MIT" that
>someone here (John L.?) recommended?
I'm leery of _anything_ Larkin recommended recently... he's gone
somewhat bonkers ;-)
Since you recommend it I'll get a copy.
>I read it on a trip back to Wisconsin
>this past week and enjoyed it, and I figure you might, even though it is set
>in the early '80s (well after you graduated!).
>
>---Joel
>
Early '80's, I was already 20+ years after MIT graduation.
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Stormy on the East Coast today... due to Bush's failed policies.
Jim Thompson
I keep getting these Amazon notices, several books I've ordered are
"delayed" :-(
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
"Socialism is a philosophy of failure, the creed of ignorance, and
the gospel of envy, its inherent virtue is the equal sharing of
misery." -Winston Churchill
Joel Koltner
> I sent the index off a week or two ago, and the cover design has converged
> on something more or less acceptable.
Wow, looks like something from the '70s! :-)
It'll definitely catch peoples' eyes and get them to take a second look...
should be good for "impulsive" sales.
---Joel
Phil Hobbs
> I keep getting these Amazon notices, several books I've ordered are
> "delayed" :-(
>
> ...Jim Thompson
That's what you get for ordering new stuff. The mailman just brought me
a copy of Phelan's control systems book from 1977. Good stuff.
Cheers
Phil Hobbs
Phil Hobbs
> "Phil Hobbs" <pcdhSpamM...@electrooptical.net> wrote in message
> news:hpqdnYh1FN4wZ4jX...@supernews.com...
>> I sent the index off a week or two ago, and the cover design has converged
>> on something more or less acceptable.
>> http://electrooptical.net/www/beos2e/beos2e_cover.pdf
>
> Wow, looks like something from the '70s! :-)
I feel so much better now, thanks. ;)
> It'll definitely catch peoples' eyes and get them to take a second look...
> should be good for "impulsive" sales.
The price went down to $145, too, even though there's about 100 pages'
worth of all new stuff. (The rest has been completely revised as well.)
Cheers
Phil Hobbs
Joel Koltner
"Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
message news:ubub15prkdt50jmgm...@4ax.com...
> I grew up in Huntington, WV. Was only in Massachusetts for my 4 years
> at MIT>
Ah, OK... so not visible in Huntington, then, eh?
> People who voted for Obama deserve the results that derive from their
> electoral idiocy. It's called "adjustment" ;-)
Yeah, but the nuke isn't going to discriminate between those who voted for him
and those who didn't!
> I'm leery of _anything_ Larkin recommended recently... he's gone
> somewhat bonkers ;-)
At times I rather think several of you older fellows are growing more
beligerant now, having perhaps personally experienced that "playing nice"
doesn't seem to help while realizing that you've been successful enough that
you no longer have much to gain via self-censorship. :-)
> Since you recommend it I'll get a copy.
With great effort, he did get his MS in mechanical engineering, but didn't
pass the qualifier for a PhD program. From the way he describes it, it sounds
like you really had to be a true genius-level individual to get into the PhD
program there -- not just, e.g., "noticeably above average" and
"hard-working." Besides his personal academic "career," though, the more
interesting part of the story is the tales of the professors and staff at MIT
and the other students he knew there.
Warning: His career goal was to figure out how to reduce energy
consumption/use alternative fuels/etc.! (And he now has his own energy
consulting company.)
> Early '80's, I was already 20+ years after MIT graduation.
Yeah, and now we're another 20+ years on. Time flies...
At Oregon State University a few years ago they decided that if you received
your MSEE/MSCS from them, you didn't even have to take a qualifying exam to
get into a PhD program. It's hard for me not to think that move wasn't more
about trying to establish OSU as a place with many PhD candidates -- and
hoping people would then assume that meant it "must be good," thereby
attracting more research dollars -- than just giving the master's students a
break and trying not to lose a few who could have been really good PhDs but
didn't want the major hassle of a qualifier.
---Joel
Michael A. Terrell
Jim Thompson wrote:
>
> I haven't figured that out, either. For some reason googlegroups
> seems to draw mostly nutcases :-(
Cox Cable gets their fair share, as well. Someone from their, in
California was trying to hack into my computer today. Two clicks, and
their IP address was blocked.
--
You can't have a sense of humor, if you have no sense!
John Larkin
I'll wait until it comes out on Netflix.
John
VWWall
> "Jim Thompson" <To-Email-Use-Th...@My-Web-Site.com> wrote in
> message news:mjob1550d681fpal6...@4ax.com...
>> Unfortunately I think we're going get far more than a Sputnik (that
>> happened in the Fall of my senior year in high school).
>
> Was it visible from... Massachusetts, was it (where you were living at the
> time)?
>
hotel, and it could be plainly seen.
The next day, in Washington, D.C., I asked some people in the Pentagon
if there was any effect on U.S. defense funds. Someone said: "Every
time it goes around the earth, a little more money falls out!"
--
Virg Wall, P.E.
John Devereux
I would think that you would get more from free access and extra book
sales, assuming the material is related. There is so much free content
around, I cannot imagine paying money for such a "subscription".
--
John Devereux
Phil Hobbs
Well, with that cover, it's bound to come out on DVD right after the
first weekend in the theatres. ;)
Cheers
Phil Hobbs
"Long long ago in a nebula far far away..."
Joel Koltner
news:87pre1z...@cordelia.devereux.me.uk...
> I would think that you would get more from free access and extra book
> sales, assuming the material is related. There is so much free content
> around, I cannot imagine paying money for such a "subscription".
I can. Free content is great, and I certainly make plenty of use of it, but
subscription services have a couple of advantages:
1) The guy providing the content now has a new incentive to keep coming up
with new material.
2) If your web site becomes popular, web hosting costs can become significant.
(This is particularly true if you start hosting videos rather than just text
files with a few snapshots...) Some income can help pay for that... and
perhaps even pay for some new equipment for the guy to test out/play with.
3) If you're paying money for something, you've made enough of a commitment to
it that you're probably more likely to "engage." This certainly isn't true
for everyone, perhaps, but at least for me, if I'm paying for, e.g., classes
at a college, my butt's going to be there for every class to "get my money's
worth" whereas if the classes are free, I'm much more likely to skip them --
even though I know in the long term I'm doing myself a disservice. (This is
somewhat similar to people figuring that if they're spending $30/mo on a gym
membership they're more likely to actually go get in shape, even though for
free they could just walk/jog/hike/bike/run around their neighborhood or
whatever... clearly that concept doesn't always pan out, but sometimes...)
I'm not wealthy, but I do have enough discretionary cash around that I
wouldn't miss $50/year, so for me the question would just be "is the content
worth $50?" and not "if I search around enough, can I find similar content for
free, and be convinced that it's coming from a source that's as reliable as
Phil, whom I already know to be not only an upstanding guy but also one very
sharp cookie?"