Kuppersbusch MW 800.0, Service Manual

Page: 12 / 39

12 Service Manual MWG 1000
Only for internal use
2.3 Description of the components and their functions
Noise filter Prevents any interference from radio or television that may occur
when the appliance is being put into operation.
Fan motor The fan motor activates the fan which sucks in air through the vents
on the right side of the appliance and which causes it to circulate
around the magnetron and the transformer. Some of the air is
directed into the case in order to start the antenna turning and to
remove any excessive steam produced by the food. This steam is
blown towards the vents on the left and at the rear and is thus
extracted.
Oven lamp The oven lamp serves to control the food which can be seen through
the viewing panel in the door. The oven lamp is always switched off
when the cooking time has been set.
H.V. transformer The H.V. transformer serves to generate a filament voltage to heat
up the magnetron and to generate high voltage for the magnetron
tubes. During cooking the 220V ~ (240V) used for the primary
winding is converted into approx. 3.3V ~ on the filament winding and
into approx. 2300V ~ on the secondary high-voltage winding of the
power transformer.
Half-wave voltage- The half-wave voltage-doubling circuit consists of a regulator and a
doubling circuit capacitor with shunt resistance whose job it is to transform the
2300V ~ from the secondary winding of the high-voltage transformer
into approx. 4000 V= in order to operate the magnetron.
Magnetron tubes The magnetron generates microwaves using strong electric and
magnetic fields. The microwaves are conducted into the oven where
they are evenly distributed by the antenna to generate the required
heat in the food.
Monitor switch This switch is usually open. It is closed when the door is open.
Should door switch remain closed for any reason, the fuse will be
short circuited and will blow. The short-circuit current is limited by
resistor 3104/3105.
Latch switches These switches are safety switches which are activated by the door.
Switch 1040 interrupts the current to the electronic controls and the
display panel. Switch 1040 is the main door switch.
Note : Defective switches should be destroyed immediately to
prevent them from being used again.
Grill The grill (MGWD 900) cannot be pulled down to make it easier to
clean the inside of the oven. The heat emanating from the grill, or the
heating element, is so intense that the dirt is burned away.
Turntable motor The turntable motor is a small synchronous motor which drives the
turntable via a roller stay. The motor can start from any position.