Re: Ignition coil abuse

-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Saturday, April 29, 2000 11:08 PM
Subject: Ignition coil abuse

>Original Poster: "sundog" <sundog-at-timeship-dot-net>
>    Hi all (again!) :))
>Well, the rotary idea is simmering as I dig up info on converting a
>motor to sync operation.  Till I have the info, I'm content with a
>simple low-powered static gap on that 4kv30ma nst (love that
>thing!)  Anywho, I got adventurous and set it up like I'm driving a
>normal TC primary, but instead substituted an old ignition coil I
>got lying around.  Yowza.  It hasn't died yet, but it gets a bit
>warm to the touch (no oil bubblin' yet, but I know the insulation
>inside is taking a pounding from the HV more than the heat).  The
>problems and questions...
>I'm running a 4kv30ma nst, using 15nf of 17.6kv MMC (trying to
>avoid resonance for the moment), across a single static gap.  The
>gap 'trodes are copper pipe (2", all I had!), set the width of a
>hacksaw blade.  The system runs beautiful, not TC like, but gives
>*very* pretty and intense white-hot sparks. I don't assume it to
>have a very long life in this kind of service tho...I'll be a
>little sad when it dies on me. *sniff*
>Now, the nst is 120watts (4kv*30ma).  The gap is around .75-1mm
>(measured at 1 side, and the spark jumps all over the entire width,
>so it's parallel I assume).  What is the firing voltage, and
>knowing the firing voltage, how do I find out how much bang I'm
>dumping into the ignition coil?
>Also, I can't get a good "spark to grounded wire" going here,
>because the sparks will crawl over the nose of the HV output to the
>terminals (not too good for my caps and NST), so I'm trying to
>eliminate that. But no matter what I've tried, as soon as the
>distance to the grounded wire approaches the distance from the
>inner electrode in the HV out of the coil to either terminal, it
>arcs over on me.
>Also, when it's running and arcing to the terminals, I'll get a
>really loud *pop* every once in a while.  I always kill it and
>check for damage to the caps, but find none.  The sound originates
>from the arc from the HV on the coil to the terminal.  Is it
>dumping the cap energy *there* as well as across the normal spark
>gap? (this only happens when the arc is hitting both input
>terminals on the coil) :(  All in all, it's fun as heck! And
>*really* good for the ozone layer ;)  Fans on over here to air it
>    Do I need to epoxy a HV bushing to the top of this thing so the
>arc will have longer to creep?  I'm also scrambling to dig up good
>HV diodes to charge a DC system.  :)  Think of this as scrambling
>to follow the rather steep learning curve to become competetive in
>Thanks for your time & info
>                                            Shad (aka Sundog)

Hey Shad

What kind of coil do you have? if ur looking for a coil that can take the
pounding and still live through it try an oil filled canister type (ford). i
dropped my coil in oil to prevent that arc from one terminal to the other.
It helps also to cool the coil. I had to go with motor oil since i ddint'
have any HV oil layin around. I keep hearing constant bangs and pops even
inside the oil and the oil seems to jump around alot, so im guessing that
the oil is leaking. even with this leakage i got 6-8 arcs. I used HV
sparkplug wires. They actually weaken the spark. The spark came out red
instead of the pure white i wanted. Im only using them for their insulation.
As I increase the power on my unit somethin ends up leaking. Either wires
break out or the motor oil fails.
check out the

------------manjinder bains----------

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