Chip with simple program for Toy

[TLOlczyk]

On Wed, 22 Jun 2005 03:29:30 GMT, "Lord Garth" <LGarth@Tantalus.net>
wrote:

The problem is powerok also know as 'power good'. The motherboard
outputs a signal to this input within a specific time frame or the ATX
will shut off. If the motherboard does not provide this signal, you can
jumper it to a 5 volt output. Lack of the power good signal is why you
must keep the switch input grounded when it is not connected to a
motherboard. Check your case switch, it is momentary.

Ok. I'm confused here. The mobo has a standard ATX connector and

expects stqandard inputs. The power supply is different and doesn't
have a powerok line ( instead it has a fan on line in it's place ).

The funny behaviour I see is after I ( partially ) install the PS. It
turns on the momment I connect the PS to a 120 outlet, not waiting
for me to "push the button", which i find confusing.

I haven't kept the system on for very long, but in the time that it is
on, it stays on.

Sense inputs measure the power supply voltage at the load and adjust
the voltage so as to be within spec.

So I guess that I should change the leads so that the connector

matches up with the ATX spec with regards to sensing. The question is
where do I put the grounded lead that is sensing. The ATX doesn't have
anything like that in it.

ATX power supplies are electronically switched. They can and do
false. This is why you should switch off or unplug the supply when
adding or removing cards from the slots.

You point here isn't clear to me. Everytime I connect the PS to a 120V

source it powers up. So this isn't some kind of "false" startup.




The reply-to email address is olczyk2002@yahoo.com.
This is an address I ignore.
To reply via email, remove 2002 and change yahoo to
interaccess,

**
Thaddeus L. Olczyk, PhD

There is a difference between
*thinking* you know something,
and *knowing* you know something.

 

[John Popelish]

thomson.eric@gmail.com wrote:

I have been frustrated for months working through an introductory
circuits book, as I want to build many of the circuits, but many of
them include constant current sources. Why is it so easy to find
voltage sources at your local store (i.e., batteries!), but searching
for current sources on the web leads to a complicated bunch of circuit
diagrams?

Voltage sources produce a fairly constant output voltage for all loads
from infinite resistance (zero current) to some minimum resistance
(more than zero current), but they are only approximate voltage
sources, because their output voltage does sag and current passes
through them. This is because they have some internal resistance.

Practical current sources hold a very nearly constant current for all
loads from zero ohms (zero voltage drop) to some maximum value of
resistance (some maximum voltage drop called the compliance voltage).

Ideal current sources would produce a constant current, regardless of
the load resistance, including infinite resistance, by producing a
compliance voltage up to infinity volts.

It is a lucky accident that we have discovered chemical cells that
produce something close to a voltage source over useful ranges of load
current. There is no similar simple power sources that provide a
constant current output.

Here is my naive question: using thevenin-norton equivalent circuits,
couldn't I transform a battery (i.e., voltage source) into the desired
equivalent current source using Vth=InorReq. That is, can I put a
voltage source in series with a resistor (as opposed to its equivalent,
a current source in parallel with the same resistor)? What is the
problem with doing that?

The problem is that it is not a current source, but a current source
in parallel with a fairly low value of resistance. Mathematically
transforming a voltage source that has a little series resistance to
the equivalent current source with parallel resistance does not
actually alter the characteristics of the source, at all.

Does anyone know where I could buy a cheap but reliable current source?
Why is this so hard?

Almost all practical current sources are actually active variable
resistances that waste all the extra voltage from a voltage supply
that is not needed to force the specified current through the load.
This active circuit has to be designed to pass the required current,
while measuring it, in some way, and using some sort of feedback, vary
an active resistance as needed to hold the measured value of current,
constant, till the load uses up all the available voltage. These
active current regulators are specified with their effective parallel
resistance (equivalent to a perfect current source in parallel with a
resistor), their voltage compliance, their frequency response, and
sometimes how long it takes for them to recover current regulation
after being exposed to an excessively high load resistance and then
the load falls to within the normal operating range.

Name your specifications, and people, here will help you design
current sources (regulators) that meet your needs.

 

[John Popelish]

obliquez wrote:

John Popelish wrote:

obliquez wrote:

If I were you, I would be searching through the thermistor section of
the catalog. Much cheaper and have lots bigger signal. They are not
linear, but for a threshold function, like this, that makes no difference.


I have no idea what you are talking about. Linear? threshold function?
-sheepish grin-


If you wanted to measure the temperature and convert the signal to a
temperature reading with an analog to digital converter (turn voltage
into number) linearity like 1 millivolt per degree is very handy. If
you just want a threshold function, like knowing whether or not the
temperature is greater or lesser than some single value, (either the
temperature exceeds the specified threshold value or it doesn't) all
you need is stability and sensitivity. That is, it doesn't matter
much how distorted the signal is at temperatures way hotter or way
colder than the one you are concerned with, but it matters that you
can measure that one temperature reliably (stability) and clearly
distinguish that temperature from those slightly hotter or slightly
colder (large temperature sensitivity).

The platinum sensor you mentioned, earlier has wonderful stability and
linearity, but it has very low sensitivity. Knowing that a
temperature is on the high or low side of a threshold by a degree is
hard to accomplish with one of those. Measuring the temperature over
a span of hundred of degrees within a several degree accuracy (an
electronic thermometer) is a better use for one of those.

Thermistors have a very distorted response to temperature, but they
are stable and can produce a large signal change for a small
temperature change, so they are well suited to threshold functions.
In order to make a thermometer out of them, you have to correct for
the distortion (varying amount of signal per degree over large
temperature swings). What you described about the requirements of
this project sounds to me like a threshold function.


Hmm.. does sound like threshold function to me as well.. Basically, i
just want a temp sensor that will ON when the liquid is too hot. Let's
say 60 degree celcius? (What's the usual temp for a hot drink that is
not too hot?)

So does that mean i sound search for a thermistor instead?

Yes. You should be able to find one like this for very little money.
http://dkc3.digikey.com/PDF/T052/1151.pdf

Btw, i have tested the buzzer. It gives off a tone, not a pop. So i
guess i can just follow what you guys suggested and use a PNP, with
resistors? Like this?


+5V +5V
` + +
` | |
` Red| .-. +5V
` .---o---. | |10K +
` | | | | |
` | | '-' |
` | LLE | | ___ |
` | Sensoro--o-|___|--| 2N3906
` | |Grn 10K |\
` | | |
` | | |
` '---o---' |
` Blue| |
` | / \
` | (BZ1)
` === \_/
` GND |
` |
` ===
` GND

will that work?

I think it will. I also think the driver is not needed. Also, try it
without the 10k to the +5 rail. I think it is not needed. A better
place for it is from the base to the +5 supply.

You will have to alter this when you get to combining the three
functions (tilt, level and temperature with logic to operate the buzzer).

 

[Don Bowey]

On 6/23/05 4:33 PM, in article
1119569604.937411.3770@o13g2000cwo.googlegroups.com, "Dave"
<dmcomm_ads@yahoo.com> wrote:

Oh, and of course I know how to post you little PerlMonkey, been
posting for 18 years now. I just CHOSE not to conform to standards
because amusing to me to see the Usenet Police monkeys come out of the
woodwork. It's good to shake things up once in a while.

The good and bad thing about the internet is that anyone can be a dumb-ass,
as you so well demonstrate.

 

[Larry Brasfield]

"davidd31415" <davidd31415@yahoo.com> wrote in message
news:1119576607.153380.149350@g44g2000cwa.googlegroups.com...

I know you can make a square wave from the sum of sinusoidals,

Not true, actually. See http://mathworld.wolfram.com/GibbsPhenomenon.html

but does
this mean that if you look at a sine-wave that wasn't made by using
sinusoids (perhaps using a switch or an oscillating crystal to turn the
signal on and off) on a spectrum analyzer that you would see all of the
harmonics required to make up the square wave?

Depending on the analyzer and its settings, you will see
harmonics as they would be computed in the usual way
for obtaining the Fourier series. Whether the "sine-wave"
(or square wave, for that matter) was made by composing
sinusoids or not, its harmonics depend only on its shape.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[John Popelish]

davidd31415 wrote:

I know you can make a square wave from the sum of sinusoidals, but does
this mean that if you look at a sine-wave that wasn't made by using
sinusoids (perhaps using a switch or an oscillating crystal to turn the
signal on and off) on a spectrum analyzer that you would see all of the
harmonics required to make up the square wave?

I assume you mean that if you look at a *square* wave that wasn't made
by using sinusoids...

The answer is yes. How the waveform is created has nothing to do with
its harmonic content. Only its shape determines its harmonic content.
The faster the rise and fall edges and the squarer the corners, the
higher the frequencies contained in the package.

 

[John Bokma]

"Dave" <dmcomm_ads@yahoo.com> wrote:

It doesn't matter...

What? Oh, your mom allowed you to be again behind the computer after a week
of punishment?

my posting irritates people like you, that's the
whole point.

Nice excuse for lack of brains: Nooooh, I do it on purpose.

Sorry for messing with you, although we doubt you'll ever get over it.
Thanks for the humor. You postings continue to amuse a number of us.

There is probably some help around the corner if you consider yourself "a
number of us".

--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html

 

[John Bokma]

"Dave" <dmcomm_ads@yahoo.com> wrote:

Oh, and of course I know how to post

Sure, but you consider it U63R733+ not to, hence the use of Google :-D

You probably also know how to use a part of your brain, but you rather
don't conform now do you?

you little PerlMonkey, been posting for 18 years now.

Some people try, but never get there. I feel sorry for you [1]

[1] Nah, I don't, the world would be boring without ignorant idiots like
you

--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html

 

[Jonathan Kirwan]

On 23 Jun 2005 19:33:53 -0700, "davidd31415" <davidd31415@yahoo.com>
wrote:

So how would the sampling rate of an oscilloscope be related to what a
square wave ends up looking like on the scope? Is there a rule of
thumb for the sampling rate of an oscilloscope when sampling square
waves?

The rule I use is to have at least a factor of 5. I get a relatively
"true" picture of the square wave with a scope (and probing setup, of
course) that passes at about 3db down at 5X the square wave frequency.
That gives you the 1X, and 3X fairly good and enough of the 5X to get
decent presentation.

....

If you want to see about what the impact of such a decision would be
on a square wave, I believe you can use Excel (or some other program)
to compute the impact on a particular square wave.

SUM [ (1/n)*SIN(n*w)/SQRT(1+(n/5)^2) ], n=1,3,5,7, ...

with w=2*PI*f

This equation, if I've got it right, assumes that the voltage is
(1/SQRT(2)) at the scope's 3db down frequency. You can see this part
in the above equation, where you see /SQRT(1+(n/5)^2). At n=5 (5X the
frequency of the square wave, which is by definition 1/5th of the
scope's bandwidth, you get /SQRT(2). I think this properly scales the
values as the frequency is increased or decreased. The leading (1/n)
part of the equation is the Fourier scaling for the components of the
square wave. Combined together and summed for some moderately sized
'n', I think this should approximate what the scope will show you,
including its roll-off behavior. Of course, I'm open to being wrong.

But regardless, my rule is 5X for the analog scopes. Works for me.

Jon

 

[Jonathan Kirwan]

On Wed, 22 Jun 2005 07:16:14 GMT, I wrote:

snip
How about this topology. I kind of like it:

: +12V
: |
: |
: / +12V
: \ R2 |
: / 47k |
: | |/e 2N3906
: +--------| Q2 PNP
: | |\c
: |/c 2N3904 |
: +5V +5V---| Q1 NPN |
: | |\e |
: Red | | |
: | | / \
: ,-------, / (BZ1)
: | | \ R1 \_/
: | LLE | / 22k |
: | Sensor| | |
: | |--------' |
: | | Green gnd
: '-------'
: |
: Blue |
: |
: gnd

Two fewer resistors, even. Make them both 22k, if two different
values is bothersome. And just nail Q1's base to the 5V wall and yank
down on its emitter. This will drive Q2's base just fine and turn on
the buzzer.

By the way, I just put a sample design into LTSpice and it proved out
as expected.

Speaking of which, Chris, I've provided a small tool for converting
LTSpice schematics to text. It's at:

http://users.easystreet.com/jkirwan/new/LTSpice.html

Source code is included.

The output from this program looks like this:

: PRIMARY SPECIFICATIONS
:
: .param Vbb=12V
:
: .param Vcc=5V
:
: .param ILoad=10mA
: +12V
: |
: |
: DESIGN ESTIMATIONS |
: ---
: .param Q1Vbe=0.6V Q1beta=200 +12V - V1
: | --- {Vbb}
: .param Q2Vce=0.2V Q2Vbe=0.7V Q2beta=50 | -
: | |
: .param IR2=0.1*Q2Ib \ |
: / R2 |
: \ {R2} +12V |
: / | gnd
: DERIVATIVE CALCULATIONS | |
: | |
: .param Q2Ic=ILoad Q2Ib=ILoad/Q2beta | |
: | |<e Q2
: .param Q1Ic=Q2Ib+IR2 Q1Ib=Q1Ic/Q1beta +------------| 2N3906
: | |\c
: .param Q1Ie=Q1Ic+Q1Ib | |
: | |
: | +---OUT
: +5V |/c Q3 |
: RESISTOR VALUES ,--------| 2N3904 |
: | |>e |
: .param RLoad=(Vbb-Q2Vce)/ILoad | | \
: --- | / R3
: .param R2=Q2Vbe/IR2 - V2 | \ {RLoad}
: --- {Vcc} | /
: .param R1=(Vcc-Q1Vbe)/Q1Ie - | |
: | \ |
: | / R1 | BUZZER
: | \ {R1} gnd
: gnd /
: |
: .tran 1m |
: SENSOR------------------'

As an example. Which is very, very close to what it looks like in
LTSpice.

Jon

 

[Jonathan Kirwan]

Q3 on the diagram is really Q1. Just forgot to rename it on the
schematic before generating the ASCII. Oh, well!

Jon

 

[James Morrison]

On Fri, 2005-06-24 at 05:01 -0700, MarkMc wrote:

I'm a new user of eagle, and I've managed to get through designing my
schematic to designing a PCB. I want to print via laser printer from
eagle on to some transfers which iron on to the copper, ready for
etching.

I can see that I can widen tracks in eagle, which is great, but the
copper area around holes is too small for me to solder on to. Is it
possible to expand these circular pads without editing each and every
library item at all?

Yes, you can change the restring (usually called annular ring) in the
Restring tab of the DRC window. Don't ask me why its in the DRC area
but it is.

You will probably want to make the minimum larger but play with it.
What you see on the screen is a close representation of what should come
out in the output files.

James.

 

[Matthias Melcher]

I'm a new user of eagle, and I've managed to get through designing my
schematic to designing a PCB.

You will probably want to make the minimum larger but play with it.

I beleive I should mention that Cadsoft has multiple great newsgroups on
their server too. Very helpful folks there including the authors:
news.cadsoft.de

 

[Bob Masta]

On 23 Jun 2005 18:30:07 -0700, "davidd31415" <davidd31415@yahoo.com>
wrote:

I know you can make a square wave from the sum of sinusoidals, but does
this mean that if you look at a sine-wave that wasn't made by using
sinusoids (perhaps using a switch or an oscillating crystal to turn the
signal on and off) on a spectrum analyzer that you would see all of the
harmonics required to make up the square wave?

You might want to have a look at DaqGen, my freeware
sound card signal generator for Windows. You can play
around with waveforms and see the effects via the built-in
spectrum analyzer.

Best regards.


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

 

[John Popelish]

Kruminilius W. wrote:

I think the optical shaft encoder would do what I want, but they appear to
be fairly expensive. The device I'm thinking of probably generates some
type of current when the knob is turned, where the current is proportional
to the rotation speed. I imagine that they're pretty cheap since I've seen
them on a variety of cheap electronic devices such as the volume/digial
tuning knob on radios.

Anything digital generates pulses, (counts) not voltage. Here is an
example of a low cost encoder used as a manual digital pulse source
available from Digikey:
http://www.grayhill.com/Grayhill.nsf/947848defbb4d47e8625682c006b98b9/206b2753570fa03f86256846007456b2/$FILE/E-33-34.pdf

 

[Matthias Melcher]

What you are looking for is a rotational encoder, or gray code encoder.
There are some low cost ($3 to $6) ones out there but some of them really
suck (they ar not sturdy, go clack clack clack, and lose contact after a
while). Optical encoders are much nicer, but incredibly expensive. $125 and
up. You can get those even with an RS232 interface that returns relative (I
moved 20 degrees) or absolute values (I am at 24 degrees).

see:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=56293&Site=US&Cat=33096389

Low end:
http://rocky.digikey.com/WebLib/Bourns/Web%20Data/ECW1J%20Series.pdf

High end:
http://rocky.digikey.com/WebLib/CUI%20Inc/Web%20data/MEH30-XXXXP-XX-XX-XX.pdf

 

[John Popelish]

Matthias Melcher wrote:

What you are looking for is a rotational encoder, or gray code encoder.
There are some low cost ($3 to $6) ones out there but some of them really
suck (they ar not sturdy, go clack clack clack, and lose contact after a
while). Optical encoders are much nicer, but incredibly expensive. $125 and
up.
(snip)

The optical encoders are more expensive than the contact types, but
there are some inexpensive ones available from Digikey.
$20.55
http://www.grayhill.com/Grayhill.nsf/947848defbb4d47e8625682c006b98b9/d6c5db22369d0aa786256846007185ff/$FILE/E-15-16.pdf
$33.20
http://www.grayhill.com/Grayhill.nsf/947848defbb4d47e8625682c006b98b9/f354f18d91ce4aba862568970060a1e5/$FILE/Bltn725.pdf
$44.62
http://www.grayhill.com/grayhill.nsf/9f8c4a13a816a6e58625681f0065ecd1/e42049beda758ae78625687b005e3a4b/$FILE/E-19-23.pdf
$30.00
http://rocky.digikey.com/WebLib/CUI%20Inc/Web%20data/RE20XXXXXXX.pdf
$51.37
http://www.bourns.com/pdf/enc1j.pdf

 

[John Popelish]

obliquez wrote:

If I were you, I would be searching through the thermistor section of
the catalog. Much cheaper and have lots bigger signal. They are not
linear, but for a threshold function, like this, that makes no difference.


I have no idea what you are talking about. Linear? threshold function?
-sheepish grin-

If you wanted to measure the temperature and convert the signal to a

temperature reading with an analog to digital converter (turn voltage
into number) linearity like 1 millivolt per degree is very handy. If
you just want a threshold function, like knowing whether or not the
temperature is greater or lesser than some single value, (either the
temperature exceeds the specified threshold value or it doesn't) all
you need is stability and sensitivity. That is, it doesn't matter
much how distorted the signal is at temperatures way hotter or way
colder than the one you are concerned with, but it matters that you
can measure that one temperature reliably (stability) and clearly
distinguish that temperature from those slightly hotter or slightly
colder (large temperature sensitivity).

The platinum sensor you mentioned, earlier has wonderful stability and
linearity, but it has very low sensitivity. Knowing that a
temperature is on the high or low side of a threshold by a degree is
hard to accomplish with one of those. Measuring the temperature over
a span of hundred of degrees within a several degree accuracy (an
electronic thermometer) is a better use for one of those.

Thermistors have a very distorted response to temperature, but they
are stable and can produce a large signal change for a small
temperature change, so they are well suited to threshold functions.
In order to make a thermometer out of them, you have to correct for
the distortion (varying amount of signal per degree over large
temperature swings). What you described about the requirements of
this project sounds to me like a threshold function.

 

[Jonathan Westhues]

"JeffM" <jeffm_@email.com> wrote in message
news:1119632027.050004.50530@g14g2000cwa.googlegroups.com...

I kow DRC stands for design Rules Check,
but does running this actually change your board layout then?
Mark (MarkMc)

No.
It flags stuff that doesn't match the specifications (e.g.,
clearances).
At that point, YOU can
1) change the layout
2) change the rules
or
3) cross your fingers and ignore the prompt

Except that in EAGLE you can set all sorts of parameters in the DRC that
actually do change how the Gerbers get generated. For example, that is where
you go to select which vias get tented, what kind of blind/buried vias are
allowed, what thermals look like, and other things like that. It is more
`design rules' than `check.'

I don't know how to widen pads that way but I can believe that you can.

Jonathan

 

[John Bokma]

"Dave" <dmcomm_ads@yahoo.com> wrote:

The use of personal cracks is the sign of an idiot,

Well, at least I don't need signs to see the obvious ;-)

If you read before all your childlike personal cracks, you'd see that
the ports (this includes 119) are not open for a much nicer newsreader.
Of course Google Groups sucks.

So you are just too lazy to copy paste some text.

Thanks for the amusement.

The pleasure was mine :-D

--
John MexIT: http://johnbokma.com/mexit/
personal page: http://johnbokma.com/
Experienced programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html