Re: Where do I get a couple Caps

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

Original poster: Tom Wideman <twidem01-at-baker.edu> 

does that 31nF include the capacitance of the discharge
terminal?

---- Original message ----
 >Date: Fri, 23 Apr 2004 21:12:56 -0600
 >From: "Tesla list" <tesla-at-pupman-dot-com>
 >Subject: Re: Where do I get a couple Caps
 >To: tesla-at-pupman-dot-com
 >
 >Original poster: Terry Fritz
<teslalist-at-twfpowerelectronics-dot-com>
 >
 >Hi,
 >
 >There are a ton of formulas at:
 >
 >http://home.earthlink-dot-net/~electronxlc/formulas.html
 >
 >In your equation below, you want to use XC not XL
 >
 >So:
 >
 >4000/.03=133333.33333Ohms Which is total resistance
 >
 >including capacitance. r=XC   XC=1/ (2pi(60Hz)C)
 >
 >133333 = 1 / ( 2 x pi x 60 x C)
 >
 >C = 19.8944 nF
 >
 >So you got it right anyway ;-))
 >
 >If you want to run LTR, which I highly recommend, you can
increase the
 >capacitor size by pi / 2 which gives 31.25nF.
 >
 >Cheers,
 >
 >         Terry
 >
 >At 09:42 AM 4/23/2004, you wrote:
 >>Ok. I get what you're saying. I am BISE student going for
an
 >>EET. So the math is nothing new. Nor is the electronic
 >>stuff. I just am new to tesla coils. So I don't know what
 >>formulas to use and so on. I am building my coil based off
 >>of Dan's MiniKatz coil.  He said he wanted to upgrade his
 >>MMC from .0112uF to .0224uF. So I just desided to start out
 >>with that.  I used .024uF in the calculator at "Classic
 >>Tesla." So first question.  Is that accurate? Does the calc
 >>work? And now that I know that little formula I feel smart!
 >>
 >>SO:
 >>
 >>4000/.03=133333.33333Ohms Which is total resistance
 >>including capacitance. r=XL^-1 XL=2pi(60Hz)L
 >>
 >>L=19.89nF
 >>
 >>L pi/2= 31.23nF
 >>
 >>OK.  BUT CAN ANYONE OUT THERE CHECK OUR MATH (Thank God for
 >>the TI-89)?? lol
 >>
 >>Thanks for your help.
 >>Nano2e
 >>
 >>
 >>
 >>---- Original message ----
 >> >Date: Thu, 22 Apr 2004 17:19:59 -0600
 >> >From: "Tesla list" <tesla-at-pupman-dot-com>
 >> >Subject: Re: Where do I get a couple Caps
 >> >To: tesla-at-pupman-dot-com
 >> >
 >> >Original poster: Terry Fritz
 >><teslalist-at-twfpowerelectronics-dot-com>
 >> >
 >> >Hi,
 >> >
 >> >Sort of.  With a 4000V NST you want 6000 volts across the
 >>caps.  In the
 >> >Tesla coil case, we can use the DC ratings.  So four
 >>942C20P1K in series
 >> >will give 8000 volts at 0.025uF.  When you put the caps
in
 >>series, the
 >> >voltages add up and the capacitance value divides by the
 >>number of
 >> >caps.  It is nice to get the 0.15 or 0.10 caps from the
 >>geek group since
 >> >they sell in small quantity.  Jim also had a suggesting
 >>using caps from
 >> >DigiKey.  I am not sure how familiar your are with all
this
 >>so let us know
 >> >if it is not clear.  We never know if noobs are plumbers
or
 >>Ph.Ds in
 >> >electrical engineering till we get to know you ;-))
 >> >
 >> >Are you sure 0.025uF is the value you need?  I would
think
 >>you would want
 >> >an "LTR" size.  What kind (static or sync) spark gap do
you
 >>want to use
 >> >(probably static)?
 >> >
 >> >4000 / 0.03 = 133333 ohms = 1 / (2 x pi x f x C)
 >> >
 >> >If f = 60Hz...  Then C = 19.56nF
 >> >
 >> >LTR (static gap) = 19.56 x pi / 2 = 0.0307uF...
 >> >
 >> >I would think that you would want 0.0307uF if you are
using
 >>a static gap
 >> >and your line frequency is 60Hz?  Of course, I may have
 >>messed up the math
 >> >'as usual' too ;o))
 >> >
 >> >Cheers,
 >> >
 >> >         Terry
 >> >
 >> >
 >> >At 01:35 PM 4/22/2004, you wrote:
 >> >>So is this the kind i want?
 >> >>
 >> >>http://www.cornell-dubilier-dot-com/film/9422000.htm
 >> >>
 >> >>(Part #:942C20S22K (3 one down))
 >> >>
 >> >>Nano2e
 >> >>
 >> >>
 >> >>---- Original message ----
 >> >> >Date: Thu, 22 Apr 2004 12:08:26 -0600
 >> >> >From: "Tesla list" <tesla-at-pupman-dot-com>
 >> >> >Subject: Re: Where do I get a couple Caps
 >> >> >To: tesla-at-pupman-dot-com
 >> >> >
 >> >> >Original poster: Terry Fritz
 >> >><teslalist-at-twfpowerelectronics-dot-com>
 >> >> >
 >> >> >Hi,
 >> >> >
 >> >> >Look here:
 >> >> >
 >> >> >http://www.thegeekgroup-dot-org/mmc/
 >> >> >
 >> >> >You could use six of the 0.15uF or four of the 0.10
uF.
 >> >> >
 >> >> >Cheers,
 >> >> >
 >> >> >         Terry
 >> >> >
 >> >> >
 >> >> >At 10:04 AM 4/22/2004, you wrote:
 >> >> >>Hey..I am looking for a total .024 uF in my MMC (did
I
 >>say
 >> >> >>that right (NOOB!)) What should the rated voltage be
if
 >>I
 >> >>am
 >> >> >>using a 4000V 30mA NST? What kind should they be (I
am
 >> >> >>looking at Metallized Polypropylene)? And where can I
 >>get
 >> >> >>just a few?
 >> >> >>
 >> >> >>Nano2e
 >> >> >
 >> >> >
 >> >
 >> >
 >
 >
Your Brother in Christ,
Tom