John,
I agree with you, but this being a magnifier with a lot of coupling demands
more attention to quenching that a two coil system.
~Dan
Kansas city area
On Wed, Jan 29, 2020 at 6:30 PM Futuret via Tesla <tesla@xxxxxxxxxx> wrote:
> I agree that 3.5 HP seems like overkill. I also agree that the rotary
> gap alone should be sufficient for excellent quenching. I don't think
> that the concept of over-quenching exists. I think that what is often
> referred to as over-quenching is simply that the voltage is having trouble
> firing across so many series and rotary gap electrodes, causing the firing
> to become sporadic and unsteady. I define quenching as something that
> occurs after the gap actually fires. Quenching depends more on the energy
> being drawn out of the system by being burned up in the output spark
> streamers. Basically quenching takes care of itself as long as the
> electrodes don't overheat. I define quenching as something that occurs
> after the gap actually fires. I agree that an excess number of series gaps
> just wastes energy, even if the coil manages to run smoothly.
> John
>
>
> -----Original Message-----
> From: David Rieben <drieben@xxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Wed, Jan 29, 2020 6:32 pm
> Subject: Re: [TCML] "Modern" Spark Gap Designs?
>
> 3.5 hp DC motor? Unless you already have this motor in your possession,
> that seems rather large for turning the rotary gap assembly of a <10 kVA SG
> coil. I believe my DC treadmill duty motor is rated up to 2.5 hp and it is
> PLENTY of motor for turning my 12” x 1/2” G-10 rotor with its (8) 3/8” dia.
> X 2” long tungsten flying electrodes. Each of the tungsten flying
> electrodes also have a 3/8” aluminum shaft collar on each side of the disc,
> so there is a total of 16 of those shaft collars that are being flung
> around, too. They help to secure the flying electrodes in place on the disc
> as well as assist in their cooling. I control the motor’s speed via a small
> panel mounted variac and a FWB rectifier to give infinite speed control of
> the ASYNCHRONOUS spark gap assembly.
>
> My stationary electrodes are (2) ea. 1/2” dia. X 3” long solid tungsten
> rods that are each simply mounted in 1 1/4” brass square stock that is
> about 2” long, and is also mounted against a 1/8” thick x 4” diameter brass
> disc, to help dissipate the heat, and is mounted against a lexan frame
> housing.
>
> I have found that this provides all of the quenching that I need and I run
> my coil at power levels that often exceed 15 kVA and can approach 20 kVA!
> From my experience, it seems that you can get to a point where you may
> actually over quench the gap when you start stacking multiple series spark
> gaps. I think someone has pointed out that each spark gap typically drops
> several hundred volts, so if you have a whole bunch of seriesed gaps,
> you’re gonna be losing some significant power in your gaps, too.
>
> Finally, Gary is correct about the PVC deteriorating in the presence of
> the strong UV that is given off by the spark gap. It will turn a dingy
> yellowish-brown and loose it’s mechanical integrity and also become
> somewhat conductive. I ended up having to wrap the 2” PVC support pillars
> of my primary circuit assembly with aluminum duct tape to reflect away and
> protect their surfaces from the intense UV of the spark gap.
>
> Hope this helps,
> David
>
> Sent from my iPhone
>
> > On Jan 29, 2020, at 12:03 PM, Daniel Kunkel <dankunkel@xxxxxxxxx> wrote:
> >
> > Hello Tesla List!
> > I am starting to work on my next spark gap for a 6-10 KVA magnifier. It
> > seems the definitive spark gap design is that from Richard Hull/TCBOR
> using
> > a rotary gap (to control timing only) combined with a multiple break
> series
> > gap (to control quench only). Is there a better approach for gap design
> and
> > construction?
> >
> > Currently my plan is to use a 3.5 HP DC motor to spin a G10 disk with
> > tungsten electrodes and combine it with the PVC + copper tubes + fan
> series
> > gap.
> >
> > Thanks,
> > ~Dan
> > Kansas City area
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxxxxxx
> > https://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla