[Prev][Next][Index][Thread]

Re: Capacitor construction?

Hi David,

	Your primary cap "could" be as large as 10nF with that transformer which
would give out more output.  Perhaps not a big deal for now.

	Your primary might have to be 9.5 to 10.5 turns for your system so I would
invest in adding those extra turns.  Better too many than too few.

	Black plastic is best avoided but give it a try since you have tons on hand.

	You toroid should be fine for now.

	Your secondary seems pretty short to me but give it a try.

	Set the spark and saftey gaps pretty small at first.  Better safe than
sorry.  If you have a variac it is much easier to control things.  If not,
stay very conservative.  I live at 5500 feet so I can't really suggest gap
widths well.  Others will probably suggest these.  I would go for 1/8" main
and 1/4" safety at first.  This will get things started fairly safely.

	Terry


At 04:16 PM 11/8/98 -0600, you wrote:
>    Greetings!   I recently obtained a  12kv 30ma NST to use for my TC.
>Before I started  putting things together I wanted to post the specs I am 
>currently planning on using, to see if anyone notices any obvious  problems
>or miscalculations.   Here are the  details:          12kV 30mA  NST (no
>power factor correction)             "" id, 8 turns           ""  " wire
>(75% spacing?)        660kHz (currently no top  capacitance)    ""od, ~3pF
>(drops frequency to about 530kHz)             (Until I have a  toroid)     
>               90 mil poly (20 layers 4.5 mil stock)                    
>13kV rating             (After I get the  toroid)                     90
>mil poly(20 layers 4.5 mil stock)                      13kv rating         
> ""(x2) steel  ground rod, ends ground flat                     spacing
>unknown            dunno yet     Questions:   On the primary I only have 8
>turns, I have  enough tubing for a few more, shall I go ahead and  (just
>have to buy some new wood to mount it  on).   For the tank cap I only have
>some 4.5 mil black  construciton type plastic   I figured a  voltage rating
>of 450v/mil, with 20 layers to get to 90 mils (and help to protect
>defects),  and a voltage rating safty factor of 3 would give me a cap that
>could  handle about 13kV total. Six plates should give me about 0.0029uF,
>and later, after I  get the toroid I can add three more plates to get to 
>0.0046uF. Anybody see any problems with this? When I have some money I may
>buy some clear  plastic, but for now I'm stuck with this stuff.   There is
>a web page out there somewhere that offers smooth  copper spheres up to
>several inches in diameter for pretty reasonable  prices. I can make a
>toroid up to about 8 inches in diameter, but its  surface   Which would be 
>a better option for this size coil?   What should I set the spark gap to
>initally?   What should I set the safty gap to?   Thanks!   David Knaack