Driver to drive?

[Kris Krieger]

John Popelish <jpopelish@rica.net> wrote in
news:u9ydnU7lafRWJ1LVnZ2dnUVZ_v7inZ2d@comcast.com:

Martin Brown wrote:
(anip)
The scaffold that allowed complex biochemistry to get started does not
have to stay around forever. A fair amount of the junk DNA sequences
we have (if they are in fact junk) may be parts of that. One day we
may have decoded enough DNA from different species to piece the
history of evolution together.
(snip)

There is a fascinating book written for the non biochemist
on this topic. "Tracing the History of Eukaryotic Cells" by
Betsey Dexter Dyer and Robert Alan Obar.
http://www.amazon.com/Tracing-History-Eukaryotic-Cells-Dexter/dp/0231075936

Not only are the facts so far uncovered a real CSI type
plot, but the processes that are used to reveal them are
really interesting to understand. I especially enjoyed thew
account of how the researcher, using many different high
tech tools, develops a visual and tactile conceptual tools
for the molecular machinery inside cells and all the junk
and souvenirs there are in the attic of each living cell,
collected by its ancestors.

A real eye opener into how far both life and biochemical
science have come, already.

You might also be interested in the confluence of genetic and molecular-
biology techniques with embryology in studies done of chicken embryos,
showing that, if a specific protein, that's present when gnes are turned on,
is introduced, chick embryos do not lose their extra tail vertebrae (they
start off with 16, which is reduced and greatly shortened when teh "tail"
gene is turned off by genetic regulators); additionally, the embryos can,
with this method, develop teeth (by keeping the "teeth" gene from being
turned off).

There is also a new theory, based upon experiments, re: "genetic toolkits",
which might be of interest to you (if you havnen't already read/heard about
them).

You might also be interested in this article, again, if you aren't already
familiar with it:
http://en.wikipedia.org/wiki/Peppered_moth_evolution

HTH

 

[Kris Krieger]

John Popelish <jpopelish@rica.net> wrote in
news:BOudnVJ8jJDPT1LVnZ2dnUVZ_hednZ2d@comcast.com:

Kris Krieger wrote:

You might also be interested in the confluence of genetic and
molecular- biology techniques with embryology in studies done of
chicken embryos, showing that, if a specific protein, that's present
when gnes are turned on, is introduced, chick embryos do not lose their
extra tail vertebrae (they start off with 16, which is reduced and
greatly shortened when teh "tail" gene is turned off by genetic
regulators); additionally, the embryos can, with this method, develop
teeth (by keeping the "teeth" gene from being turned off).

I'm not a biochemist, so cannot absorb much from scientific
papers on the topic. Have you got any good book suggestions?

Sorry, no . I tend towards journals - Cell, C&E News, Nature, even
Scientific American, and so on. THere is also the occasional decent program
on teh educational Cable channels which provide seach terms and topics to
investigate. I also don't make an effort to keep citations/references for
everything, because I read for personal enjoyment and education (since my
major, and a significant part of my work life, was in Microbiology, I enjoy
keeping in touch with the Biological sciences).

So I unfortunately can't help you much with journal references, either

I did read through this, however, and, much as I distrust over-reliance on
Wikipedia, it does jibe with what I've read elsewhere, is a very decent
summary of the "genetic toolkit"/"modularity" pardigm, and offers some good
links and references:

http://en.wikipedia.org/wiki/Evolutionary_developmental_biology

The links I think you might find most useful are:
http://en.wikipedia.org/wiki/Gene_regulatory_network
http://en.wikipedia.org/wiki/Cell_signaling


Hopefully that helps re: the "big picture" - especially since Molecular
Biology texts can be *very* dry reading for us non-specialists , and the
summary does touch upon the salient points.

- Kris

 

In sci.physics bg_fisted <bg_fisted@hotmail.com> wrote:

fg

Allow me to answer on Le Chaud Lapin's behalf...these are of course,
simply my guesses as to what he would say... he is always welcome to
answer on his own behalf

On Sep 15, 9:05?pm, j...@specsol.spam.sux.com wrote:
Do you know what a "?" at the end of a sentence means?

If the "?" does not follow a question that I can easily respond to
with obfuscation and hand-waving, or an insult that I can react
indignantly to, then I must ignore the sentence completely.

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

Fail to exist in the real world.

What materials are you going to use to build the airframe of your home
built?

I will build my fully pressurized airframe out of commodity building
materials that can be purchased from Home Depot and Walmart, and
whichever major electronics chain happens to have a sale on Blu-Ray
players (gotta pimp my ride with hi-def entertainment system). These
materials will be commodity, but lightweight, such as tinfoil and
carbon fiber-looking plastic (real carbon fiber would be too
expensive). Any leaks in the airframe will be plugged with spackling
compound. Fiberglass insulation will allow me to maintain a
comfortable temperature inside.

If you encounter significant turbulence, what is the first thing you do
and why?

The first thing I will do is attempt to figure out the transfer
functions for the turbulence in my head. This is how the Blue Angels
do it; it is not the result of thousands of hours of flying as
everyone believes. At the first sign of turbulence, a pilot must think
about the transfer functions (convolution, Fourier, Laplace), work it
out in their head. Don't fight the humps. It's just like riding my
VFR-800 at 240 km/h (150mph US). Most pilots don't seem to understand
how much math is involved in flying. They learn by role. As an
engineer, I am trained to think about the math, to ask "what is really
going on here?" when my aircraft starts to wiggle.

bg
+fisting stopped

Sounds about right...


--
Jim Pennino

Remove .spam.sux to reply.

 

[Kris Krieger]

George Herold <gherold@teachspin.com> wrote in news:1fd1a809-bae9-40c5-8f45-
c7228a2efb6f@k7g2000hsd.googlegroups.com:

On Sep 16, 2:48 am, Jamie Morken <jmor...@shaw.ca> wrote:
Hi,

How long would it take a "good" engineer, say in the $150,000 a year
salary range to build this system and/or what would a fair value be for
the intellectual property of the system once complete, also what would
the prototyping fees be expected to be to reach a working prototype?

home energy system:

[snip]

Jamie, I have no idea of the cost.

But why do you have both a wind turbine and solar panels? What do you
do if the winds blowing and the sun is shining? If I was going to buy
such a system I would either dump the solar panels and buy a bigger
turbine/ tower or dump the turbine and buy more solar panels.
George

Why? With both in place, you can sell excess power back to the grid, yet be
covered in the event of clouds or low eindspeeds...I've also been considering
a dual-mode system, at least in the next house (can't have eitehr solar
panels or wind turbine here, the HOA forbids them). Expect that I'm thinking
of an integrated roof ssytem, as opposed to a roof with solar panels
attached.

Heck, I'd like to throw in a solar water-heater, passive but controllable
heating (thermal panels and an attached "greenhouse" area that could also be
used to grow fresh vegetables in Winter), a water-collecting roof and
cistern, and passive cooling (if I end up in a dry climate) which utilizes
passively opening/closing thermally-controlled vents in combination with the
use of ground-cooled air drawn in when the vents open. I already have a lot
of these things diagrammed out.

It seems to me that the more energy-independent one can be, the better off
one is, so I'm just wondering why you advise against a dual system.

Thanks,

- Kris

 

In sci.physics Don Klipstein <don@manx.misty.com> wrote:

Oh, now I learn something - if an aircraft has GPS and/or radar
altimeter, does it also require a pressure one? If so, is that for
usefulness in areas where there is chance to interact with aircraft that
have pressure altimeters and no other altimeters?
Or is this so that all aircraft can clear mountains (and each other
at the same time?) based on controller instructions (or navigation
maps) that assume adjusted-to-current pressure altimeters, which also
assume that the pilots keep their pressure altimeter settings current then
and there?

All airplanes in the US (other countries are similar) must have at a
minimum:

An airspeed indicator
A pressure altimeter
A magnetic compass
A fuel quatity indicator for each tank
An oil pressure indicator for each engine
An oil quantity measuring device for each tank (e.g. a dipstick)
A tachometer for each engine


--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Richard Herring <junk@[127.0.0.1]> wrote:

In message <slrngcuibo.23l.don@manx.misty.com>, Don Klipstein
don@manx.misty.com> writes
Oh, now I learn something - if an aircraft has GPS and/or radar
altimeter, does it also require a pressure one? If so, is that for
usefulness in areas where there is chance to interact with aircraft that
have pressure altimeters and no other altimeters?

All vertical coordination is based on pressure altitudes.

Or is this so that all aircraft can clear mountains (and each other
at the same time?) based on controller instructions

The pilot, not the controller, is always responsible for terrain
clearance.

(or navigation
maps) that assume adjusted-to-current pressure altimeters, which also
assume that the pilots keep their pressure altimeter settings current then
and there?

Yes, but not entirely. In some areas, "regional pressure settings" are
used: that's a pessimistic forecast of the pressure over some region for
the next hour - so for that period you are guaranteed to be higher over
the terrain than the altimeter is indicating.

Also, above some defined "transition altitude" (the actual value varies
from place to place) altitude is defined by "flight levels", which are
effective altitudes (in hundreds of feet) based on setting the altimeter
to standard pressure (1013 mb, whatever that is in inches.)

Provided you're high enough to be guaranteed clear of the mountains,
it's only the relative altitude of nearby aircraft that matters, and
using standard pressure means you don't have the problem of constantly
resetting the altimeter (and getting the data to reset it to, in remote
areas.)

[this is from a European perspective - there may be some differences in
US practice]

It is the same in the US except we use 29.92" instead of 1013 mb.

Such things are pretty concistant world wide by treaty.


--
Jim Pennino

Remove .spam.sux to reply.

 

[Nico Coesel]

Fred <frederick.brown@gmail.com> wrote:

I have an audio amp based on the LM3886. In order to get 50W out of
it I need to use a transformer who voltage rises too high for the
LM3886 to tolerate during no or light load times.

I have modeled a linear regulator for the amp, but is is very
wasteful, it dissipates over a hundred watts a channel. I had to
parallel four regulators on each rail in order to keep their
individual dissipations manageable.

I have started considering a switched mode power supply, and have been
looking at chips such as the LM5116. Some time ago, I heard using
SMPSs in audio amplifers in problematic because of the difficulty in
filtering out the switching noise from the output.

Any suggestions would be appreciated.

Several years ago I designed a class-D amp with an off-line SMPS. I
used a common mode filter transformer at the output of the SMPS to get
rid of the noise (windings arranged so that the AC currents cancel
each other). It works great.

--
Programmeren in Almere?
E-mail naar nico@nctdevpuntnl (punt=.)

 

[BobW]

"Helmut Sennewald" <helmutsennewald@t-online.de> wrote in message
news:gap9ab$cll$02$1@news.t-online.com...

"Joerg" <notthisjoergsch@removethispacbell.net> schrieb im Newsbeitrag
news:tyVzk.365$Ei5.320@flpi143.ffdc.sbc.com...
Helmut Sennewald wrote:
"Joerg" <notthisjoergsch@removethispacbell.net> schrieb im Newsbeitrag
news:f1Vzk.498$x%.5@nlpi070.nbdc.sbc.com...
Ok, simple circuit: Schmitt inverter, 10K resistor from output to
input, 1000pF capacitor from input to ground. Vh set to about 20% of
Vhigh. Should happily oscillate but I get the error message "Time step
too small". Also there is a noted dip in voltage down to about 80%,
something which should even be possible with a digital behavioral
device.

What gives? How can I fix that and make it run? Does it need some kind
of kicker?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.



Hallo Joerg,

I don't know what you did wrong.
Have you set the trigger levels vt and vh?

hysteresis: vh
trigger levels:
v1 = vt+vh
v2 = vt-vh

Example: Right-mouse-click on teh schmitt device.
Vhigh=5 Vt=2.5 Vh=1
td=5n

"osc.asc"-file:

Version 4
SHEET 1 880 680
WIRE 144 0 96 0
WIRE 288 0 224 0
WIRE 96 96 96 0
WIRE 128 96 96 96
WIRE 176 96 128 96
WIRE 288 96 288 0
WIRE 288 96 240 96
WIRE 320 96 288 96
WIRE 96 112 96 96
WIRE 96 192 96 176
FLAG 96 192 0
FLAG 320 96 out
FLAG 128 96 rc
SYMBOL Digital\\schmtinv 176 32 R0
SYMATTR InstName A2
SYMATTR Value2 Vhigh=5 Vt=2.5 Vh=1
SYMATTR SpiceLine Td=5n
SYMBOL cap 80 112 R0
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL res 128 16 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 10k
TEXT 80 -104 Left 0 !.tran 0 100u 0 100n


Thanks, Helmut. I did have everything in there except td since it wasn't
mentioned in the LTSpice manual. That did it. But I still have a weak
output, dips about 3V from the rails with Vhigh=12 with some serious
inductive load and 2ohms in series. Somehow that doesn't look normal. Do
they have a finite output current capability?

When I tried to open your file I got a syntax error.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.


Hello Joerg,

I copied my attached circuit into a file "osc.asc" and it worked.
You should copy the text from line "Version 4" to the end.
(The line "Version 4" is already part of the schematic file osc.asc.)

Yep. I tried that and it worked, too (had to replace some "> " with ""). In
fact, I just double clicked on the osc.asc file (in Explorer) and it brought
up LTSpice and it ran fine.

Bob
--
== All google group posts are automatically deleted due to spam ==

 

[john jardine]

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:f1Vzk.498$x%.5@nlpi070.nbdc.sbc.com...

Ok, simple circuit: Schmitt inverter, 10K resistor from output to input,
1000pF capacitor from input to ground. Vh set to about 20% of Vhigh.
Should happily oscillate but I get the error message "Time step too
small". Also there is a noted dip in voltage down to about 80%,
something which should even be possible with a digital behavioral device.

What gives? How can I fix that and make it run? Does it need some kind
of kicker?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Add something like "vhigh=5 trise=10n". Essentially the 'trise' adds a bit
of time reality to the gate. The help file is particularly obtuse in this
area. I've still to discover what that "ref" thing is there for.

 

[Mike Monett]

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 16 Sep 2008 05:54:36 +0000, Mike Monett <None@here.adr
wrote:

[...]

Darn, now you've got me curious. I wish people wouldn't do that.

Why? How can you consider possibilities without curiosity?

ftp://66.117.156.8/VAT-20.zip

That's a Mini-Circuits VAT-20, a cheap 6 GHz, 20 dB attenuator.

The 18 GHz parts are a lot smaller.

What's the schematic look like? The black rectangles look like thick
film resistors. But you can barely see the outline of something else
on the surface. Is that thin-film?

Also, it looks like a single section 40dB attenuator for 18GHz may
be difficult for a number of other reasons besides the ones I gave
above. I did some research on microwave attenuators.

Agilent states their attenuators use thin film:

"Agilent attenuators achieve flat-frequency response and high
accuracy through the use of thin-film attenuator cards. These cards
are composed of high-stability tantalum nitride resistive film,
deposited on sapphire or alumina substrates."

http://www.nit.eu/oferta/wypozyczanie/pdf/g30/Agilent-8494B.pdf

Vishay sells microwave thin-film resistors that go up to 2kohm:

"Industry's Smallest Thin-Film Resistors for Microwave Applications
Offer High Performance in Chip as Small as 0.010" by 0.020""

http://www.vishay.com/company/press/releases/2003/030425resistor/

Hittite recently announced three wideband attenuators for the DC to
25 GHz frequency band. The maximum attenuation is 20dB:

http://www.hittite.com/products/view.html/view/HMC656LP2

Barrie Industries offers a thin-film chip attenuator. The maximum
attenuation is 30dB:

http://www.barryind.com/en/AT.html

IMS offers thin-film attenuators for DC to 20 GHz. The maximum
attenuation is only 10dB. The higher attenuations have a much lower
frequency range:

http://www.ims-resistors.com/A-series.pdf.

MSI offers thin film attenuators to 24dB at 20GHz:

http://www.rikei.co.jp/dbdata/pdf/MSAT567.PDF

So the maxium attenuation I could find in a single section
attenuator for 20GHz is 30dB or less. If a 40dB attenuator exists,
it didn't show up in an extensive search.

I did find another on-line attenuator calculator. It handles PI, T,
Bridged-T, and Balanced attenuators. It doesn't require javascript:

http://www.microwaves101.com/encyclopedia/calcattenuator.cfm

Benjamin Lewis has calculators that allow different input and output
impedances. They also don't require javascript:

http://benl.co.uk/webapps/attenuator-calculators/pi-type

Microwaves 101 has an excellent page on microwave thin-films. They
explain that 2 microinches of tantalum nitride (TaN) has a DC
resistance of about 50 ohms per square. They go on to explain:

"This thickness of TaN is less than 1% of a skin depth at X-band, so
the RF sheet resistance is very nearly equal to the DC value. The
plot below shows how the RF skin depth varies over frequency; the
error is only about 1% all the way up at W-band, less at lower
frequencies. Nothing to concern yourself with."

http://www.microwaves101.com/encyclopedia/RF_sheet_res_examples.cfm

So thin film is a necessity at these frequencies due to skin effect.

Here's the catch of the day. Triquint Semiconductors show how to
calculate the attenuation of the evanescent wave in microwave
cavities. The following paragraphs are especially interesting:

"Design Guidelines for Microwave Cavities"

"These equations provide a good first order approximation to the
problem and can sometimes highlight serious radiation issues before
the design is frozen. Due to the many other variables which can add
to, or subtract from, the radiating or propagating signal
(bondwires, substrates, microwave structures, filters, passive
components, etc), it is best to stay as conservative as the design
will allow. At higher frequencies such as 40 GHz it becomes
difficult to build a channel below the waveguide cutoff frequency
(b=0.147 inches at 40 GHz) and still support the circuit element
sizes. To achieve a 3x ratio at 40 GHz would require a channel width
of 0.049 inches and a height from module floor to lid less than this
value."

"If the design dictates that active components, such as MMIC
amplifiers, be placed in a propagating waveguide channel, it is
prudent to limit their gain to 20 or 30 dB maximum. The use of
absorber on the lid in this case will almost always be required and
some gain ripple due to radiative feedback of the output signal can
be expected. The best course of action is to keep everything very
close to the ground plane. This reduces to a minimum the radiation
of components such as bondwires and other transitions. It is not
uncommon for a MMIC amplifier with 15 or 20 dB of gain to lose about
1 dB when a lid with absorber is placed above the MMIC. This is an
indication that the radiative signal level is not negligible."

http://www.triquint.com/prodserv/tech_info/docs/mmw_appnotes/DesignGuidel
inesApNote.pdf

This indicates you might want to stay at or below 20 dB in
single-section precision attenuators, as well as wideband
amplifiers.

For critical high frequency work, you might want to look at chip
bonding. Luis Cupido has started a Yahoo group to discuss the
issues. The registration is free.

http://tech.groups.yahoo.com/group/chip-hybrids/

(Thanks to John Miles KE5FX for mentioning this group in one of the
mailing lists.)

Luis Cupido's web site is a cornucopia of information for anyone
interested in high frequency work. He even describes a Corner Cube
Harmonic Mixer for 411GHz:

http://w3ref.cfn.ist.utl.pt/cupido/

We are surrounded by a wealth of information that is available
instantly for little or no effort. But the answers to one question
immediately create more questions.

How can you not be curious?

John

Mike Monett

 

[Don Klipstein]

In <72a0d4l07ro0tmpcgccg1hkiveonc3njfi@4ax.com>, Jim Thompson wrote:

On Tue, 16 Sep 2008 12:00:59 -0700 (PDT), mpm <mpmillard@aol.com wrote:
On Sep 16, 10:33?am, me <m...@here.net> wrote:

Nebraska has a Hooker county...

There's also an "Athol, Idaho". Try to say it three times fast...

There's also a "Knob Lick" in KY. Another one in Missouri.

Blue Bell, PA, used to be "Blue Balls"... I kid you not ;-)

Do you have an easy cite for that?

I live about a county SSE of Blue Bell. My parents, although divorced,
live in separate locations at most several miles from Blue Bell - I could
say a few miles. Both have done so since 1991. One of my parents is
employed much closer to Blue Bell than a few miles. The story of "blue
balls" for Blue Bell is news to me!

Of course, Blue Bell is about 50 miles (about 80 km) east of
Intercourse! But Blue Bell is definitely a Philadelphia suburb, while
Intercourse is in "PA 'Dutch'/deutsch Amish country", so religiously
conservative as to dress like Lubavitch sect of orthodox Jews and to
eschew lightning rods and in-home telephones along with almost everything
else developed during or after the Industrial Revolution. With web
citations for "reasonably innocent" reasoning for name of that town.

- Don Klipstein (don@misty.com)

 

http://neilkalo.googlepages.com/keithley2100
It must have been programmed in PL/M

It's a Chinese rebrand. The hardware seems good, but the firmware is
absolutely brain-damaged, and the engineers at Keithley are powerless
to fix it.

I have 4 of them. No Keithley, ever again.

With nothing to loose maybe one could make shoot at trying some own
firmware?
If it becomes bricked it can be used a doorstop

 

[Mike Monett]

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 16 Sep 2008 23:58:26 +0000, Mike Monett <None@here.adr> wrote:

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 16 Sep 2008 05:54:36 +0000, Mike Monett <None@here.adr
wrote:

[...]

Darn, now you've got me curious. I wish people wouldn't do that.

Why? How can you consider possibilities without curiosity?

ftp://66.117.156.8/VAT-20.zip

That's a Mini-Circuits VAT-20, a cheap 6 GHz, 20 dB attenuator.

The 18 GHz parts are a lot smaller.

What's the schematic look like? The black rectangles look like thick
film resistors. But you can barely see the outline of something else
on the surface. Is that thin-film?

Thickfilm on alumina; screened and fired conductors, screened and
fired cermet resistor elements, laser trimmed.



in >-----+-----R2-------R3------+------< out
| |
| |
R1 R4
| |
| |
| |
gnd>-----+----------------------+------< gnd

The R2-R3 node is a pretty big hunk of conductor, essentially a C to
ground, probably to kill capacitive shoot-through, maybe to
deliberately limit the bw to 6 GHz.

A la Winfield's high voltage probe. But the thick film will also have a
built-in frequency limit due to skin effect, as described in the Microwaves
101 web page.

You said the 18 GHz parts are smaller. What do they look like?

John

Mike Monett

 

[Phil Allison]

"Fred"

I got to thinking. If we work backwards from the speaker to the
transformer some thing interesting shows up.

We need 20Vpk and 5Apk at the speaker to get 50Wrms into 4 Ohms.

So add 4 for the dropout voltage and 0.7 for the bridge, that gives us
a minimum of +/-24.7V at full load load.

Since the 5A figure is peak the rms is 5/sqrt(2)= ~3.6A

** This is where you went 100% WRONG !!

Current is only drawn in HALF cycles from each DC rail - so with a peak of
5 amps, the *average DC value* is 5/pi = 1.6 amps per rail.

The actual current comes mostly from the FILTER CAPS - not the
transformer windings which merely top up the cap's lost voltage twice each
cycle of the AC supply.

Thus, the transformer needs to supply a minimum of 24.7V @ 3.6A for
each rail. That is approximately 89VA for each rail.

** BOLLOCKS.

The correct VA figure can only be approximated by calculation - the
formula for which is 1.6 times the DC power draw - which is 40 watts for
each rail ( ie 1.6 x 25).

Accordingly for the four rails, the transformer must supply a minimum
of 4 * 89VA = 356VA.

** The correct figure is 4 x 40 x 1.6 = 256 VA ( approx.)

Therefore, a 360VA rating is the minimum to get 50rms out of the the
chip.

** Nonsense.

You could easily use a 160 VA rated tranny with music signals.

That IS the size used in the majority of 100 watt class B audio
amplifiers.



...... Phil

 

[Mike Monett]

Hammy <spamme@hotmail.com> wrote:

Would this actually work?

Stabilizing regulators with low esr output caps (Ceramics and
polymer)

http://i33.tinypic.com/20rsqyg.png

The full note is here. Wayne Rewinkel National Semi

http://www.powerdesignindia.co.in/STATIC/PDF/200809/PDIOL_2008SEP12_SUP
PLY_TA_01.pdf?SOURCES=DOWNLOAD

Are there any negatives other then decreased dropout voltage and
power dissipation in the series resistor?

One of the problems with LDO design is the ESR of the output cap
must fall within a certain range for the loop to remain stable.

Here are some comments from a post by Tim Shoppa on using ceramic
caps with LDO regulators. The ESR is usually too low and can cause
oscillation, and the bias voltage on Y5V dielectric can cause a
significant drop in capacitance:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
09 Feb 2004 09:14:28
Tim Shoppa
Selecting > 1uF ceramic caps

R. Legg:

The ESR problem with 'LDO' regulators is not one that applies
specifically to ceramic capacitors, or even to LDOs; it's a problem
that applies generally to all regulators with PNP or P-chanel output
pass transistors, due to the added inversion in their control
structure and the capacitive nature of their normal load.

Leeper:

Take a 6V 10uf Y5V, put it on a 5V rail for filtering, and you end
up with an effective capacitance of 1uf.

http://www.avx.com/docs/Catalogs/cy5v.pdf
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Here are some articles showing why LDO regulators are sensitive to
output cap ESR. The url's are omitted since they often change, but
google will find them very quickly.

AN1148.PDF 205,195 Compensating Low-Dropout Regulators
AN682.PDF 879,026 New Generation of Low Dropout Regulators
AND8028.PDF 38,766 Precision Sub-One Volt 1.7 Ampere Output LDO
SLVA068.PDF 68,595 LDO Fundamental Theory
SLVA072.PDF 291,538 LDO Technical Review
SLVA079.PDF 202,342 LDO Terms and Definitions
SLVA115.PDF 85,754 Regulator ESR Stability
SLYT151.PDF 468,245 Compensation Transient Response
SLYT187.PDF 254,973 Understanding the Stable ESR Range
SLYT194.PDF 246,355 LDO Linear Stability Analysis
SR003AN.PDF 73,945 Compensation for Linear Regulators
SR004AN.PDF 41,598 Linear Regulator Output Structures

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Analog Devices has found a solution to the ESR problem:

"Solving Stability Problems of Low Dropout Regulators"

http://www.analog.com/en/content/0,2886,766_818_11812,00.html

and National Semiconductor solved it also:

"Capacitors are key to voltage regulator design"

http://www.national.com/nationaledge/jul02/article2.html

So with careful design, you can make a LDO regulator immune to the
ESR of the output cap.

Regards,

Mike Monett

 

[Jon Slaughter]

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:48D03577.D85BB536@hotmail.com...

Jim Thompson wrote:

Freddie Mac and Fannie Mae Political Contributions...

Heading the list of recipients:

#1 Senator Dodd
#2 Senator Obama
#3 Senator Kerry

each with over $100K

McCain is very far down the list... he's averaged less than $1K per
year.

Contributions ? Isn't a bit too late for that ? What are these ?
Contributions to the 'poor pot'.

Who next after Lehman Bros ? Citibank ?

I suggest all banking employees including the board should have wages
capped at $300,000 and no bonuses.

For years, it's been obvious that the 'money market' has been nothing
other than a Mafia run casino.

Thats not going to happen but I like it. Although then it opens up another
can of worms. If you cap them then will the good ones leave to find other
jobs(probably go to other countries) or will they find ways to steal the
money?

I bet it's a psychologic issue where these people value themeselfs through
their financial success. Hence theirs no solution. It's ego and greed and
only by changing that will you solve the problems... but how? The very
people who control everything have those problems. (And all these problems
didn't happen over night but built up over many years, decades at least)

In any case I hope America can recover but I think we are just seeing the
tip of the iceberg right now.

 

[Phil Allison]

<idkfaidkfaidkfa@gmail.com>

I'm studying buffered opamp and i've found this configuration
http://img156.imageshack.us/img156/5640/afsdafen7.png

i don't understand second statement
"reduces output load at the drains of M6 and M7"

I don't understand why a large resistance at the drains of M6 and M7
is a bad thing...

** When the " load " on some source is " reduced " - it means the load
impedance seen by that source is increased.

The logic is simple - if you add load to the back of a horse, the horse is
not so happy about it.




...... Phil

 

[Szczepan Białek]

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote
news:kb31d4tro39gk2chcosc965jn11gniverj@4ax.com...

Solids support both compression (longitudinal) and shear (transverse)
waves. Bulk liquids support only compression waves.

" Some liquid media at usual temperatures and pressures are good
shear wave conductors at high frequencies (0.5-1.0 MHz and above) [16]. "
This is from: http://ethertheory.chat.ru/epart3.htm

Is it possible that all liquids support shear wave at very high frequencies?

http://en.wikipedia.org/wiki/Wave

"While a mechanical wave exists in a medium (which on deformation is capable
of producing elastic restoring forces), waves of electromagnetic radiation
(and probably gravitational radiation) can travel through vacuum, that is,
without a medium"

It is in agreement with this: http://www.victorianweb.org/science/ether.htm

But all big scientists try to make a model of ether. Up to now without
success.
F. Gorbatshevich assumed that planets moves in ether without resistance.
Planets travel with ether. Only satellites "plough" eter. Is there any
resistance?
S*

 

[JB]

"JosephKK" <quiettechblue@yahoo.com> wrote in message
news:ger0d4ps6tfbf89gan8d73rdgkfej8sirn@4ax.com...

I am working on a project that legitimate requirement for such cable.
I have not been able to find such as a stock product. I am uneasy
about the temperature rating of EPR and XLPE insulation materials.

There are silicone insulated cables rated for these voltages/temps. We use
them in the lighting industry for cables connecting ignitors to lampholders.
They are not cheap however.

JB

 

[Phil Allison]

"MooseFET"

We need 20Vpk and 5Apk at the speaker to get 50Wrms into 4 Ohms.

20 * 5 / sqrt(2) = 70W


** Huh ????????

Why the root 2 ??

Peak power = double "watts rms" - you dumb asshole.



...... Phil