Description And Function Of Components - Sharp R-21LCF Service Manual

R21LCF
2. Cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. LIGHT UP DIAL ON.
NOISE FILTER
AC120V
60 Hz

[3] DESCRIPTION AND FUNCTION OF COMPONENTS

1. DOOR OPEN MECHANISM
The door is opened by grasping the door handle, refer to Figure D-1.
When the door handle is grasped, the handle lever is pulled. And then
the upper and lower latch heads are moved upward by the handle
lever, and they are released from the latch hook. Now the door will
open.
Latch Head
Handle
Lever
Door
Handle
Latch
Lever
Latch Head
Latch Switch
Lever C
Figure D-1. Door Open Mechanism.
THERMAL THERMAL
CUT-OUT CUT-OUT
125ºC (OVEN) 145ºC (MAG.)
A5
CONTROL UNIT
A3 A1
DOOR SENSING
SWITCH
SECONDARY
INTERLOCK SWITCH
Figure O-2. Oven Schematic-Cooking Condition
Latch Hook
Latch Switch
Lever A
Secondary
Interlock
Switch
Latch Switch
Lever B
Monitor
Switch
Door
Sensing
Switch
OL FM AM
OVEN FAN ANTENNA
LAMP MOTOR MOTOR
2. DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the upper position of the
latch hook and the door sensing switch in the primary interlock system
is mounted in the lower position of the latch hook. The secondary inter-
lock switch is activated by the latch switch lever A. The latch switch
lever A is activated by the upper latch head. The door sensing switch
is activated by the latch switch lever C. The latch switch lever C is acti-
vated by the lower latch head. When the door is opened, the switches
interrupt the power to all high voltage components. A cook cycle can-
not take place until the door is firmly closed thereby activating both
interlock switches. The primary interlock system consists of the door
sensing switch and primary interlock relay located on the control circuit
board.
3. MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the latch
switch lever B on the latch hook while the door is closed. The latch
switch lever B is activated by the lower latch head. The switch is
intended to render the oven inoperative, by means of blowing the mon-
itor fuse, when the contacts of the primary interlock relay (RY1) and
secondary interlock switch fail to open when the door is opened.
Functions:
1) When the door is opened, the monitor switch contacts close (to the
ON condition) due to their being normally closed. At this time the
primary interlock relay (RY1) and secondary interlock switch are in
the OFF condition (contacts open) due to their being normally open
contact switches.
2) As the door goes to a closed position, the monitor switch contacts
are first opened and then the door sensing switch and the second-
ary interlock switch contacts close. (On opening the door, each of
these switches operate inversely.)
6 – 2
POWER
TRANSFORMER
CAPACITOR
1.00 μF
2300V