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



Original poster: robert & june heidlebaugh <rheidlebaugh-at-desertgate-dot-com> 

The 555 timing circuit is low power and easly altered by stray signals. May
I suggest some older technology using the unijunction timimg circuit. This
can provide over 22 volts of signal and 500 ma of current  with good
stability using few compoments.
    Robert   H
-- 


 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > Date: Tue, 27 Jan 2004 07:54:15 -0700
 > To: tesla-at-pupman-dot-com
 > Subject: Re: SSTC problems1 (no its not a PlasmaSonic ;-))
 > Resent-From: tesla-at-pupman-dot-com
 > Resent-Date: Tue, 27 Jan 2004 08:02:32 -0700
 >
 > 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
 >
 > --
 > ****************************************************
 > Helsinki University of Technology
 > Dept. of Electrical and Communications Engineering
 > http://www.hut.fi/~jwagner/ - jwagner-at-cc.hut.fi
 >
 >