RE: [TCML] quench times againInbox

["Lau, Gary" <Gary.Lau@xxxxxx>]

> The longer a gap is conducting the more loss it incurs is not a
> vacuously true statement:    I have an electric stove, I can set it on
> high for a few seconds. Or I can set it on low for a longer period and
> get the same quantity of energy. In the first instance the power level
> is high and in the second instance the power level is low.

But unlike your stove analogy, the rate of energy loss in a gap is the same regardless of the degree of coupling.  The longer the gap fires, the more energy is lost.  By your assertion that lower coupling is more efficient, wouldn't coil with a coupling of say .01 result in better performance than a more typical 0.1?  Do you think it would?

> Entropic losses are related to rates of change. We get higher entropic
> losses when we run a capacitor at high frequencies (they get warm)

I would agree that dielectric losses in capacitors go up as frequency increases, although there are wide ranges (like how we use them) where losses are relatively flat wrt/ frequency.  But I don't believe that one can broadly state that losses in *everything* increase with rate of change.  And more importantly, changing coupling is not changing frequency; there is NO analogy between increasing dielectric losses vs. increasing frequency, and gap losses vs. changing coupling.

> The relationship between amplitude, frequency and power is something
> you need to look up in Wikipedia.

I would be *astounded* if there was a credible Wikipedia reference that could broadly relate those 3 parameters and losses that was applicable to Tesla coils.

Regards, Gary Lau
MA, USA

> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of Jared Dwarshuis
> Sent: Monday, November 26, 2007 9:30 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] quench times againInbox
>
> On Nov 26, 2007 12:58 PM, Lau, Gary <Gary.Lau@xxxxxx> wrote:
> > Where do you get that slow reactions equate to higher efficiency in a Tesla Coil?
> Pri/sec coupling affects the rate at which energy is traded between the two
> systems.  A higher coupling means that the transfer occurs is a shorter period of
> time.  Energy transfer occurs only while the spark gap is conducting, so a lower
> coupling takes longer to transfer the energy, and the gap is conducting longer.  It
> should be clear that a spark gap is the greatest loss-component in a Tesla coil.
> The longer that the gap is conducting, the more losses it incurs.
> >
> > I'm not sure what you mean by "if a spark gap took forever to act".  A spark gap is
> either conducting or it's not.  If it were conducting forever, it certainly would have a
> heat loss.
> >
> > Please explain the basis for your statement "For a given level of power we can
> always expect the amplitude to decrease as we increase the frequency."  And
> please be clear on amplitude of what, keeping what else constant?
> >
> > Thanks, Gary Lau
> > MA, USA
> >
> >
> > > -----Original Message-----
> > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> > > Behalf Of Jared Dwarshuis
> > > Sent: Monday, November 26, 2007 5:29 AM
> > > To: tesla@xxxxxxxxxx
> > > Subject: [TCML] quench times againInbox
> >
> > As for conduction loss at the spark gaps, in wires, and between tank capacitor
> plates. One can make a general remark regarding thermodynamic efficiency. As we
> slow down the flow of energy across dielectrics and imperfect conductors we will
> find that our entropic losses decrease This may sound trivial, but it is not. In theory
> if a spark gap could take forever to act, it would have no heat loss.  Of course it is
> also true that a spark gap that took forever to act would process very little power.
> (the catch- 22)
> >
> > As a general trend, slow reactions equate to higher efficiency.
> >
> > For a given level of power we can always expect the amplitude to
> > decrease as we increase the frequency.
> >
> > This also holds true for coupling. As we diminish the transfer time
> > the amplitude decreases
> >
> > Hence a rather good recipe for poor coil performance is high frequency
> > with tight coupling.
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
>
> The longer a gap is conducting the more loss it incurs is not a
> vacuously true statement:    I have an electric stove, I can set it on
> high for a few seconds. Or I can set it on low for a longer period and
> get the same quantity of energy. In the first instance the power level
> is high and in the second instance the power level is low.
>
> Entropic losses are related to rates of change. We get higher entropic
> losses when we run a capacitor at high frequencies (they get warm)
>
> Entropic losses will also occur from rapid heating of an electrode, or
> rapid heating of the air between the electrodes.
>
> Entropic loss means energy lost from our system that cannot go into
> spark production. Oddly enough, without entropy the spark gap would be
> loss less and the process would be completely reversible. (Admittedly
> a strange abstraction)
>
> The relationship between amplitude, frequency and power is something
> you need to look up in Wikipedia.
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
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