R-671 - 20
LSI(IZA909DR)
The I/O signal of the LSI(IZA909DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
1-2
VL2-VL1
IN
Power source voltage input terminal.
Standard voltage for LCD.
3-5
AN7-AN5
IN
Terminal to change functions according to the Model.
DC voltage in accordance with the Model in operation is applied to set up its
function.
6
AN4
OUT
Terminal not used.
7
AN3
IN
Signal coming from potentiometer.
By inputting DC voltage corresponding to the cooking mode set by the potentiometer,
this input is converted into the cooking mode by the A/D converter built into the LSI.
8
AN2
IN
Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal.
Door opened; "L" level signal.
9-10
P01-P00
OUT
Terminal not used.
11
P57
IN
Terminal not used.
The touch control section consists of the following units as
shown in the touch control panel circuit.
The principal functions of these units and the signals
communicated among them are explained below.
Tact Switch
Signals generated in the LSI are sent to the tact switches.
When a tact switch is touched, a signal is completed
through the tact switch and passed back to the LSI through
to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, relay
circuit, back light circuit, synchronizing signal circuit, ACL
circuit, buzzer circuit, encoder circuit, potentiometer cir-
cuit and indicator circuit.
1) LSI
This LSI controls the tact switch strobe signal, encoder
signal, potentiometer signal, relay driving signal for
oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
Symbol
Voltage
Application
VC
-5.0V
LSI(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 accompanies a very small error because it
works on commercial frequency.
CONTROL PANEL ASSEMBLY
4) ACL Circuit
A circuit to generate a signals which resets the LSI to
the initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (tact switch touch sound and comple-
tion sound).
6) Door Sensing Switch
A switch to "tell" the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, fan motor, turntable motor, top
heating element, bottom heating element and light the
oven lamp.
8) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-
common electrodes using a Liquid Crystal Display.
9) Encoder
The encoder converts the signal generated by LSI into
the pulse signal, and the pulse signal is returned to the
LSI.
10) Potentiometer Circuit
The circuit makes setting of the cooking mode by
variable resistance.
11) Back Light Circuit
A circuit to drive the back light (Light emitting diodes
LD1-LD4).
12) Auto Indicator Circuit
A circuit to drive the light (Light emitting diodes LD5).
OUTLINE OF CONTROL PANEL
DESCRIPTION OF LSI
