Re: First Light!!! Now, how to tune it?

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Pete,

At 10:42 PM 5/12/2001 -0400, you wrote:
>Tesla list wrote:
>> 
>> Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
>> 
>> 15/180 resonant size is 31.83nF and LTR is 45nF.  With 60nF I think you
>> will hit a 60Hz charge BPS which probably is not too bad.  You should use
>> input line fuses to each transformer.  With such a large cap, the shunts
>> may saturate and it could draw a lot of current.  Maybe a 15 amp fuse per
>> NST.  However, this is far less a problem with a static gap design.  You
>> should consider getting one more 15/60 NST :-))  You may also want to add
>> about 150uF of power factor correction to each NST.  That will drop the
>> current to each NST about 6 amps for a total of 18 amps less current draw
>> which is a big deal in this case.
>
>Can you recommend a particular PFC cap?  Maybe something from digikey?

A number of people have mentioned surplus ones for a very good price.  I
use 20uF ones from DigiKey but they are like $6 each.  Good for
experimental work to get any value but too expensive considering they can
be had in large values for a few dollars on the surplus market.  I forget
the places that have them right off but look in the archives.

>
>I did pop the house line breaker a couple of times.  Is this a serious
>problem?  If so, I'll put fuses on the NST's.  Can breakers be used
>instead of fuses, if only so as not to have to replace fuses?

Breakers are fine.  The PFC caps may help prevent the house circuit
breakers from tripping.

>
>
>> >Toroid: 6" aluminum dryer duct wrapped around an 8" diameter disk
>> >(actually two aluminum pie
>> >pans).  Used a thumbtack as a breakout point, but there were streamers
>> >coming out all over (is that a good sign?).
>> 
>> 6 inch cord with 14 inch center to center spacing...
>> 
>> >Toroid?  Does it need to be bigger?  How big?
>> 
>> It does strike me as small for 2700 Watts input.  You will get smaller
>> multiple streamers instead of a longer single streamer.  But that is cool
>> too so what ever you like.
>
>I'll probably make another, maybe a double toroid.  The pie pans work
>real well - very easy construction - but they only come so big.

Get Pizza pans from K-Mart or whatever.  Mine are 16 inches in diameter.
The stainless steel ones are cheaper than the aluminum ones here.

>
>Another question:  I have my NST's mounted on a cart, and they sit
>alongside the coil during operation.  Should I be concerned about
>strikes to the power supply?  I thought about putting some grounded
>chicken wire over the supply to catch strikes; would that help?

Streamers don't have a lot of current but it is hard to say.  I have done
fault studies that suggest there is little danger but a grounded wire sure
seems like a great idea.

Cheers,

	Terry


>
>Thanks again for the help.
>
>	- Bill Vanyo
>