Touch Control Panel Operation - Electrolux EI30MH55GBA Technical & Service Manual

HOOD FAN MOTOR
The hood fan motor is a two-speed, single-phase,
double pole induction type, requiring a hood fan
capacitor. It is located outside the upper rear part of
the oven cavity, is to remove, from around the oven,
hot air rising from the conventional electric or gas
range over which it is installed. This air is then
expelled either vertically or horizontally through the
customer supplied duct system, or discharged back
into the kitchen.
STIRRER MOTOR
The stirrer motors drive the stirrer fans to stir the
microwave radiation from the waveguide.
HOOD LAMP
The hood lamps are mounted at the hood lamp angle.
The hood lamps can be turned off and on by touching
the Light Options pad. And also the brightness can be
varied to high or low by touching the Light Options
pad.

Touch Control Panel Operation

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 Unit)
The principal functions of these units and the signals
communicated 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 P43, P44, P45 and P46 to perform the
function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, syn-
chronizing signal circuit, reset circuit, buzzer circuit,
relay circuit indicator circuit, back light circuit and
humidity sensor 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
VC -5.0V
3) Synchronizing Signal Circuit
The power source synchronizing signal is avail
able 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) Reset 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) Stop Switch
A switch to inform the LSI if the door is open or
closed.
7) Relay Circuit
To drive the inverter unit, fan motor, stirrer motor,
hood motor, and light the oven lamp and hood
lamp.
8) Indicator Circuit
This circuit consists of 25 segments and 4
common electrodes using a Light Crystal Display.
9) Back Light Circuit
A circuit to drive the back light (Light emitting
diodes LD1-LD5).
10) Humidity Sensor Circuit
This circuit detects moisture of the cooking food
to allow its automatic cooking.
11) Inverter Unit Control Circuit
This is the circuit to control inverter unit.
2-7
Operation
Application
LSI(IC1)