Sharp R-530EK-T, Руководство по обслуживанию

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R530EWT
9 – 1
R530EWT
Service Manual
CHAPTER 9.
TOUCH CONTROL PANEL ASSEMBLY
[1] 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 CPU
Unit).
The principal functions of these units and the signals communicated
among them are explained below.
1. Key Unit
The key unit is composed of a matrix, signals generated in the LSI are
sent to the key unit through P00-P07. When a key pad is touched, a
signal is completed through the key unit and passed back to the LSI
through P17, P16,P15, P14, AIN7 and AIN6 to perform the function
that was requested.
2. Control Unit
Control unit consists of LSI, reset circuit, indicator circuit, power
source circuit, relay circuit, buzzer circuit, synchronizing signal circuit,
absolute humidity sensor circuit and back light circuit.
1) Reset Circuit
This circuit generates a signal which resets the LSI to the initial
state when power is supplied.
2) Indicator Circuit
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.
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 com-
pose a basic standard time in the clockcircuit.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 LD10- LD15).
9) Absolute Humidity Sensor Circuit
This circuit detects moisture of the cooking food to allow its auto-
matic cooking.
Symbol Voltage Application
VSS -5V LSI (IC1)