R-7N76(W)M
R-7N76(B)M
21
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.
Key Unit
The key unit is composed of a matrix, signals generated
in the LSI are sent to the key unit through
P05,P06,P07,P10, P11 and P12. When a key pad is
touched, a signal is completed through the key unit and
passed back to the LSI through P24,P25,P26 and P27 to
perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit,
synchronizing signal circuit, ACL circuit, buzzer circuit
and indicator circuit.
1) LSI(IC1)
This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltages necessary in the control
unit.
Symbol
Voltage
Application
VC
-5V
LSI(IC1)
VP
-26V
Fluorescent display tube : Grid
and anode voltage
VF1
3Vac
Filament of fluorescent display
tube
VF2
(VF1 to VF2 voltage)
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
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.
4) ACL Circuit
A circuit to generate a signal 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
noticing sounds (key touch sound and completion
sound).
6) Door Sensing Switch (Stop 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,
convection motor, damper motor, convection heater,
grill heater and light the oven lamp.
8) Indicator Circuit
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 has 6-digits, 14-segments are
used for displaying figures.
9) Absolute Humidity Sensor Circuit
The circuit detects absolute humidity of a food whith is
under cooking, to allow its automatic cooking.
10)
IC2 (IC)
This is a memory IC, responsible for "LOGICOOK"
function.
