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RE>Re: RE>Re: UK coilers ? (fwd)
---------- Forwarded message ----------
Date: 05 Aug 1998 11:07:52 -0700
From: Dale Hall <Dale.Hall-at-trw-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: RE>Re: RE>Re: UK coilers ?
RE>Re: RE>Re: UK coilers ? + stuff (fwd)
Chris,
Determining RMS for any impulse measurement such as tesla coil corona or
sparks is not very easy to do nor useful, except perhaps to determine loss
relative to input power consumption. The nature of converting the corona or
spark sharp impulses of varying amplitude, width and shape are beyond
simple calculations. Even estimating peak envelope power viewing a frozen
oscilloscope event leaves much to be desired ! The output is not a square
wave nor a simple part of a sine wave but a complex high frequency dynamic
time, shape and amplitude varying spike, each one different. However
measuring damped ringing is very nearly pure sinusoidal where RMS would
be appropriate (period just before a spark). Corona does occur during this
time before main spark, extracting energy in sharp high current spikes
during the ringdown, taking away from energy available for a long discharge.
Dale
------------------------------
Date: 8/5/98 1:05 AM
To: Hall, Dale
From: List, Tesla
Date: Tue, 4 Aug 1998 18:04:11 +0100
From: "chris.swinson" <chris.swinson-at-zetnet.co.uk>
Subject: Re: RE>Re: UK coilers ? + stuff (fwd)
>Chris & Al,
>
>I agree with Al's good comments, except,
>
>I disagree regarding the uA output current of a TC, seems he was talking
>average where it the peak values that need to be considered (or perhaps
>he is referring to overall corona current with no concentrated spark ?)
>Sparks and corona represent impulse events necessitating peak terminology.
>Wire ratings are for heating values (cross section area).
>Surface area & skin affect at relevant tesla frequencies determine peak
>current capability. The pulse repetitiion rate never gets high enough to
>become a wire heating restriction.
>
The way I see it, Is the corona is the RMS value, and when there is a spark,
thats the high current comming into play. More current being a brigther
spark.
>In my battery powered DC TC, 12v .04A to 5kVDC, .1uF, .125" ~4turn pri,
> 6.25"x20" sec #24 ~20mHy, 8"x20" toroid, 8" to 10" sparks:
Have you a web ste where I can see you DC coil ? I'd like to try one of
them out and compair it to my normal sparkgap coil.
Chris.swinson-at-zetnet.co.uk Thanks all :-)
>Ipri ~ 600 A pk measured with a Tektronix current probe (220kHz).
>
>Isec ~22 A pk measured spark return line current (~2 to 20mHz)
>
>Dale Redondo Beach, Calif
>
>------------------------------
>Date: 8/1/98 8:45 PM
>To: Hall, Dale
>
>Date: Sat, 1 Aug 1998 17:04:53 EDT
>From: Alfred A Skrocki <alfred.skrocki.sr-at-juno-dot-com>
>Subject: Re: UK coilers ? + stuff (fwd)
>
>On Fri, 31 Jul 1998 18:37:50 +0100 Chris Swinson
><chris.swinson-at-zetnet.co.uk> wrote;
>
>snip.....