21
R-420CK
R-420CW
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units.
(1) Key Unit
(2) Control Unit (The Control Unit consists of Power Unit and
LSI Unit).
The principal functions of these units and the signals com-
municated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in
the LSI are sent to the key unit through P10-P17.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through AN11,
AN10, AN9, P42, P41 and AN8 to perform the function that
was requested.
Control Unit
Control unit consists of LSI, ACL circuit, indicator circuit,
power source circuit, relay circuit, buzzer circuit, synchro-
nizing signal circuit and back light circuit.
1) ACL
This circuit generates a signal which resets the LSI to the
initial state when power is supplied.
2) Indicator Circuit
This circuit consists of 36 segments and 3 common
electrodes using a Liquid Crystal Display.
3) Power Source Circuit
This circuit generates voltages necessary in 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
-5V
LSI(IC1)
4) Relay Circuit
A circuit to drive the magnetron, fan motor, turntable
motor and light the oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion sound).
6) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit.
It accompanies a very small error because it works on
commercial frequency.
7) Door Sensing Switch
A switch to “tell” the LSI if the door is open or closed.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1-
LD4).
9) Absolute Humidity Sensor Circuit
This circuit detects moisture of the cooking food to allow
its automatic cooking.
LSI(IZA966DR)
The I/O signal of the LSI(IZA966DR) is detailed in the following table.
Signal Coming from touch key.
1
AN10
IN
When either G10 line on key matrix is touched, a corresponding signal out of P10-P17 will
be input into AN10. when no key is touched, the signal is held at "H" level.
2
AN11
IN
Signal similar to AN10.
When either G9 line on key matrix is touched, a corresponding signal will be input into AN11.
3
AVSS
IN
Connected to VC.
4
P10
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to AN9, AN10, AN11, P41and
P42 terminal while one of G8 line keys on key matrix is touched
5
P11
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to AN9, AN10, AN11, P41and
P42 terminal while one of G7 line keys on key matrix is touched
6
P12
OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to AN9, AN10, AN11, P41and
P42 terminal while one of G6 line keys on key matrix is touched
Pin No.
Signal
I/O
Description
