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Magnify Power?
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From: Gomez [SMTP:gomez-at-netherworld-dot-com]
Sent: Monday, February 09, 1998 6:54 PM
To: Tesla List
Subject: Re: Magnify Power?
John H. Couture wrote:
> I agree electrical power is volts x amps. However, in the Tesla coil
> secondary when power is increased it is usually the voltage and the current
> is not important.
How can we be talking about power as being important, and have the current be
unimportant, if power depends in part upon current?!
> A large voltage increase is necessary to make
> those big sparks.
I agree.
> Pulse forming network in the TC secondary that stores energy etc. There is
> energy storage in both the pri and sec circuits. The important energy
> storage is in the charging of the pri cap under RMS conditions. Next are the
> RF dampened waves (not RMS conditions)
What on earth is an "RMS condition"? Even damped ringing pulses that repeat
themselves have RMS power. I remind you that RMS power is simply that power
which is capable of doing work- it's what you get when you measure the voltage drop
across a resistor and calculate (I!2)R.
> that occur when the pri cap
> discharges into the pri coil. These RF waves are then transferred to the sec
> coil by induction at much higher voltages (not resonance?).
Urm, that last is a rather confusing sentence. When speaking of "voltage"
transformers, Tesla or otherwise, the voltage is usually thought of as the product,
rather than the mechanism doing the energy transfer. The energy is transfered
between primary and secondary by magnetic field, no? The intensity of the primary's
magnetic field is determined by the primary current, all other things being equal, no?
And yes, of course the current depends on the dV/dT and the inductance of Lp, it's just
confusing to hear someone say "RF waves are...transferred...by induction at much
higher voltages".
And what do you mean "not resonance"?
> I do not agree that average power must always be lower due to losses.
Then we must agree to disagree, I am afraid, because I will not ever believe that you
can transfer _average_ power from the primary circuit to the secondary circuit with
100% efficiency. Some current will be converted to heat in the copper of both Ls and
Lp. Some magnetic flux from the primary will not intersect the secondary. That
current and flux represents power that is gone forever- it is not available to make
sparks, regardless of how you believe the transformation mechanism works.
> Losses are always energy
Since, as you say in the next paragraph, P=E/dT, then if energy is lost, power is lost,
else the energy was not "lost" but stored somewhere. Or are you suggesting that dT
becomes infinitely small?
> and power equals energy/dt.
"Average" power ignores (integrates) dT. Average power is something we probably
can't observe anyway, since we all seem to agree that we can't measure the output
voltage of a Tesla secondary, and the _average_ power in the secondary must surely
have _something_ to do with the secondary voltage, no?
> In other words it is
> possible to have a gain of power (reduction of dt) in a TC even when there
> are losses of energy.
It is not possible to have a gain of _average_ power, which is really the thing I have
been talking about. I think you are talking about peak power, since you emphasize dT.
> Conservation of energy per unit time? Are you saying that power/time
> equals what?
Pick one, I don't care: conservation of energy over a longer enough period of time so as
not to matter, ie, "average" energy, or conservation of energy within some smaller
unit of time.
-Gomez,
Mad Scientist: have attitude, will travel
--
Gomez: card-carrying mad scientist, extreme fetishist, fiction dabbler,
pyrophiliac, technomage, goth, SF fan, lighting designer, dominant
pervert, and juggler of labels... http://www-dot-netherworld-dot-com/~gomez