Making sense of watts, amps and volts -- a typo?

[Jasen Betts]

On 2012-04-12, krw@att.bizzzzzzzzzzzz <krw@att.bizzzzzzzzzzzz> wrote:

On Wed, 11 Apr 2012 15:24:39 -0500, John Fields
jfields@austininstruments.com> wrote:


You're a lying piece of shit, Fields. Even a first year college kid knows
"=>" means "implies". Of course, since you never went to college...

but it doesn't

implies is normally used with truth values, it's not defined for scalars.
and the presence of a voltage (even a ssquared one) does not imply a flow
of energy.

the symbol you want is ∝ (which looks a bit like a lower case alpha)



--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[krw@att.bizzzzzzzzzzzz]

On 12 Apr 2012 06:55:52 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-04-12, krw@att.bizzzzzzzzzzzz <krw@att.bizzzzzzzzzzzz> wrote:
On Wed, 11 Apr 2012 15:24:39 -0500, John Fields
jfields@austininstruments.com> wrote:


You're a lying piece of shit, Fields. Even a first year college kid knows
"=>" means "implies". Of course, since you never went to college...

but it doesn't

Wrong.

http://en.wikipedia.org/wiki/List_of_logic_symbols

implies is normally used with truth values, it's not defined for scalars.
and the presence of a voltage (even a ssquared one) does not imply a flow
of energy.

the symbol you want is ? (which looks a bit like a lower case alpha)

Sorry, it's not on my keyboard. "=>" should get the meaning across to even a
moron. If someone doesn't understand they can ask, assuming they're not a
pendant cruising to boost their ego, like Fields (and apparently, you).

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 12 Apr 2012 03:31:52 GMT, Chiron
<chiron613.no.spam.@no.spam.please.gmail.com> wrote:

On Wed, 11 Apr 2012 22:14:40 -0400, krw@att.bizzzzzzzzzzzz wrote:


It's *NOT* an opinion. It's a fact. What meaning did you find? How
the hell can I offer support for a position when you won't say what you
found?

Well, as I said, I am not going to engage in a flame war with you. Your
statements are opinions. Your equations, if correct, are facts.

My statements about RMS, power, and voltage (squared) are *facts*. There are
no opinions, here. If you found some moron who believes there is something
meaningful about RMS power, let us all in on the joke.

I've already participated in more than my fair share of flame wars. Not
one of them did a thing for me; I never learned from them, didn't become
a better person, nothing. Oh, except I did learn (after way more time
than it should have taken) that I was utterly wasting my time.

So be well, Godspeed, and all that. No hard feelings, no malice, and no
thanks to the flame war.


Oh, well. Wander in the dark with Fields.

Refusing to participate in an idiotic flame war is hardly "wandering in
the dark." In fact, a case could be made that it's *refusing* to wander
in the dark.

You *still* refuse to answer the question. I think you're the troll, here.

Be well.

I am very, thank you.

 

[John Fields]

On Thu, 12 Apr 2012 12:42:13 -0400, "krw@att.bizzzzzzzzzzzz"
<krw@att.bizzzzzzzzzzzz> wrote:

On 12 Apr 2012 06:55:52 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-04-12, krw@att.bizzzzzzzzzzzz <krw@att.bizzzzzzzzzzzz> wrote:
On Wed, 11 Apr 2012 15:24:39 -0500, John Fields
jfields@austininstruments.com> wrote:


You're a lying piece of shit, Fields. Even a first year college kid knows
"=>" means "implies". Of course, since you never went to college...

but it doesn't

Wrong.

http://en.wikipedia.org/wiki/List_of_logic_symbols

implies is normally used with truth values, it's not defined for scalars.
and the presence of a voltage (even a ssquared one) does not imply a flow
of energy.

the symbol you want is ? (which looks a bit like a lower case alpha)

Sorry, it's not on my keyboard. "=>" should get the meaning across to even a
moron. If someone doesn't understand they can ask, assuming they're not a
pendant cruising to boost their ego, like Fields (and apparently, you).

---
What's moronic is your using a symbol which has nothing to do with
whatever point it is you're trying to make and then calling someone
else a moron because they can't read your mind and they dare to
question your use of the symbol.

And, besides, voltage squared doesn't imply power any more than
resistance does, so, for clarity, what you should have used was
E˛/R = P or even - if you wanted to be tricky dickie - E˛/R => P.

In any case, you've become terminally boring with your never-ending
witless buffoonery, so into my filter you go.

--
JF

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 12 Apr 2012 13:17:13 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Thu, 12 Apr 2012 12:42:13 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On 12 Apr 2012 06:55:52 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-04-12, krw@att.bizzzzzzzzzzzz <krw@att.bizzzzzzzzzzzz> wrote:
On Wed, 11 Apr 2012 15:24:39 -0500, John Fields
jfields@austininstruments.com> wrote:


You're a lying piece of shit, Fields. Even a first year college kid knows
"=>" means "implies". Of course, since you never went to college...

but it doesn't

Wrong.

http://en.wikipedia.org/wiki/List_of_logic_symbols

implies is normally used with truth values, it's not defined for scalars.
and the presence of a voltage (even a ssquared one) does not imply a flow
of energy.

the symbol you want is ? (which looks a bit like a lower case alpha)

Sorry, it's not on my keyboard. "=>" should get the meaning across to even a
moron. If someone doesn't understand they can ask, assuming they're not a
pendant cruising to boost their ego, like Fields (and apparently, you).

---
What's moronic is your using a symbol which has nothing to do with
whatever point it is you're trying to make and then calling someone
else a moron because they can't read your mind and they dare to
question your use of the symbol.

Peck, peck, peck. Of course you're wrong but the pendant won't give it up.
You have too much to "lose" if you stopped yapping.

And, besides, voltage squared doesn't imply power any more than
resistance does, so, for clarity, what you should have used was
E˛/R = P or even - if you wanted to be tricky dickie - E˛/R => P.

More bullshit.

In any case, you've become terminally boring with your never-ending
witless buffoonery, so into my filter you go.

Then leave. No one, other than your ego, is forcing you to reply to my posts.

 

[Fred Abse]

On Wed, 11 Apr 2012 20:44:56 -0600, m II wrote:

Power factor is the Cosine of the angle between VA and Watts

Only if everything is sinusoidal. Harmonics and DC components screw that
up.

Power factor = True Power / Apparent power = Watts / Volt-amperes. in all
cases.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Tue, 10 Apr 2012 20:03:34 -0600, m II wrote:

That power factor percentage is just another name for the cosine of
the angle between VA and Watts. No angle = Cos (0) = 1 = 100 percent.

Only in the case of sinusoidal quantities is power factor equal to cos(phi).

The broad definition is: true power / apparent power. Where there are
harmonics present, such as where the load is nonlinear, for example a
rectifier, cos (phi) is not the full story,

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Sun, 08 Apr 2012 20:14:00 -0400, krw@att.bizzzzzzzzzzzz wrote:

The boss
doesn't trust recent graduates (recent ~= 20-30 years). ;-)

I didn't know you worked for me ;-)

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Mon, 09 Apr 2012 00:57:45 +0000, Chiron wrote:

The only thing I can figure is that power never becomes negative

Careful!

Power sourced vs. power dissipated.

In electromagnetic terms, the Poynting vector has direction, by
definition, too.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Sun, 08 Apr 2012 23:26:07 +0000, Chiron wrote:

These are all pretty fundamental concepts that don't require much
preparation except for some math.

Perzactly.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Mon, 09 Apr 2012 06:43:38 +0000, Chiron wrote:

Actually, that was what my vague wonderings were trying to get at. I
remembered that RMS had *something* to do with values going negative; but
I couldn't remember the details. Of course, what I was groping for only
applied to the values that tended to average out to zero, so I was still
pretty wide of the mark... Oh, well.

It's kind of strange to find pedantry in an electronics group. Back in
the day (late seventies, early eighties) we were happy if we were within
10% of reality.

It isn't pedantry, it's basic electrical principles. Something that is
widely misunderstood, misinterpreted, and misused. Largely due to
inadequate explanation at the foundation stage.

It can be very difficult to explain to someone without a grounding in
basic calculus.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Chiron]

On Fri, 13 Apr 2012 01:44:10 -0700, Fred Abse wrote:

It isn't pedantry, it's basic electrical principles. Something that is

The comment concerning pedantry was in reference to the flame war that
was triggered by this simple question. That was a good deal of pedantry,
as well as pointless insults and other such waste.


--
QOTD:
"I only touch base with reality on an as-needed basis!"

 

[m II]

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Hash: SHA1

Fred Abse wrote:

On Wed, 11 Apr 2012 20:44:56 -0600, m II wrote:

Power factor is the Cosine of the angle between VA and Watts

Only if everything is sinusoidal. Harmonics and DC components screw
that up.

Power factor = True Power / Apparent power = Watts / Volt-amperes.
in all cases.

What could we call this ratio? Seems to me that the better meters go
to great lengths to get an RMS equivalent of the readings. If RMS
equivalent readings are assumed, would not the cosine aspect apply again?

'True Power / Apparent power' or 'Watts / Volt-amperes' **IS** the
Cosine of the angle between VA and Watts. That would seem to disagree
with your first sentence. Would you like to reconsider the 'in all
cases' portion of the statement?

Also, how would the current know it was in an AC circuit? It may well
be merely on the up/down slope of a changing DC situation. Reactance
can happen with pulsating DC, too. It the same, just different....

Remember the Mnemonic SohCahToa?

Sine = opposite/hypoptenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent

mike






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[Chiron]

On Fri, 13 Apr 2012 11:42:00 -0600, m II wrote:

Remember the Mnemonic SohCahToa?

Sine = opposite/hypoptenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent

I always had it as sin, cos, tan:

Old Houses
Always Have
Old Attics

Opposite/hypotenuse;
Adjacent/hypotenuse;
Opposite/adjacent.



--
The trouble with telling a good story is that it invariably reminds
the other fellow of a dull one.
-- Sid Caesar

 

[krw@att.bizzzzzzzzzzzz]

On Fri, 13 Apr 2012 11:42:00 -0600, m II <C@in.the.hat> wrote:

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Hash: SHA1

Fred Abse wrote:

On Wed, 11 Apr 2012 20:44:56 -0600, m II wrote:

Power factor is the Cosine of the angle between VA and Watts

Only if everything is sinusoidal. Harmonics and DC components screw
that up.

Power factor = True Power / Apparent power = Watts / Volt-amperes.
in all cases.

What could we call this ratio? Seems to me that the better meters go
to great lengths to get an RMS equivalent of the readings. If RMS
equivalent readings are assumed, would not the cosine aspect apply again?

Because RMS applies to all waveforms, not just sine waves.

'True Power / Apparent power' or 'Watts / Volt-amperes' **IS** the
Cosine of the angle between VA and Watts. That would seem to disagree
with your first sentence. Would you like to reconsider the 'in all
cases' portion of the statement?

*ONLY* with sine waves. COS(theta) means nothing for a square wave, for
instance.

Also, how would the current know it was in an AC circuit? It may well
be merely on the up/down slope of a changing DC situation. Reactance
can happen with pulsating DC, too. It the same, just different....

What's sine(theta) of this random waveform?

Remember the Mnemonic SohCahToa?

Sine = opposite/hypoptenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent

Since grade school, the unit circle has worked for me.

 

[Fred Abse]

On Fri, 13 Apr 2012 11:42:00 -0600, m II wrote:

What could we call this ratio? Seems to me that the better meters go
to great lengths to get an RMS equivalent of the readings. If RMS
equivalent readings are assumed, would not the cosine aspect apply again?

No. What you call the "cosine aspect" only applies when voltage and
current are *both* pure sine or cosine functions.

'True Power / Apparent power' or 'Watts / Volt-amperes' **IS** the
Cosine of the angle between VA and Watts.

I think you mean between applied voltage and resulting current. Then only
in the case of sinusoidal voltage *and* current. Consider the current
drawn from a sinusoidal supply by a full wave rectifier with reservoir
capacitor as an example. Current is far from sinusoidal, but power factor
still applies. Modern PSU designs go to some length to address this.

That would seem to disagree
with your first sentence. Would you like to reconsider the 'in all
cases' portion of the statement?

No.

Also, how would the current know it was in an AC circuit? It may well be
merely on the up/down slope of a changing DC situation. Reactance can
happen with pulsating DC, too. It the same, just different....

Reactance is a concept devised to obviate the need to do lots of tiresome
differential equations.

Power factor does not exclusively depend on reactance. Non-linear elements
have just as big an effect.

Remember the Mnemonic SohCahToa?

No. That sounds like a Native American word to me

I don't do mnemonics.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)