Sharp R-305EW Service Manual download pdf (Page 20)

R-305EW

3) Power Source Circuit

This circuit generates voltages 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.

Symbol Voltage Application

VC -5V LSI(IC1)

4) Relay Circuit

A circuit to drive the magnetron, fan motor, turntable

motor and light the oven lamp.

5) Buzzer Circuit

The buzzer is responsive to signals from the LSI to emit

audible sounds (key touch sound and completion sound).

6) 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.

7) Door Sensing Switch

A switch to “tell” the LSI if the door is open or closed.

8) Back Light Circuit

A circuit to drive the back light (Light emitting diodes

LD1- LD4).

1-2 VL2-VL1 IN Power source voltage input terminal.

Standard voltage for LCD.

3-6 AN7-AN4 IN Terminal to change cooking input according to the Model.

By using the A/D converter contained in the LSI, DC voltage in accordance with the Model

in operation is applied to set up its cooking constant.

7 P63 OUT Terminal not used.

8 AN2 IN Input terminal to judge the model.

Connected to GND through the pull-down resistor R78.

9 AN1 IN To input signal which communicates the door open/close information to LSI.

Door close "H" level signal (0V). Door open "L" level signal (-5V).

10 AN0 IN Input terminal to judge the model.

The signal out of P22 will be input into AN0 through G3 line on key matrix. The LSI will

judge the model by this signal.

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units.

(1) Key Unit

(2) Control Unit (The Control Unit consists of Power Unit and

CPU Unit).

The principal functions of these units and the signals com-

municated 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 P20, P21, P22, P23,

P24, P25, P26 and P27.

When a key pad is touched, a signal is completed through

the key unit and passed back to the LSI through P41, P43,

P44, P45 and AN0 to perform the function that was re-

quested.

Control Unit

Control unit consists of LSI, ACL circuit, indicator circuit,

power source circuit, relay circuit, buzzer circuit, synchro-

nizing signal circuit and back light circuit.

1) ACL

This circuit generates a signal which resets the LSI to the

initial state when power is supplied.

2) Indicator Circuit

This circuit consists of 22 segments and 3 common

electrodes using a Liquid Crystal Display.

LSI(IXA096DR)

The I/O signal of the LSI(IXA096DR) is detailed in the following table.

Pin No. Signal I/O Description

1 2 ... 15 16 17 18 19 20 21 22 23 24 25 ... 39 40

Comments to this Manuals

No comments

Sharp R-305EW Service Manual Page 20

Comments to this Manuals

Related products and manuals for Microwaves Sharp R-305EW