Re: Tube Coils.

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

I agree.  I was running my SSTC today trying some audio modulation with
200VDC input at about 1.5kW and I was getting nasty burns from touching my
chassis controller which was about 10 feet away.  I mean real nasty.

60kW????  Being in the room with a thing running at that power would be the
same as touching your pole transformer primary voltage!  Downright extremely
hazardous.  Might as well
stand right in front of an open waveguide radiating the same power.

The Captain



 >
 > John brought up a very good point!
 > An animal like that belongs in a faraday cage!
 > The RF field that a CW coil at that power level would produce would be
very
 > dangerous. Mysterious fires could start in hidden places within the room,
 > and I would be very fearful about the high RF field damaging human tissue.
 > You may not feel the effects until it's too late.
 >
 > Sue
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Saturday, March 01, 2003 7:05 PM
 > Subject: Re: Tube Coils.
 >
 >
 >  > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > <FutureT-at-aol-dot-com>
 >  >
 >  > In a message dated 3/1/03 1:39:06 PM Eastern Standard Time,
 >  > tesla-at-pupman-dot-com writes:
 >  >
 >  > > >Original poster: "Paul Marshall by way of Terry Fritz
 >  > ><teslalist-at-qwest-dot-net>" <klugmann-at-hotmail-dot-com>
 >  > > >
 >  > > >I have a friend who recently aquired (2) 3CX10000 Tubes. He would
like
 > to
 >  > > >make a tube powered coil. Does anyone have a schematic I could give
him
 > ? I
 >  > > >think he is planning on winding a 6" or 8" diameter coil...
 >  > > >
 >  > > >Paul S. Marshall
 >  > >
 >  > >
 >  >
 >  >
 >  > Paul,
 >  >
 >  > Unless your friend has a lot of electrical power available, he may
 >  > want to use a pulsed (staccato) feature on the coil to reduce the
 >  > input power.  The size of the coil should depend on the desired
 >  > spark length.  I use the formula,
 >  >
 >  >     spark length inches = 0.49*sqrt input power
 >  >
 >  > for a tube coil.  So if 60kW input is used, the coil should give
 >  > 10 foot sparks.  If you figure you want the spark length to be
 >  > twice the height of the coil, then the secondary should be 5 feet tall.
 >  > I've obtained spark lengths up to almost 4 times the secondary
 >  > length on tube coils, but flashovers may be a problem.  Perhaps
 >  > 3 times the secondary length would be OK, making the secondary
 >  > about 3.3 feet tall.  Of course your friend could used just one tube,
 >  > or run the tube at less than its full capabilities, and keep the spark
 >  > length and power input lower.  If you want long sparks, then AC not
 >  > DC should be used for the plate supply.  Other than that you can
 >  > probably just scale up an existing tube coil schematic pretty much.
 >  >
 >  > If he wants to limit the secondary to 8" diameter, then a height of
 >  > 24" to 34" may be good, depending on the desired spark length.
 >  >
 >  > I wouldn't recommend being too close to the coil when it's running
 >  > if he uses the full capability of the tubes. It will be a fearsome
 >  > beast indeed !
 >  >
 >  > John
 >  >
 >
 >
 >
 >
 >