Re: Bleeder resistors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ben McMillen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <spoonman534-at-yahoo-dot-com>


Hi Terry, all,

>>After chugging out some equations I figured out that
> I'll
> >need a 410 meg bleeder for my .01uF 75kV transmitter
> cap.. 
> >
> >Does this sound right? I figured a max voltage of 75kV
> >because I wasn't srue what the max voltage on the cap
> would
> >be with a 15/30 resonant charging.. 
> 
> The maximum voltage should only get to around 21kV where
> the spark gap
> should fire.  The resonant size for a 15/30 is 0.0053uF. 
> A static gap LTR
> size is 0.008uF and a sync gap LTR is 0.0138uF.  Perhaps
> you have a 15/60?
> See chart at:
> 
> http://hot-streamer-dot-com/temp/MMCcapSales.gif
> 
> A 10uF cap will probably work in any case, just a little
> roughly.

No.. it's a 15/30.. I don't have any 60's.. I wish I did...
it looks like my cap will be smaller than LTR for my sync
rotary.. I guess I'll just have to try it and see how it
performs until I get my 6 MOT stack built.. (or get a
15/60)

> 
> >
> >With max 15kV, it takes 10 seconds to get down to 50V.
> Is
> >that right? If so, is the time constant long enough that
> it
> >doesen't interfere with the coil's operation?
> 
> It take this long for a cap to discharge across a
> resistor:
> 
> T = 5 x R x C
> 
> So   5 x 410e6 x 10e-9 = 20.5 seconds
> 
> The power dissipated is Vrms^2 / R  so  21000^2 / 410e6 =
> 1 watt total
> 
> I thing you could probably got down to 100 Meg  for 5
> seconds at 5 watts.

That sounds good to me.. Thanks for the help!!

> 
> Cheers,
> 
> 	Terry
> 
> 

Coiling In Pittsburgh
Ben McMillen