The magnetron is the heart of the microwave
oven.
With the help of transformer, rectifier and
magnetic field, it converts the 230 Volt-50 Hz
into microwave energy with the frequency of
2,450 MHz.
The magnetron consists of following parts:
Main body with anode (positive) and cathode
(negative), cooling ribs, permanent magnet,
connections for heating and high voltage as
well as antenna, in order to radiate the
microwave energy.
The inner cylinder is heating element and
cathode at the same time.
The outer cylinder is the anode block with
the resonant chambers.
Due to the big difference in potential between
anode and cathode, the electrodes are
moving from the inner to the outer cylinder.
The magnetron requires a high DC voltage (4,000 Volt), a low AC
voltage for the heating of cathodes and a magnetic field to be able
to work.
The cathode is heated in order to cause the electrons emitting, so
that they will flow to the anode.
In order to achieve the oscillation, one needs a permanent
magnet. Because of its magnetic field, the electrons are moving
in an orbit round the cathode, instead of flowing in a straight line
from the cathode to the anode.
In this connection, the electrons are passing the resonant
chambers and produce oscillations.
These resonant chambers are specially formed. Within the high-
voltage frequency range they have a capacitive and even inductive
effect. They also determine the produced microwave frequency.
These oscillations are then guided via the antenna into the oven.
Magnetron
created by TSE-N, Reiner Kurzke
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