Chapter 7. Function Of Important Com; Door Open Mechanism; Switch; Fuse - Sharp AX-1100 Service Manual

AX1100(R)
CHAPTER 7.
FUNCTION OF IMPORTANT COMPONENTS

[1] DOOR OPEN MECHANISM

1. The door lever is gripped and the door open handle is pulled.
2. The latch head L is lifted up by the door lever.
3. The latch head U is lifted up by the linked latch lever.
4. Now both latch heads are lifted up, so they can be released from
the latch hook.
5. Now the door can be opened.
Latch head U
Latch angle
Door lever
Figure D-1. Door Open Mechanism

[2] SWITCH

1. MONITORED INTERLOCK SWITCH SW1
1. When the oven door is closed, the contacts (COM-NO) of the
switch must be closed. And the contacts (COM-NC) must be
opened.
2. When the oven door is opened, the contacts (COM-NO) of the
switch must be opened. And the contacts (COM-NC) must be
closed.
2. MONITOR SWITCH SW2
The monitor switch is activated (the contacts opened) by the latch
head U on the door while the door is closed. The switch is intended to
render the oven inoperative by means of blowing the fuse F2 F8A
when the contacts of the monitored interlock switch SW1 fail to open
when the door is opened.
Function
1. When the door is opened, the contacts (COM-NC) of monitor
switch SW2 close. At this time the contacts (COM-NO) of moni-
tored interlock switch SW1 are open.
2. As the door closed, the monitor switch SW2 contacts (COM-NC)
are opened.
The contacts (COM-NO) of monitored interlock switch SW1 and
door sensing switch SW3 are closed (On opening the door, each of
these switches operate inversely.).
Service Manual
3. If the door is opened and the monitored interlock switch SW1 con-
CAUTION: BEFORE REPLACING A BLOWN FUSE F2 F8A, TEST
3. DOOR SENSING SWITCH SW3
1. When the oven door is closed, the contacts (COM-NO) of the
2. When the oven door is opened, the contacts (COM-NO) of switch
4. INTAKE DAMPER SWITCH SW4
The intake damper switch is turned on and off by the air damper cam
which is rotated by the intake damper motor.
Latch lever
5. ANTENNA SWITCH SW5
The antenna switch is turned on and off by the shaft assembly which is
rotated by the antenna motor.

[3] FUSE

1. FUSE F1 20A 250V
If the wire harness or electrical components are short-circuited, this
fuse F1 blows to prevent an electric shock of fire hazard.
2. FUSE F2 F8A 250V
1. If the wire harness or electrical components are short-circuited, this
Latch head L
2. The fuse also blows when the monitored interlock switch SW1
3. The fuse also blows when the asymmetric rectifier, H.V. rectifier,

[4] ASYMMETRIC RECTIFIER

The asymmetric rectifier is solid state device that prevents current flow
in both directions. And it prevents the temperature rise of the high volt-
age transformer by blowing the fuse F2 F8A when the high voltage
rectifier is shorted.
The rated peak reverse voltage of D1 of the asymmetric rectifier is 6
kV The rated peak reverse voltage of D2 of the asymmetric rectifier is
1.7 kV. D1 and D2 of the asymmetric rectifier or high voltage rectifier
are shorted when the each peak reverse voltage goes beyond the
each rated peak reverse voltage. (The process of the blowing the fuse
F2 F8A.)
1. The high voltage rectifier is shorted by some fault when microwave
2. The peak reverse voltage of D2 of the rectifier goes beyond the
3. D2 of the rectifier is shorted.
7 – 1
tacts (COM-NO) fail to open, the fuse F2 (F8A) blows immediately
after closing of the monitor switch (COM-NC) contacts.
THE MONITORED LATCH SWITCH SW1 AND MONITOR
SWITCH SW2 FOR PROPER OPERATION. (REFER TO
CHAPTER "TEST PROCEDURE").
switch must be closed.
must be opened
fuse blows to prevent an electric shock or fire hazard.
remains closed with the oven door open and when the monitor
switch SW2 contact (COM-NC) closes.
H.V. wire harness, H.V. capacitor, magnetron or secondary winding
of high voltage transformer is shorted.
D2 D1
ASYMMETRIC
RECTIFIER
cooking or dual cooking.
rated peak reverse voltage 1.7 KV in the voltage doubler circuit.
AX1100(R)
HIGH VOLTAGE
RECTIFIER