R216LS

CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY

[1] OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units as shown in the touch control panel circuit.

(1) Key Unit (2) Control Unit

The principal functions of these units and their related signals are explained below.

1. Key Unit

The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit through P24, P25, P26, P31, P32 and P33. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P50, P51, P52 and P53 to perform the function that was requested.

2. Control Unit

Control unit consists of LSI, reset circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit and synchronizing signal 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 4-digits, 12-segments and 3-common electrodes using a Liquid Crystal Display.

3)Power Source Circuit

This circuit generates voltage 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

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.

[2] SERVICING FOR TOUCH CONTROL PANEL

1. Precautions for Handling Electronic Components

This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit.

In order to protect CMOS LSI.

1)When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap PW boards containing them in aluminium foil.

2)When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.

approx. 1M ohm

2. Servicing of Touch Control Panel

We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so. To perform the servicing, power to the touch control panel is available either from the power line of the oven itself or from an external power source.

1. Servicing the touch control panel with power supply of the oven :

CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZ- ARD .

Therefore, before checking the performance of the touch control panel, 1) Disconnect the power supply cord and then remove outer case.

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Sharp R-216LS Touch Control Panel Assembly, Outline of Touch Control Panel, Servicing for Touch Control Panel

R-216LS specifications

The Sharp R-216LS is a versatile microwave oven that combines affordability with a range of features designed to enhance your cooking experience. Compact yet powerful, this model is especially suitable for small kitchens or dorm rooms, where space is at a premium.

One of the standout features of the Sharp R-216LS is its impressive 800 watts of cooking power. This ensures quick and efficient heating, allowing users to prepare meals in a fraction of the time compared to conventional ovens. The microwave also features a variety of power levels, providing flexibility for different types of cooking and reheating tasks, from defrosting frozen food to cooking delicate items like baked goods.

The R-216LS comes equipped with a spacious 20-liter capacity, which is surprisingly roomy for its size. This allows for ample space to heat up large dishes or multiple servings at once. The interior is designed with easy cleaning in mind, featuring a non-stick coating that prevents food from adhering to the surfaces and simplifies maintenance.

In terms of usability, the Sharp R-216LS boasts a user-friendly interface with straightforward knobs and buttons. It includes a timer and a range of pre-programmed cooking options, enabling users to cook a variety of foods with just the touch of a button. This is particularly beneficial for those new to microwave cooking or for busy individuals looking to save time.

The microwave also incorporates advanced technologies, including inverter microwave technology, which provides a continuous stream of cooking power for more even heating and defrosting. This ensures that your food is cooked thoroughly without the risk of hot and cold spots.

Safety is another priority in the design of the R-216LS. It features a child safety lock, which prevents accidental operation, making it a perfect choice for families with young children. The model also has an automatic shut-off feature, ensuring that the microwave turns off when not in use.

In summary, the Sharp R-216LS is a compact microwave that offers a blend of power, convenience, and safety features, making it an excellent choice for anyone seeking a reliable cooking appliance. Whether for reheating leftovers, cooking meals, or defrosting ingredients, this microwave is designed to meet the diverse needs of modern kitchens. With its combination of thoughtful design and functionality, the R-216LS stands out as a worthy investment for those looking for efficiency and performance in their cooking appliances.