Section 2 Operation
2-4
Touch Control Panel Assembly Outline
The touch control section consists of the following units.
(1) Key unit
(2) Control Unit: The Control unit consists of Logic Unit and
Power Unit.
The principal functions of these units and the signals
communicated among them are explained below.
KEY UNIT
CONTROL UNIT
Control unit consists of Logic Unit, power source circuit,
synchronizing signal circuit, reset circuit, buzzer circuit,
relay circuit indicator circuit and back light circuit.
1. (Logic Unit)
This Logic controls the key strobe signal, relay driving
signal for oven function and indicator signal.
2. Power Source Circuit
This circuit generates voltages necessary for the
control unit from the AC line voltage. In addition,
the synchronizing signal is available in order to
compose a basic standard time in the clock circuit.
Symbol Voltage
Application
VC -5.3V
Logic Unit(IC1)
3. Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It incorporates a very small error because it
works on commercial frequency.
4. Reset Circuit
This circuit generates a signal which resets the Logic
5. Buzzer Circuit
The buzzer is responds to signals from the Logic unit to
emit audible sounds (key touch sound and
completion sound).
6. Door Sensing Switch
A switch to inform the Logic Unit if the door is open or
closed.
7. Relay Circuit
To drive the magnetron, fan motor, turntable motor,
hood motor, and light the oven lamp and hood lamp.
8. Indicator Circuit
This circuit consists of 25 segments and 4 common
electrodes using a Light Crystal Display.
9. Back
Light
Circuit
A circuit to drive the back light (Light emitting diodes
LD1-LD4).
DOOR OPEN MECHANISM
The door is opened by pulling the door handle, refer to
the Figure 2-3.
DOOR SENSING SWITCH AND PRIMARY
INTERLOCK SWITCH
The primary interlock switch is mounted in the upper
position of the latch hook. The door sensing switch in
the primary interlock system is mounted in the lower
position of the latch hook which is mounted on the upper
position of the latch hook. They are activated by the
latch heads on the door. When the door is opened, the
switches interrupt the circuit to all components. A cook
cycle cannot take place until the door is firmly closed,
thereby activating both interlock switches. The primary
interlock system consists of the door sensing switch and
secondary interlock relay located on the control circuit
board.
Figure 2-3. Door Open Mechanism
Component Descriptions
Latch Heads
Door
Latch Hook
Primary Interlock Switch
Monitor Switch
Door Sensing Switch
Remark: Logic Unit stands for Large Scale Integrated Circuit.
Unit (IC1) to the initial state when power is supplied.
The key unit is composed of a matrix, signals generated
in the Logic Unit are sent to the key unit through P20,
completed through the key unit and passed back to the
Logic unit through P43, P44, P45 and P46 to perform the
function that was requested.
P25, and P26. When a key pad is touched, a signal is
P21
P2
,
