[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [TCML] First TC firing
A dielectric puncture is a hole in the dielectric (plastic bottle), that shorts out the cap.
Having a thick enamel coating on wire is never a bad thing in and of itself, but having any kind of insulation on the primary would make it hard to "tap" it - to experimentally connect one terminal of the primary coil to each of the primary turns, to determine which one results in the best tuning and best spark. That's why 1/4" copper tubing is commonly used for primary coils. It's rigid enough to hold its shape without flopping around (given some sort of hold-down strategy), and allows easy access to connect to each turn.
Regards, Gary Lau
MA, USA
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of Matt
> Sent: Wednesday, December 10, 2008 9:35 AM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] First TC firing
>
> Thanks for all feedback, it has been very helpful.
>
> Spark gap does not fire - I've had the gap practically closed and still no
> response. I'm pretty sure the wiring is fine - I checked it many times, and
> even when I wired it with the caps in parallel with the spark gap on their
> own there was still no spark. I'm not quite sure what you mean by a
> dielectric puncture - I will have to look it up but I suspect this may be
> very likely as the caps were pretty makeshift. As I've said - the spark gap
> if definitely not too wide.
>
> The OBIT still works though - I set up a quick jacobs ladder to make sure
> and it works fine.
>
> On top of that I do probably need to have done my calculations a lot better.
> Will the fact that my wire for the primary is enameled pretty thickly affect
> it adversely?
>
> -Matt
>
> On Wed, Dec 10, 2008 at 1:36 PM, Lau, Gary <Gary.Lau@xxxxxx> wrote:
>
> > A plastic bottle cap with a dielectric puncture WOULD render the coil
> > completely non-functional.
> >
> > Does the spark gap fire? If it does not fire, the possible causes are 1)
> > dead OBIT, 2) wiring error, 3) shorted cap (dielectric puncture), 4)
> > too-wide gap.
> >
> > If the gap does fire, it's likely that the primary/secondary tuning is way
> > off. How do you know that you are correctly tuned? One cannot simply wind
> > a bunch of heavy wire for the primary, make a cap out of whatever bottles
> > are available, wind a bunch more thinner wire for the secondary, put an
> > arbitrary lump of metal on top for a top load, and expect the primary and
> > secondary frequencies to match.
> >
> > Gary Lau
> > MA, USA
> >
> > > -----Original Message-----
> > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> > > Behalf Of Matt
> > > Sent: Wednesday, December 10, 2008 3:14 AM
> > > To: Tesla Coil Mailing List
> > > Subject: Re: [TCML] First TC firing
> > >
> > > I am aware the coke bottles will not last long (temporary measure for the
> > > moment). However at the moment the coil is completely non-functional.
> > Does
> > > anyone have any ideas where I'm going wrong?
> > >
> > > Here's an ASCii diagram of my current layout;
> > >
> > > O--o--O
> > > (
> > > (
> > > |---------|-------|-----o o-----| (
> > > | | | SG | (
> > > | | - | (
> > > OBIT GAP CAP ) (
> > > | | - ) (
> > > | | | L1 ) ( L2
> > > |---------|-------|-------------| |
> > > RF
> > > GND
> > >
> > > On Wed, Dec 10, 2008 at 3:35 AM, Lau, Gary <Gary.Lau@xxxxxx> wrote:
> > >
> > > > The amount of RF that your xfmr is exposed to is less if you swap the
> > > > positions of your main gap and the cap. Performance is the same, but
> > > > placing the main gap across the xfmr effectively shorts out most of the
> > RF
> > > > energy from going back to the xfmr.
> > > >
> > > > If you are using plastic coke bottles, they're not likely to last very
> > long
> > > > :-(
> > > >
> > > > You give no specifics (a few turns, don't know exact gauge, vague
> > copper
> > > > vase topload...) that would allow one to calculate if you are properly
> > > > tuned, so I'll leave that to you.
> > > >
> > > > Regards, Gary Lau
> > > > MA, USA
> > > >
> > > > > -----Original Message-----
> > > > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx]
> On
> > > > > Behalf Of Matt
> > > > > Sent: Tuesday, December 09, 2008 4:21 PM
> > > > > To: Coil Mailing List
> > > > > Subject: [TCML] First TC firing
> > > > >
> > > > > Hello everyone, thanks for your help so far.
> > > > >
> > > > > I am about to test my coil and would like some input to make sure
> > things
> > > > > won't go drastically wrong.
> > > > >
> > > > > I have my transformer (2x 7.5kv outputs at 40ma Danfoss OBIT) wired
> > to
> > > > the
> > > > > mains. From there it is wired in parallel to first my safety gap,
> > then my
> > > > > capacitor bank (two 2l coke bottles, wrapped in foil and filled with
> > > > water
> > > > > saturated with table salt). In series to that I have my spark gap,
> > and
> > > > then
> > > > > my primary coil (a few turns of thick enamelled wire)
> > > > >
> > > > > The primary is at the base of the secondary (1000+ turns of very thin
> > > > magnet
> > > > > wire - I don't know the exact gauge, but it was the second thinnest I
> > > > could
> > > > > get from Maplins, and is thin enough to snap under force applied by
> > me).
> > > > The
> > > > > secondary is grounded to a square sheet of chicken wire, and the
> > topload
> > > > is
> > > > > the bottom of a copper vase.
> > > > >
> > > > > I include a VERY simple circuit diagram.
> > > > >
> > > > > Some feedback would be MUCH appreciated soon as I am about to turn it
> > on
> > > > and
> > > > > could do with some reassurance that I'm not going to destroy
> > something...
> > > > >
> > > > > Thanks a lot,
> > > > >
> > > > > Matt
> > > > _______________________________________________
> > > > Tesla mailing list
> > > > Tesla@xxxxxxxxxxxxxx
> > > > http://www.pupman.com/mailman/listinfo/tesla
> > > >
> > > _______________________________________________
> > > Tesla mailing list
> > > Tesla@xxxxxxxxxxxxxx
> > > http://www.pupman.com/mailman/listinfo/tesla
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> >
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla