Coil Efficiency (Bad)
From: Julian Green[SMTP:julian-at-glosilk.demon.co.uk]
Sent: Sunday, June 01, 1997 5:03 AM
Subject: Re: Coil Efficiency
> From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> Sent: Wednesday, June 18, 1997 3:55 PM
> To: tesla-at-pupman-dot-com
> Subject: Coil Efficiency
> Hi all,
> I think we could be on the verge of making some real
> progress in nailing down the merits of actual coil parameters. There
> is much to be done in the wall socket -> coil efficiency stakes. But
> if we look at the raw E x BPS vs spark length figures, we can start
> to see where the coils themselves might be improved. I think there is
> now a most fruitful area of research open to us. We might at last
> have a platform from which to examine L/C ratios and the like. It
> seems obvious now that when using current efficiency measurements we
> are floundering around in the dark (with an arc to light the way :)
Not having much luck with my coil and effeciency is terrible!
My coil is now powered by a pole pig and draws 20A at 240v thats 4800VA!
And all I get is a miserable 3' spark. The tune is OK as adjustments of
the primary plus/minus one turn result in shorter spark length.
I have had longer sparks than this from the coil before the rotary spark
gap broke, but still not as long as I would like. Its the darn spark
gap that gives me trouble.
One point of interest though, I am running my pole pig without balast and
I am achieving 'smooth' running. I put this down to my spark gap which
is built around a 10,000 rpm motor. The rotor on the gap has only two
electrodes mounted on a 6" disk. Only when I run the motor at maximum
speed do I get this smooth running, with lower speeds loud bangs and blown
fuses result. Have others tried fast motors and few electrodes on their
Is the apparant high VA a result of 'out of phase' amps and volts? If I
added some PFC capacitors would this help.
Is the spark gap quenching well enough? If not then how do I tell? I
have a scope and I remember a thread on monitoring quenching using a scope.
Can anyone recall how this can be done?