16
R-2S56
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOIUCH CONTROL PANEL
4) 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.
5) ACL Circuit
A circuit to generate a signals which resets the LSI to the
initial state when power is supplied.
6) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
noticing sounds (key touch sound and completion sound).
7) Door Sensing Switch
A switch to “tell” the LSI if the door is open or closed.
8) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp.
9) Indicator Circuit
Indicator element is a Light-emitting diode.
Basically, a Light-emitting diode is triode having a cathode
and an anode.
The Light-emitting diode has 4-digits, 8-segments are
used for displaying figures.
Control Unit
Control unit consists of tact switches, LSI, power source
circuit, synchronizing signal circuit, ACL circuit, buzzer
circuit and indicator circuit.
1) Tact Switches
The tact switches are composed of a matrix, signals
generated in the LSI are sent to the tact switches through
R6
0
-R6
2
. When a tact switches is touched, a signal is
completed through the tact switches and passed back to
the LSI through R8
1
-R8
3
to perform the function that was
requested.
2) LSI
This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.
3) Power Source Circuit
This circuit generates voltages necessary in the control
unit.
Symbol
Voltage
Application
VC
-5V
LSI(IC1)
DESCRIPTION OF LSI
LSI(IZA582DR):
The I/O signal of the LSI(IZA582DR) is detailed in the following table.
Pin No.
Signal
I/O
Description
1
X
OUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of X
OUT
.
2
X
IN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to X
IN
terminal.
3
RESET
IN
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied. Temporarily
set to “L” level the moment power is supplied, at this time the LSI is set. Thereafter set
at “H” level.
4
R7
0
OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay. In Low operation, the signals holds “L” level during
microwave cooking and “H” level while not cooking. In other cooking modes
(70%,50%,30%,10%) the signal turns to “L” level and “H” level in repetition according
to the power level.
5
R7
1
OUT
Oven lamp,turntable motor and cooling fan motor driving signal. (Square
Waveform : 50Hz)
To turn on and off the control relay. The pulse signal (50Hz) is delivered to the control
relay driving circuit and cook relay control circuit.
6
R7
2
OUT
Terminal not used.
