Sharp R-480J Operation Sequence, OFF Condition, Microwave Cooking Condition, Variable Cooking

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R-480J

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates all door interlock switches (1st. latch switch, 2nd. interlock relay control switch)

IMPORTANT

When the oven door is closed, the monitor switch contacts (COM-NC) must be open.

When the microwave oven is plugged in a wall outlet, rated voltage is supplied to the noise filter and the control unit.

Figure O-1 on page 29

1.The display shows SHARP, MICRO-WAVE and OVEN.

2.To set any programs or set the clock, you must first touch the STOP/CLEAR pad.

3.“ : “ appears in the display.

NOTE: When the oven door is opened, the oven lamp comes on at this time.

MICROWAVE COOKING CONDITION

HIGH COOKING

Enter a desired cooking time with the touching Number pads and start the oven with touching START pad.

Function sequence

Figure O-2 on page 29

CONNECTED COMPONENTS

RELAY

Oven lamp, Fan motor, Turntable motor

RY1

Power transformer

RY2

because the relay (RY1) stays closed. Shown in the display is the remaining time.

6.MONITOR SWITCH CIRCUIT

The monitor switch is mechanically controlled by oven door, and monitors the operation of the 1st. latch switch and 2nd. interlock relay.

6-1 When the oven door is opened during or after the cycle of a cooking program, the 1st. latch switch and 2nd. interlock relay control switch must open their contacts first. After that the contacts (COM-NC) of the monitor switch can be closed.

6-2. When the oven door is closed, the contacts (COM- NC) of the monitor switch must be opened first. After that the contacts of the 1st. latch switch and 2nd. interlock relay control switch are closed.

6-3. When the oven door is opened and the contacts of the 1st. latch switch and 2nd. interlock relay remain closed. The fuse F10A will blow, because the monitor switch is closed and a short circuit is caused.

VARIABLE COOKING

When the microwave oven is preset for variable cooking power. Rated voltage is supplied to the power transformer intermittently within a 32-second time base through the relay contact which is coupled with the relay (RY2). The following levels of microwave power are given.

1.

Rated voltage is supplied to the primary winding of the

 

power transformer. The voltage is converted to about

 

3.3 volts A.C. output on the filament winding and high

 

voltage of approximately 2000 volts A.C. on the

 

secondary winding.

2.

The filament winding voltage (3.3 volts) heats the

 

magnetron filament and the high voltage (2000 volts) is

 

sent to the voltage doubling circuit, where it is doubled

 

to negative voltage of approximately 4000 volts D.C..

3.

The 2450 MHz microwave energy produced in the

 

magnetron generates a wave length of 12.24 cm. This

 

energy is channelled through the waveguide (transport

 

channel) into the oven cavity, where the food is placed

SETTING;

32 sec. ON

HIGH

 

24 sec. ON

8 sec. OFF

MEDIUM HIGH

 

 

 

18 sec. ON

14 sec. OFF

MEDIUM

 

 

 

12 sec. ON

20 sec. OFF

MEDIUM LOW

 

 

 

6 sec. ON

26 sec. OFF

LOW

 

 

Approx. 70%

Approx. 50%

Approx. 30%

Approx. 10%

 

to be cooked.

4.

When the cooking time is up, a signal tone is heard and

 

the relays (RY1+RY2) go back to their home position

 

(off condition)º. The circuits to the oven lamp, power

 

transformer, fan motor and turntable motor are cut off.

5.

When the door is opened during a cook cycle, the

 

switches come to the following condition

 

 

CONDITION

 

 

DURING

DOOR OPEN

SWITCH

CONTACT

COOKING

(NO COOKING)

 

 

 

 

1st. latch switch

COM-NO

Closed

Open

 

 

 

 

2nd. interlock relay

 

 

 

control switch

COM-NO

Closed

Open

Monitor switch

COM-NC

Open

Closed

The circuits to the power transformer, fan motor and turntable motor are cut off when the 1st. latch switch and 2nd. interlock relay control switch are made open. The oven lamp remains on even if the oven door is opened after the cooking cycle has been interrupted,

NOTE: The ON/OFF time ratio does not exactly correspond to the percentage of microwave power, because approx. 3 seconds are needed for heating up the magnetron filament.

SENSOR COOKING CONDITION

Using the SENSOR COOK or SENSOR INSTANT RE- HEAT function, the foods are cooked or reheated without figuring time, power level or quantity. When the oven senses enough steam from the food, it relays the informa- tion to its microprocessor which will calculate the remaining cooking time and power level needed for best results. When the food is cooked, water vapor is developed. The sensor “senses” the vapor and its resistance increases gradually. When the resistance reaches the value set according to the menu, supplementary cooking is started. The time of supplementary cooking is determined by ex- periment with each food category and inputted into the LSI.

An example of how sensor works:

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Contents Table of Contents Microwave Oven Model R-480J480J 480J Sharp Corporation OSAKA, JapanMicrowave Oven General Important InformationDescription Product SpecificationsGeneral Information This Appliance Must be EarthedAppearance View Touch Control PanelMicrowave Cooking Condition Operation SequenceOFF Condition Variable CookingPower Output Reduction Cooking SequenceSensor Instant Reheat Function of Important Components Remember to Check 3D Troubleshooting GuideServicing Remember to Check 4RTest Procedure Possible Cause Defective Parts ProblemTest Procedures Procedure Component Test Letter Magnetron TestMicrowave Output Power 1 litre water load High Voltage Rectifier Assembly Test Test Procedures Letter Component TestPower Transformer Test High Voltage Capacitor TestNoise Filter Test Carry OUT 3D Checks Procedure Component Test LetterSwitch Test Thermal CUT-OUT TestTouch Control Panel Assembly Test Blown Fuse F10A Carry OUT 3D ChecksHigh Voltage Fuse Test KEY Unit Test Relay TestAH Sensor Test Carry OUT 3D Checks Steps Occurrence Cause or CorrectionOmif Checking the initial sensor cooking conditionChecking Control Unit Test Procedures LetterTesting Method for AH Sensor AND/OR Control Unit Sensor Dummy Resistor CircuitPower Source Circuit Reset CircuitIndicator Circuit Synchronizing Signal CircuitLSI Signal similar to P17 Pin No Signal DescriptionSignal coming from touch key Power source voltage GND0VCommon data signal COM6 Common data signal COM8Common data signal COM7 Common data signal COM5Absolute Humidity Sensor Circuit Structure of Absolute Humidity SensorShapes of Electronic Components Other PrecautionsTouch Control Panel Servicing Servicing of Touch Control PanelComponent Replacement and Adjustment Procedure Power Transformer RemovalOuter Case Removal Magnetron Removal Positive Lock Connector NO-CASE Type RemovalHOW to RE-INSTALL the Turntable Motor Cover Turntable Motor RemovalInstallation Control Panel Assembly RemovalCPU Unit and Power Unit Oven Lamp and Lamp Socket RemovalRear View Power Supply Cord ReplacementAfter adjustment, check the following Side ViewRemoval Door ReplacementRE-INSTALL View back side of door frameAfter any service, make sure of the following InstallationSealer Film Requirement Preparation for TestingMicrowave Measurement Holaday HI Simpson 380MFigure O-1. Oven Schematic-OFF Condition Figure S-1. Pictorial Diagram High Voltage ComponentsFigure S-2. Power unitl Circuit Unit FigureS3.CPUCN a CN D D10 CN CZD1 SP1 VRB RY2 RY1 RY3 TTMParts List SCREWS, Nuts and Washers Packing and AccessoriesMiscellaneous Not replaceable items84-21 Control Panel Parts Door Parts Miscellaneous Copyright 2004 by Sharp Corporation ALL Rights Reserved

R-480J specifications

The Sharp R-480J is a notable microwave oven that combines advanced technology with practical design, catering to both everyday cooking needs and more complex culinary tasks. This model is designed for consumers seeking reliability and efficiency in their kitchen appliances.

One of the standout features of the Sharp R-480J is its powerful 900-watt output. This high wattage allows for faster cooking times, making meal preparation a breeze. The microwave also offers multiple power levels, which provides the user with the flexibility to cook a variety of dishes. Whether you are reheating leftovers, defrosting meats, or cooking fresh vegetables, the R-480J delivers consistent and thorough results.

The microwave is equipped with a spacious interior, accommodating larger dishes with ease. Its turntable design ensures even cooking by allowing food to rotate during the cooking process. This feature minimizes cold spots in the food, ensuring that meals are heated uniformly.

User-friendliness is a key aspect of the Sharp R-480J. The appliance comes with an intuitive control panel featuring pre-programmed settings for common food items such as popcorn, pizza, and dinner plates, making it easy for users to select the right cooking time and power level with just a few button presses. Additionally, the digital display shows cooking times and power levels clearly, enhancing the overall cooking experience.

The R-480J also incorporates advanced sensor cooking technology. This innovative feature detects humidity levels emitted by food and adjusts cooking time accordingly. This means users can achieve perfect results without constantly monitoring the microwave, allowing for greater convenience and efficiency in daily cooking.

Moreover, the microwave's sleek and modern design fits well into various kitchen aesthetics. Its easy-to-clean surfaces minimize maintenance efforts, while the compact build allows it to be placed in smaller kitchens without taking up too much space.

In conclusion, the Sharp R-480J microwave oven stands out for its powerful performance, user-friendly features, and practical design. Its combination of high wattage, multiple power levels, and sensor cooking technology makes it a versatile appliance for any kitchen. Whether tackling daily meals or experimenting with new recipes, the R-480J is equipped to meet diverse cooking needs with ease and efficiency.
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