Sharp Carousel R-380E, Руководство по обслуживанию

Страница: 18 / 40

R-380E
16
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
communicated 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 P00-P07.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through P14-P17,
AIN6 and AIN7 to perform the function that was re-
quested.
Control Unit
Control unit consists of LSI, ACL circuit, indicator circuit,
power source circuit, relay circuit, buzzer circuit, synchro-
nizing 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
This circuit consists of 40 segments and 16 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) 2nd. Interlock Relay Control 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 automatic cooking.
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
(10) Disconnect the power supply cord, and then remove outer case.
(11) Open the door and block it open.
(12) Discharge high voltage capacitor.
(13) Disconnect the dummy resistor circuit from the sensor connector of control panel.
(14) Carry out necessary repair.
(15) Reconnect all leads removed from components during testing and repairing.
(16) Re-install the outer case (cabinet).
(17) Reconnect the power supply cord after the outer case is installed. Run the oven and check all
functions.
(18) Carry out "Water load cooking test" again and ensure that the oven works properly.
R1,R2 : 22
Ω ±
1% 1/2W
R3 : 4.3k
Ω ±
5% 1/4W
R4 : 1M
Ω ±
5% 1/4W
Sensor Dummy Resistor Circuit
Plunger
NC
NO
COM
COM
NO
NC
R3 R4
R1
R2
1
2
3
F-1
F-2
F-3
To connector (F)
on Control Unit.
CONNECTOR