Re: High voltage standing waves with a magnetron?

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

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

"Hi,

Someone earlier suggested that the only way to stop the magnetron
drawing 'normal' current is to reduce the voltage a lot, which of course
kills the oscillation.

Frankly, I don't know enough about magnetrons to be authoritative, but I
would expect one to oscillate when fed from a current-limited supply of
the appropriate voltage.

I'm not suggesting it's simple, but it's certainly possible to build
such a supply."

	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.

	If I were going to play around I'd start with a 10k 10 watt resistor
in  series with the regular oven supply, measure the voltage across it
(and hence the current).  If the resistor blows because of too high
current increase it, etc.  I suspect it wouldn't take too much fiddling
with a box of resistors to find a combination which would let the thing
put out a watt or so, which should be good for a lot of experiments.

	Remember that tissue damage is due to thermal effects (heating), which
are a function of the exposure time and the amount of energy absorbed
during that time.  Runs of a few seconds at lower power should be safe
enough if you keep your wits about you.

Ed.