multiple magnetrons in bigger microwave oven
 

I am interested to know if more than one magnetron can be used with a
bigger cavity to enhance cooking more quantity of stuff..... relation
of cavity with magnetron's frequency/ power output etc.

-Harry

I once worked on a commercial Panasonic microwave oven, it ran on 220 vac
and had two complete maggies and two separate HV supplies. One maggie fed
into the bottom of the cavity and the other one fed the top as in a
conventional home oven. Both feeds had stirrers. Unfortunately, one of the
maggies was bad, and the cost of repair vs the age, cost of new oven, etc
etc was not favorable. We scrapped the oven, but I bet that momma would cook
like nobody's business! According to the nameplate, it had a 3600 watt
input/ 2100 watt output. It was used in a fast food joint to heat food just
before sale.
I always wondered how they kept those two maggies from cooking each other.
Regards,
Tom
"Rich.Andrews" wrote in message
. 1...
(T.J. Harry) wrote in
news:e6f7d414.0410021025.92c63a9
@posting.google.com:

I am interested to know if more than one magnetron can be used with a
bigger cavity to enhance cooking more quantity of stuff..... relation
of cavity with magnetron's frequency/ power output etc.

-Harry


I think you would have to make a waveguide multiplexer.

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

When using dual magnetrons, there has to be a consideration for their
phase correction. If there is any shared area of radiation, and if there
is any phase shift between them that is leading to being out of phase,
there will be some wasted energy. This would cause them to be
cancelling each other, rather than be summing their energy outputs to
the target, which is the food inside the microwave oven. The wasted
energy would be causing the magnetrons and the power supply to run
hotter, and thus become less efficient.

As for home use, when considering that these systems are working at
about 900 to 1200 Watts each, depending on the type and model, having 2
magnetrons would be a bit much.

--

Jerry G.
======

"t.hoehler" wrote in message
news:TuL7d.158766$MQ5.15304@attbi_s52...
I once worked on a commercial Panasonic microwave oven, it ran on 220
vac
and had two complete maggies and two separate HV supplies. One maggie
fed
into the bottom of the cavity and the other one fed the top as in a
conventional home oven. Both feeds had stirrers. Unfortunately, one of
the
maggies was bad, and the cost of repair vs the age, cost of new oven,
etc
etc was not favorable. We scrapped the oven, but I bet that momma would
cook
like nobody's business! According to the nameplate, it had a 3600 watt
input/ 2100 watt output. It was used in a fast food joint to heat food
just
before sale.
I always wondered how they kept those two maggies from cooking each
other.
Regards,
Tom
"Rich.Andrews" wrote in message
. 1...
(T.J. Harry) wrote in
news:e6f7d414.0410021025.92c63a9
@posting.google.com:

I am interested to know if more than one magnetron can be used with
a
bigger cavity to enhance cooking more quantity of stuff.....
relation
of cavity with magnetron's frequency/ power output etc.

-Harry


I think you would have to make a waveguide multiplexer.

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

"Jerry G." writes:

When using dual magnetrons, there has to be a consideration for their
phase correction. If there is any shared area of radiation, and if there
is any phase shift between them that is leading to being out of phase,
there will be some wasted energy. This would cause them to be
cancelling each other, rather than be summing their energy outputs to
the target, which is the food inside the microwave oven. The wasted
energy would be causing the magnetrons and the power supply to run
hotter, and thus become less efficient.

If they are not phase locked, then the power will add. On a short time
scale, there may be interference effects but they should average out.

I wonder if they deliberately make sure the frequencies aren't quite the
same?

If they phase lock to each other, then indeed care must be given to
interference, hot spots, reflected power damage, etc.

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Jerry G. wrote:
When using dual magnetrons, there has to be a consideration for their
phase correction.

Magnetrons will always phaselock to any signal that is back fed into them,
provided it is close to their own natural resonant frequency. So, the two
magnetrons will reach a compromise and oscillate, in phase, at some frequency
between their natural resonances.

-Chuck Harris

If there is any shared area of radiation, and if there
is any phase shift between them that is leading to being out of phase,
there will be some wasted energy. This would cause them to be
cancelling each other, rather than be summing their energy outputs to
the target, which is the food inside the microwave oven. The wasted
energy would be causing the magnetrons and the power supply to run
hotter, and thus become less efficient.

As for home use, when considering that these systems are working at
about 900 to 1200 Watts each, depending on the type and model, having 2
magnetrons would be a bit much.

T.J. Harry wrote:

I am interested to know if more than one magnetron can be used with a
bigger cavity to enhance cooking more quantity of stuff..... relation
of cavity with magnetron's frequency/ power output etc.

My microwave oven has two magnetrons. So apparently it is possible,
never bothered to figure out how they did it though.

--
Peter van Merkerk
peter.van.merkerk(at)dse.nl