Touch Control Panel Assembly - Sharp R-1600 Service Manual

Over the range microwave oven

Hide thumbs Also See for R-1600:

Operation manual (28 pages)

Table of Contents

The touch control section consists of the following units

as shown in the touch control panel circuit.

(1) Key Unit

(2) Control Unit (The Control unit consists of LSI Unit and

Power U nit)

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 P10, P11, P12, P13,

P14 and P17.

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

the key unit and passed back to the LSI through P41, P42,

AN8, AN9, AN10 and AN11 to perform the function that was

requested.

Control Unit

Control unit consists of LSI, power source circuit, synchro-

nizing signal circuit, ACL circuit, buzzer circuit, relay circuit

indicator circuit and back light circuit.

1) LSI

This LSI controls the key strobe signal, relay driving

signal for oven function and indicator signal.

2) Power Source Circuit

This circuit generates voltages necessary for 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

-5.1V

3) Synchronizing Signal Circuit

The power source synchronizing signal is available in

order to compose a basic standard time in the clock

circuit. It incorporates a very small error because it works

on commercial frequency.

4) ACL Circuit

A circuit to generate a signals which resetting the LSI to

the initial state when power is applied.

5) Buzzer Circuit

The buzzer is responds to signals from the LSI to emit

audible sounds (key touch sound and completion sound).

6) Door Sensing Switch

A switch to inform the LSI if the door is open or closed.