off. When cooking, touch the starting switch to power the timer and the power relay.
RY2 closed the power
supply to the anodę of the magnetron and the filament, changing the power frequency electric energy to
microwave energy, the microwave energy then transferred to the heating chamber for food heating. At the same
the lamp turned on, the fan motor begins to
the magnetron. The turntable motor set off to drive the food
around and making the food heated evenly. The microcomputer begins reckon the time, when it reached the sets
power relay
cut
the power of the lamp,
the motor and the magnetron
cut off, the food -
heating process ended. During the heating, if the door was opened, the interlock
S2 will cut off, S3 will
all the motors and the magnetron will
be cut off, the lamp will turn on, the oven stop heating immediately. If
heating need go on,
push down the starting button and closed the door, the oven will continue its working.
When something wrong with the fan motor or the air vent was blocked that breakdown the cooling system, the
magnetron temperaturę
rise high
quickly. When the temperaturę reached the working point of the
thermal cutout (S6), S6 will be cut off immediately to cut off the power supply to the magnetron and the
magnetron will stops working right away. The PC board is cut off to prevent the magnetron from being damaged
by overheating. When the thermal cutout is cut off, the magnetron, motors and the lamp would stop working
simultaneously. Moreover, the thermal cutout has the
- resuming character, when the temperaturę Iowered, it
will resume to close condition.
Circuit diagram of computer controlled microwave ovens:
Circuit diagram for mechanical controlled microwave ovens:
4
TO
AND
OVEN
COMPONENTS
In the following pages, we will introduce the ways in
the various
of a typical microwave oven can be
disassembled and assembled.
4.1 THE
To disassemble the cabinet
out the power
Loosen the four screws at the back of the oven with a
screwdriver.
a)
Push the cabinet back 25mm according to the arrow direction shown at
(b), and the cabinet can be taken
off.
(a)
4-1
To assemble the cabinet
Put the cabinet on the oven, and push it
ahead.
2. Check whether the up, right and
troughs have been
with the
with the
rim of the
oven (FIG.4-1
If the cabinet and the oven
not tallied exactly, then it should be reassembled or those
untallied parts should be smoothed.
