Gary,
I found a photo hosting site and posted some pics of the coil early on.
http://tdg8934.smugmug.com/Sample-Gallery/
The fan is a 120 vac squirrel cage fan blowing on the tungsten spark gaps.
However, I don't think its really that strong but I was told this is what
was needed so I bought it. I don't have a lot of tools so I'm buying what I
can to get it together quickly. The sucker gap you have sounds great but
may be too complicated without the experience and materials to do this.
The gaps on my coil are set about 1/4" or so apart. Using my 130vac 20A
variac, it starts sparking on the gaps at about 1/2 to 2/3rds power of
120+vac (to 145vac "measured" max when 20A fuse blows before getting to
this).
I did not know about how to set the gaps properly (i.e. as you said no
caps) from the NSTs.
As stated before I am moving in another week or so...so I can't make these
changes till next month most likely. I will set the gaps to serial not
parallel.
Comments?
Thanks, Tim
On Wed, Apr 8, 2015 at 8:30 PM, Gary Lau <glau1024@xxxxxxxxx> wrote:
> Hi Tim,
>
> Posting some detailed photos of your coil components, in particular your
> spark gap, would be very useful. But from what's been said, I think your
> spark gap may be fertile ground for improvement. I agree with what others
> have said as far as you cannot have spark gaps operating in parallel.
> Series operation is often done but gap losses are higher when having
> multi-segment gaps - there is a fixed on-voltage drop (not the breakdown
> voltage) across each one. Quenching is believed to be better but I'm not
> convinced that offsets the greater losses.
>
> Nothing has been said about the airflow through your gap, and that is VERY
> important. Just having a fan nearby wafting air in the general vicinity of
> the gap does very little - you need the air focused in the very small area
> that is arcing, particularly in high power static gaps. For this reason, a
> sucker-gap is very good (mine is at
> http://www.laushaus.com/tesla/onegap.htm,
> many others can be found by Googling "sucker gap"). Sucker gaps are also
> very easy to adjust. You DO set your gap by determining at which point it
> will just begin to arc with only the NST output (no caps) applied, right?
> ;-)
>
> Regards, Gary Lau
> MA, USA
>
> On Tue, Apr 7, 2015 at 1:34 PM, Timothy Gilmore <tdg8934@xxxxxxxxx> wrote:
>
> > David,
> >
> > Luckily I have 3-4 pairs of Tungsten rods but unfortunately only a 2
> pairs
> > of 3" high insulators. I'll have to see if I can find something like wood
> > to temporarily mount them too. I'm assuming the more you have the closer
> > they should be to have an over all gap of about 1/4" (i.e. 4 pairs should
> > have 1/16" gap each to make an overall 1/4" gap total).
> >
> > But first I'll try the 2 I have in "series" set to 1/8" gap each and see
> if
> > there is any significant improvement in spark length.
> >
> > I am moving in a couple of weeks so I wont be able to try it for a 2-3
> > weeks though.
> >
> > Thanks,
> >
> > Tim
> >
> > On Tue, Apr 7, 2015 at 10:22 AM, David <zipo@xxxxxxxxxxx> wrote:
> >
> > > Tim - It wouldn't hurt to try them in series, maybe even 3 or 4 gaps in
> > > series and then adjust the total gap for best running. I believe you
> > trying
> > > and experimenting will tell you a hole lot and be very worthwhile.
> > Without
> > > some sort of elaborate ballasting it has been shown that two sparks in
> > > parallel can't happen, as soon as one gap fires the other gap goes to
> > zero
> > > volts. And please let us know how the experiments go.
> > >
> > > to find the best answer you have to eliminate all of the bad answers
> > first.
> > >
> > >
> > > David
> > >
> > > On 4/7/2015 10:39 AM, Timothy Gilmore wrote:
> > >
> > >> David,
> > >>
> > >> When I bought the tungsten spark gaps and fan I received this email:
> > >>
> > >> *Most folks use them in series and reduce the gap width on each one.
> For
> > >> example for a 1/4 inch gap (a good place to start) they use two gaps
> in
> > >> series set a 1/8". I have had excellent results using them in
> parallel.
> > >> For
> > >> the amount of current you are using I would use two gaps in parallel
> > both
> > >> set at 1/4 inch. It works great and is easier to line up with the
> fan.*
> > >>
> > >>
> > >> Should I be using them at 1/8" gaps in serial then?
> > >>
> > >> Tim
> > >>
> > >> On Tue, Apr 7, 2015 at 8:26 AM, David <zipo@xxxxxxxxxxx> wrote:
> > >>
> > >> Tim - Here is my take on spark gaps. First you say you have two gaps
> in
> > >>> parallel, not series but parallel? Only one spark at a time can
> happen
> > >>> in a
> > >>> parallel gap set up, maybe it will switch back and forth from one to
> > the
> > >>> other but only one at a time. A single gap can provide the least
> > >>> resistance
> > >>> and more current in the primary circuit but does not quench and
> control
> > >>> ring down very well. putting multiple gaps in Series seems to provide
> > an
> > >>> improvment in quenching and ring down control. To experiment with
> > series
> > >>> multiple gaps would seem to be a logical next step, two, four, maybe
> > even
> > >>> six gaps in series. A lot of people have had good results with the
> > >>> Richard
> > >>> Quick multi gap and is not to difficult to construct. The next step
> up
> > >>> would be a sucker gap, a lot of people like these and they give real
> > good
> > >>> results, there are examples on the net. But I believe the best and
> most
> > >>> difficult is the Sync Rotary gap. my recommendation would be to
> > >>> experiment
> > >>> with the progression of gaps above but keep an eye to words the sync
> > >>> Rotary. Some thing I wish more people would do too, is cover your
> spark
> > >>> gap, put a largish box over it to block the light from it and to
> quiet
> > it
> > >>> down a bit, doesn't have to be fancy, just a simple wooden box placed
> > >>> over
> > >>> it wile your running. Nasty gasses build up inside but for the length
> > of
> > >>> time most of us run our coil it will be ok. For a 15kv NST the max
> > >>> voltage
> > >>> it can handle is about 25kv +- a bit peak, so you want the largest
> cap
> > >>> you
> > >>> can charge to 25kv. The Geek group capacitor chart is very good at
> > >>> appropriate cap values for a type of setup/gap being used.
> > >>>
> > >>> Thanks
> > >>> David
> > >>>
> > >>> On 4/7/2015 8:00 AM, Timothy Gilmore wrote:
> > >>>
> > >>> David,
> > >>>>
> > >>>> 72" WOW as I have similar specs but only get 36-48" or so.
> > >>>>
> > >>>>
> > >>>> Here are my specs:
> > >>>> 15kv, 120ma <-- Same (2 15kv 60mA NSTs)
> > >>>>
> > >>>> 3 levels of 0.010uf in parallel for 0.030uf mmc (30kv) <--- Seems
> > >>>> like
> > >>>> your double of what mine is
> > >>>>
> > >>>> 2 parallel tungsten gaps "about" 1/4" separation each (with a
> squirrel
> > >>>> cage
> > >>>> fan blowing on them) <--- *Should these be tighter since there
> are 2
> > >>>> of
> > >>>> them? (i.e. 1/8" inch each)*
> > >>>>
> > >>>> Secondary - 6"dia x 31"lg 1400 turns No. 24
> > >>>>
> > >>>> Top load - 6" x 25" aluminum dryer ducting and foil pizza pans with
> > foil
> > >>>> wrapped cardboard between and nylon toilet bolt <-- NOT wrapped in
> > 3"
> > >>>> aluminum tape
> > >>>> (Would wrapping this improve the length significantly). I have the
> > >>>> materials for an 8" aluminum dryer ducting, aluminum tape, 17.75" x
> 1"
> > >>>> circular wood table (to be wrapped in foil and then glued and
> possibly
> > >>>> aluminum taped). *Should I just wrap the 6" more flimsy version or
> go
> > >>>> with
> > >>>> the bigger 8" more solid heavier version (to construct) - OR use
> both
> > on
> > >>>> top (wrapped/unwrapped in aluminum tape)?*
> > >>>>
> > >>>> Primary 0.25" copper refrigerator coil in single layer tapped at
> 12.5
> > >>>> turns
> > >>>>
> > >>>> I was thinking of the rotary gap motor version for the spark gap but
> > >>>> have
> > >>>> no idea where to even start on this. I was hoping to get everything
> > the
> > >>>> best I could first before and if I go down that route.
> > >>>>
> > >>>> *So what has the greatest impact on spark length - the rotary spark
> > gap
> > >>>> or
> > >>>> the wrapped aluminum tape on the toroid - or are both necessary?*
> > >>>>
> > >>>>
> > >>>> Thoughts?
> > >>>>
> > >>>> Tim
> > >>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>> On Mon, Apr 6, 2015 at 8:56 PM, David <zipo@xxxxxxxxxxx> wrote:
> > >>>>
> > >>>> Timothy, List - I too have recently put together a 15kv, 120ma
> coil.
> > >>>> I'm
> > >>>>
> > >>>>> still tweaking for best out put. So far I'm getting 72" output and
> > >>>>> based
> > >>>>> on
> > >>>>> the way it was running and the way it was tuned I believe it will
> do
> > at
> > >>>>> least 80" after it's fully peaked. I can only run outside so I'm
> > having
> > >>>>> to
> > >>>>> wait for good weather.
> > >>>>> Here is a brief over view:
> > >>>>> 15kv, 120ma
> > >>>>> .0625uf mmc
> > >>>>> sync rotary gap @ 120 breaks/sec
> > >>>>> secondary - 7"dia x 27.3"lg 1500 turns No.26 wire
> > >>>>> Top load - 5" x 20" spun aluminum toroid
> > >>>>> primary - 10 turn 2 layer spiral
> > >>>>> Tesla equi drive circuit.
> > >>>>>
> > >>>>> There are two aspects of tuning and peaking that seem not to get
> the
> > >>>>> attention that they should (in my opinion).
> > >>>>> First is that if tuning with a signal generator and a oscilloscope
> > you
> > >>>>> need to simulate the added capacitance of the spark. Adding a piece
> > of
> > >>>>> wire
> > >>>>> the length of the spark your expecting to the top load and then
> tune
> > >>>>> with
> > >>>>> sig gen and o scope. This seems to be overlooked a lot. Java TC
> shows
> > >>>>> this
> > >>>>> very well. If you ad an additional cylindrical top load, on JTC,
> > >>>>> .02dia x
> > >>>>> length of spark (JTC will point it straight up) you will see a
> marked
> > >>>>> reduction in res. frequency.
> > >>>>> Second is that the safty gap or static gap width has a large impact
> > on
> > >>>>> output. There are way of setting these gap for safest operation.
> > >>>>> However
> > >>>>> I'm guessing these gap widths get pushed a bit by savvy coilers but
> > >>>>> don't
> > >>>>> talk about it. At least on a sync rotary safety gap width has a big
> > >>>>> bearing
> > >>>>> on output. I would find it very interesting to hear what gap width
> > >>>>> people
> > >>>>> are using with what setup. And in full disclosure :) I have set
> both
> > >>>>> of
> > >>>>> my
> > >>>>> safety gaps at .22 using rounded brass draw pulls for electrodes.
> > >>>>> It just seems to take a lot of time to get every thing tweaked to
> > >>>>> Perfection.
> > >>>>>
> > >>>>> Carry on
> > >>>>> David
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>> On 4/6/2015 9:34 AM, Timothy Gilmore wrote:
> > >>>>>
> > >>>>> Has anyone put together any sort of a listing of others Tesla
> Coils
> > >>>>>
> > >>>>>> built
> > >>>>>> with parameters listed such as:
> > >>>>>>
> > >>>>>> (for example): I have 2 NSTs (15kv, 60ma) each, 6" diameter, 31"
> > high
> > >>>>>> secondary, torroid is ....
> > >>>>>>
> > >>>>>> I am getting 3-4' sparks and wondering if I should be getting
> longer
> > >>>>>> sparks. Is this normal? or should I add another NST or bigger
> Toroid
> > >>>>>> (working on an 8" diameter ducting bigger one). How do I know
> since
> > >>>>>> the
> > >>>>>> Tesla Map software says I should get "ideally" 72.6 inch sparks
> and
> > >>>>>> I'm
> > >>>>>> getting about 1/2 to 2/3 of that. Just wondering if it's not tuned
> > >>>>>> properly
> > >>>>>> (but I think it is) - or making a larger toroid is worth the
> effort
> > if
> > >>>>>> I'll
> > >>>>>> gain a foot or more sparks.
> > >>>>>>
> > >>>>>> How does one know they are getting close to the best they can get
> in
> > >>>>>> spark
> > >>>>>> length?
> > >>>>>>
> > >>>>>> I have attached my Tesla Map file of current settings.
> > >>>>>>
> > >>>>>> Thanks,
> > >>>>>>
> > >>>>>> Tim
> > >>>>>> _______________________________________________
> > >>>>>> Tesla mailing list
> > >>>>>> Tesla@xxxxxxxxxx
> > >>>>>> http://www.pupman.com/mailman/listinfo/tesla
> > >>>>>>
> > >>>>>>
> > >>>>>> _______________________________________________
> > >>>>>>
> > >>>>> Tesla mailing list
> > >>>>> Tesla@xxxxxxxxxx
> > >>>>> http://www.pupman.com/mailman/listinfo/tesla
> > >>>>>
> > >>>>> _______________________________________________
> > >>>>>
> > >>>> Tesla mailing list
> > >>>> Tesla@xxxxxxxxxx
> > >>>> http://www.pupman.com/mailman/listinfo/tesla
> > >>>>
> > >>>>
> > >>>> _______________________________________________
> > >>> Tesla mailing list
> > >>> Tesla@xxxxxxxxxx
> > >>> http://www.pupman.com/mailman/listinfo/tesla
> > >>>
> > >>> _______________________________________________
> > >> Tesla mailing list
> > >> Tesla@xxxxxxxxxx
> > >> http://www.pupman.com/mailman/listinfo/tesla
> > >>
> > >
> > > _______________________________________________
> > > Tesla mailing list
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> > > http://www.pupman.com/mailman/listinfo/tesla
> > >
> > _______________________________________________
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> >
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