Digital Analogue Control Panel Assembly - Sharp R-211(W)M Service Manual

DIGITAL ANALOGUE CONTROL PANEL
OUTLINE OF CONTROL PANEL
Control Unit
Control unit consists of LSI, power source circuit, synchro-
nizing signal circuit, ACL circuit, buzzer circuit, encoder
circuit, indicator circuit and potentiometer circuit.
1) LSI
This LSI controls the encoder signal, potentiometer
signal, relay driving signal for oven function, buzzer
signal and LED signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
unit.
Symbol Voltage
VC -5.0V
VR -12.0V
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.
Application
LSI(I-1)
RELAY(RY1,2)
211M -
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to
emit audible 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, heating element, fan motor,
turntable motor and light the oven lamp.
8) Encoder
The encoder generates the pulse signal, and the
pulse signal is sent to the LSI.
9) Indicator Circuit
Indicator elements are the Light-emitting diodes
(LD1-LD24).
10) Potentiometer Circuit
The circuit makes setting of the power level by
variable resistance.
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