[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] 6" Tesla coil plexiglass secondary - FOR SALE
Hi Don and Jon,
I'm thinking the "truth" here may lie somewhere in
between your two opposing viewpoints ;^) Don,
although your position is most likely correct in re-
gards to the relatively high radio frequnecies (10's
or 100's of MHz, or more), I believe Jon's position
is probably more relavent for the relatively very low
frequencies of TC operation -10's or low 100's
of KHz (that's 3 orders of magnitude lower!) and
you would be hardpressed to actually
notice a difference in the output of a PVC vs. a
plexiglas formed secondary coil without some pret-
ty fancy instrumentation. My Green Monster 10 kVA
pole pig driven, ARSG coil has a 12" gray PVC duct
pipe secondary form and it really rocks and I've
never been able to detect notable warmth of the
form above ambient temperature after running it.
Of course, with the massive 12x56 topload, I'm
running around the high 50's KHz, which is ex-
tremely LOW frequency compared to the typical
modern radio or television communication frequen-
cies, with a possible exception of AM bands - from
the mid 500 KHz to 1.6 MHz range. I'm thinking
that the SG losses as well as the internal dielectric
losses of the primary capacitor are far more con-
sequential, as this is the main place that one tends
to noticed heat significantly above ambient tempe-
ratures. And if you have a good, low loss dielectric
capacitor, you won't notice significant heating here,
either.
BTW, "I" have experienced the electret effect with
PVC formed secondaries and I believe others in
this forum have mentioned it in the past as well.
David
----- Original Message -----
From: <dfroula@xxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Wednesday, January 16, 2013 8:35 AM
Subject: Re: [TCML] 6" Tesla coil plexiglass secondary - FOR SALE
One interesting effect of using a plexiglass form for the secondary is
that the plexiglass seems hold a charge after the coil is shut off
(depending where in the charging cycle the coil is shut off). The
prevalent theory is that the plexiglass exhibits an "electret" effect
where the polymer structure of the material will hold an electrical charge
for some time. PVC forms I have used do not seem to exhibit the effect.
A true electret is a sort of "permanent magnet", except that the material
retains a permanent electrical, rather than magnetic charge. True electret
polymers are used to construct electret microphones, tha depend on the
charge to produce an output signal.
I have gotten minor zaps from a plexiglass secondary hours after the coil
has been turned off.
Don
--- On Tue, 1/15/13, Jon Danniken <danniken@xxxxx> wrote:
From: Jon Danniken <danniken@xxxxx>
Subject: Re: [TCML] 6" Tesla coil plexiglass secondary - FOR SALE
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Date: Tuesday, January 15, 2013, 8:42 PM
On 01/15/2013 11:53 AM, dfroula@xxxxxxxxxxxxx
wrote:
>
> Wound on low-loss plexiglass form. Far superior to
lossy PVC coil form!
I don't think the difference in RF losses between a
"low-loss plexiglass form" and a PVC form are even
noticeable in a tesla coil.
Is this just advertising hype, or do have actual data from
real-world operation showing "far superior" performance with
a "low-loss plexiglass" form?
Also, is this a special "low-loss" version of plexiglass,
because I have yet to come across any type of plexiglass
that specifies lower RF losses in any of the plastics
dealers I have come across.
Thanks,
Jon
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla