In article ,
mentioned...
When I need to power some of my smaller creations I use an ohmmeter as a
power supply...

Must be _very_ low power!


--
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In article ,
mentioned...

"Tim Williams" wrote in message
...
"Ratch" wrote in message
news:BZmRa.80118$Ph3.9181@sccrnsc04...
While correct and true in all
cases, those formulas are NOT Ohm's law, and it is wrong to call them
that.

Dude, go back to school, Algebra 1. V=IR I=V/R R=V/I etc.
The equation can be rearranged to any of the others by simple
multiplication and division by whichever variable.

Tim

I believe everyone on this newsgroup can isolate each of the terms
algebraically. What is your point? What don't you agree with? What is
incorrect? Be specific. Ratch

I think the point of everyone here is that you're being pedantic,
pointing out something that has no real relation to the topic being
discussed.


--
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###Got a Question about ELECTRONICS? Check HERE First:###
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goes directly to the trash unless you add NOSPAM in the
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Don't be ripped off by the big book dealers. Go to the URL
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@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

In article ink.net,
mentioned...
After all that I still can't get my ohmmeter to work as a power supply!!!

Tsk-tsk! Siwwy wabbit! You have to unscrew the back of the meter,
and remove the 9V battery, then connect the wires to it! Simple!

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
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In article ,
mentioned...


Tim Williams wrote:


Tim (can't believe the number of negative replies on this thread)

Exactly. It is un-eff-ing believable how some people just love
to snipe.

I wonder how many of the "snipers" ever had to brew a meter shunt?
You can use the "Watson ohmmeter" for that - and, as another
poster mentioned - toss your Fluke in the dustbin. :-)

Hey, I like that.. It has a nice ring to it: "Watson Ohmmeter".

One of the maintenance guys at work gave me a Fluke 23 meter which is
just a yellow cased version of the 73, I believe. Said he sent it to
Fluke but they sent it back because it it was beyond repair or it
would cost more than a new meter. He might have done something really
stoopid like set it to the ohms range and put it on the 480VAC. In
any case, the display comes on, but nothing happens when the test
leads are connected to a V source. Apparently something major has
been zapped. It's been laying around at work for a couple years, it
probably oughtta be tossed in the trash can. The case is kind of
grubby so it's not worth saving for the case. Maybe I should give it
to the theater dept to use as a prop.

Recently the theater guy came over and asked our help desk lady for a
dozen telephone handsets and curly cords. She asked him what they
were going to do with them. He said they were going to use them as
props in a play, the actors would be dancing around with the handset
and the curly cord on stage. He said they would give them back after
the play was over.

Maybe they were going to imitate that Sprint guy: "Can you hear me
now?"...


--
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###Got a Question about ELECTRONICS? Check HERE First:###
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My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 at hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

"Ratch" wrote in message
news:BZmRa.80118$Ph3.9181@sccrnsc04...
While correct and true in all
cases, those formulas are NOT Ohm's law, and it is wrong to call
them
that.

Dude, go back to school, Algebra 1. V=IR I=V/R R=V/I etc.
The equation can be rearranged to any of the others by simple
multiplication and division by whichever variable.

Tim

I believe everyone on this newsgroup can isolate each of the terms
algebraically. What is your point? What don't you agree with? What is
incorrect? Be specific. Ratch

I think the point of everyone here is that you're being pedantic,
pointing out something that has no real relation to the topic being
discussed.

Good. You finally gave a valid reason for your gripe and did not deny
my "factoid". I can understand and appreciate your concern and irritation.
However, these threads are not just read and appreciated by you , I, and a
select few. There are plenty of lurkers who don't mind learning something,
and inserting ancillary facts into a discussion is not beyond what is
normally done here. Look at how some of the other threads have morphed.
Anyway, I don't think I was out of line in pointing out that Ohm's law is
usually used as a misnomer. The choice to keep on doing so is up to the
individual. Ratch

Hi Ratch,

It is not as simple as all that. E = Ri has been called "Ohm's" law for
as far back as my reference library goes, which is 1907. I cannot
verify, but I would presume that the origin of the the alleged misuse
goes even further back.

In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

As a possible explanation for the term Ohm's law, consider that the unit
of resistivity has been called the ohm, as a tribute to Georges Ohm.

The equation that describes the relationship of resistance, voltage,
and current would naturally be called the law of resistance, or the
law of the ohm. It wouldn't take much to morph that to ohm's law.

-Chuck, WA3UQV



Good. You finally gave a valid reason for your gripe and did not deny
my "factoid". I can understand and appreciate your concern and irritation.
However, these threads are not just read and appreciated by you , I, and a
select few. There are plenty of lurkers who don't mind learning something,
and inserting ancillary facts into a discussion is not beyond what is
normally done here. Look at how some of the other threads have morphed.
Anyway, I don't think I was out of line in pointing out that Ohm's law is
usually used as a misnomer. The choice to keep on doing so is up to the
individual. Ratch

On Fri, 18 Jul 2003 01:51:58 GMT, "Peter Gottlieb" wrote:

When I need to power some of my smaller creations I use an ohmmeter as a
power supply...
Hummm ... I have actually seen CMOS circuits run! With just test equipment attached and the power supply off!

In sci.electronics.misc Lizard Blizzard wrote:
Ian Stirling wrote:
In sci.electronics.misc Watson A.Name - 'Watt Sun' wrote:

In article ,
mentioned...

In sci.electronics.misc Watson A.Name - 'Watt Sun' wrote:

I got tired of switching the leads of my DMM. Suddenly if dawned on
me that I can just set the power supply to 10.0V for exaample, and
read the current, and then divide the voltage by the current to find
the resistance. Like I put a resistance on the PS, it reads 10.0V and
the current is .018A, so 10 / .018 gives 555.6 ohms. Must be a 560
ohm resistor.

I turned my PS into an ohmmeter - FREE!

Hee-hee - Work smarter, not harder!

Of course, make sure the current stays low so the resistance doesn't
overheat. For low resistances use a volt or less.

This isn't especially usefull usually.
However, with low ohm resistors, it can be.

Given a constant current of an amp, the $5 meters mentioned elsewhere
can now measure with a resolution of .1mohm.

I bought a few of those $5 DMMs from Futurlec a few months ago,
actually I think they were about $6. 9V vattery included(!)


Very handy indeed.
The ones I bought were 3 pounds 99p, ($6us?) I have around 8.
Soon after buying one, I thought I'd discovered that they have an
overvoltage LED.
However, the smell of burning FR4 soon made me realise otherwise.

But, But.. Doesn't the FR in FR4 mean flame resistant? If so, how
could it burn? Char?

Hmm, probably, yes.
It went out when the source of 2000V (at moderate current) was turned off.

--
http://inquisitor.i.am/ | | Ian Stirling.
---------------------------+-------------------------+--------------------------
Lord, grant me the serenity to accept that I cannot change, the
courage to change what I can, and the wisdom to hide the bodies
of those I had to kill because they ****ed me off. - Random

Chuck Harris wrote:
Hi Ratch,

It is not as simple as all that. E = Ri has been called "Ohm's" law
for
as far back as my reference library goes, which is 1907. I cannot
verify, but I would presume that the origin of the the alleged misuse
goes even further back.

A friend of mine took an electronics class at a local JC, and he learned
"Ohm's Three Laws": E=IR, I=E/R, and R = E/I.

--

Mike Russell
http://www.curvemeister.com
http://www.zocalo.net/~mgr
http://geigy.2y.net

"Ratch" wrote in
news:BZmRa.80118$Ph3.9181@sccrnsc04:


"Mark D. Zacharias" wrote in message
link.net...
Yes, and Ohm's Law describes the interaction of resistance, voltage,
and current. Not just resistance.
I'm not an engineer, granted, but I don't require an education on
Ohm's
Law.

Mark Z.

I belive that you are missing the point. The resistance (or
impedance)
formula V=IR (or V=IZ), describes the describes the interaction of
resistance (impedance), voltage, and current. While correct and true
in all cases, those formulas are NOT Ohm's law, and it is wrong to
call them that. As shown in the second link I gave, Ohm's law is a
property of resistive linearity in a material. Just as the specific
gravity of a material is a property. If it conforms to Ohm's law, it
is ohmic. Otherwise it is nonohmic. Ratch


What the heck is "nonohmic"? Is this a word you just made up? I have been
an electronis tech for 30+ years and thats a new one on me. It all doesn't
matter. Wether it is inductance, capacitive impedance, a thermistor, a
varistor, or what ever. Ohm's law still stands firm. For changing
"impedance" or fixed resistance. At any moment in time, there is a certain
resistance(impedance), a certain voltage and a certain current and ohm's
law always applies. Even in a combined circuit of capacitance and
inductance with an appplied frequency signal. At 1 instantaneous moment,
there is a vectored impedance and associated voltage and current. It is a
law of physics and there is no getting around it no matter what you call
it. A rose is a rose is a rose.
Here are the formulae and you believe what you will.

"Chuck Harris" schreef in bericht
...
Hi Ratch,

It is not as simple as all that. E = Ri has been called "Ohm's" law for
as far back as my reference library goes, which is 1907. I cannot
verify, but I would presume that the origin of the the alleged misuse
goes even further back.

In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

As a possible explanation for the term Ohm's law, consider that the unit
of resistivity has been called the ohm, as a tribute to Georges Ohm.

The equation that describes the relationship of resistance, voltage,
and current would naturally be called the law of resistance, or the
law of the ohm. It wouldn't take much to morph that to ohm's law.

Let's go all nuts and talk about ohmistance & ohmistors from now on

--
Thanks,
Frank Bemelman
(remove 'x' & .invalid when sending email)

In article ,
mentioned...
In sci.electronics.misc Lizard Blizzard wrote:
Ian Stirling wrote:
In sci.electronics.misc Watson A.Name - 'Watt Sun' wrote:

In article ,
mentioned...

In sci.electronics.misc Watson A.Name - 'Watt Sun' wrote:

I got tired of switching the leads of my DMM. Suddenly if dawned on
me that I can just set the power supply to 10.0V for exaample, and
read the current, and then divide the voltage by the current to find
the resistance. Like I put a resistance on the PS, it reads 10.0V and
the current is .018A, so 10 / .018 gives 555.6 ohms. Must be a 560
ohm resistor.

I turned my PS into an ohmmeter - FREE!

Hee-hee - Work smarter, not harder!

Of course, make sure the current stays low so the resistance doesn't
overheat. For low resistances use a volt or less.

This isn't especially usefull usually.
However, with low ohm resistors, it can be.

Given a constant current of an amp, the $5 meters mentioned elsewhere
can now measure with a resolution of .1mohm.

I bought a few of those $5 DMMs from Futurlec a few months ago,
actually I think they were about $6. 9V vattery included(!)


Very handy indeed.
The ones I bought were 3 pounds 99p, ($6us?) I have around 8.
Soon after buying one, I thought I'd discovered that they have an
overvoltage LED.
However, the smell of burning FR4 soon made me realise otherwise.

But, But.. Doesn't the FR in FR4 mean flame resistant? If so, how
could it burn? Char?

Hmm, probably, yes.
It went out when the source of 2000V (at moderate current) was turned off.

Eeww!! StinkCity!

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/e...s/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 at hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

Its one of those connie current things getting ronnie resistor ... hot.

"Sofie" wrote in message
...
How hot?
--------------
And besides that, it measures actual in-circuit conditions, because a
resistor is *supposed* to get hot, at least if it's doing its job...

"Sofie" wrote in message
...
Sir Charles W. Shults III:
That is a good in depth, overly complicated, answer but not the one I was
looking for

There was these two Engineers.... leaving the work place, they were headed
home.
They left the building headed out to the parking lot when the first engineer
stopped at a brand new 10 speed bike,
bent over and unlocked it. The second engineer looked at the first and
said, "Hey, I didn't know you got a new bike."
The first engineer started recounting his experience at getting the new
bike, "Yeah, I was out jogging my 1/2 block down the street when a lady on
this ten speed bike came by. She stopped. Got off the bike. Took all her
clothes off. Stood in front of me and said to me that I could have anything
I wanted." The second engineer thought for a moment and replied, " Yeah,
good choice, I don't think you'd fit into any girlie clothes, either."

So, now that we've had a nice discussion about ohm's law, explain that
fangled volt/amps rating on stuff.
I'm sure someone will note it is "nonohmic" somewhere...

"Mark Mcmillan" wrote in message
rthlink.net...
After all that I still can't get my ohmmeter to work as a power supply!!!

Probably an analog meter multimeter.
You'll have to get with the program and buy a digital one.

"Mark Jones" 127.0.0.1 wrote in message
news
Oh well it might have been funnier with the actual drawing. Man I need to
get out more...

I understand there are occasionally sightings of 'wild bike riding' women
when our sorts take to jogging 1/2 a block.


(I haven't tried jogging a full block ... my luck, I'd run into wild cement
truck driving women ... )

"Mike Russell" wrote in message
. ..
A friend of mine took an electronics class at a local JC, and he learned
"Ohm's Three Laws": E=IR, I=E/R, and R = E/I.

That'll teach me to let my education lapse.

I remember Charles Coulomb, and how charged objects have force; F ~
(q*q1)/d^2
which relates in some small way to an electric field having force, magnitude
and direction.
Giving the Electric potential equaling the work done (force, magnitude, and
direction of the energy) divided by charge.
Which explains George Ohm's law E=I*R. Claiming there is 'three' is just
comical.

Ask your buddy about Van De Graaf Generators and how ohm's three laws apply.

That should be even more comical.

"Frank Bemelman" wrote in message
...
Let's go all nuts and talk about ohmistance & ohmistors from now on

Cripes, You want these guys/gals to actually learn something ??

"Mark Jones" 127.0.0.1 wrote in message
...
Ratch wrote:
"Tim Williams" wrote in message
...
"Ratch" wrote in message
news:BZmRa.80118$Ph3.9181@sccrnsc04...
While correct and true in all
cases, those formulas are NOT Ohm's law, and it is wrong to
call them that.

Dude, go back to school, Algebra 1. V=IR I=V/R R=V/I etc.
The equation can be rearranged to any of the others by simple
multiplication and division by whichever variable.

Tim

I believe everyone on this newsgroup can isolate each of the
terms algebraically. What is your point? What don't you
agree with? What is incorrect? Be specific. Ratch


I think, for "practical" electronics, the "ohmic" and "non-ohmic"
properties of resitance and its implication in the Ohm's Law equation is
largely depreciated. All resistors are likely assumed ohmic except for
specialty devices or applications, most of which deal with temperature and
not voltage. Personally, I find the
voltage-dependant-negative-coefficient
resistances (such as carbon fiber) particularly interesting.


As I pointed out earlier, there is no "Ohm's law equation". I believe
you are referring to the resistance formula R=V/I and its variations, which
is not Ohm's law, although it is often mistakenly called that. Ohm's law is
a property of a material as explained in
http://www.launc.tased.edu.au/online...Resistance.htm
which I posted earlier. Did you read it? Ratch

"Chuck Harris" wrote in message
...
Hi Ratch,

It is not as simple as all that. E = Ri has been called "Ohm's" law for
as far back as my reference library goes, which is 1907. I cannot
verify, but I would presume that the origin of the the alleged misuse
goes even further back.

The publication that gets it wrong first should not be the one to
follow.


In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

Calling R=V/I the resistance formula does not seem confusing. What are
you going to call the resistive linearity property of a material as
explained in
http://www.launc.tased.edu.au/online...Resistance.htm
if you insist on hijacking its name for something else?

By the way, I can quote a couple of snippets from two good physics books
that back up what the above site contends.


As a possible explanation for the term Ohm's law, consider that the unit
of resistivity has been called the ohm, as a tribute to Georges Ohm.

The equation that describes the relationship of resistance, voltage,
and current would naturally be called the law of resistance, or the
law of the ohm. It wouldn't take much to morph that to ohm's law.

-Chuck, WA3UQV



Good. You finally gave a valid reason for your gripe and did not
deny
my "factoid". I can understand and appreciate your concern and
irritation.
However, these threads are not just read and appreciated by you , I, and
a
select few. There are plenty of lurkers who don't mind learning
something,
and inserting ancillary facts into a discussion is not beyond what is
normally done here. Look at how some of the other threads have morphed.
Anyway, I don't think I was out of line in pointing out that Ohm's law
is
usually used as a misnomer. The choice to keep on doing so is up to the
individual. Ratch

"Mike Russell" wrote in message
. ..
Chuck Harris wrote:
Hi Ratch,

It is not as simple as all that. E = Ri has been called "Ohm's" law
for
as far back as my reference library goes, which is 1907. I cannot
verify, but I would presume that the origin of the the alleged misuse
goes even further back.

A friend of mine took an electronics class at a local JC, and he learned
"Ohm's Three Laws": E=IR, I=E/R, and R = E/I.

And the misnomer propagates on, and on, and on .... Ratch


--

Mike Russell
http://www.curvemeister.com
http://www.zocalo.net/~mgr
http://geigy.2y.net

"Ratch" wrote in message
news:NK1Sa.94625$N7.12062@sccrnsc03...
those formulas are NOT Ohm's law, and it is wrong to
call them that.
As I pointed out earlier, there is no "Ohm's law equation". I
believe
you are referring to the resistance formula R=V/I and its variations,
which
is not Ohm's law, although it is often mistakenly called that. Ohm's law
is
a property of a material as explained in

http://www.launc.tased.edu.au/online...ctric/resistnc
/Resistance.htm
which I posted earlier. Did you read it? Ratch

I keep getting "Can not find server - the page you are looking for is
unavailable."
send me a copy.

I'm piqued. I'd like to know why you think E=I*R is not "Ohm's Law".

William Hayes, Ph.d. E&E.

"By Trying to understand the natural world around us, we gain confidence in
our ability to determine whom to trust and what to believe about other
matters as well. Without this confidence, our decisions about social,
political, and economic matters are inevitably based entirely on the most
appealing lie that someone else dishes out to us. Our appreciation of the
noticings and discoveries of both scientists and artists therefore serves,
not only to delight us, but also to help us make more satisfactory and valid
decisions and to find better solutions for our individual and societal
problems." - Frank Oppenheimer.

"William Hayes" wrote in message
news:UY1Sa.94927$Ph3.11524@sccrnsc04...

"Ratch" wrote in message
news:NK1Sa.94625$N7.12062@sccrnsc03...
those formulas are NOT Ohm's law, and it is wrong to
call them that.
As I pointed out earlier, there is no "Ohm's law equation". I
believe
you are referring to the resistance formula R=V/I and its variations,
which
is not Ohm's law, although it is often mistakenly called that. Ohm's
law
is
a property of a material as explained in


http://www.launc.tased.edu.au/online...ctric/resistnc
/Resistance.htm
which I posted earlier. Did you read it? Ratch

I keep getting "Can not find server - the page you are looking for is
unavailable."
send me a copy.

I'm piqued. I'd like to know why you think E=I*R is not "Ohm's Law".

William Hayes, Ph.d. E&E.

My apologies, try this. I can also post a couple of snippets from two good
physics books which back up the link. Ratch
http://www.launc.tased.edu.au/online...Resistance.htm
http://maxwell.byu.edu/~spencerr/websumm122/node50.html

"Ratch" wrote in message
news:bc2Sa.94711$N7.12100@sccrnsc03...
I'm piqued. I'd like to know why you think E=I*R is not "Ohm's Law".
My apologies, try this. I can also post a couple of snippets from two
good
physics books which back up the link. Ratch

http://www.launc.tased.edu.au/online...ctric/resistnc
/Resistance.htm
http://maxwell.byu.edu/~spencerr/websumm122/node50.html

Try this :
http://voltaicpower.com/Biographies/OhmBio.htm

Pay particular attention to the part referring to George Ohm determining
that the current that flows through a wire is proportional to its cross
sectional area and inversely proportional to its length provided temperature
remains constant. This is refereed to as Ohm's Law.

In your reference you have :
His rule is "that the ratio of potential difference to the current flowing
through a conductor is constant, providing all other influences such as
temperature are kept constant."

While basically your reference is almost correct, it is not fully correct.
A more appropriate reference would have been : The potential difference of
the current flowing through the conductor is proportional to its cross
sectional area and inversely proportional to its length provided temperature
remains constant. However, this would negate the relative nonsense that
followed in your link. While you can snippet links to other references,
sit back and think about how the conductor's cross sectional area relates to
the length of the conductor verses the potential difference to allow energy
(electrons) to flow through the conductor with room temperature remaining
constant.
Once you invision it, you will have grasped Ohm's Law.

In your reference you have :
This particular formula, often written as V = IR is extremely useful. It
is often known (incorrectly) as "Ohm's Law".

Why ?

William Hayes wrote:
"Frank Bemelman" wrote in
message ...
Let's go all nuts and talk about ohmistance & ohmistors from
now on

Cripes, You want these guys/gals to actually learn something
??

Did I hear someone say "MHO's?" : )

Hi Ratch,

What do G. Ohm, J. Maxwell, N. Tesla, J. Watt, Coulomb, Hertz, ...
all have in common?

They were dead and buried before the various engineering and physical
societies named equations and constants in their honor.

Tesla's body of work far exceeded the study of static magnetic fields;
Watt worked on steam engines, and developed the horsepower, he knew
nothing of electricity, and the metric system; Hertz was way more than
a cycle per second; and Ohm worked on more than that one equation
for resistivity.

These men were honored by various societies for their work in the
sciences. It is quite natural that the physicists and engineers
would honor different parts of these guys lifes works.

If you ask engineers what is Ohm's law, they will say E = iR,
if you ask physicists, they will give a long boring diatribe about
bulk resistivity, and cross sectional areas. If you asked George's
wife and children, they would come up with yet another entirely
different answer.

This is not the first time engineers and physicists have differed
in their approaches to academic study. Just think of the different
meanings of E and V, i and i and j, ....

So, just as you can quote a couple of physics text books and "prove"
that ohm's law is one thing, I can quote an equal number of
engineering text books that say otherwise.

-Chuck

Ratch wrote:

No matter what you call V = I*R, circuits will still get designed and
analyzed, and science will still progress. In any case, be aware that V =
I*R is not Ohm's law, but the V vs. I linearity, if present, is the law.

In article Zj1Sa.94494$N7.11951@sccrnsc03,
mentioned...

"Sofie" wrote in message
...
Sir Charles W. Shults III:
That is a good in depth, overly complicated, answer but not the one I was
looking for

There was these two Engineers.... leaving the work place, they were headed
home.
They left the building headed out to the parking lot when the first engineer
stopped at a brand new 10 speed bike,
bent over and unlocked it. The second engineer looked at the first and
said, "Hey, I didn't know you got a new bike."
The first engineer started recounting his experience at getting the new
bike, "Yeah, I was out jogging my 1/2 block down the street when a lady on
this ten speed bike came by. She stopped. Got off the bike. Took all her
clothes off. Stood in front of me and said to me that I could have anything
I wanted." The second engineer thought for a moment and replied, " Yeah,
good choice, I don't think you'd fit into any girlie clothes, either."

Heh-heh. I think I posted that or something similar a couple weeks
ago.

So, now that we've had a nice discussion about ohm's law, explain that
fangled volt/amps rating on stuff.
I'm sure someone will note it is "nonohmic" somewhere...

So if a regular diode is nonohmic, what's a schottky diode? Half a
nonohmic? Sort of like the sound of one hand clapping... ;-)


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/e...s/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 at hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

"Chuck Harris" wrote in message
...
Hi Ratch,

What do G. Ohm, J. Maxwell, N. Tesla, J. Watt, Coulomb, Hertz, ...
all have in common?

They were dead and buried before the various engineering and physical
societies named equations and constants in their honor.

Tesla's body of work far exceeded the study of static magnetic fields;
Watt worked on steam engines, and developed the horsepower, he knew
nothing of electricity, and the metric system; Hertz was way more than
a cycle per second; and Ohm worked on more than that one equation
for resistivity.

These men were honored by various societies for their work in the
sciences. It is quite natural that the physicists and engineers
would honor different parts of these guys lifes works.

What does the fact of receiving awards and honors posthumously have to
do with what we are discussing?


If you ask engineers what is Ohm's law, they will say E = iR,

Only because they learned it that way. If you explained the misnomer,
then what would they say?

if you ask physicists, they will give a long boring diatribe about
bulk resistivity, and cross sectional areas.

No they won't. Cross sectional areas have to do with the Resistance
formulas, not the real Ohm's law.

If you asked George's
wife and children, they would come up with yet another entirely
different answer.

Pure speculation. Was he even married? Would his family understand
the question? Would their answer have any meaning?


This is not the first time engineers and physicists have differed
in their approaches to academic study. Just think of the different
meanings of E and V, i and i and j, ....

A misnomer is not a study approach. Voltage and current have the same
meaning throughout science no matter how many different ways they are
studied or explained by representative analogs.


So, just as you can quote a couple of physics text books and "prove"
that ohm's law is one thing, I can quote an equal number of
engineering text books that say otherwise.

Those texts I quoted are really good college level textbooks. Would
the authors you would quote be able to defend their writings after being
shown what I believe is the error of their ways? Ratch


-Chuck

Ratch wrote:

No matter what you call V = I*R, circuits will still get designed and
analyzed, and science will still progress. In any case, be aware that V
=
I*R is not Ohm's law, but the V vs. I linearity, if present, is the law.

In article Sm1Sa.94175$ye4.66541@sccrnsc01,
mentioned...

"Mark Jones" 127.0.0.1 wrote in message
news
Oh well it might have been funnier with the actual drawing. Man I need to
get out more...

I understand there are occasionally sightings of 'wild bike riding' women
when our sorts take to jogging 1/2 a block.


(I haven't tried jogging a full block ... my luck, I'd run into wild cement
truck driving women ... )

Oohh, Kinky!

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/e...s/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 at hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

Aaarghhh!!!

V = I * R

I = V / R

R = V / I

Call them what you will... When R is independent of I, I call this Ohm's
law.

Can we drop it now please...? Ta.

Costas

"Ratch" schreef in bericht
news:xscSa.97708$Ph3.10866@sccrnsc04...

"Chuck Harris" wrote in message
...

If you ask engineers what is Ohm's law, they will say E = iR,

Only because they learned it that way. If you explained the
misnomer,
then what would they say?

....they'd say you're a pain in the butt. You belong to the same category
as the ones that always have to say that RS232 is about voltage levels
and has nothing to do with serial ports. Strictly that is correct, but
at the the same time the *entire* world uses the term when referring
to typical serial ports such as COM1 and COM2 on your PC.

E = I * R. Ohm's Law. Always has been, and always will be.

--
Thanks,
Frank Bemelman
(remove 'x' & .invalid when sending email)

"Frank Bemelman" wrote in message
...
"Ratch" schreef in bericht
news:xscSa.97708$Ph3.10866@sccrnsc04...

"Chuck Harris" wrote in message
...

If you ask engineers what is Ohm's law, they will say E = iR,

Only because they learned it that way. If you explained the
misnomer,
then what would they say?

...they'd say you're a pain in the butt. You belong to the same category
as the ones that always have to say that RS232 is about voltage levels
and has nothing to do with serial ports. Strictly that is correct, but
at the the same time the *entire* world uses the term when referring
to typical serial ports such as COM1 and COM2 on your PC.

And you would rather blame the messenger than appreciate the message.


E = I * R. Ohm's Law. Always has been, and always will be.

You are in denial. Ratch


--
Thanks,
Frank Bemelman
(remove 'x' & .invalid when sending email)

"Costas Vlachos" wrote in message
...
Aaarghhh!!!

V = I * R

I = V / R

R = V / I

Call them what you will... When R is independent of I, I call this Ohm's
law.


Your above statement is correct.

Can we drop it now please...? Ta.

It depends on others.... Ratch


Costas

In article PT1Sa.94662$N7.11173@sccrnsc03,
mentioned...

"Chuck Harris" wrote in message
...
[snip]

In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

This is sort of like the SI prefix Giga. The standards publications
of NBS (now the NIST), U.S. Navy, ASME (American Society of Mechanical
Eng'rs), and others all show the pronunciation as Jiga, but people
have been mispronouncing it for so long that all hope is lost of ever
going back to the original.

And then there's the mess NIST and the international standards bodies
got us into regarding the binary prefixes (see the last two lines of
my .sig below for the URL). I've yet to hear anyone use those in a
conversation, or even in print. Just remember that 1024 kilobytes is
_not_ called a megabyte anymore!

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/e...s/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 at hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

Hi Ratch,

Ratch wrote:
"Chuck Harris" wrote in message
...

Hi Ratch,

What do G. Ohm, J. Maxwell, N. Tesla, J. Watt, Coulomb, Hertz, ...
all have in common?

What does the fact of receiving awards and honors posthumously have to
do with what we are discussing?

I said nothing of awards and honors! The various scientific societies
went on a spree of naming every little thing after the giants
in the field. Torr, Tesla, Hertz, Ohm, Coulomb, Maxwell, Heisenberg,
Watt, Ampere, Curie, Voltair, and on and on and on. The things that
were named after these people were not necessarily things they had had
anything to do with.

George Ohm did NOT name this, or any other formula after himself!
That was done long after his death by fellow engineers and scientists.
It was done to honor the man. His contribution was large, so he got
a fundumental principal.


If you ask engineers what is Ohm's law, they will say E = iR,


Only because they learned it that way. If you explained the misnomer,
then what would they say?

They would say, it is not a misnomer, it is just a different equation
that is also given Ohm's name.

A misnomer is not a study approach. Voltage and current have the same
meaning throughout science no matter how many different ways they are
studied or explained by representative analogs.

You imagine that Ohm did only one thing, and that he named that thing
after himself. He did not. He did many things over his lifetime.
There is no one equation that sums up his life's work. The equations
named for Ohm were named by others long after his death. The naming
was done to honor the man for his contributions to the sciences.

So, just as you can quote a couple of physics text books and "prove"
that ohm's law is one thing, I can quote an equal number of
engineering text books that say otherwise.


Those texts I quoted are really good college level textbooks. Would
the authors you would quote be able to defend their writings after being
shown what I believe is the error of their ways? Ratch

And the texts in my library are also "really good college level
textbooks", written by prominent members of the electrical engineering
field.

Resnick is just another contemporary author of a physics book.
He is only restating what he was told, or what he believes to be true.
If you check his book out, you will find that there are no references
cited to back up his work. This is primarily because the college
text books are restatements of restatements .... It is hard to tell
where all the info originlly came from. The books are written by
professors, and professors, well, profess.

-Chuck

Ratch wrote:
"Chuck Harris" wrote in message
...

Hi Ratch,

What do G. Ohm, J. Maxwell, N. Tesla, J. Watt, Coulomb, Hertz, ...
all have in common?

What does the fact of receiving awards and honors posthumously have
to
do with what we are discussing?

I said nothing of awards and honors! The various scientific societies
went on a spree of naming every little thing after the giants
in the field. Torr, Tesla, Hertz, Ohm, Coulomb, Maxwell, Heisenberg,
Watt, Ampere, Curie, Voltair, and on and on and on. The things that
were named after these people were not necessarily things they had had
anything to do with.

All right, I'll buy that. But if they were awarding names to physical
laws, were they not honoring the men?


George Ohm did NOT name this, or any other formula after himself!
That was done long after his death by fellow engineers and scientists.
It was done to honor the man. His contribution was large, so he got
a fundumental principal.

I will agree to that also



If you ask engineers what is Ohm's law, they will say E = iR,


Only because they learned it that way. If you explained the
misnomer,
then what would they say?

They would say, it is not a misnomer, it is just a different equation
that is also given Ohm's name.

But wrongly. Ohm's law is a property, not a equation.


A misnomer is not a study approach. Voltage and current have the
same
meaning throughout science no matter how many different ways they are
studied or explained by representative analogs.

You imagine that Ohm did only one thing, and that he named that thing
after himself. He did not. He did many things over his lifetime.
There is no one equation that sums up his life's work. The equations
named for Ohm were named by others long after his death. The naming
was done to honor the man for his contributions to the sciences.

I know that Ohm did many things, just like Newton did things other than
explain mass attraction. I maintain that
Ohm's law is named after a resistive linearity principle, and the resistance
formula V=IR is used to explain that
principle. Some people later got careless and started calling the resistance
formula Ohm's law.


So, just as you can quote a couple of physics text books and "prove"
that ohm's law is one thing, I can quote an equal number of
engineering text books that say otherwise.

Physics and mathematics are foundation sciences of
electrical/electronics engineering. If they don't agree, then EE is the one
that should change, unless it can be proved that physics is in error.
Otherwise it is the tail wagging the dog.



Those texts I quoted are really good college level textbooks.
Would
the authors you would quote be able to defend their writings after being
shown what I believe is the error of their ways? Ratch

And the texts in my library are also "really good college level
textbooks", written by prominent members of the electrical engineering
field.

I know, I have a lot of them myself. But the parts that do not follow
physics are suspect.


Resnick is just another contemporary author of a physics book.

I don't think that Prof Resnick is with us anymore.

He is only restating what he was told, or what he believes to be true.

Right, see below.

If you check his book out, you will find that there are no references
cited to back up his work.

True, it is a textbook, not a physics reference. The book already is
huge. Most textbooks don't give references because of bloat, and it becomes
subjective on how extensive they should be.

This is primarily because the college
text books are restatements of restatements .... It is hard to tell
where all the info originlly came from. The books are written by
professors, and professors, well, profess.

It is certainly true that what a professor writes is going to be what
he believes to be factual. And impossible to discern how he came upon his
knowledge. But you have to ask yourself, why did Professors Resnick and
Serway go out of their way to make a point that Ohm's law is a property of a
material and not V=IR? Does that not indicate that they looked into the
matter more closely that their contemporaries? The next time I get to a
good college library, I will look at other college physics textbooks. Ratch

On Sat, 19 Jul 2003 09:12:20 -0700, Watson A.Name - 'Watt Sun'
put finger to keyboard and composed:

In article PT1Sa.94662$N7.11173@sccrnsc03,
mentioned...

"Chuck Harris" wrote in message
...
[snip]

In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

This is sort of like the SI prefix Giga. The standards publications
of NBS (now the NIST), U.S. Navy, ASME (American Society of Mechanical
Eng'rs), and others all show the pronunciation as Jiga, but people
have been mispronouncing it for so long that all hope is lost of ever
going back to the original.

I would think the most sensible pronunciation would be "giga" as this
prefix is derived from the Greek word, "gigas", meaning "giant".

The most mispronounced metric measure, IMO, is kilometre. The correct
pronunciation is kill-oh-meeter, not ki-lometter, if you know what I
mean.

And then there's the mess NIST and the international standards bodies
got us into regarding the binary prefixes (see the last two lines of
my .sig below for the URL). I've yet to hear anyone use those in a
conversation, or even in print. Just remember that 1024 kilobytes is
_not_ called a megabyte anymore!


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

On Sun, 20 Jul 2003 08:50:43 +1000, Franc Zabkar
put finger to keyboard and composed:

On Sat, 19 Jul 2003 09:12:20 -0700, Watson A.Name - 'Watt Sun'
put finger to keyboard and composed:

In article PT1Sa.94662$N7.11173@sccrnsc03,
mentioned...

"Chuck Harris" wrote in message
...
[snip]

In any case, this relation has been called Ohm's law for so long, that
regardless of its origin, it *is* Ohm's law. To try and change the
common usage at this late date would just needlessly confuse the issue.

This is sort of like the SI prefix Giga. The standards publications
of NBS (now the NIST), U.S. Navy, ASME (American Society of Mechanical
Eng'rs), and others all show the pronunciation as Jiga, but people
have been mispronouncing it for so long that all hope is lost of ever
going back to the original.

I would think the most sensible pronunciation would be "giga" as this
prefix is derived from the Greek word, "gigas", meaning "giant".

The most mispronounced metric measure, IMO, is kilometre. The correct
pronunciation is kill-oh-meeter,

Or "ki-low-mee-ter".

... not ki-lometter, if you know what I
mean.

And then there's the mess NIST and the international standards bodies
got us into regarding the binary prefixes (see the last two lines of
my .sig below for the URL). I've yet to hear anyone use those in a
conversation, or even in print. Just remember that 1024 kilobytes is
_not_ called a megabyte anymore!


- Franc Zabkar


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

"Sir Charles W. Shults III" wrote in
. com:

How hot? One solution is P=EI, where power in watts is equal to
the product
of voltage and current. So the voltage drop across the resistor
multiplied by the current in amps through the resistor will yield
watts of heat created by the resistor.
Now, if you know the composition of the resistor, you can look up
the
specific heat of the material and calculate how much energy it takes
to change its temperature. You will need to know how many joules of
energy have been applied. Calculate the joules by multiplying the
time that the power was applied in seconds by the power in watts. Now
look at the specific heat table and it will tell you how many joules
per Kelvin it takes to raise the temperature.
If you have any physics experience, it will be very simple.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip




Now your getting logical and there is evidently no room for logic in this
thread.

"Sofie" wrote in
:

Sir Charles W. Shults III:
That is a good in depth, overly complicated, answer but not the one I
was looking for..... obviously since the Tim Williams posting said
".And besides that, it measures actual in-circuit conditions,
because a resistor is *supposed* to get hot, at least if it's doing
its job..." ..... and since the overly discussed "2 meters and power
supply" ohm meter method can overheat low-ohm resistors..... and the
resistance of any resistor will vary with temperature..... I was
wondering at what exact "hot" temperature the resistor should be at to
make an accurate measurement..... LOL Obviously I am not looking for
any kind of answer here....... I just think that this thread went
bonkers when all the original poster wanted to do is, as Chuck Harris
indicated in his reply post, show off his new found factoid....
however it seems clear that it may not be a very practical and
convenient method as evidenced by the length and tone of the majority
of the reply posts.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


My goodness! FINALLY! An intelligent reply! At least somebody is using
their head, instead of the other end.