Re: High voltage standing waves with a magnetron?

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

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

I keep reading this post and wonder why you dont just use a PFN (pulse
forming netwotk) and a SCR like a thyratron and build a circuit like a
radar. No the peak power would not change , but the avarage power would be
very low and the tube would function normaly for a controled pulse time. The
PFN would be just 1 diode, 3 capacitors, and 2 toroid coils about 1-2 cu
inches in size to produce 6-12 uS of pulse power.
       A second point; the frequency is 14 CM to heat organic bonds and it
dose not evaporate water. The H-OH bond is 28 Cm and that wavelength would
evaporate water with out heating it. The second harmonis frequency heats /
cooks the organic H-OH bond  like in your eyes and skin so use due caution
and control the radiation patern in a safe direction away from you. The
frequency is chosen for best cooking use, so don't get fried. YOU ARE
ORGANIC     !!!!!!!!!!!!!!!
       Robert   H
-- 


 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > Date: Thu, 05 Feb 2004 18:07:10 -0700
 > To: tesla-at-pupman-dot-com
 > Subject: RE: High voltage standing waves with a magnetron?
 > Resent-From: tesla-at-pupman-dot-com
 > Resent-Date: Thu, 5 Feb 2004 18:57:46 -0700
 >
 > Original poster: "Philip Chalk" <phil-at-apsecurity-dot-com.au>
 >
 > Simple enough - just a series resistor!  Note that the magnetron
 > volt/ampere curve is not like a Zener diode (battery in series with a
 > low-resistance diode, but that it also has a series resistance. I
 > couldn't find an oven magnetron characteristic data sheet in a Google
 > search but came up with a lot of hits on non-oven uses, primarily ham
 > radio.
 >
 > Ed.
 >
 >
 > Hi Ed, all,
 >
 > Granted, but it would have shocking regulation.  In order to limit the
 > current to the extent required, (using the normal MWO supply) most of
 > the voltage would appear across the resistor, & it would need to
 > dissipate several hundred watts.
 >
 > [Clang -another late-nighter]
 >
 > Sorry, that's wrong.  To limit 4kV DC to 1mA (into a short circuit)
 > would dictate 4M Ohm. It would dissipate 4W. Horrendously inefficient
 > anyway - not that it matters.
 > However, as soon as the tube started drawing current (I agree it would
 > drop out of oscillation & behave as a diode at some lower threshold
 > voltage.), the bulk of the voltage would appear across the resistor; its
 > apparent resistance would be way below 4M resistor. So it wouldn't make
 > a practical oscillator.
 >
 >
 > I was thinking more along the lines of a voltage & current regulated
 > supply, or the normal MWO supply followed by a current regulator, or
 > constant-current source.  Your series resistor approximates a constant
 > current source, but with awful voltage regulation.
 >
 > Phil Chalk.
 >
 >