Re: blowing fuses: troubles with a new system

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

Original poster: "D.Wightman by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dwightman1-at-cox-dot-net>

Had the exact same problem with my system.
Replace the inductive phase controll with a rock solid manual one.
Anmd make sure your ground is good.
That will solve the problems, At least for my system it did.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, June 26, 2003 10:18 PM
Subject: blowing fuses: troubles with a new system


 > Original poster: "Steven Ward by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<srward16-at-hotmail-dot-com>
 >
 > HI everyone,
 >
 > its been awhile since ive built a spark gap coil (ive been doing VTTC and
 > SSTC work), so i put a new one together.  But im having problems in that
 > the coil appears to have terrible power factor!  Here are the specs:
 >
 > 15/120NST (was a France 15/60, but i removed shunts (left 12 leaves in
each
 > packet for a rough estimate of 120ma))
 >
 > 238uf of PFC (its too small, maybe my problem???)
 >
 > .045uf MMC (also a bit too small for the system)
 >
 > 120BPS sync gap
 >
 > 7.5" ID 23"OD flat primary, 14 turns 1/4" tube, tapped at 11.
 >
 > 6.3"OD x 24" winding of 24awg magnet wire for a secondary
 >
 > 4.5"x30" toroid.
 >
 > So far, ive been using the phase controller that John Freau has on his
site
 > (variable inductance and an extra capacitor with a small sync motor).  The
 > SRSG is similar to a Terry Blake setup, it uses a 7" tungsten rod with 4
 > electrodes spaced around it.  Would be similar to an 8" SRSG disc.
 >
 > Ok, so when i test with power, i can get up to about 50% input on the
 > variac, then the 20A fuse blows!  The coil puts out 3-4 feet of sparks at
 > that point.  Ive noticed that, as i turn up the power, i need to reset the
 > phase controller (lower the inductance) to keep the coil happy (otherwise
 > the safety fires, and the coil looses the synchronous tone).  Though, im
 > sure the motor is still spinning sync, since its fine at a lower
 > level.  Ok, so i get to about 50% and adjust the RSG for maximum output
 > (which is JUST before it starts to flash on the safety gap) and
 > watch.  Then the fuse blows.  It seems that, when i turn up the power
 > without adusting the phase controller, the SRSG pulses or surges, but i
 > dont know why.  Though John Freau told me this is common ( the need to
 > reset the phasing at higher powers).  I notice that if i adjust the
phasing
 > in the other direction, the sparks get shorter, and there is a wide area
of
 > settings that will work fine (and this does not seem to blow the fuse),
but
 > the spark output is MUCH weaker :o(  So does anyone have some advice for
me
 > besides get a bigger fuse??  (by the way, its it ever ok to put a 30A fuse
 > inplace of a 20 ;) ).
 > Im actually going to hire my uncle (electrician) to wire me my own power
 > box off of the mains with a 240V and high current 120V line, but that wont
 > be for a while.  So i need answers now!
 >
 > here are my thoughts on a possible solution. 1) put all of the shunts back
 > into the NST and run it at 60ma (though im sure the setup will pull much
 > more power out of it).  Im not sure how effective it would be with a
.045uf
 > cap.  I could run .030 uf i guess, but i want big sparks!  2) add more
PFC?
 > I think i really need like 450uf or something like that for this amount of
 > power. 3) whatever anyone else could suggest!!
 >
 > Thank you all in advance.
 >
 > Steve Ward.
 >
 >