"msg" wrote in message
ernet...
Daniel Who Wants to Know wrote:

snip

Yes like my Amana commercial RadarRange which is 4KW in 2.2KW out and has
3 HV magnetrons along with 3 each of the other necessary items (cap,
diode, etc.).

Does this oven somehow injection-lock the magnetrons? Can you describe
the (RF) plumbing?

Michael

Each mag has its own waveguide with a rotating antenna at the end that
extends into the oven cavity. 2 of the waveguides are at the top of the
cavity firing down and the third is at the bottom firing up. The HV
transformer primaries are wired so that the top 2 mags fire on the positive
alternation of the AC sine wave and the bottom mag fires on the negative
alternation. The top 2 antennas are driven by a single timer motor with
large plastic gears (complete with timing marks) so that they both are
pointing the same direction at all times as they rotate. The HV
transformers have tapped primaries so that the oven can operate on either
208 or 230 volts with no change in output power. Also there is a small
208-230 volt boost autotransformer that boosts the voltage for the cavity
lamp, cooling blower, and antenna motors when the oven is plugged in to 208.
When the microwave is first plugged in it sits for about 30 seconds to (I
assume) to sense the supplied voltage and frequency so that it uses the
correct taps on the 4 transformers. Oh yeah when the oven is set for less
than 100% power the HV transformers are cycled on and off by 3 triacs (1
each) with arc snubbers across them and there is a relay that cuts the power
to the triac/transformer circuits when the oven is off. Each mag has 2
thermal cutouts, 3 cut off the power to the respective transformer primary
and the other 3 are wired in series and are connected to the logic board
which makes the vacuum fluorescent display show HOT and also causes the oven
to refuse to operate. There is also a thermal fuse in the oven cavity air
discharge duct.

I think I have provided WAY more info than anybody wanted or needed.