a question about resistors in an arc experiment

[JosephKK]

On Jan 19, 6:37 pm, John Larkin
[....]

I still can't get my head around the fundamental reason why there's
only one kind of positive resistor but two kinds of negative resistor.

I think I can add to the confusion:

We are thinking "number line like this:

-3, -2, -1, 0, 1, 2, 3, ..... really big, infinite, -really big ...

There are two ways to get to a negative number.  One takes you past
the "infinite" value.  In truth though. we have a 2D world we can
avoid hitting the singular value by going a little reactive.

As often happens in math, the pole is the center pole of a spiral
staircase.  You have to go around the pole twice to get back where you
started.

For projective infinity kind of, for affine infinity no.

Since we are adding to the confusion:

As we consider the impedance values, we are not considering how they
depend on frequency.  We can have frequency dependent resistances and
positive and negative reactive values that depend in various ways on
the frequency.  This makes it at least a 3 dimensional space.

Now you are making progress.  And that 3rd dimension is non-linear and
twisted, it goes through a transition between 300 MHz and 3 GHz where
lumped constants give way to transmission line techniques.

I don't see that as a real transition in the extra dimension. That is
an artifact created by the mechanical sizes we can do. Real
transitions would be the places where the wavelength passes some size
determined by physics.

BTW: We have 60Hz transmission lines near my house so the 300MHz
lower edge on you 300MHz and 3GHz is a little high.

That would require the use of extremely loose and sloppy definition of
transmission line.

 

[Rich Grise]

That would require the use of extremely loose and sloppy definition of
transmission line.

Sorry, no cigar:
http://www.google.com/search?hl=en&q=define:"transmission+line"

IOW, it's perfectly appropriate for either application.

Hope This Helps!
Rich

 

[JosephKK]

Sorry, no cigar:
http://www.google.com/search?hl=en&q=define:"transmission+line"

IOW, it's perfectly appropriate for either application.

Hope This Helps!
Rich

Think what you wish. The properties of RF types, such as controlled
impedance, are not preserved in the power distribution types. So, it
is not the same definition but two different definitions overlaid on
the same term. See computer language term overloading, a relative of
operator overloading from mathematics. See also disambiguation.

 

[MooseFET]

04:05 -0800 (PST), MooseFET
On Jan 19, 6:37 pm, John Larkin
[....]
I still can't get my head around the fundamental reason why there's
only one kind of positive resistor but two kinds of negative resistor.
I think I can add to the confusion:
We are thinking "number line like this:
-3, -2, -1, 0, 1, 2, 3, ..... really big, infinite, -really big ....
There are two ways to get to a negative number.  One takes you past
the "infinite" value.  In truth though. we have a 2D world we can
avoid hitting the singular value by going a little reactive.
.................................
.................----------......
..-...0...-------....*.....------
...-------.......................
.................................
As often happens in math, the pole is the center pole of a spiral
staircase.  You have to go around the pole twice to get back where you
started.
For projective infinity kind of, for affine infinity no.
Since we are adding to the confusion:
As we consider the impedance values, we are not considering how they
depend on frequency.  We can have frequency dependent resistances and
positive and negative reactive values that depend in various ways on
the frequency.  This makes it at least a 3 dimensional space.
Now you are making progress.  And that 3rd dimension is non-linear and
twisted, it goes through a transition between 300 MHz and 3 GHz where
lumped constants give way to transmission line techniques.

I don't see that as a real transition in the extra dimension.  That is
an artifact created by the mechanical sizes we can do.  Real
transitions would be the places where the wavelength passes some size
determined by physics.

BTW:  We have 60Hz transmission lines near my house so the 300MHz
lower edge on you 300MHz and 3GHz is a little high.

That would require the use of extremely loose and sloppy definition of
transmission line.

That is what the power company calls them. :> It was a joke.


The power lines are actually long enough in some places that the
transmission line effects do start to matter. Even though a
wavelength is about half a million kilometers in space, the effects
still matter, partly because the power levels are so high that 1% ends
up big.

 

[Rich Grise]

Think what you wish.

I wish to think that the dictionary is generally accurate.

The properties of RF types, such as controlled
impedance, are not preserved in the power distribution types. So, it
is not the same definition but two different definitions overlaid on
the same term.

"Same term" being the operative phrase here. You can have an RF
transmission line, or you can have a power transmission line, and
they both use the same word.

And don't think that the people who make power transmission lines
don't have to consider the inductive, capacitive, and resistive effects,
It's just that it's at 60Hz instead of RF.

Cheers!
Rich

 

[JosephKK]

I wish to think that the dictionary is generally accurate.

They normally are, however both dictionaries and encyclopedias have
"false entries (which are used to detect copyright infringement)".
They are often placed in the commonest of lookups.

"Same term" being the operative phrase here. You can have an RF
transmission line, or you can have a power transmission line, and
they both use the same word.

And don't think that the people who make power transmission lines
don't have to consider the inductive, capacitive, and resistive effects,
It's just that it's at 60Hz instead of RF.

Having done the calculations a few times recently they normally pay no
attention to capacitance per se. Furthermore line impedances are
length dependant when calculated at all, and there are many more
differences. The math is nowhere near the same, thus nor is the
physics that is modeled.

Have some fun by learning it, if you never learned it in school.

 

[JosephKK]

On Jan 19, 6:37 pm, John Larkin
[....]

I still can't get my head around the fundamental reason why there's
only one kind of positive resistor but two kinds of negative resistor.

I think I can add to the confusion:

We are thinking "number line like this:

-3, -2, -1, 0, 1, 2, 3, ..... really big, infinite, -really big ...

There are two ways to get to a negative number.  One takes you past
the "infinite" value.  In truth though. we have a 2D world we can
avoid hitting the singular value by going a little reactive.

As often happens in math, the pole is the center pole of a spiral
staircase.  You have to go around the pole twice to get back where you
started.

For projective infinity kind of, for affine infinity no.

Since we are adding to the confusion:

As we consider the impedance values, we are not considering how they
depend on frequency.  We can have frequency dependent resistances and
positive and negative reactive values that depend in various ways on
the frequency.  This makes it at least a 3 dimensional space.

Now you are making progress.  And that 3rd dimension is non-linear and
twisted, it goes through a transition between 300 MHz and 3 GHz where
lumped constants give way to transmission line techniques.

I don't see that as a real transition in the extra dimension.  That is
an artifact created by the mechanical sizes we can do.  Real
transitions would be the places where the wavelength passes some size
determined by physics.

BTW:  We have 60Hz transmission lines near my house so the 300MHz
lower edge on you 300MHz and 3GHz is a little high.

That would require the use of extremely loose and sloppy definition of
transmission line.

That is what the power company calls them. :> It was a joke.

Missed that part, oops.

The power lines are actually long enough in some places that the
transmission line effects do start to matter. Even though a
wavelength is about half a million kilometers in space, the effects
still matter, partly because the power levels are so high that 1% ends
up big.

I would be glad to discuss what i do know of power transmission lines
and equipment at any time. Though there is still a lot more that i
could learn if i had sufficient use to keep it refreshed.

 

[Archimedes' Lever]

They normally are, however both dictionaries and encyclopedias have
"false entries (which are used to detect copyright infringement)".
They are often placed in the commonest of lookups.

This has to be one of the most retarded claims I have ever seen.

More like retardedtechyou@yahoo you fucking yahoo.

 

[Archimedes' Lever]

I would be glad to discuss what i do know of power transmission lines
and equipment at any time. Though there is still a lot more that i
could learn if i had sufficient use to keep it refreshed.

You mean like capitalizing the word "I", or refraining from making
claims that dictionary publishers print false definitions merely to catch
a plagiarizer or copyright infringer. Yes, I'd say there is still much
to learn about the world by you.

 

[Rich Grise]

What's different? The equations and the physics are the same.

He's just addicted to making me wrong, even when I'm right.

Thanks,
Rich

 

[Jasen Betts]

That is what the power company calls them. :> It was a joke.

The power lines are actually long enough in some places that the
transmission line effects do start to matter. Even though a
wavelength is about half a million kilometers in space, the effects
still matter, partly because the power levels are so high that 1% ends
up big.

velocity factor is in the ball park of 0.7

300000km/s / 60Hz *0.7 = 3500km

significantly short of "half a million"

 

[krw]

velocity factor is in the ball park of 0.7

What's the permativity of air?

300000km/s / 60Hz *0.7 = 3500km
~5Mm

significantly short of "half a million"

a bit. ;-)

 

[Jasen Betts]

What's the permativity of air?

close to 1

that 0.7 was a guess, I should have looked it up.
it looks much closer to 1 for real power transmission lines,
only coax and other small scale lines are that slow.

~5Mm

yeah, that's a better figure,