Sharp R-520LK Key Unit, Control Unit, Reset Circuit, Indicator Circuit, Power Source Circuit

Page 23

R - 5 2 0 L K

R-520LW

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

LSI 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-P27.

When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P70, P71, P41, P45, P47 and AN3 to perform the function that was requested.

Control Unit

Control unit consists of LSI, reset circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit, synchroniz- ing signal circuit and back light circuit.

1)Reset Circuit

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.

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

 

 

 

VSS

-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).

9)Night Light Circuit

A circuit to drive the light emitting diode (LD10).

10)Absolute Humidity Sensor Circuit

This circuit detects moisture of the cooking food to allow its automatic cooking.

23

Page 22 Page 24
Image 23
Page 22 Page 24
Contents 520LW Table of ContentsBefore Servicing Dont Touch Before Servicing When the testing is completedLeakage test Microwave Measurement ProcedureRequirements Foreword Sharp PLAZA, MahwahMicrowave Ovens 520LK/R-520LWGrounding Instructions SpecificationGeneral Information DescriptionTouch Control Panel Oven DiagramOFF Condition Power Level P-0 to P-90 CookingOperation Description of Operating SequenceMicrowave Sensor Cooking ConditionClock Appears on Display SchematicDescription and Function of Components Troubleshooting Guide Procedure Component Test Letter Magnetron Assembly Test Test ProceduresTest Procedure ProblemPower Transformer Test Procedure Component Test LetterMicrowave Output Power High Voltage Capacitor Test Procedure Component Test Letter High Voltage Rectifier TestCavity Temperature Fuse Test Magnetron Temperature Fuse TestSecondary Interlock System Test Replace Temperature FusePrimary Interlock Switch Test Run the oven and check all functionsTouch Control Panel Assembly Test Procedure Component Test Letter Monitor Switch TestKEY Unit Test Figure of all digits flickerMenu 1ST Stage 2ND Stage 3RD Stage STEAKS/CHOPS Level Time Relay TestCompu Defrost Test Steps Occurrence Cause or Correction Primary on the PWB, this foil pattern acts as a fuseChecking the initial sensor cooking condition Testing Method for AH Sensor AND/OR Control UnitAH Sensor Test Sensor Dummy Resistor Circuit Checking Control UnitR1, R2 22Ω ± 1% 1/2W R3 4.3Ω ± 5% 1/4W R4 1MΩ ± 5% 1/4W Synchronizing Signal Circuit Reset CircuitIndicator Circuit Power Source CircuitLSI Description of LSIKey strobe signal Signal similar to ANI3Internal clock oscillation frequency control input setting Power source voltageCommon data signal Converter power source voltage GND0VConverter power source voltage Detector Circuit of Absolute Humidity Sensor Circuit Absolute Humidity Sensor CircuitStructure of Absolute Humidity Sensor Operational Principle of Absolute Humidity SensorServicing Tools Other PrecautionsTouch Control Panel Servicing Servicing of Touch Control PanelTo prevent an electric shock, take the following pre Component Replacement and Adjustment ProcedureOuter Case Removal Magnetron Removal Power Transformer RemovalRe-install High Voltage Rectifier and High Voltage Capacitor RemovalOven Lamp and Lamp Socket Removal Positive Lock Connector NO-CASE Type RemovalControl Panel Assembly Removal Graphic Sheet and Membrane Switch ReplacementTurntable Motor Removal InstallationRear View InstallationCooling FAN Motor Removal RemovalAfter adjustment, check the following Door ReplacementSealer Film RE-INSTALLAfter any service, make sure of the following High Voltage Components DiagramCircuit Control Unit Figure S-5 . Printed Wiring Board of Power Unit Parts List Model Number HOW to Order Replacement PartsMiscellaneous SCREWS,NUTS and WashersOven and Cabinet Parts Control Panel Parts Door Parts Miscellaneous Packing and Accessories Copyright 2006 by Sharp Corporation ALL Rights Reserved

R-520LK, R-520LW specifications

The Sharp R-520LW and R-520LK are innovative microwave ovens that combine advanced technology with user-friendly features to enhance cooking experiences. Designed with modern kitchens in mind, these models embody efficiency, precision, and versatility.

One of the defining characteristics of both the R-520LW and R-520LK is their powerful 900-watt output, which allows for speedy cooking and reheating. This high wattage ensures that food is cooked evenly and retains its moisture, preventing the common issue of dry or unevenly heated meals. Furthermore, the inclusion of multiple cooking power levels provides users with flexibility, making it easy to select the ideal setting for various types of food.

Both models feature Sharp's signature Inverter Technology. Unlike traditional microwaves that use a turn-on and turn-off cycling method, inverter technology delivers a steady stream of cooking power. This results in more consistent heating, allowing delicate foods such as fish or custards to be cooked perfectly without overcooking the edges. This technology not only enhances the quality of cooked food but also improves the overall efficiency of the microwave.

The R-520LW and R-520LK come equipped with a variety of auto-cook settings that cater to different culinary needs. From popcorn to frozen vegetables, these pre-programmed settings allow users to prepare meals with just a touch of a button, making cooking uncomplicated for all skill levels. The large, user-friendly control panel features intuitive buttons and a digital display, ensuring effortless operation and visibility.

In terms of design, the R-520LW boasts a sleek white finish, while the R-520LK offers a modern black aesthetic. Both models are compact yet spacious, with a generous interior capacity that can accommodate a range of dish sizes. The turntable feature further enhances cooking efficiency by ensuring even cooking all around.

Cleaning and maintaining the R-520LW and R-520LK is a breeze, thanks to their easy-to-wipe surfaces and the interior's cavity that can be easily accessed. The durable construction of these microwaves means they are designed to withstand the rigors of daily use.

In summary, the Sharp R-520LW and R-520LK microwave ovens stand out with their advanced features, such as inverter technology and pre-programmed cooking settings, making them excellent choices for anyone looking to streamline their kitchen tasks. Their stylish designs and user-friendly interfaces further enhance their appeal, making them valuable additions to any modern home.
Top Page Image Contents