Re: SSTC problems1 (no its not a PlasmaSonic ;-))

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

Original poster: Jan Wagner <jwagner-at-cc.hut.fi> 


On Mon, 26 Jan 2004, Tesla list wrote:
 > Original poster: "Jim Mitchell" <electrontube-at-sbcglobal-dot-net>
 >
 > I have ruled the problem out to be in the section that receives feedback
 > from the coil.  The reason the coil is running crappy is because the 555
 > timer is running it, instead of the feedback.  It seems the feedback doesn't
 > have enough "oomph" to kcik in and take over the 555.  So I removed the 555
 > and banged on the antenna with a screwdriver.  Neon bulb on the breakout
 > point flickered and I hear a 60hz hum in the GDT section, and thats it.  I
 > will try more filtering on the input and see if I can get it to run with out
 > the 555.

If you've a filter after the feedback antenna, don't! Filters just
attenuate or screw up the phase. (on the mains voltage side, a larger
smoothing cap is of course fine, but streamers will start looking
different)

Placement of the antenna is often surprisingly critical. You can try using
different lengths of wire (~20..40cm) and lying it out in different ways
e.g. on the desk/floor: towards coil, counterclockwise along coil,
clockwise, ... Or sticking up vertically, etc.

good luck,
  - Jan

--
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  Helsinki University of Technology
  Dept. of Electrical and Communications Engineering
  http://www.hut.fi/~jwagner/ - jwagner-at-cc.hut.fi