Driver to drive?

[John Larkin]

On Tue, 12 Oct 2004 20:26:19 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hi All,

Micro controllers can be used to drive a switcher from their PWM output.
Most of us know how to do that. But my question: Is there some nifty
literature on the web or elsewhere about all the trade-offs this entails?

What I mean are trade-offs with respect to PWM granularity, for example.
Suppose the counter runs off 5MHz. In order to arrive at reasonable cost
for the magnetics the PWM output needs to be, say, 300KHz or higher.
That leaves only 4 bits of granularity. So it would idle like a Harley
with worn spark plugs, something that may be ok. Then there is the
feedback. Most uCs with an on-board ADC are out of price range so slope
may have to do. On top of that there may be a limit of one slope
conversion unless eternal muxing is done.

Current mode is another topic. Tough to do on a uC but then again if one
can measure both current and voltage the uC "knows" where about the PWM
should be. But it's all not very precise. Then there is the issue of
making the code that runs the PWM safe and fast enough. After all, one
minor hangup in this area could result in a plume of smoke. Next, there
is the trend to ever lower VCC levels which renders the task of turning
on a FET hard enough non-trivial.

Regards, Joerg

http://www.analogconsultants.com

I just received this month's Power Electronics Technology mag. There
are two switchers that have pic's in the loop, although both use
analog pwm generators. The one on page 28 describes "a 24-v to 5-v
dc-dc buck regulator" that is clearly a push-pull forward regulator,
and a bizarre mess at that.

John

 

[Jim Yanik]

"Frank Bemelman" <f.bemelmanx@xs4all.invalid.nl> wrote in
news:41705630$0$566$e4fe514c@news.xs4all.nl:

"Julie" <julie@nospam.com> schreef in bericht
news:41704F6C.43FCA600@nospam.com...

[snip]

Do any nationals care about what outsiders think about their leader?
For 99.999% of outsiders, their opinion of an extranational leader is
based
solely
on news/media -- hardly suitable to make an informed decision.

What do you base your opinion on, besides news/media?

It all depends on *which* "news/media".
The mainstream news/media is clearly biased and twists their reporting.
CBS news is just the latest example.

--
Jim Yanik
jyanik-at-kua.net

 

[Winfield Hill]

John Larkin wrote...

I'm working on some stuff to test radars on B-52s. The plan
is to keep them in service until 2044, at which point many
of the planes will be 80 years old.

I'm reminded of the old Jimmy Stewart metal fatigue movie.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Fred Bloggs]

Tom Seim wrote:

Fred Bloggs <nospam@nospam.com> wrote in message news:<416FDDBA.7090005@nospam.com>...

Rich Grise wrote:

On Thu, 14 Oct 2004 20:23:50 -0700, Tom Seim wrote:



Fred Bloggs <nospam@nospam.com> wrote in message news:<416E92E2.60807@nospam.com>...


Bush has made several characteristics of his leadership style clear: 1)
he refuses to acknowledge reality, 2) he refuses to acknowledge that he
made *any* mistakes whatsoever

Sounds like you, fredrook.


Is this supposed to have some significance? I'd certainly think something
that Fred Bloggs says would sound like Fred Bloggs. But who's this
"fredrook" you seem to have conjured up?

Thanks,
Rich



The Seim weakling has run out of steam- or should I say hackneyed Bush
campaign slogans. But then this is to be expected of a slothful,
incompetent, and arrogant government welfare parasite who makes his
living with specious vu-graph shows with little substance and lots of
fraudulent misrepresentation. As the posting history shows, it doesn't
take much of hammer to shatter weaklings like Seim, he retreats into his
world of hallucinations of superiority, a form of self-preservation at
which he should be very well-practiced by now since he is a complete phony.


Well, I called your bluff and you folded, fredrook. You are, indeed, the phony here.

Looks like you're the one with a multitude of challenges you are
slinking away from- isn't that typical of your kind.

 

[Joel Kolstad]

"Clarence" <no@No.com> wrote in message
news:Xo_bd.31094$QJ3.5263@newssvr21.news.prodigy.com...

Since I have implemented a telephone system on an aircraft with Internet
access, I can say that there was nothing in any of those web sites to
inform
anyone except at a marketing level......

Not to worry, plenty of the kids getting BSEE's today are going to end up in
marketing anyway.

 

[Ken Smith]

In article <ecef0ac4.0410150702.dbd8e8d@posting.google.com>,
Kranthi Q <kranthi_q@graffiti.net> wrote:

Hi

I need some help in understanding the difference between -

Gate Length

Only 2 dimemsions of the gate really matter. The length and width. The
length is the one that is not the width.

Gate width

That is how far it is from the Gate Hinges to the Gate Latch.

Channel Length

You can think of any channel as a series of short channels placed end to
along the direction of travel.

Channel Width

This is the distance from the odd numbered marker to the even numbered
marker.

Channel Depth

This comes from the fathom meter.


--
--
kensmith@rahul.net forging knowledge

 

[Rich Grise]

On Fri, 15 Oct 2004 01:02:01 -0300, Chaos Master wrote:

, that posted to
sci.electronics.design on 14 Oct 2004 00:18:12 -0700:


I agree, M$ do not have full control of the operating system.

Once M$ wanted to end the BIOS, and create a custom loader. Obviously... it
would only work with MS products!

Back in the days when he was growing up, computers didn't even have
BIOSes in ROM - it was on an 8" floppy disk, along with CP/M. You had
to write your own "device drivers," which were basically the I/Os for
your hardware.

And Control-C rebooted the whole system, which nowadays I find kinda
cute.

Cheers!
Rich

 

[Rich Grise]

On Monday 11 October 2004 02:12 pm, CFoley1064 did deign to grace us with
the following:

Subject: Re: Need a little help building a 12 volt timer
From: Joerg notthisjoergsch@removethispacbell.net

Excellent advice. When stuff goes past the one minute marker these 4000

Thank you.

logic choices are clearly better than some RC combination on a one-shot.

Regards, Joerg

Joerg speaks truth -- the longer the time delay, the more chance of
something coming around to mess timing up like electrical noise from the
relay you're driving, power supply hash, you name it.

A lot of time delay relays built in the 1970s and 1980s were based on the
4060, mostly because if noise from the relay caused the oscillator to add
a count,
well, there are always 16383 other counts to keep timing stable. These
relays were never specified at better than 1% repetitive anyway.

Here's something that should work for you (view in fixed font or M$
Notepad):

What???!!!!???? A 555????? We don' need no steeenkeeeng 555!

VCC VCC VCC VCC
+ + + +
VCC | | | |
+ .----o-----o----. | |
| | 12 7 | | C|
.-------o---------. | | 1N4002- C|RY1
| 16 | | | ^ C|
| 4o------------o2 | | |
| 5o------------o3 | | |
| 6o------------o4 | | |
| 7o------------o5 1o------. '---o
| 4060 13o------------o9 | | |
.-o8 14o------------o10 | | |
| | 15o------------o11 | | |
| | | note: | | .-. |
| | | these pins | 4068 | 1K| | |
| | 11 10 9 | are | | | | |
| '-o------o------o-' inter- | | '-' |
| | | | change- | | | |/
| .-. .-. | able. | | o-----|2N3904
| | | | | --- | 14 | | |
| | | * | | --- '----o----------' .-. |
| '-' '-' | * | 1K| | |
| | * | | === | | |
| | | | GND '-' |
| '------o------' | |
| | |
=== === ===
GND GND GND
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
Modified by Rich Grise v0.999.69 Alpha 3 ;-)

* component values for proper timing are left as an exercise for the
reader. (I didn't even check yours, and am too lazy to figure it out
for whatever freq you'd need for the above)

Cheers!
Rich

 

[John Larkin]

On 15 Oct 2004 18:24:14 -0700, Winfield Hill
<Winfield_member@newsguy.com> wrote:

John Larkin wrote...

I'm working on some stuff to test radars on B-52s. The plan
is to keep them in service until 2044, at which point many
of the planes will be 80 years old.

I'm reminded of the old Jimmy Stewart metal fatigue movie.

There's a bunch on airframe fatigue in here:

http://www.globalsecurity.org/wmd/systems/b-52.htm


John

 

[Ken Smith]

In article <Xns9583D51252510jyanikkuanet@129.250.170.83>,
Jim Yanik <jyanik@abuse.gov.> wrote:
[...]

It all depends on *which* "news/media".
The mainstream news/media is clearly biased and twists their reporting.
CBS news is just the latest example.

I'm sure Fox-News just broadcast a newer example.

--
--
kensmith@rahul.net forging knowledge

 

[Spehro Pefhany]

On Thu, 14 Oct 2004 19:35:47 GMT, the renowned Rich Grise
<rich@example.net> wrote:

On Thu, 14 Oct 2004 10:36:53 -0400, Spehro Pefhany wrote:

On Thu, 14 Oct 2004 14:56:53 +0100, the renowned Paul Burridge
pb@notthisbit.osiris1.co.uk> wrote:

On 14 Oct 2004 06:09:07 -0700, photo@metrodiapo.com (Pol Guerin Ph.D)
wrote:

Dearest photographers,

Metroscope research group is inviting photographers to submit any
image of metros from around the world.

What's a "metro"?

Subway. Err..."Underground"/"Tube".

In some parts of the US, the Metro is buses or trolleys, or both.
When I was in the AF, a Metro was a blue bread truck.
In France, isn't it the sewer or something?

Whaaa? The Paris Metro (Le Métropolitain) is one of the finest public
transit systems in the world. Nice rubber wheels on the cars. Man,
would I love to be at the St-Michel station right now. 8-( The
Montreal Metro was okay last I saw of it. Washington DC's excellent
subway system is called the Metro as well- they spared no expense
there.

http://www.citefutee.com/picts/plans/gif/reseaux/metro.gif
http://www.stcum.qc.ca/English/metro/a-mapmet.htm
http://www.wmata.com/metrorail/systemmap.cfm


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Spehro Pefhany]

On Wed, 13 Oct 2004 23:46:01 -0400, the renowned "Tam/WB2TT"
<t-tammaru@c0mca$t.net> wrote:

"yar" <st_yar@yahoo.com> wrote in message
news:9581531f.0410131735.468d69e4@posting.google.com...
hi

I want build a power amplifier for a video signal from a ccd camera
I don't know what is the information I need to do this ?
&what is the steps?


note : I want make it as push-pull amplifier and I select the
transistor c1815 as the 1st stage & 2n2222 as the 2nd stage if this
is wrong what the right transistor number I can use & how I select it


thank you for any help
yar

Don't know anything about the C1815, but I have built wideband amplifiers
and found the 2N2369 to be much superior to the 2N2222 as far as bandwidth
goes; that is, if you can live with the 15 V breakdown. For PNPs, the 2N5771
works well. In any case, you will have to frequency compensate the feedback
loop for good video response. You should be able to find an IC that will do
the job.

Tam

Here's the jellybean C1815
http://www.semicon.toshiba.co.jp/td%5Cen%5CTransistors/Bipolar_SmallSignal_Transistors%5Cen_20030328_2SC1815_datasheet.pdf


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Fred Bloggs]

John Larkin wrote:

On 15 Oct 2004 18:24:14 -0700, Winfield Hill
Winfield_member@newsguy.com> wrote:


John Larkin wrote...

I'm working on some stuff to test radars on B-52s. The plan
is to keep them in service until 2044, at which point many
of the planes will be 80 years old.

I'm reminded of the old Jimmy Stewart metal fatigue movie.


There's a bunch on airframe fatigue in here:

http://www.globalsecurity.org/wmd/systems/b-52.htm


John

The official figure is 90 year operational life. Get it right.

 

[Scott Stephens]

Dirk Bruere at Neopax wrote:

Scott Stephens wrote:

His midnight downloads made me suspect his guilt. Then I heard an
interview (CSPAN) and changed my mind.

Do you have a leech agent? Ever leech websites or ftp sites thinking
they might disappear? Honestly, if I had access to computers with a
great deal of information, I would be greatly tempted to "back it up"
also.

Being an insomniac, I download at night. Even on Christmas Eve.

True.
I have 'backed up' at least one document from Los Alamos on nuclear
weapon design that was later removed for security reasons.

No idea why they bothered really, since anyone who is interested had
already sucked the site dry. Including every govt and terrorist org
worthy of the name.

IIRC a (F.A.S.?) web site has a bunch of those documents. They have the
ones listed that have been removed too. When I saw the list, I was
disappointed I didn't have a look at some of them. One I think was for
an infrared guided bullet.

At least I occasionally get something for my tax money from the feds, in
spite of the immense opportunity cost they inflict.

--
Scott

**********************************

DIY Piezo-Gyro, PCB Drill Bot & More Soon!

http://home.comcast.net/~scottxs/

Those who sow excuses shall reap excuses

**********************************

 

[Dirk Bruere at Neopax]

John Larkin wrote:

On Tue, 12 Oct 2004 03:20:46 GMT, Scott Stephens <scottxs@comcast.net
wrote:



Why do you accuse benevolent genius out of the context they lived in,
judging them with our modern standards? That really is superficial,
cheap, easy to say. These people, behaving in typical European fashion,
could well have murdered each other, factionalized into states each
fighting to devour the other. But no, because they were not perfect,
angelic enough, to overcome every conceivable human vice you must smear
the immense good which they accomplished.



My point, perhaps stated too subtly for the audience at hand, is that
America has made steady and impressive advancements in the definition
of "liberty" and in the classes of people who are allowed to exercize
it. And America will, I trust, continue to do so. So I am mystified
why so many people get hysterical about truly trivial things, like
airline security and postal inspections, and declare hyperbolically -
in total ignorance of the history of this country - that we suddenly
live in repressive times. We don't.

IMHO the 'free times' are coming to an end.
This is the peak.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org

 

[Spehro Pefhany]

On 14 Oct 2004 20:06:52 GMT, the renowned cfoley1064@aol.com
(CFoley1064) wrote:

Subject: Re: Want independant pulse width variation on + and - side of
gnd;square wave of about 1kHz
From: Spehro Pefhany speffSNIP@interlogDOTyou.knowwhat
Date: 10/14/2004 1:58 PM Central Daylight Time
Message-id: <j4htm09e04voj3s78495417k3ip0o5sd47@4ax.com

snip

Yes, but how would I get a (say) drop from ground to -5V lasting for
1/4000th second , returning to 0V for 1/4000th second (1/2 cycle of 1kHz at
50%) followed by (say) a rise from 0V to +5V lasting for 1/8000th second,
returning to 0V for 3/8000ths of a scond (1/2 cycle of 1Khz at 25%)?

Okay. If you use a single 555 in astable mode you can steer the
currents through both ends of your two pots to get this effect by
using a FF (eg. 1/2 4013) and 2 complimentary pairs of transistors.

Driving the output to the 3 levels depends on how much drive you need.
One possibility would be to use 1/2 of a 4052. It could also be done
with discretes.


Best regards,
Spehro Pefhany

I believe this is something close to what Mr. Pefhany is talking about. Unless
you want to change something else, this should do the job (view in fixed font
or M$ Notepad):
snip

That's pretty simple. I was thinking of something more along the lines
of:

+5V +5V
o o
| |
| |
.-------. .-------.
| 4066 | Pin 6,2 | 4066 |
State 0-----| 1/4 | LMC555 | 1/4 |---- State 2
'-------' o '-------'
| | |
Ton + .-. | .-. Ton-
| |<-----+------>| |
| | | | |
Toff + '-' --- '-' Toff-
| --- |
.-------. | .-------.
| 4066 | o | 4066 |
State 1-----| 1/4 | -5V | 1/4 |---- State 3
'-------' '-------'
| |
| |
o o
-5V -5V

Plus the 555 itself, the decoding logic for the states and the output.

The above should require no adjustment (though if it was required, a
trim could be made using pin 5 on the 555, either a single trim to
compensate for capacitor variation or a dual-level trim to compensate
for the differences in the pot elements). It should be very linear
with pot resistance. Also no other passive components except perhaps
an output resistor to ground depending on how that bit is done. Using
1/2 a 4052 and a 4-resistor network could take care of the decoding
and the second half could drive the output positively to each of the
three levels. So, parts count:

1 - 4066
1 - LMC555
1 - 4052
1 - 4013 (1/2 used)
1 - 4-resistor network
2 - pots
1 - capacitor
-----------
8 (+ bypass caps)




Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Robert Monsen]

Julie wrote:

Robert Monsen wrote:

Ah, Cincinatus, the great dictator who saved Rome in 16 days, then
returned to his plow. Hardly. His stupid, arrogant, vanity war in Iraq
has cost far more lives than it could have possibly saved, while
weakening us both internally, in the form of our economy, and
externally, in the form of fear of our military.


Just out of personal curiosity, excluding Bush, US policy, UN policy, etc. for
the moment, what do you think of Saddam and his established genocidal behavior?

a) Not my problem
b) Not anyone's problem except Iraqi's
c) Someone else's problem
d) Out of sight, out of mind
e) Arab's problem
f) Israel's problem
g) Other (describe: _____)

b) bad guy, but not a threat to anybody outside Iraq. The UN sanctions
were killing far more people in Iraq than he was, by at least 1000x. He
had no weapons, no plans for weapons, and was apparently writing romance
novels. UN sanctions would never have been lifted while he or his boys
were in power. We have veto power in the UN.

In other words, he was contained, not a friend to terrorists, and
isolated from the world community. He had no possible way to hurt the
US. He was actually deterring Iran for us with his silly 'find the WMD'
game.

So, my question to you is why spent 120e9 USD (at last count) that we
could not afford after the tax cuts and recession; the lives of almost
1100 soldiers; and, the lives of 20,000 Iraqis taking him out? Why get
us into a quagmire that it'll take years to extract ourselves from? What
good has it done for the Iraqi people? What good has it done us?

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Rich Grise]

On Sat, 16 Oct 2004 00:16:28 +0000, Robert Monsen wrote:

Ken Finney wrote:
Yes we do. But it is of no import. Smart Americans realize GWB is the
third incarnation of Cincinnatus. Unfortunately, they are many less than
smart Americans! ;^)


Ah, Cincinatus, the great dictator who saved Rome in 16 days, then
returned to his plow. Hardly. His stupid, arrogant, vanity war in Iraq
has cost far more lives than it could have possibly saved, while
weakening us both internally, in the form of our economy, and
externally, in the form of fear of our military.

Given the way things are going, I'd say he is more like Caligula (little
boot). Wild youth. Pretty boy. Gets power because of family connections.
Sponsors huge, ruinous giveaways to make people love him. Starts show
wars in an attempt to ingratiate himself with the masses. Messes things
up so badly that his own military turns against him, and takes him out.

Now, there's a thought. I hear that there's some disgruntlement amongst
the troops....

Cheers!
Rich

 

[Rich Grise]

On Fri, 15 Oct 2004 17:49:21 -0700, Julie wrote:

Robert Monsen wrote:
Ah, Cincinatus, the great dictator who saved Rome in 16 days, then
returned to his plow. Hardly. His stupid, arrogant, vanity war in Iraq
has cost far more lives than it could have possibly saved, while
weakening us both internally, in the form of our economy, and
externally, in the form of fear of our military.

Just out of personal curiosity, excluding Bush, US policy, UN policy, etc. for
the moment, what do you think of Saddam and his established genocidal behavior?

I thought somebody had him in a cage somewhere. Sounds pretty harmless to

me.

Thanks,
Rich

 

[Dave]

"Paul Burridge" <pb@notthisbit.osiris1.co.uk> wrote in message
news:7obrm0tkfp3os2c6pjnrdn0k4fpoauceg8@4ax.com...

On Wed, 13 Oct 2004 11:59:18 -0500, "Dave" <db5151@hotmail.com> wrote:

Could not find any of this, even with Google. Really beginning to wonder
now...

Sigh...
Post this link into your browser:

http://whatis.techtarget.com/definition/0,,sid9_gci803019,00.html
--

"What is now proved was once only imagin'd." - William Blake, 1793.

Okay, yeah, I went there earlier and checked out (I thought) everything
there, but didn't see any of the symbols described, and didn't know how to
type them into the search field or what to call them. There *is* the
absolute value and "is parrallel" symbols, but those don't make any sense in
the context in which the symbols I am describing are used in the PDF
document I referrenced elsewhere. Example: Vin = Vcc(R2/R1+R2)&Rb = R1 II
R2. (There is no Rb in the circuit illustration, and R1 is *not* parrallel
with R2. R1 and R2 form what I think is called a bias stick, providing bias
voltage for the base of the transistor in the circuit.) The PDF article is
about biasing transistors, BTW. Am I missing something?

Thanks,

Dave
db5151@hotmail.com