Re: Gadzooks, sparks are pretty

Subject:     Re: Gadzooks, sparks are pretty
      Date:  Sun, 15 Jun 1997 15:01:06 -0500
      From:  Chuck Curran <ccurran-at-execpc-dot-com>
        To:  Tesla List <tesla-at-pupman-dot-com>
References:  1

Tesla List wrote:
> Subject:  Gadzooks, sparks are pretty
>   Date:  Sat, 14 Jun 1997 15:03:25 -0400
>   From:   Michael Bauer <mbauer-at-execpc-dot-com>
>     To:   tesla-at-pupman-dot-com
>         I just got back from taking my coil out to the country whar I
> wouldn't bother the neighbors.  I started out with 1 inch of vertical
> spacing between the primary and secondary.  I was watching for
> overcoupling
> from arcs to the middle of the coil, but it was really was arcing from
> the
> bottom secondary turn up to the side of the coil several inches.  I
> raised
> the coil by an inch at a time and it progressively reduced in intensity
> and
> disappeared at 5 1/2 inches lift.  I never did see any primary to
> secondary
> arcing.  As a refresher, my secondary is 20" by 40" on a wooden form
> with a
> 6 X 30 toroid.  The primary is 9 turns of 5/8" copper with a 0.1 uf/40
> Kv
> capacitor, rotary gap, pole pig, welder ballast.  the one big mistake
> was
> that I only had a 20 amp breaker in the wall and I kept blowing it.  I
> had
> to keep the power low, about 25-30 amps on the meter to get a little run
> time.  Even though, I had consistently 6 foot sparks!  I had more room
> on
> the variac and on the welder.
>         Best spark output was about 2400 RPM on the rotary with 12
> posts.
> Any higher, and the current limit didn't allow the caps to charge up
> high
> enough.  With extra line filter, I was able to keep the SCR motor
> control
> working without failure.  Speed control was never a problem.  I also
> added
> 60 amp RF line filters between the pig and ballast to keep RF out the
> control cabinet and off the mains.  The electronic meters I built also
> keep
> working.  I use analog meters with op-amp front ends and buffering to
> the
> scope.  The current bounced around way too much as the secondary strikes
> changed for digital meters to be read.
>         Dr. Resonance is right that I need more toroid load.  The arcs
> were
> fast moving and thin.  A larger toroid would concentrate these into
> thicker,
> slower moving strikes.  I need to make a run to the hardware store this
> week
> for toroid parts and larger breakers fro the mains.
>         I couldn't wait for nightfall to come the last few days to run
> the
> coil.  Daytime sparks just isn't the same as nighttime.  Next week my
> wife
> will also come along up to our other place to see the show and see that
> all
> my hard work has paid off.  But what the heck, she could care less about
> sparks.  In fact, she would rather have me painting the house.
>         So much to do, so little time....


Great job on getting your coil fired up and generating sparks.  To the
rest of the group, I drove over to Michael's house last week and saw his
coil.  He's really put alot of work into the control cabinet and made
good use of the 19" rack cabinet he had along with a number of other
nice goodies.  I am very interested in following the secondaries
performance since the form was crafted out of all wood and varnished.  
Michael, I am wondering if you got a hernia when you moved that pole
pig.  That's the biggest 10 KVA unit I've seen yet, must be 375 -400
pounds total!  Keep us posted with the next test.

Chuck Curran 
Cedarburg, WI