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Re: CPU question

Jim Purcell
 

Saad,

Old PC's can be
combined to make a super computer.
I've heard about that but I wonder whether it is a practical idea. The
controlling software that would assign parts of the computing task to various
computers would have to be vary sophisticated. Then
there would be the distances between computers. It would probably be better
to just use the
system cards otherwise all those old power supplies would consume lots of
energy and there'd be
the problem of varying power supply connectors and voltage requirements,
maybe some kind
of bus communication would be necessary to avoid port bottlenecks. It would
certainly be a
good project for some IT students but I think the work involved in making it
happen in a
real world situation would more than cancel most benefits.
But then I could be wrong, wouldn't be the first or last time.

Jim


Re: optoisolators

Borut Wagner
 

¿ªÔÆÌåÓý

You may use transformers, which are made for telephony?(here in Slovenia we use 300-3400Hz bandwidth?for POTS, I don't know what is in USA, but I think?it isn't much different). Ask in Radio Shack store.
?
Best regards,
?
Borut from Slovenia.

-----Original Message-----
From: sjohns10@... [mailto:sjohns10@...]
Sent: Thursday, November 01, 2001 3:59 AM
To: Electronics_101@...
Subject: [Electronics_101] optoisolators

I'm a beginner in electronics and I would like to know if there are
any optoisolators out there that would work with audio. I want to
record my phone conversations (4 seperate lines) but without
grounding the actual lines together. Would this work or is there a
better way? Thanks.


LM3914 vs LM3915 vs LM3916

Curtis Sakima
 

I saw on this group .... somebody wanted to know the
difference between the LM 3914 / 3915 / 3916 ?? I
accidentally erased that original email so I can't
recall what the original question was!!

Anyways.....

You're right ... that schematically, the LM39XX chip
ARE the same. The ONLY difference is the CALIBRATION.
The 3914 is a linear-ly calibrated device. It's
output changes one-per-volt (or per-amp or per ohm or
whatever)

The 3915 is LOGRITHMILLY (maybe someone could correct
my spelling!) CALIBRATED.

The 3916 is calibrated by dB's (like in audio/VU
metering etc). It's output changes
one-per-(audio)dB.

Now I'm NOT sure what the difference is between
LOGRITHMILLY (again, spelling) and DB calibrated is.
I've always thought that dB's WERE log.

I just know that because once upon a time a project
required me to read the spec sheets and that is what
it said. So I thought I'd pass it on.

Hope that helps!!

Curtis

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Re: International agreement on allocation of frequencies.

Jim Purcell
 

Himanshu,

Not exactly....each use its own...and have some common understandings...
But those understandings are usually formalized by treaty.

Jim


555 Observation

 

In my class today, I hooked a 555 in astable mode to an o'scope.
Before powering up the scope, I centered the trace. After powering
up the 555 I noticed the output from pin 3 was going from +v to -V (I
didn't check the voltage scale, so I don't know how large V is). I
don't understand why that happened. I should have gone from 0V
to +V.

Am I missing something?

Paul


Re: International agreement on allocation of frequencies.

Jim Purcell
 

angtengchat,

Is there an international agreement whereby each radio / tv station from
different countries are allocated certain frequencies so that they would not
"clash" with each other?
Yes, each country has allotted bands, sometimes shared. For example in N.A.
Canada and Mexico share our broadcast band, to the delight of broadcast
DXers. (DX = distant) who listen to distant radio stations. One interesting
frequency is 800 kHz, where a Windsor, Ontario, CA has a 50 000 watt
station and the Netherlands Antilles has a 500 thousand watt station.
DXing those can be fun, I have heard both in Milwaukee, but not at the
same time.

Jim


Re: Fw: communication concepts ??

Jim Purcell
 

angtengchat,

Seeing how you could do calculations and your detailed explanation, I
regretted that I did not have a formal electrical-electronic education.
Self education is an alternative. That's how I got my initial training,
two home study courses. The second got me my FCC license and a job
in broadcasting. That was a good learning opportunity. A broadcaster
had to be jack of all trades and was seldom master of any of them.

Jim


Re: newbie inquiry

Jim Purcell
 

angtengchat,

Discarding time factor, in short, it is the current passing thru that body
that electrocute that person.
Yes, I agree, especially at higher voltages. OTOH look at how long some people
take to die in the electric chair. And when there are problems sometimes a
person doesn't die and they have to go through all that again. I would favor
a law that says a person who goes through that once automatically has his
sentence commuted to life... without parole.

Jim


Re: Bomb

Jim Purcell
 

angtengchat,
To understand how bomb works IS an electronic question.
Not at 101 level.

Jim


Re: PIC resources

Teodoro M. Villamarzo
 

Hi Mounir,
Thanks for the concise definitions. I suspect that you can make mechanical devices using them. Maybe even a small robot? I haven't seen one, though. Are they commercially available? And how do you program them?

Ted

At 04:12 AM 11/1/01 +0000, you wrote:
Hi Ted,

PIC stands for Peripheral (okay, I'm bad in English spelling)
Interface Controller. Its a microcontroller manufactured by Microchip.

PIC17 and PIC18 is two different microcontroller families. PIC18 was
just released last year I think. So it is very new.

Difference between them aren't really to much. I personally find
PIC18 easier to program. The architecture is much more programming
friendly (I think).

Hope this helps :)

Mounir
~No question is to dumb. Only the answer~


--- In Electronics_101@y..., "Teodoro M. Villamarzo" <tedmv@m...>
wrote:
Sorry for this newbie question, but I'm really interested:

Can some tell me what a PIC is, and what it does, and what the
differences
between the PIC17 and 18?

Thanks...

Ted


At 08:48 PM 10/30/01 -0500, you wrote:

Must agree, 18 is way better than 17. Hopefully soon they'll get
all
their parts out in flash versions. Have you thought about using
the
dsPIC, when it comes out, to something ? I'm very excited about
that
part. Price wise, its very close to the PIC18-family. However,
its 16
bit and much faster.


From what I have read about the dsPIC it sounds impressive.
However at
present time I think I will have little use for it at work. But
I might
play around with it at home some when it come out, just for fun.
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Re: PIC resources

Mounir Shita
 

¿ªÔÆÌåÓý

Hi Ted,
?
Yeah, actually I'm currently working on putting a PIC into a toy robot.
?
They are available commercially. Actually, PIC are one of the most popular microcontrollers among hobbyist. You can by them at about any electronic component store/distributor. Check out for example. To program them you either:
?
(1) Need a programmer. Which can be pretty expensive. But if you have one of those, then you're set for a long long time.
(2) You can get a In-Circuit Debugger which will program a few Flash parts.
(3) Make your own programmer (tons of schematics for this on the web) and use in-serial programming.
?
Mounir

-----Original Message-----
From: Teodoro M. Villamarzo [mailto:tedmv@...]
Sent: Thursday, November 01, 2001 8:54 AM
To: Electronics_101@...
Subject: Re: [Electronics_101] Re: PIC resources

Hi Mounir,
???????? Thanks for the concise definitions. I suspect that you can make
mechanical devices using them. Maybe even a small robot? I haven't seen
one, though. Are they commercially available? And how do you program them?

Ted


At 04:12 AM 11/1/01 +0000, you wrote:
>Hi Ted,
>
>PIC stands for Peripheral (okay, I'm bad in English spelling)
>Interface Controller. Its a microcontroller manufactured by Microchip.
>
>PIC17 and PIC18 is two different microcontroller families. PIC18 was
>just released last year I think. So it is very new.
>
>Difference between them aren't really to much. I personally find
>PIC18 easier to program. The architecture is much more programming
>friendly (I think).
>
>Hope this helps :)
>
>Mounir
>~No question is to dumb. Only the answer~
>
>
>--- In Electronics_101@y..., "Teodoro M. Villamarzo"
>wrote:
> > Sorry for this newbie question, but I'm really interested:
> >
> > Can some tell me what a PIC is, and what it does, and what the
>differences
> > between the PIC17 and 18?
> >
> > Thanks...
> >
> > Ted
> >
> >
> > At 08:48 PM 10/30/01 -0500, you wrote:
> >
> > >>Must agree, 18 is way better than 17. Hopefully soon they'll get
>all
> > >>their parts out in flash versions. Have you thought about using
>the
> > >>dsPIC, when it comes out, to something ? I'm very excited about
>that
> > >>part. Price wise, its very close to the PIC18-family. However,
>its 16
> > >>bit and much faster.
> > >
> > >
> > >
> > > From what I have read about the dsPIC it sounds impressive.
>However at
> > > present time I think I will have little use for it at work.? But
>I might
> > > play around with it at home some when it come out, just for fun.
> > >Yahoo! Groups Sponsor
> > >ADVERTISEMENT
> > >
> > >To unsubscribe from this group, send an email to:
> > >Electronics_101-unsubscribe@y...
> > >
> > >
> > >
> > >Your use of Yahoo! Groups is subject to the
> > ><>Yahoo! Terms of Service.
>
>
>
>To unsubscribe from this group, send an email to:
>Electronics_101-unsubscribe@...
>
>
>
>Your use of Yahoo! Groups is subject to


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Re: Fw: communication concepts ??

Doug Hale
 

I wouldn't let that stop me, I have the degree but I don't work in that field. I am completely self taught in the field I currently work in, and the one before that, and the one before that, ...

You can do ANYTHING, you just have to decide to pay the price. (study)

The key to electronics is math. Math is nothing more than a modeling language. It provides us with a way to model/describe natural behavior in an unambiguous may.

My formal training is mainly in Control Theory. My first job out of school was in computers. I learned digital electronics from Manufacture's data sheets and application notes - primarily Signetics because they gave them away instead of charging for them.

I got my BS in 1975 but I have never stopped learning. Learn from whatever source you can find. The web is full of stuff, course materials, data sheets, application notes, white papers, ... There are some good beginning books at the ubiquitous Radio Shack. I f there is a college or university near you, you can find some real good used text books - and actually the older the better. My favorite sources are still my OLD college texts (yep, I've still got them all).

But most of all, have fun and enjoy what you are doing, it makes overcoming the difficult thing that much more rewarding.


Doug Hale

angtengchat wrote:

Seeing how you could do calculations and your detailed explanation, I
regretted that I did not have a formal electrical-electronic education.

Sigh!


Re: newbie inquiry: what kills

dragnfyr
 

I had a brother who was struck directly by lightning, had the scars on his
head and foot where it went in and out till his dieing day... also worked
with someone who took enough charge to burn off a finger on each hand and
blow himself out of the bucket on our truck... he lived as well (although
they say its only because he hit flat on his back and that restarted his
heart)

Drag

-----Original Message-----
From: Keith Messent [mailto:rkmessent@...]
Sent: Tuesday, October 30, 2001 11:28 PM
To: Electronics_101@...
Subject: Re: [Electronics_101] Re: newbie inquiry:what kills


I think that there is a difference between those who have been struck
directly by a lightning flash (now deceased!) and those who have been in
the close vicinity of a strike! I find it just about impossible to
allow that anyone directly struck and burned by a discharge could
possibly survive. As I reported earlier, it is generally accepted by
Health & Safety authorities that 10 Joules (via PD >230V) through a
vital organ would be lethal!
Keith Messent, Skipton, UK
----- Original Message -----
From: <adityanewalkar@...>
To: <Electronics_101@...>
Sent: Wednesday, 31 October, 2001 07:17 AM
Subject: [Electronics_101] Re: newbie inquiry:what kills


Think about lightning. Lightning has millions (10^6) of amperes of
current, several millions of volts of voltage, (sometimes measuring
650 Coulumbs of charge) ... still there are quite a lot of people who
turn up alive even after being hit by lightning. I think that is
becoz of the fraction of a second the charge passes through the body
of the person.



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Re: International agreement on allocation of frequencies.

Himanshu Sharma
 

Not exactly....each use its own...and have some common understandings...

Like we may use some wave-length for some transmission and some other
country may use it for some-other...but they both use all the frequencies...
Hope that I am correct...

Regards :-),

--himanshu sharma

----- Original Message -----
From: angtengchat <angtengchat@...>
To: <Electronics_101@...>
Sent: Thursday, November 01, 2001 6:34 AM
Subject: [Electronics_101] International agreement on allocation of
frequencies.


: ----- Original Message -----
: From: "Jim Purcell" <jpurcell@...>
:
: > Well, there are two factors, what the modulation
: > frequencies the transmitter is capable of and what
: > bandwidth the FCC allows. Both are +/- 15 kHz in
: > most cases. How can this be, simple, stations are
: > never assigned frequencies close enough to interfere.
: > You won't have one station at 1000 kHz and a near
: > by one at 1010 kHz or 990 kHz, and probably none
: > at 1020 or 980.
: > Jim
:
: Is there an international agreement whereby each radio / tv station from
: different countries are allocated certain frequencies so that they would
not
: "clash" with each other?
:
: Thanks
:
:
: _________________________________________________________
: Do You Yahoo!?
: Get your free @yahoo.com address at
:
:


Re: Energy

Himanshu Sharma
 

Hey,

The best option is the Hydrogen Energy...(We make controllable Nuclear
Fusion Reactors and we are through...)And as far as the studies show we are
very near to it....So energy won't be a problem...

So be happy and forget about this problem a little...Just think that how
will we take the energy to the Vehicles and other movables.....
Regards :-),

--himanshu sharma

----- Original Message -----
From: angtengchat <angtengchat@...>
To: <Electronics_101@...>
Sent: Thursday, November 01, 2001 12:50 PM
Subject: [Electronics_101] Energy


: As oil / energy is scarce, it would be great if we could find an
: "alternative source of energy" before oil gets depleted in about 200 - 300
: yrs from now.
:
: I'm fully aware of that theory of concervancy of energy.
:
: Therefore, I would appreciate if someone here could teach / tell us how
: energy could be tap from the sky (solar energy) or some other sources.
:
: Thanks.
:
:
:
:
: _________________________________________________________
: Do You Yahoo!?
: Get your free @yahoo.com address at
:
:


Re: Bomb

 

angtengchat wrote:

To understand how bomb works IS an electronic question. We have things
like the atomic , nuclear and neutron bomb which comes from the
electronic word atom neutrons and nucleus.???I ask because I am curious
and to be curious is natural, it is educational. There's no way
mankind could STOP humans from exploiting knowledge, so one of the
many ways to stop the explosion of these arsenals is to understand how
they work in the hope that we could "invent an anti-dote".???Do members
think we could make a bomb out of this discussions? It must be a joke
if members think we could.
????????? For those of you who do not know Who I am, I am the owner of this
list. This subject is OFF TOPIC. I don't think I can make things any
more clearer here. This topic is closed. There are young members on this
group, I do not wish them to think that it is necasary to know this sort
of information. I have stated before that??? I am not for censorship in
any form. However I do not consider this subject suitable material for
this forum. We have already lost at least one member becuase of this
topic, and I personally feel this is one too many, regardless of how
many posts they may have made.

????????? I hope that this will end the discusion and I will not have to take
further action.
???

)O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(

???????????? The Sinister Dragon
???

Hey, Just because I'm EVIL,
???????????? Doesn't make me a bad person......????????? >:-)
???


Re: CPU question

 

Well there is one more thing that can be done with old
PC's - while we are at the subject. Old PC's can be
combined to make a super computer. The idea and
technique are those of the Bewoulf Cluster Computing.
Incase somebody wants a starter on this they can get
a very good article from the Scientific American
Website where three chaps from Oak Ridge National
Laboratory got together to build a super computer
using old 486's and Pentium computers.

-Saad

--- Doug Hale <doughale@...> wrote:
It is doable. There are many companies out there
that build single board
embedded x86 computers.
It is quite expensive to build a board to handle the
high clock rate
cpus though.

Doug Hale

epsulon@... wrote:

While we are on the topic of microcontrollers and
such, here is my question.
With the pentium 3 500MHZ and 700 MHZ at prices of
$50 dollars and less, I
was wondering if it is possible to actually use
this CPU's for dedicated
computing? If this is possible I would love to
learn about these
oppurtunities. I would think that with all of the
power in these processors
you could do make some really strong projects.
Thanks for any help.
Jon



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Energy

angtengchat
 

As oil / energy is scarce, it would be great if we could find an
"alternative source of energy" before oil gets depleted in about 200 - 300
yrs from now.

I'm fully aware of that theory of concervancy of energy.

Therefore, I would appreciate if someone here could teach / tell us how
energy could be tap from the sky (solar energy) or some other sources.

Thanks.




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Do You Yahoo!?
Get your free @yahoo.com address at


Energy

Keith Messent
 

Use of fossil ('mineral') oils usually results in the ultimate
production of carbon dioxide which ends up in the atmosphere.
The only effective means of depleting the atmosphere of carbon dioxide
is by photobio-synthesis of sugars (and via bio-chemical pathways within
living organisms to other complex organic substances, including fats and
oils). When the supplies of mineral oils in the world have been
depleted to the point where it it would be uneconomic to try and extract
more, perhaps the salvation of the Human species will come to rely upon
oils derived a) from uni-plast micro-organisms like yeasts, and b)
essences expressed from renewable resource higher plants ('essential'
oils). The energy for both syntheses comes, of course, from the Sun
(provided this source is not blocked by thick cloud of whatever earthly
origin and continues to wander through the Milky Way free from celestial
collision with some other body, which would be the end of everything!).
The technology probably already exists, or could be adapted from known
technology, whereby sufficient oils for lubrication purposes could be
produced to satisfy world needs! Whether sufficient oil for fuel
purposes could ever be produced this way may be debatable, but at least
technology has already come up with a variety of renewable and
environmentally friendly resources which could keep humanity going until
some genius comes up with a better way of generating power. Perhaps we
should be looking with more interest at the living organisms which are
independent of direct sunlight! I refer to the bathysperic bacteria and
other deep-sea organisms of the volcanic 'smokers' of the mid-Atlantic
ridges.
Keith Messent, Skipton, UK

----- Original Message -----
From: Himanshu Sharma <hs_ramdev@...>
To: <Electronics_101@...>
Sent: Thursday, 01 November, 2001 10:28 AM
Subject: Re: [Electronics_101] Energy


Hey,

The best option is the Hydrogen Energy...(We make controllable Nuclear
Fusion Reactors and we are through...)And as far as the studies show
we are
very near to it....So energy won't be a problem...


Re: PIC resources

Teodoro M. Villamarzo
 

Sorry for this newbie question, but I'm really interested:

Can some tell me what a PIC is, and what it does, and what the differences between the PIC17 and 18?

Thanks...

Ted


At 08:48 PM 10/30/01 -0500, you wrote:

Must agree, 18 is way better than 17. Hopefully soon they'll get all
their parts out in flash versions. Have you thought about using the
dsPIC, when it comes out, to something ? I'm very excited about that
part. Price wise, its very close to the PIC18-family. However, its 16
bit and much faster.



From what I have read about the dsPIC it sounds impressive. However at present time I think I will have little use for it at work.? But I might play around with it at home some when it come out, just for fun.

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