Sharp R-530EK Absolute Humidity Sensor Circuit, Common data signal COM9, Common data signal COM10

Page 27

R - 5 3 0 E K

R - 530EW

Pin No.

Signal

I/O

 

Description

 

 

 

 

 

 

 

143

COM7

OUT

Common data signal : COM9.

Connected to LCD signal COM9.

 

 

 

 

 

 

 

144

COM6

OUT

Common data signal : COM10.

Connected to LCD signal COM10.

 

 

 

 

 

 

 

ABSOLUTE HUMIDITY SENSOR CIRCUIT

(1)Structure of Absolute Humidity Sensor

The absolute humidity sensor includes two thermistors as shown in the illustration. One thermistor is housed in the closed vessel filled with dry air while another in the open vessel. Each sensor is provided with the protective cover made of metal mesh to be protected from the

external airflow.

Thermistors

ventilation opening for sensing

 

Sensing part

Sensing part

 

(Open vessel)

(Closed vessel)

 

 

 

 

(2)Operational Principle of Absolute Humidity Sensor The figure below shows the basic structure of an absolute humidity sensor. A bridge circuit is formed by two thermistors and two resistors (R1 and R2).

The output of the bridge circuit is to be amplified by the operational amplifier.

Each thermistor is supplied with a current to keep it heated at about 150˚C (302˚F), the resultant heat is dissipated in the air and if the two thermistors are placed in different humidity conditions they show different degrees of heat conductivity leading to a potential difference between them causing an output voltage from the bridge circuit, the intensity of which is increased as the absolute humidity of the air increases. Since the output is very minute, it is amplified by the operational amplifier.

 

 

 

 

Absolute humidity vs,

C

 

Operational

output voltage characteristic

R1

amplifier

voltageOutput

S

R2

 

S : Thermistor

 

 

 

Output

 

 

 

+

voltage

 

R3

 

 

open vessel

 

 

 

C : Thermistor

 

 

 

 

closed vessel

 

 

 

 

 

Absolute humidity (g/m 2)

(3)Detector Circuit of Absolute Humidity Sensor Circuit This detector circuit is used to detect the output voltage of the absolute humidity circuit to allow the LSI to control sensor cooking of the unit. When the unit is set in the sensor cooking mode, 16 seconds clearing cycle occurs than the detector circuit starts to function and the LSI observes the initial voltage available at its AIN5 terminal.

With this voltage given, the switches SW1 to SW5 in the LSI are turned on in such a way as to change the resistance values in parallel with R98 ~ R102. Changing the resistance values results in that there is the same potential at both F-3 terminal of the absolute humidity sensor and AIN4 terminal of the LSI. The voltage of AIN5 terminal will indicate about -2.5V. This initial balancing is set up about 16 seconds after the unit is put in the Sensor Cooking mode. As the sensor cooking proceeds, the food is heated to generate moisture by which the resistance balance of the bridge circuit is deviated to increase the voltage available at AIN5 terminal of the LSI.

Then the LSI observes that voltage at AIN5 terminal and compares it with its initial value, and when the comparison rate reaches the preset value (fixed for each menu to be cooked), the LSI causes the unit to stop sensor cooking; thereafter, the unit goes in the next operation automatically.

When the LSI starts to detect the initial voltage at AIN5 terminal 16 seconds after the unit has been put in the Sensor Cooking mode, if it is not possible to balance the bridge circuit due to disconnection of the absolute humidity sensor, ERROR will appear on the display and the cooking is stopped.

1) Absolute humidity sensor circuit

 

 

 

R98

 

620k

 

 

26

SW1

 

 

 

 

 

 

P20

 

 

 

 

 

 

 

 

 

 

 

 

R99

 

300k

 

 

25

SW2

 

 

 

 

 

 

 

 

 

P21

 

 

 

R100

 

150k

 

 

24

SW3

 

 

 

 

 

 

 

 

 

P22

 

 

 

R101

 

75k

 

 

23

SW4

 

 

 

 

 

 

 

 

 

P23

C. Thermistor in

R102

 

37.4k

 

 

22

SW5

 

 

 

 

 

 

P24

closed vessel

 

 

 

 

 

 

 

S. Thermistor in

 

 

 

 

 

 

 

 

open vessel

 

R97

 

 

 

50

AIN4

 

 

 

47k

0.01uF

0.015uF

 

 

 

 

 

0.01uF

 

 

F-1

 

 

 

C93

 

LSI

 

 

 

 

 

C

 

R96

 

 

C91

 

C92

 

(IC1)

 

 

 

 

 

 

F-3

3.57k

 

 

 

 

 

 

 

 

 

 

R94

 

 

 

 

 

 

 

R95

49

 

 

 

C90

0.1 uF

8 7 6 5

AIN5

 

 

 

 

 

S

 

1 2 3 4

10k

47k

 

 

R91

 

 

 

 

R92

 

 

 

 

F-2

3.32k

IC2

R93

 

 

 

 

 

 

1.8k

360k

 

D91

 

 

 

 

 

 

 

 

 

 

 

R90

 

 

D90

 

 

 

 

 

VA : -15V

 

VA : -15V

VC : -5V

 

 

25

Image 27
Contents Models R 5 3 0 E K R-530EW Table of ContentsBefore Servicing Dont Touch Before Servicing When the testing is completedMicrowave Measurement Procedure RequirementsLeakage test Foreword Sharp PLAZA, MahwahMicrowave Oven 530EK/ R-530EWGrounding Instructions SpecificationGeneral Information DescriptionTouch Control Panel Oven DiagramDescription of Operating Sequence OperationCooking Sequence MicrowaveFigure O-1. Oven Schematic-Off Condition Description and Function of Components Troubleshooting Guide CK = Check / RE = Replace Power Transformer Test Test ProceduresProcedure Letter Component Test Magnetron Assembly Test Microwave Output PowerHigh Voltage Rectifier Test Procedure Letter Component TestCavity Temperature Fuse Test Magnetron Temperature Fuse TestPrimary Interlock System Test Secondary Interlock Switch TestDoor Sensing Switch Monitor Switch TestTouch Control Panel Assembly Test Before testingBlown Monitor Fuse Test KEY Unit Test Compu Defrost Test Relay TestFoil Pattern on the Printed Wiring Board Test Procedure Component Test LetterWater load cooking test Testing Method for AH Sensor AND/OR Control UnitAH Sensor Test Checking the initial sensor cooking conditionSensor Dummy Resistor Circuit Checking Control UnitTouch Control Panel Assembly LSIIXA098DR Signal coming from touch key Pin No Signal DescriptionSignal synchronized with commercial power source frequency Key strobe signalCommon data signal COM7 Power source voltage GND0VInternal clock oscillation frequency control input setting Common data signal COM8Structure of Absolute Humidity Sensor Common data signal COM9Common data signal COM10 Absolute Humidity Sensor CircuitKRC243M Touch Control Panel ServicingOuter Case Removal Component Replacement and Adjustment ProcedureMagnetron Removal Power Transformer RemovalReinstallation High Voltage Rectifier and High Voltage Capacitor RemovalTurntable Motor Removal Positive Lock Connector NO-CASE Type RemovalControl Panel Assembly Removal Oven Lamp and Lamp Socket RemovalRemoval AH Sensor ReplacementInstallation Cooling FAN Motor RemovalDoor Replacement After adjustment, check the followingRemoval Sealer Film ReinstallationAfter any service, make sure of the following InstallationHigh Voltage Components Figure S-1. Pictorial DiagramFigure S-2. Power Unit Circuit OFF Cook CircuitRY1 RY3 TTM ZD1SP1 VRB RY2Control Panel Parts Parts ListElectric Parts Cabinet PartsSCREWS,NUTS and Washers HOW to Order Replacement PartsDoor Parts MiscellaneousOven and Cabinet Parts Control Panel Parts Door Parts Miscellaneous Packing and Accessories Copyright 2001 by Sharp Corporation ALL Rights Reserved

R-530EK specifications

The Sharp R-530EK is a notable microwave oven that combines functionality with innovation to enhance cooking convenience. With a sleek design and user-friendly interface, this model has earned a place in many kitchens around the globe.

One of the primary features of the Sharp R-530EK is its powerful microwave output. The oven boasts a maximum power of 900 watts, ensuring that food can be heated quickly and evenly. This power level allows users to prepare a variety of meals, from reheating leftovers to cooking dishes from scratch, in significantly less time than traditional cooking methods.

The R-530EK is equipped with a spacious interior, offering 25 liters of capacity. This ample space allows for cooking larger dishes or multiple servings at once. The turntable design ensures even cooking by rotating food during the heating process, further enhancing the microwave's efficiency.

Another standout feature of the Sharp R-530EK is its array of pre-programmed auto-cook menus. These presets simplify cooking by providing specific times and power levels for various types of food, including popcorn, pizzas, and oatmeal. Users can simply select the appropriate setting, and the microwave takes care of the rest, making it ideal for those who may not have extensive cooking experience.

The microwave utilizes advanced inverter technology, a feature that sets it apart from many conventional microwave ovens. Inverter technology allows for continuous and consistent power output, providing more precise temperature control. This means that delicate foods such as seafood or chocolate can be heated without the risk of overcooking or burning, resulting in better texture and flavor.

Additionally, the R-530EK is designed with multiple cooking functions that enhance its versatility. These include defrosting capabilities, grilling options, and even signals indicating the completion of cooking cycles. The easy-to-read digital display and intuitively designed buttons contribute to the overall user experience, making it accessible for individuals of all ages.

Moreover, this microwave oven ensures safety with features such as a child lock, which prevents accidental operation by little hands. The Sharp R-530EK is both an efficient and reliable addition to any kitchen, embodying the perfect blend of cutting-edge technology and practical design to meet the demands of modern cooking. With its impressive range of features and performance capabilities, it stands as a valuable tool for aspiring chefs and busy families alike.