Sharp R-771(W)N - Touch Control Panel Assembly; Outline of Touch Control Panel

TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units as
shown in the touch conirol panel circuit.
(1) Key Unit
(2) Control Unit (The Control unit consists of Power unit
and CPU unit.)
The principal functions of these units and signals commu-
nicated among them are explained below.
Key Unit
The key unitis composed of a matrix, signals generated in
the LSI are sent to the key and jog unit from P40, P41, P77
and P76.
When a key pad is touched, a signal is completed through
the key unit and passed back to the LSI through P47 - P44
to perform the function that was requested.
Control Unit
Conirol unit consists of LSI, power source circuit, synchro-
nizing signal circuit, ACL circuit, buzzer circuit, indicator
circuit, encoder circuit, potentiometer circuit and back light
circuit.
1) LSI
This LS! controls the key strobe signal, relay driving
signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
Symbol Voltage Application
VC -5.2V LSHIC1)
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
A circuit to generate a signals 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
audible sounds (tact switch touch sound and compie-
tion sound).
6) Door Sensing Switch (Stop Switch)
A switch to "tell" the LSI if the door is open or closed,
7
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Relay Circuit
To drive the magnetron, top and bottom heating ele-
ments, fan motor, turntable motor and light the oven
lamp. .
8) Encoder
The encoder converts the signal generated by LSI into
the pulse signa!, and the pulse signal is returned to the
LSI.
ed
9) Potentiometer Circuit
The circuit makes setting of the cooking mode by
variable resistance.
i
10)Back Light Circuit _
A circuit to drive the back light (Light emitting diodes
LD1 - 1D10).
11)Indicator Circuit
This circuit consists of 7-digits, 39-segments and 3-
common electrodes using a Liquid Crystal Display.
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