Pa=KE
5
Pa Stands for the power the heated
adsorbed
the microwave
K Stands for a constant
E Stands for the
frequency.
f Stands for the microwave
tg 6 Stands for
tangent of the heated matter.
Er Stands for relative dielectric constant of the heated matter.
Voltage
220V
2
THE STRUCTURE AND
OF
Microwave oven can be classified to
kinds
according to
volume and control
function. But anyhow, the
electric
composed of high voltage
cooling system.
Microwave generator, electric control system and heating
chamber
working process
as follows:
220V power frequency voltage transferred to the rectifier
through electric control
and then be changed to
4000V direct volt-age by the rectifier, and be then
transferred to the microwave generator, the generator
stars working to transfer the microwave energy to the
heating chamber for heating food through wave guide
At the same time, the electric control system set off
the cooling system to
the working rectifier and the
microwave generator to keep the oven working steadily
from a too high temperaturę. something wrong with the
cooling system cause the temperaturę too high, the control system would cut off the power automatically to
prevent microwave generator being damaged form the high temperaturę.
we'd
to introduce the working
principle of each
of the widely used model, mechanical control and touch control microwave oven.
2,1 HIGH
At present,
use microwave oven adopt this high voltage
circuit as shown at diagram 2-2.The
circuit is a single phase, semi-wave, double voltage rectifying circuit. The circuit has
a high voltage capacitor,
a high voltage diodę, a magnetic leakage transformer besides the magnetron, is
simple.
The working principle of the circuit: 220V power boosted through the transformer, output about 2000V alternating
high voltage current when the high voltage winding is at the positive half-circle, the high voltage winding is at the
negative
the diodę is cut off and the magnetron is conducted. The
charged at the positive
half-circle of the capacitor is series connected with the positive phase of the winding
and got a doubled,
about 4000V direct high voltage, then transferred to
the cathode and the anodę of the magnetron.
Control
220V
Fig. 2-2
Fig. 2-3
