Sharp R-9380

TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following
units as shown in the touch control panel circuit.
(1) Key Unit
(2) Control Unit
The principal functions of these units and the signals
communicated among them are explained below.
(RD91 lA3U)
Key Unit
The key unit is composed of a matrix, signals generated
in the LSI are sent to the key unit through P62, P63
and P70- P73.
-..-. .- -
When a key pad is touched, a signal is completed
through the key unit and passed back to the LSI
through PIO-PI3 to perform the function that was re-
quested.
Control Unit
Control unit consists of LSI, power source circuit,
synchronizing signal circuit, ACL circuit, buzzer circuit
and indicator circuit.
(RD915BlU)
1)
2)
3)
LSI
This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.
(RD916Al U)
Power Source Circuit
This circuit generates voltage necessary in the
control unit.
Svmbol Voltaae Aoolication
VDD
-12v LSI (ICI ), ACL circuit
VREF -6.15V LSI (ICI)
VP -26.5V Fluorescent display tube : Grid
and anode voltage
VF+
-15.2V F$rrent of fluorescent display
VF-
(VF+ to VF- voltage: AC 3.5V)
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
4)
ACL Circuit
A circuit to generate a signal which resets the LSI
to the initial state when power is supplied.
(RDSl SAl U)
5)
Buzzer Circuit
The buzzer is responsive to signals from the LSI
to emit noticing sounds (key touch sound and
completion sound).
6)
Stop Switch
A switch to “tell” the LSI if the door is open or
closed.
(RD91 BA2U)
7)
Relay Circuit
To drive the magnetron, fan motor, turntable motor
and light the oven lamp.
8)
Indicator Circuit
(RD91 AA1 U)
(RD91 CB2U)
Indicator element is a Fluorescent Display.
Basically, a Fluorescent Display is triode having a
cathode, a grid and an anode. Usually, the cathode
of a Fluorescent Display is directly heated and the
filament serves as cathode.
The Fluorescent Display 6-digits, 13-segments are
used for displaying figures.
(RD91 DA1 U)
I
I
on commercial frequency.
(RD918Al U)
15