Touch Control Panel - Sharp R-320CD Service Manual

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 commu-
nicated 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, synchronizing signal
circuit, absolute humidity sensor 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
For R-320CD/CK/CW
This circuit consists of 36 segments and 3 common elec-
trodes using a Liquid Crystal Display.
For R-330CK/CW
This circuit consists of 40 segments and 16 common
electrodes using a Liquid Crystal Display.
The Liquid Crystal Display (LCD) is drived by LCD driver
IC3.
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
VC -5V
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.
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
Application
LSI(IC1)
7) Door Sensing Switch
A switch to "tell" the LSI if the door is open or closed.
8) Back Light Circuit
For R-320CD/CK/CW
A circuit to drive the back light (Light emitting diodes LD1-
LD4).
For R-330CK/CW
A circuit to drive the back light (Light emitting diodes LD10-
LD19).
9) Absolute Humidity Sensor Circuit
This circuit detects moisture of the cooking food to allow its
automatic cooking.
10)Memory IC(IC4)
For R-330CK/CW only
This is a memory IC to adjust the contrast of LCD.
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R-320CD/CK/CW
R-330CK/CW