Toshiba TV29C90 problem; Image fades to black...

[Do Little2]

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d7a69f2aadave@davenoise.co.uk...

In article <THgre.2831$EP2.14167@newscontent-01.sprint.ca>,
Do Little2 <listed@space.com> wrote:
[...snip...]

Just out of curiosity: How many Megawatts of electricity is
the UK capable of exporting before its own network collapses?

Dunno - it's never happened. The whole idea of a grid is that you share
power, so any fault is likely to be local. And in event of a grid failure,
the power may be routed in a different way.

Yes, but the limiting factors are the few wires connecting to Europe.
How much voltage/current can they handle? Certainly, for the bottom
line, someone in the UK will know just how much electricity they can
export/sell or must import/buy on any given day.

FWIW, I can't remember an outage here in this part of London.
Nor do I have or need an UPS etc. Of course there are rural parts
that still may have problems due to overhead lines etc.

True, I also heard some horror stories about old electricity switches
in some rural areas of the UK. Apparently they were still using "open air
240 Volts line switches" like the old knife type. Scary stuff indeed.

Do Little2

 

[NSM]

"rainbow" <rain.bowwwwt.net> wrote in message
news:B5SdnQlIPYGWLjDfRVn-rA@rogers.com...

... Jesus died on a cross for the sins of all, 2005 years ago ...

You can't even get the date right?

 

[Dave Plowman (News)]

In article <Rdjre.2841$EP2.14240@newscontent-01.sprint.ca>,
Do Little2 <listed@space.com> wrote:

Yes, but the limiting factors are the few wires connecting to Europe.
How much voltage/current can they handle? Certainly, for the bottom
line, someone in the UK will know just how much electricity they can
export/sell or must import/buy on any given day.

They're used when demand is low in one country while high in another.

FWIW, I can't remember an outage here in this part of London.
Nor do I have or need an UPS etc. Of course there are rural parts
that still may have problems due to overhead lines etc.

True, I also heard some horror stories about old electricity switches
in some rural areas of the UK. Apparently they were still using "open air
240 Volts line switches" like the old knife type. Scary stuff indeed. >

Don't be silly. All overhead supplied domestic supplies are RCD protected.
Fitted by the supply provider.

None of the silly thermal devices so loved across the pond. ;-)

--
*If God dropped acid, would he see people?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Larry Brasfield]

"John Fields" <jfields@austininstruments.com> wrote in message
news:rv7ra1ldpn3f6e86j9r7ojdd7rnq5clp3p@4ax.com...
....

Yes, it is. In order for the current in a load to alternate, the
polarity of the generator's output voltage must alternate as well.

Consider a voltage source with output Eo = 2 + sin(w t)
driving a capacitor as its load. The voltage does not
alternate but the current will.

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

 

[--]

"Floyd L. Davidson" <floyd@barrow.com> wrote in message
news:877jgyuu2x.fld@barrow.com...

"--" <dehoberg@comcast.com> wrote:
Strictly speaking, I believe the reactance (part of impedance)
equations apply to any variation in current magnitude. Their appropriate
application does not in any way require reversing the charge.

Exactly.

1) I think one needs to define the term "alternating current" by its
phenomena rather than define it by what applies to "AC". In other
words,
define AC as alternating current -rather than defining AC as "anything
requiring an impedance calculation because of its magnitude variation".

What value does that have? The problem is circuit analysis,

No, rather the problem is that many of the fundamental physical sciences and
most of electrical engineering use the concept, and it is not used merely by
a small corner of circuit analysis. The definition has to work for all the
sciences where it may be used.
E.g., many switches use the "AC as reversing" concept for quenching
contact arcs during switching (as the current passes thru zero as direction
reverses) and the defintion of AC as varying DC falls flat for that purpose.
Install an AC designed switch on a varying DC circuit, and you may well have
a safety switch contacts welded shut. Here, AC DEFINITELY means reversing
direction.

which requires the division between DC and AC,

I believe the equations are not DC-AC specific - the "AC" term drops to
zero if the change in magnitude drops to zero. Your rationale of using the
equations does not hold up.

and the only
division that makes sense is between non-changing current and
changing current.

changing in direction or magnitude?

You suggest we use AC is defined as:
"regularly or irregularly varying uni- or bi- directional current if it
varies at a frequency that could have an effect for that application; unless
it is digital, where then the one-time rise time and the fall time of each
state change is calculated as AC, too, even though it 'alternates' once for
each pulse"

vs.

AC is defined as:

charge flow that changes direction.


which leaves the calculations for reactance out of the definition.

3) In the definition approach to a phenomena, one deals with the
descriptive term and the phenomena itself and ignores the present
attached

The problem is defining something with no practical value.

We define air, and black holes, and impracticality.
The circular logic that has your AC/DC missing half the paramters of the
phenomena also has no use for defining air since we only feel wind, for not
defining black holes which have no practical value since we have never seen
one, and no use for the definition of impracticality because by definition
it has no practical value.

If

AC is a changing current, that includes changing polarity, and
covers the actual significant difference from DC. If AC is
defined only as changing polarity, we also have to have an
entire separate set of identical functions and definitions, one
for "varying DC" and one for "AC".

not if we consider the two paramters that make up the phenomena - direction
and magnitude.
And if memory serves me correctly, the "AC" equations are rigorous, and
apply equally well to your one-voltage DC when the frequerncy drops to zero-
the reactance term of the changing magnitude goes to zero.

Since the analysis is the

same, there is no point in separation of the two.

And "varying DC" is a contradiction in terms to begin with. Do
we actually need *four* states:

1 -- DC
2 -- Varying DC
3 -- AC
4 -- Steady AC

no, just two - reversing flow direction, and varying magnitude.

Because the reactance equations only apply to varying magnitude, and they do
not apply to reversing direction.

Boy, that should may first year text books *really* interesting!

Either that or we are back to Don Lancaster's correct statement
that they are meaningless terms anyway. They certainly are if
that is the way they are defined!

If one has never heard of the ocean, one finds the ocean meaningless.
And for the memebrs of that society, they also would find ocean-going
boats useless. because they have to define the ocean thru their own
experience.
As I understood, scienctific method is designed to remove personal views
from science. Thus the definition,must stand alone, and since we can't see
all that is ahead, science has to fall in behind a definition of that
phenomena in pure terms.

imho.......

----------------

Alternating-direction Current, aka Alternating Current

Direction-specific Current, aka Direct Current.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[Do Little2]

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d7a7a9f8bdave@davenoise.co.uk...

In article <Rdjre.2841$EP2.14240@newscontent-01.sprint.ca>,
Do Little2 <listed@space.com> wrote:
Yes, but the limiting factors are the few wires connecting to Europe.
How much voltage/current can they handle? Certainly, for the bottom
line, someone in the UK will know just how much electricity they can
export/sell or must import/buy on any given day.

They're used when demand is low in one country while high in another.

That is the principal idea for most electrical grids or networks.
But since all the European grid connections are routed through a
few wires in one tunnel towards the UK, one tends to think that
this is a very limited or primitive grid. A 'real electrical grid' will
have more than one access point! Maybe there isn't enough room
for another grid connection on that small island?

FWIW, I can't remember an outage here in this part of London.
Nor do I have or need an UPS etc. Of course there are rural parts
that still may have problems due to overhead lines etc.

True, I also heard some horror stories about old electricity switches
in some rural areas of the UK. Apparently they were still using "open
air
240 Volts line switches" like the old knife type. Scary stuff indeed.


Don't be silly. All overhead supplied domestic supplies are RCD protected.
Fitted by the supply provider.

Not silly at all, I only wrote what a Canadian
visitor saw in a barn near Whitby in the UK.

None of the silly thermal devices so loved across the pond. ;-)

Good point!
However, most thermal devices have been
outlawed (in the 1970's ?) in television, radios, etc..

BTW, just how do they adjust the electrical
heating for the houses in the UK ?

Do Little2

 

[John Fields]

On Mon, 13 Jun 2005 11:20:43 -0700, "Larry Brasfield"
<donotspam_larry_brasfield@hotmail.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:rv7ra1ldpn3f6e86j9r7ojdd7rnq5clp3p@4ax.com...
...
Yes, it is. In order for the current in a load to alternate, the
polarity of the generator's output voltage must alternate as well.


Consider a voltage source with output Eo = 2 + sin(w t)
driving a capacitor as its load. The voltage does not
alternate but the current will.

---
True, but in the context of the post from which the excerpt came
capacitive loads had not yet been introduced into the discussion.

--
John Fields
Professional Circuit Designer

 

[Dave Plowman (News)]

In article <Itkre.2854$EP2.14294@newscontent-01.sprint.ca>,
Do Little2 <listed@space.com> wrote:

Don't be silly. All overhead supplied domestic supplies are RCD
protected. Fitted by the supply provider.

Not silly at all, I only wrote what a Canadian visitor saw in a barn
near Whitby in the UK.

A barn is unlikely to be directly supplied, but 'exported' from the
adjacent farm house. And will then be protected by the supplier's RCD.
And if it really did have a knife switch that dates back to DC days - ie
before WW2. I've never seen one outside a museum of such things. ;-)

None of the silly thermal devices so loved across the pond. ;-)

Good point! However, most thermal devices have been outlawed (in the
1970's ?) in television, radios, etc..

But as circuit breakers in domestic installations?

BTW, just how do they adjust the electrical heating for the houses in
the UK ?

No one in their right mind uses electricity for heating. We use gas or oil.
It would only make sense if that electricity was generated by some other
fuel - like renewable energy. But not if it's generated by oil or gas.

You can get very close to 100% efficiency with a condensing gas boiler -
not really possible with a variable demand gas burning power station, even
before the transmission losses.

--
*Life is hard; then you nap

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Floyd L. Davidson]

John Fields <jfields@austininstruments.com> wrote:

On Mon, 13 Jun 2005 07:37:08 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:
---
Well, Floyd, Take a look at the schematics below and you may notice
that while the first one (the one without the cap in series with the
load) puts out a sinusoidally varying unipolar signal, (DC) the second
one (the one _with_ the cap in series with the load) puts out a
sinusoidally varying bipolar signal. (AC)

Now, since the only difference between them is the cap and one puts
out a varying DC signal while the other one puts out a true signal,
then the cap _must_ be generating the AC signal.

Reality check! Capacitors are passive devices. They do *NOT*
generate signals.

All that has happened is the capacitor does not pass DC. You
haven't generated AC on one side, you've merely removed the DC.

I don't see how that could be any more obvious. You did take
a high school physics class, didn't you? *Use* what you learned!

Poppycock. It's precisely the alternations in the direction of charge
flow which cause it to be called "Alternating Current".

It is defined by a differential (which necessarily will have a
sign reversal), not "polarity" reversals.

---
Specious gobbledygook.

A reversal of sign is, by definition, a reversal of polarity.

Okay, so you not only need to restudy high school physics, but
differential equations too.

The point is that you didn't point out a non sequitur. (notice that
there's no apostrophe in there) The definition, which I got from
Webster's College Dictionary and posted for your edification, should
have made that clear.

If you had read the definition you posted, you might have
noticed that it perfectly described the remark that I was
commenting on. It had nothing to do with the discussion.

And, speaking of manners, I suggest that yours need a little trip past
Emily Post.

You are the one stooping to spelling flames.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[Floyd L. Davidson]

John Fields <jfields@austininstruments.com> wrote:

On Mon, 13 Jun 2005 07:47:51 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:
No, if the direction of charge flow alternates between two states,
then it's Alternating Current.

That fits my definition, but not yours! Are you changing your definition
or is that just a momentary bit of logical thought?

---
Try not to be a stupid fuck. Flames will get you nothing back but more
flames. Is that what you want?

Oh, my. And you said what about Emily Post.

Nothing I said was a flame. And I'd suggest you go practice (a *lot*)
before you try me on for a flame war. Especially if you think *that*
is a flame.

I'm starting to think you're having a real problem with reading
comprehension.

Apparently I read a lot better than you write.

I write that for the current in a load to alternate,

You write a lot of things that are not valid.

Don't you understand that an alternation in polarity means that the
polarity changed???

Do you understand that is not significant? The reactance of circuit
components, the fundamental significance of AC circuit analysis, does
not depend upon polarity alternation in any way. What else is there
to talk about? How many chocolate drops should be in each chocolate
chip cookie? I await your essay on *something* of significance.

But please, that is the *end* of discussion on your confusion about
AC.


--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[Floyd L. Davidson]

The Phantom <phantom@aol.com> wrote:

On Mon, 13 Jun 2005 07:58:46 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:

*Snip*

Either that or we are back to Don Lancaster's correct statement
that they are meaningless terms anyway. They certainly are if
that is the way they are defined!

Don first said:
---------------------------------------
'"DC" is simply the first (or "offset" term in the Fourier expression
of
any repetitive waveform.

"AC" are all of the remaining components.'
----------------------------------------

Then he said:
----------------------------------------
'"AC" or "DC" are gross and meaningless oversimplifications.'
----------------------------------------

Which are we to believe?

There is no contradiction, so what is wrong with understanding both
statements?

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[Floyd L. Davidson]

"--" <dehoberg@comcast.com> wrote:

"Floyd L. Davidson" <floyd@barrow.com> wrote:
"--" <dehoberg@comcast.com> wrote:
Strictly speaking, I believe the reactance (part of impedance)
equations apply to any variation in current magnitude. Their appropriate
application does not in any way require reversing the charge.

Exactly.

1) I think one needs to define the term "alternating current" by its
phenomena rather than define it by what applies to "AC". In other
words,
define AC as alternating current -rather than defining AC as "anything
requiring an impedance calculation because of its magnitude variation".

What value does that have? The problem is circuit analysis,

No, rather the problem is that many of the fundamental physical sciences and
most of electrical engineering use the concept, and it is not used merely by
a small corner of circuit analysis. The definition has to work for all the
sciences where it may be used.
E.g., many switches use the "AC as reversing" concept for quenching
contact arcs during switching (as the current passes thru zero as direction
reverses) and the defintion of AC as varying DC falls flat for that purpose.
Install an AC designed switch on a varying DC circuit, and you may well have
a safety switch contacts welded shut. Here, AC DEFINITELY means reversing
direction.

Bad example. That does *not* require a direction reversal. All
it requires is understanding that it is relative to the static
state.

It does happen that the static state in that specific case is
when a polarity reversal takes place, but in the general case it
is not required. In other examples both sides of the switch
might well be at some DC potential, that happens to be equal on
both sides at the time the switch is made, even though there is
no direction reversal.

which requires the division between DC and AC,

I believe the equations are not DC-AC specific - the "AC" term drops to
zero if the change in magnitude drops to zero. Your rationale of using the
equations does not hold up.

Everything concerned with reactance is AC specific. Nothing
concerned with reactance requires a polarity reversal.
Reactance is the essence of the difference between DC and AC,
not some notion of reversing polarity.

AC is defined as:

charge flow that changes direction.

which leaves the calculations for reactance out of the definition.

Which means it is worthless. Reactance *is* the significance.

3) In the definition approach to a phenomena, one deals with the
descriptive term and the phenomena itself and ignores the present
attached

The problem is defining something with no practical value.

We define air, and black holes, and impracticality.

All of which *does* have practical value.

And if memory serves me correctly, the "AC" equations are rigorous, and
apply equally well to your one-voltage DC when the frequerncy drops to zero-
the reactance term of the changing magnitude goes to zero.

That is an hilarious idea! If the magnitude is zero all the way
around... we aren't talking about AC or DC... maybe about
blown breakers or taking a coffee break, but not about current.

And "varying DC" is a contradiction in terms to begin with. Do
we actually need *four* states:

1 -- DC
2 -- Varying DC
3 -- AC
4 -- Steady AC

no, just two - reversing flow direction, and varying magnitude.

Oh? DC doesn't exist? What about "steady AC"? (That's two
exactly equal signals 180 degrees out of phase, combined in that
capacitor which can generate AC mentioned by John Fields,
perhaps???)

Because the reactance equations only apply to varying magnitude, and they do
not apply to reversing direction.

Then why would we be concerned at all about this reversing
direction, and give it a specific name and have a whole separate
field of study for it? Sounds like we need to be concerned with
varying magnitude, *not* with reversing direction. (Which is
what I've been saying...)

As I understood, scienctific method is designed to remove personal views
from science. Thus the definition,must stand alone, and since we can't see
all that is ahead, science has to fall in behind a definition of that
phenomena in pure terms.

imho.......

A nice goal.

----------------

Alternating-direction Current, aka Alternating Current

Except that alternating direction has no significance. Changing
magnitude does. Why bother with alternating-direction at all,
it is just an insignificant, though interesting, part of the
more general case of changing magnitude. All of the same
equations apply.

Direction-specific Current, aka Direct Current.

And if you claim that only alternating direction current is AC,
then you have to have two sets of equations for DC, one for
non-varying magnitude and one for varying magnitude.

That doesn't make a lick of sense.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[mike]

larry moe 'n curly wrote:

If a clamp-on ammeter probe is clamped around both the power wires and
the ground wires, shouldn't it read zero amps because the magnetic
fields should cancel?

I recently measured the amps that my computer motherboard drew by
clamping the AC/DC probe around the two yellow +12V wires of the
auxillary 4-pin power connector. The meter read 4.7A, but when I tried
also clamping the two black ground wires on the same cable, the reading
dropped to 2.6A. I taped the wires together and even tried arranging
them to alternate yellow-black-yellow-black, but the reading stayed at
2.6A.

Did you also try removing ALL the other ground return paths?

There are technologies available that claim to be able to measure the
current in a two-wire cable. Something about slight differences in the
field due to slightly different wire distances. Read it somewhere on
the web so it must be true...
mike

--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted 12" LCD for Compaq Armada 7770MT.
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[Arfa Daily]

Crikey !! I didn't know what I was starting when I opened this thread !

OK. Lets put some figures on it.

Last figures I could find were for 2003. Total UK generation capacity was
78.5GW at that time. Power generation for the year was 376.8 BkWH. Power
consumption for the year was
399.8 BkWH, a shortfall of some 5.1 BkWH, which was imported from our grid
connection to mainland Europe, via France.

There are some 23 countries cross connected in the European grid, supplying
approx 450m people ( that's a few more than the U.S. grid ... )

The typical cross border capacity appears to be 2 way - ie to two adjacent
network operators -at 2.5 GW per way - a net import / export capability of 5
GW per border crossing.

The original UK / France undersea cableway, comprised two single conductor
cables with a DC capacity of 160MW total ( the power is rectified to DC and
reinverted to AC at either end ). This cable has since been replaced with a
4 cable system, each comprising a positive / negative pair. These are buried
in the sea floor in trenches 600mm wide, separated by 1 km to avoid
interaction of the magnetic fields with marine navigation equipment.

The total capacity of this connection is 2GW DC net import / export.

The total consumption of the 23 countries, is around 2300 TW.

So, a total grid somewhat larger than the US one,in terms of subscribers,
and quite possibly in distances and geographical area, and to the best of my
knowledge, it has never fallen over in such a spectacular way as the US one
sometimes does.

Geoff


"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d7a8240d4dave@davenoise.co.uk...

In article <Itkre.2854$EP2.14294@newscontent-01.sprint.ca>,
Do Little2 <listed@space.com> wrote:
Don't be silly. All overhead supplied domestic supplies are RCD
protected. Fitted by the supply provider.

Not silly at all, I only wrote what a Canadian visitor saw in a barn
near Whitby in the UK.

A barn is unlikely to be directly supplied, but 'exported' from the
adjacent farm house. And will then be protected by the supplier's RCD.
And if it really did have a knife switch that dates back to DC days - ie
before WW2. I've never seen one outside a museum of such things. ;-)

None of the silly thermal devices so loved across the pond. ;-)

Good point! However, most thermal devices have been outlawed (in the
1970's ?) in television, radios, etc..

But as circuit breakers in domestic installations?

BTW, just how do they adjust the electrical heating for the houses in
the UK ?

No one in their right mind uses electricity for heating. We use gas or
oil.
It would only make sense if that electricity was generated by some other
fuel - like renewable energy. But not if it's generated by oil or gas.

You can get very close to 100% efficiency with a condensing gas boiler -
not really possible with a variable demand gas burning power station, even
before the transmission losses.

--
*Life is hard; then you nap

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[John Popelish]

Choreboy wrote:

John Popelish wrote:
(snip)

That is Fourier analysis.

The rest is about making the math more efficient.


That's easy for you to say!

I think you've shown me something. When I hear "sine wave" I imagine
one cycle. I guess that's wrong, and a wave is a train of cycles.

True mathematical sine waves extend from infinite negative time to
infinite positive time. Practical sine waves last long enough for
things to respond to their frequency. How long that is, depends o
what is reacting to it. A frequency counter operating in period mode
needs only a single cycle to make its measurement. An ear needs
several cycles to several dozen cycles, depending on exactly what part
of the audible spectrum being detected (this property of ears is part
o the MP3 music encoding scheme). A quartz lattice filter may need
thousands of cycles to of a pure frequency before it develops a nearly
steady state output.

Musical harmony is in a sustained interaction between trains of cycles.
The interaction won't be simple enough to hear unless the quotient
between the frequencies is a small integer.

Something like that. Each frequency component in the signal has to
last long enough for the time response of that frequency of the ear's
sorting system to respond to it. If two frequencies fall within a
single reception band, they are not heard as two tones, but as a beat
addition and cancellation) as a single tone at about the average of
the two frequencies and an AM modulation at the difference of the two
frequencies. Obviously, if the beat is very long period, you have to
hear the two beating tomes for a cycle or two of the beat period to
detect that effect. Harmonically related tones just produce a
repeating pattern at some integer multiples of each of the component
frequencies. This can produce a very pleasing effect. You hear sound
from one musical source as a fundamental and several harmonically
related frequencies. If a second musical source (a harmonizing voice,
for example) has its fundamental at one of the harmonics of the other
signal, your brain recognizes this simple multiple relationship as a
pleasing musical harmony. For some ratios. This page shows some of
the approximate ratios between notes that sound interesting together:
http://www.jimloy.com/physics/scale.htm

When they talk about harmonics in an electrical wave, I guess they're
talking about the potential for energy transfer.

Not really. since linear circuit components react to many frequencies
by the addition if the effect of each frequency, it is a very powerful
analytical procedure to break a signal down into its harmonics and
evaluate the response of a circuit to each of those harmonics, and add
all the effects together to get the total response.

In that case, only odd
multiples of the fundamental will stay in phase to tap the energy from
the distortion.

Symmetrical distortion of a sine wave (shape of positive half cycle is
a mirror image of that on the negative half cycle) can be shown to be
made up of only the fundamental and odd harmonics (3 times. 5 times,
etc.). If the distortion peaks up one half cycle and flattens the
other or shifts the zero crossing so that one half cycle lasts longer
than the other, there are even harmonics in the wave shape. There may
also be odd ones, too. Got to do that Fourier analysis to quantify that.

Where a wave is flattened it may resemble part of a
sine curve with a longer period than the fundamental, but that doesn't
count because you can't tap energy from the flat part.

You can with a resistor. From a Fourier perspective, that flat part
just represents a time when the curve of some frequencies is nearly
canceled by the curve from other frequencies. You need an infinite
number of harmonics to make a truly flat square wave with perfectly
square corners.

If there's any truth in what I've said, I'll forget in a flash. In 1975
I was working in a repair facility. We'd use Bird Wattmeters to see
forward and reflected power in antenna feeds. We knew the jargon and
how to use the meters, but one day it struck me that none of us
understood why they worked. I had a flash of insight and everybody
stopped work to listen to me explain. Their faces lit up with
comprehension. I felt pretty smart. The next day I couldn't remember
whatever it was I'd figured out.

I hate it when that happens.

 

[John Fields]

On Mon, 13 Jun 2005 11:59:48 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:

John Fields <jfields@austininstruments.com> wrote:
On Mon, 13 Jun 2005 07:37:08 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:
---
Well, Floyd, Take a look at the schematics below and you may notice
that while the first one (the one without the cap in series with the
load) puts out a sinusoidally varying unipolar signal, (DC) the second
one (the one _with_ the cap in series with the load) puts out a
sinusoidally varying bipolar signal. (AC)

Now, since the only difference between them is the cap and one puts
out a varying DC signal while the other one puts out a true signal,
then the cap _must_ be generating the AC signal.

Reality check! Capacitors are passive devices. They do *NOT*
generate signals.

---
Hah! Just as I thought you would, you disingenuous little twat, you
snipped my:

"If you have a problem with 'generating' then perhaps 'converting'
would be more to your liking. I doubt it though, you seem to be in
this only for the argument and I'm sure you'll come up with reason why
you're unhappy with 'convert'."

for the purpose of being able to reiterate the obvious. Seems that's
one of your devices, reiteration. Jumble the right with the wrong,
but just keep saying them over and over and perhaps you'll confuse
someone with a lower mentality than yours into believing that you know
what you're talking about. Not bloody likely, boyo, since someone
like that would be hard to find outside of Mickey D's and you're about
as transparent as they come.

BTW, capacitors, (even though passive) are quite capable of actually
generating signals. Consider ceramic capacitors with lead
zirconate-titanate dielectrics. Often capable of _generating_
acoustic signals. Also consider passive electrets. Nice little
microphones they are. And, even parametrically varying caps can be
used as pumps to _generate_ RF signals.

But, I digress... We're really talking about your colors starting to
show and what a dishonest little sneak you're turning into.
---

All that has happened is the capacitor does not pass DC. You
haven't generated AC on one side, you've merely removed the DC.

I don't see how that could be any more obvious. You did take
a high school physics class, didn't you? *Use* what you learned!

---
Rather than merely parroting: "removing the DC", ad nauseam, it might
be helpful if you actually studied the mechanism which causes that
phenomenon to occur. Hint: the capacitor allows the load to "float"
without regard to the voltage on the other side of the cap since
there's a galvanic barrier between the load and its driver.
---

Poppycock. It's precisely the alternations in the direction of charge
flow which cause it to be called "Alternating Current".

It is defined by a differential (which necessarily will have a
sign reversal), not "polarity" reversals.

---
Specious gobbledygook.

A reversal of sign is, by definition, a reversal of polarity.

Okay, so you not only need to restudy high school physics, but
differential equations too.

---
No, for this exercise all I have to do is point out the untenability
of your position and watch you squirm trying to work your way out from
under my thumb.
---

The point is that you didn't point out a non sequitur. (notice that
there's no apostrophe in there) The definition, which I got from
Webster's College Dictionary and posted for your edification, should
have made that clear.

If you had read the definition you posted, you might have
noticed that it perfectly described the remark that I was
commenting on. It had nothing to do with the discussion.

---
If you think that what I posted was a non sequitur, then I invite you
to expound on why you think that.
---

And, speaking of manners, I suggest that yours need a little trip past
Emily Post.

You are the one stooping to spelling flames.

---
A correction isn't a flame unless you take it that way.

--
John Fields
Professional Circuit Designer

 

[John Fields]

On Mon, 13 Jun 2005 12:10:18 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:

John Fields <jfields@austininstruments.com> wrote:
On Mon, 13 Jun 2005 07:47:51 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:
No, if the direction of charge flow alternates between two states,
then it's Alternating Current.

That fits my definition, but not yours! Are you changing your definition
or is that just a momentary bit of logical thought?

---
Try not to be a stupid fuck. Flames will get you nothing back but more
flames. Is that what you want?

Oh, my. And you said what about Emily Post.

---
I said nothing about Emily Post. What I alluded to was that you have
bad manners and could use a little training in etiquette.
---

Nothing I said was a flame. And I'd suggest you go practice (a *lot*)
before you try me on for a flame war. Especially if you think *that*
is a flame.

---
Oh, my! She says one thing, then does another and pulls herself up to
her full 4 foot height and threatens to strike a match! Don't forget
what your mommy taught you about playing with fire.
---

I'm starting to think you're having a real problem with reading
comprehension.

Apparently I read a lot better than you write.

---
More unsubstantiated twaddle.
---

I write that for the current in a load to alternate,

You write a lot of things that are not valid.

---
Just because you can't understand them doesn't mean they're not valid.
---

Don't you understand that an alternation in polarity means that the
polarity changed???

Do you understand that is not significant?

---
It most certainly _is_, since it's what determines the difference
between fluctuating direct current and true alternating current.
---

The reactance of circuit
components, the fundamental significance of AC circuit analysis, does
not depend upon polarity alternation in any way. What else is there
to talk about? How many chocolate drops should be in each chocolate
chip cookie? I await your essay on *something* of significance.

---
Well, since you consider matters of significance to be what you can
understand and what pleases your ego, it's not likely that your wait
will bear fruit.
---

But please, that is the *end* of discussion on your confusion about
AC.

---
I see. You've come to the end of your rope and your exit strategy is
to make it seem like everyone is wrong but you.

--
John Fields
Professional Circuit Designer

 

[JANA]

This is a good excuse to put out an advert to acquire a new lab assistant.
It would be best to carry some extra insurance, so that you can be paid back
the expenses for the cleanup of the next one...

--

JANA
_____


"Tristan Beeline" <mist_distance@hotmail.com> wrote in message
news:55f4364e.0506121950.19b23dbc@posting.google.com...
I accidently killed my lab assistant with my new railgun and his body
is badly damaged.

Do you think I can repair the body with some electronic parts, so that
it will work again or should I throw it away and get a new one ?

 

[Floyd L. Davidson]

John Fields <jfields@austininstruments.com> wrote:

Hah! Just as I thought you would, you disingenuous little twat, you
snipped my:
....
what you're talking about. Not bloody likely, boyo, since someone
like that would be hard to find outside of Mickey D's and you're about
as transparent as they come.
....
But, I digress... We're really talking about your colors starting to
show and what a dishonest little sneak you're turning into.
....
No, for this exercise all I have to do is point out the untenability
of your position and watch you squirm trying to work your way out from
under my thumb.
....
A correction isn't a flame unless you take it that way.

Your flaming is as poor as your electrical theory.

You need to get a handle on your temper as well as learn some
manners and some theory.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

 

[John Fields]

On Mon, 13 Jun 2005 15:38:18 -0800, floyd@barrow.com (Floyd L.
Davidson) wrote:

John Fields <jfields@austininstruments.com> wrote:
Hah! Just as I thought you would, you disingenuous little twat, you
snipped my:
...
what you're talking about. Not bloody likely, boyo, since someone
like that would be hard to find outside of Mickey D's and you're about
as transparent as they come.
...
But, I digress... We're really talking about your colors starting to
show and what a dishonest little sneak you're turning into.
...
No, for this exercise all I have to do is point out the untenability
of your position and watch you squirm trying to work your way out from
under my thumb.
...
A correction isn't a flame unless you take it that way.

Your flaming is as poor as your electrical theory.

You need to get a handle on your temper as well as learn some
manners and some theory.

---
Hmmm....
Seems like I've picked up a secretary/archivist.
Categorize and file away, honey!

Yawnnnn...

--
John Fields
Professional Circuit Designer