🚀 go-pugleaf

In article <1ii7fgINNh20@shelley.u.washington.edu> whit@carson.u.washington.edu (John Whitmore) writes:
>In article <1993Jan7.005550.6869@kodak.kodak.com> ornitz@kodak.kodak.com (Barry x24904/ER/167B-TED) writes:
>	
>	In the context of the original question (lowering the power
>density in the microwave oven), this is irrelevant.  First, the
>load is the contents of the microwave oven (and this can, we all know,
>vary quite a lot without stalling the oven).  Second, we don't
>care about the exact frequency (nor the exact power); only large 
>power-output changes are of interest.

Most of the higher class microwave ovens I have seen vary the (time)
average power output by varying the duty cycle of the magnetron.

Older ones do this on ten-second time scale (power knob changes the
duty cycle between 1 and 10 seconds out of every 10).  Newer ones
with electronic controls seem to change the duty cycle on about a
1/4 second time scale.  Maybe this would be helpful, depending on
the thermal time constant of your plasma etching process.

-- 
        carl lowenstein         marine physical lab     u.c. san diego
        {decvax|ucbvax} !ucsd!mpl!cdl                 cdl@mpl.ucsd.edu
                                                  clowenstein@ucsd.edu