Driver to drive?

[Rich The Philosophizer]

On Sun, 14 Nov 2004 00:15:12 +0000, Paul Burridge wrote:

On Sat, 13 Nov 2004 20:25:28 GMT, Rich The Philosophizer
null@example.net> wrote:

My theory, of course, is that the flow of enzymes or hormones
or whatever caused by emotionsl movement can stimulate, or
maybe just catalyze, this synapse growth. I.e., emotional
release dramatically empowers the learning process.

Ah, but did you formulate your theory after smoking a doobie or two?
That might invalidate it. ;-}

In your mind, of course it does. Marijuana or other drugs couldn't
_possibly_ have _any_ beneficial effects _at_all,_whatsoever_, because
Big Brother says so.

Thanks for so clearly delineating the limits of your powers of
reason and/or discernment for us.

;^j
Rich

 

[Leon Heller]

"Kim" <ksleep@sympatico.ca> wrote in message
news:i1Cld.53162$Z7.1588245@news20.bellglobal.com...

I don't have enough experience, or common sense to complete this project,
so
I need some help, and finally realised that I will have to pay for someone
else to do it for me. I'll list the basic requirements, but Email me for
specifics for the job, or if you are willing to take it on, along with a
price quote. As well, if you think that the project is impossible, then
also
let me know. There is no real time constraints, so if you only do it in
your spare time, and it takes a long time to do, that will also be ok.

I require a circuit that will:
-display in 5 second increments, every time a switch is closed, on a basic
1
line lcd display (it wont actually be a 5 second increment in reality,
this
is count, not a time, but the count has to be in 5 second increments)
-add up these 5 second increments, until they "rollover" into minutes,
hours
days months, years.
-be battery operated (If it could be run for long periods of time on
button
cells, or equivalent batteries, then that would be great, if not... a few
AAA cells, or a 9v batteries size is ok).
-the display only needs to turn on for a minute after the switch is
closed,
if this will help extend the battery life.
-and be as small, and thin as possible (space is at a ABSOLUTE premium)
-the unit can be hard-wired or wire-wrapped, it doesn't need to look
"finished", or be done on a pcb.
-as a matter of fact, if I can be supplied with a chip, display, and
schematic, I can wire it myself.

IF there is a way to do this with a small, single chip
microcontroller....fairly easily, please let me know.
If you require more specifics, please email me with any questions you may
have. This is NOT going into mass production, so I WILL NOT be making
buckets of cash with this. This is just a item for a specific piece of
machinery at my work, and will DEFINATLY be a one-off.

This is an ideal application for the free 'watch' that was given out at the
TI MSP430 Day held a few months ago. The source code includes the time and
date display routines, and the input connection could be taken to one of the
switch inputs. Software development would be trivial. The coin cell should
last for a couple of years, at least.

Leon

 

[Kevin Aylward]

sjcma wrote:

Hi,

I'm hoping someone can enlighten me on the definition(s) of a Colpitts
oscillator. I've seen many circuits diagrams that show a Colpitts
oscillator, but they don't always look the same.

Assuming an NPN device, some show the capacitive feedback from
collector to emitter, some show the capacitor feedback from emitter
to base, and some show the tap between the 2 tank capacitors
grounded. I've seen circuits that are common base, common emitter,
and common collector all claming to be Colpitts.

What's the common link between all these circuits besides tapping the
tank in between two capacitors and connecting it somewhere (sometimes,
even ground!).

If someone feels like typing a lot, perhaps a quick explanation of the
advantages of each topology would be nice

Thanks in advance.

Well, I disagree with the other definitions in this thread on the taped
cap, especially the one by Tim with no cap directly from collector to
emitter. Here's the real deal.

Consider 3 impedances on a transister. Zcb, Zbe Zce.

The load on the collecter is Zce || (Zcb + Zbe).

The loop gain is therefore:

Av = gm.(Zce || (Zcb + Zbe)).Zbe/(Zbe + Zcb)

Setting this to one, one finds that the only too solutions are where
Zbe, Zce are capacitice with Zcb inductive or Zbe, Zce are inductive
with Zcb capacitive.

That is, a Colpits oscillator is when, topological, there are caps
across base emitter and collector emitter, with an inductance from base
to collector (Colpits), or where the caps and inducters are swaped
(Hartly).

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Leon Heller]

"Leon Heller" <leon_heller@hotmail.com> wrote in message
news:41972a84$0$29190$cc9e4d1f@news-text.dial.pipex.com...

This is an ideal application for the free 'watch' that was given out at
the TI MSP430 Day held a few months ago. The source code includes the time
and date display routines, and the input connection could be taken to one
of the switch inputs. Software development would be trivial. The coin cell
should last for a couple of years, at least.

Actually, it doesn't include date routines, but those would be easy to add.
The display is eight digits only (not character), but it could alternate
between date and time, represented numerically.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

 

[John Fields]

On 13 Nov 2004 15:28:15 -0800, bill.sloman@ieee.org (Bill Sloman)
wrote:

John Fields <jfields@austininstruments.com> wrote in message news:<imacp09ug5gr716a2l4mcgnmdes5uu41jd@4ax.com>...

---
OK, but disenfranchisement because of ignorance isn't going to happen
(again) anytime soon, I think.
---

Self-serving optimism.

---
Sure. I see the glass half full and filling, while you see the glass
half empty and emptying. Besides, I can't think of any optimism which
_isn't_ self-serving, can you?
---

Sounds to me like a case of the literati being more equal than the
illiterati.

As it should be. Do you want your diseases treated by someone who
lacks a medical eductation?
^^^^^^^^^^----<G>!

---
Apples and oranges.
---

What do you suggest? A purge? Sterilization?
Euthanization of the offspring of parents with IQ's lower than _or_
higher than "x"? Euthanization of that portion of the population with
equally "unacceptable" IQ's?

Electoral expenditure rules with teeth, so that multi-millionaires
can't buy up TV time to push electoral misinformation into the brains
of the couch potatoes.

---
Agreed, but I'd go farther than that.
As part of the licensing procedure for commercial broadcast stations
I'd include a requirement for the donation of a certain amount of free
time during election years (perhaps restricted to a month or so before
the election) for each/all of the candidates who have managed to meet
certain requirements; perhaps 100,000 signatures. Dunno... haven't
worked it out yet. What do you think?

--
John Fields

 

[Winfield Hill]

Andrew Holme wrote...

Frank Birbacher wrote:
For the comparator I thought of chip 74684, but maybe I
cannot get it. Are there alternatives to 74684/685?

Just spotted 25 x SN74LS682N on ebay (UK) with no bids...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=3851722229

The HC series of these parts are still in production by TI,
http://focus.ti.com/docs/prod/folders/print/sn74hc684.html
(who offers free samples), and they are in stock at DigiKey.


--
Thanks,
- Win

 

[John Fields]

On Sun, 14 Nov 2004 04:29:39 GMT, Rich The Philosophizer
<null@example.net> wrote:

On Fri, 12 Nov 2004 13:23:45 -0600, John Fields wrote:

Hmmm... Sorry, I guess allusion is lost on you.

maybe you'll get it if it's written like this:

RICH BUT GROUNDED

Rich is a gadwalk.
Small of brain but large with turd,
too heavy to fly

Well, your estimation of me certainly confirms what I have already
been able to discern about your capacity for rational thought.

---
Since your filters seem to be set to notch out anything which
conflicts with your heady view of yourself, I doubt whether "discern"
is the proper word.

--
John Fields

 

[John Fields]

On Sun, 14 Nov 2004 09:15:31 GMT, Rich The Philosophizer
<null@example.net> wrote:

I wonder what kind of conclusions you could come to if you made
a graph of various trends and stuff, like economies, wars,
weather, populations, just all sorts of cyclic-looking things,
and see if any kind of pattern would come out. I'm not motivated
on my own to go search out a pile of historical data and graph
it all, but I'd think that even as a thought experiment, a
whole lot of things seem to be coming to some kind of head.

What if that turns out to actually be an asymptote?

---
We might just have to put our heads between our legs and kiss our
asymptotes goodbye.

--
John Fields

 

[John Fields]

On Sun, 14 Nov 2004 09:22:17 GMT, Rich The Philosophizer
<null@example.net> wrote:

Well, the most recent "information" I've heard about Fallujah was that
there was surprisingly little resistance encountered, and they're about
to declare it "secure."

What would it happen if the "terrorists" just laid low for a few
months, acting like it's normal friendly occupation forces, serving
drinks in the off-base clubs and all that "entertain the GIs" crap,
and when it's loaded with GIs, and it's so secure that troops are
going there for R&R from Afghanistan and Pakistan, and when it gets
loaded to capacity, blow up the whole town?

---
Then the whole town and everybody in it would be killed.

--
John Fields

 

[Tim Wescott]

Kevin Aylward wrote:

sjcma wrote:

Hi,

I'm hoping someone can enlighten me on the definition(s) of a Colpitts
oscillator. I've seen many circuits diagrams that show a Colpitts
oscillator, but they don't always look the same.

Assuming an NPN device, some show the capacitive feedback from
collector to emitter, some show the capacitor feedback from emitter
to base, and some show the tap between the 2 tank capacitors
grounded. I've seen circuits that are common base, common emitter,
and common collector all claming to be Colpitts.

What's the common link between all these circuits besides tapping the
tank in between two capacitors and connecting it somewhere (sometimes,
even ground!).

If someone feels like typing a lot, perhaps a quick explanation of the
advantages of each topology would be nice

Thanks in advance.


Well, I disagree with the other definitions in this thread on the taped
cap, especially the one by Tim with no cap directly from collector to
emitter. Here's the real deal.

Consider 3 impedances on a transister. Zcb, Zbe Zce.

The load on the collecter is Zce || (Zcb + Zbe).

The loop gain is therefore:

Av = gm.(Zce || (Zcb + Zbe)).Zbe/(Zbe + Zcb)

Setting this to one, one finds that the only too solutions are where
Zbe, Zce are capacitice with Zcb inductive or Zbe, Zce are inductive
with Zcb capacitive.

That is, a Colpits oscillator is when, topological, there are caps
across base emitter and collector emitter, with an inductance from base
to collector (Colpits), or where the caps and inducters are swaped
(Hartly).

Argh. Yes, I got the transistor in there wrong -- I was concentrating

on the nifty notion that you draw the circuit free of any entanglements
from bias networks, then you ground whatever point is most convenient
for you.

Oddly enough I almost never do that in practice -- its only when I have
an audience that I screw up in such a stupid way.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Jeff Stout]

I can understand how the design of an LED signal would more difficult if the
controller is dropping half sin waves periodically. But then I realized
that the controller can be programmed to not dim the intersection at night.
But then, the dimming problem remains.

Jeff Stout

 

[Jonathan Kirwan]

On Sun, 14 Nov 2004 14:05:29 +0000, Guy Macon <http://www.guymacon.com> wrote:

Jonathan Kirwan wrote:

On Sun, 14 Nov 2004 06:33:53 +0000, Guy Macon <http://www.guymacon.com> wrote:

This is a perfect match for a BasicX controller, and I think that
you can do it all yourself (possibly with a few questions posted
here) using that technology.

I'm a little worried about the 20mA @ >=5V (quiescent, without taking into
account any I/O requirements.) AAA's are rated for 20mA, but it would require 4
of them in order to meet the 5V minimum. At 20mA, the four AAA's would last
(down to 1.25V each) for about 40 hours according to the Eveready chart.

The BasicX can be set to go into CPU Sleep mode (a microamp or so) and
to wake up with a timer or an external signal such as a switch closing.
(See atmel 8535 data sheet for the various sleep options) so it would
spend most of it's time drawing minimal power.

The MSP430 can keep a precise 32kHz crystal oscillator running with about 2uA
and start up the internal DCO from "stopped dead cold" to full up, high speed
running in typically 2us. Now, I just downloaded the data sheet for the
ATmega8535, looking at and scanning over the various lower power modes. Can you
point out the specific mode you are thinking here? Keep in mind that a precise
clock needs to continue running (at least, tentatively speaking.)

I'm at a loss to see the "a microamp or so" on this score and would appreciate
your guidance. (It's been years since I did a professional AVR product based on
the AT90S2313 and I've never used a mega part, yet.)

From the writing, my guess is that this is some kind of "engine hour" meter that
logs operational time to a resolution of 5 seconds. The unit would also turn on
the display long enough to read the accumulation (1 minute), but could go blank
after that. But that's hard to say from the way it is written out.

The LCD draws minimal power unless you turn on the backlight. It's fairly
easy to read unlit, or he can get one with a reflective backing.

The board I mentioned has it built in, using the MSP430's built-in LCD
controller. Very easy to use and full access to every segment. Nothing more to
attach. It's all there, I think.

If my wild guess is close to it, I'd imagine that if and when the
batteries need to be replaced, it still needs to remember the accumulation.

No problem. It has 32K of EEPROM (100,000 write cycles minimum).

Good.

Anyway, please educate me a little bit about the lower power modes. (I'm
thinking here that an external oscillator needs to be operating during the sleep
time.) The MSP430 board I mentioned includes two of them, a 32kHz and an 8MHz.
The MSP430 can run either, both, or neither (using the internal DCO which runs
the CPU at near full speed.) But when running asleep, it can keep the 32kHz hot
and ticking for 2uA total. I've measured it. Can the Atmel part do that, too?

(Plus, the MSP430 includes two complete external crystal oscillators and the
board I mentioned stuffs both of them for you, so you have at least three
distinct oscillators to work with. In this application, only the 32kHz is
required to keep time during sleeping, I think. And when running, the external
8MHz isn't needed, so I'd just fire up the DCO while keeping the 32kHz hot.)

Jon

 

[John Smith]

"Jeff Stout" <nobody@nowhere.com> wrote in message
news:cn8ebg$lbg@library1.airnews.net...

I can understand how the design of an LED signal would more difficult if
the
controller is dropping half sin waves periodically. But then I realized
that the controller can be programmed to not dim the intersection at
night.
But then, the dimming problem remains.

Jeff Stout

Not just difficult. I would think that designing a current-regulated power
factor controlled power supply would be next to impossible where the input
voltage has missing half cycles arbitrarily. But then there are a number of
brilliant design engineers in this group who could probably do it with their
eyes closed.

The problem disappeared when the controller was programmed to not dim and
the signals with the dimming option were installed. Everybody was happy.

John

 

[ChrisGibboGibson]

R Steve Walz

RSW

A girls bike range marketed by Raliegh in the 1970s and 80s. With a shopping
basket, and little wheels.

Gibbo

 

[Jonathan Kirwan]

On Sun, 14 Nov 2004 14:17:01 -0800, Tim Wescott <tim@wescottnospamdesign.com>
wrote:

The OP would have to clarify, but it appears he wants each external
pulse to be given a value of 5 seconds and counted -- if so then no
real-time clock is necessary.

This would certainly be something that affects processor choice!

I'm kind of wondering (and it isn't clear to me, anyway) if this is supposed to
count the time that the switch is on in 5 second intervals. But it would help
to know what problem this thing is supposed to solve.

Jon

 

[hamilton]

From the original post from Kim:

I don't have enough experience, or common sense to complete this
project, so
I need some help, and finally realised that I will have to pay for someone
else to do it for me. I'll list the basic requirements, but Email me for
specifics for the job, or if you are willing to take it on, along with a
price quote. As well, if you think that the project is impossible,
then also
let me know. There is no real time constraints, so if you only do it in
your spare time, and it takes a long time to do, that will also be ok.

The rest of the post describes the project.

Jonathan Kirwan wrote:

On Sun, 14 Nov 2004 14:17:01 -0800, Tim Wescott <tim@wescottnospamdesign.com
wrote:


The OP would have to clarify, but it appears he wants each external
pulse to be given a value of 5 seconds and counted -- if so then no
real-time clock is necessary.

This would certainly be something that affects processor choice!


I'm kind of wondering (and it isn't clear to me, anyway) if this is supposed to
count the time that the switch is on in 5 second intervals. But it would help
to know what problem this thing is supposed to solve.

Jon

 

[Tim Wescott]

Jonathan Kirwan wrote:

On Sun, 14 Nov 2004 14:17:01 -0800, Tim Wescott <tim@wescottnospamdesign.com
wrote:


The OP would have to clarify, but it appears he wants each external
pulse to be given a value of 5 seconds and counted -- if so then no
real-time clock is necessary.

This would certainly be something that affects processor choice!


I'm kind of wondering (and it isn't clear to me, anyway) if this is supposed to
count the time that the switch is on in 5 second intervals. But it would help
to know what problem this thing is supposed to solve.

Jon

And people wonder why engineers are so very picky about getting the
details right in the specification.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[ChrisGibboGibson]

Tim Wescott wrote:

Jonathan Kirwan wrote:

On Sun, 14 Nov 2004 14:17:01 -0800, Tim Wescott
tim@wescottnospamdesign.com
wrote:


The OP would have to clarify, but it appears he wants each external
pulse to be given a value of 5 seconds and counted -- if so then no
real-time clock is necessary.

This would certainly be something that affects processor choice!


I'm kind of wondering (and it isn't clear to me, anyway) if this is
supposed to
count the time that the switch is on in 5 second intervals. But it would
help
to know what problem this thing is supposed to solve.

Jon

And people wonder why engineers are so very picky about getting the
details right in the specification.

And then wonder why we consider being called "pendantic" a compliment.

Gibbo

 

[Rich The Philosophizer]

On Sun, 14 Nov 2004 09:12:54 -0600, John Fields wrote:

On Sun, 14 Nov 2004 04:29:39 GMT, Rich The Philosophizer
null@example.net> wrote:

On Fri, 12 Nov 2004 13:23:45 -0600, John Fields wrote:

Hmmm... Sorry, I guess allusion is lost on you.

maybe you'll get it if it's written like this:

RICH BUT GROUNDED

Rich is a gadwalk.
Small of brain but large with turd,
too heavy to fly

Well, your estimation of me certainly confirms what I have already
been able to discern about your capacity for rational thought.

---
Since your filters seem to be set to notch out anything which
conflicts with your heady view of yourself, I doubt whether "discern"
is the proper word.

Probably not, in your box <insert smiley of sticking out tongue>.

And, of course, we both see ourselves as having a battle of wits with
an unarmed man.

;^j
Rich

 

[John Fields]

On Sun, 14 Nov 2004 23:17:37 GMT, Rich The Philosophizer
<null@example.net> wrote:

On Sun, 14 Nov 2004 10:05:53 -0600, John Fields wrote:

On Sun, 14 Nov 2004 09:22:17 GMT, Rich The Philosophizer
null@example.net> wrote:

Well, the most recent "information" I've heard about Fallujah was that
there was surprisingly little resistance encountered, and they're about
to declare it "secure."

What would it happen if the "terrorists" just laid low for a few
months, acting like it's normal friendly occupation forces, serving
drinks in the off-base clubs and all that "entertain the GIs" crap,
and when it's loaded with GIs, and it's so secure that troops are
going there for R&R from Afghanistan and Pakistan, and when it gets
loaded to capacity, blow up the whole town?

---
Then the whole town and everybody in it would be killed.

Yes, we established that in the previous paragraph.

---
Hmmm... maybe it's just me, but when someone starts a paragraph with a
question, like: "What would happen if"... and then doesn't answer it,
I kinda tend to think that it needs to be answered before anything's
really "established".
---

Then what?

---
Hey, it's _your_ movie, so what would _you_ do?

--
John Fields