Read Sharp R-205WM Service Manual online
R-205M - 9
OUTLINE OF CONTROL UNIT
The control unit consists of the following circuits as shown in the control unit circuit.
The principal functions of these circuits and their related signals are explained below.
Control Unit
Control unit consists of LSI, reset circuit, power source circuit, relay circuit and synchronizing signal circuit.
1) Reset Circuit
Control Unit
Control unit consists of LSI, reset circuit, power source circuit, relay circuit and synchronizing signal circuit.
1) Reset Circuit
This circuit generates a signal which resets the LSI to the initial state when power is supplied.
2) Potentiometer Circuit
The circuit makes setting of the power level by variable resistance.
3) Power Source Circuit
This circuit generates voltage necessary in the control unit from the AC line voltage. In addition, the synchronizing signal
is available in order to compose a basic standard time in the clock circuit.
is available in order to compose a basic standard time in the clock circuit.
Symbol
Voltage
Application
VDD
+5V
LSI(IC-1)
VSS
0V
LSI(IC-1)
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and light the oven lamp.
5) 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.
accompanies a very small error because it works on commercial frequency.
LSI(IXA128DR)
The I/O signals of the LSI(IXA128DR) are detailed in the following table.
The I/O signals of the LSI(IXA128DR) are detailed in the following table.
Pin No.
Signal
I/O
Description
20 msec
During cooking
H
L
1
VDD
IN
Power source voltage: 5V.
Connected to 5V.
Connected to 5V.
2
VSS
IN
Power source voltage: 0V.
Connected to 0V.
Connected to 0V.
3
XIN
IN
Internal clock oscillation frequency input setting.
The internal clock frequency is generated by connecting the capacitor and resistor
to XIN.
The internal clock frequency is generated by connecting the capacitor and resistor
to XIN.
4
XOUT
OUT
Terminal not used.
5
CNVSS
IN
Connected to VSS through resistor.
6
RESET
IN
Auto clear terminal.
Signal is inputted to reset the LSI to the initial state when power is supplied.
Signal is inputted to reset the LSI to the initial state when power is supplied.
7
AIN1
IN
Signal coming from potentiometer.
Voltage from potentiometer is converted into the power level by the A/D converter
built into the LSI.
Voltage from potentiometer is converted into the power level by the A/D converter
built into the LSI.
8
AIN0
IN
Cooking start detection terminal.
When "H" level is inputted to AIN0, cooking starts.
When "H" level is inputted to AIN0, cooking starts.
9
D3
OUT
Signal to allow Magnetron high-voltage circuit to be drived.
While the signal (Sqrare Waveform) is
generating from D3, the Magnetron high-
voltage circuit is allowed to be drived.
generating from D3, the Magnetron high-
voltage circuit is allowed to be drived.
10
D2
OUT
Signal to check the model.
CONTROL UNIT ASSEMBLY
DESCRIPTION OF LSI
Click on the first or last page to see other R-205WM service manuals if exist.