NN-SD698S / NN-ST678S / NN-ST658W

2 DESCRIPTION OF OPERATING SEQUENCE

2.1.Variable power cooking control

High Voltage Inverter Power Supply (U) controls output power by the signal from Digital Programmer Circuit (DPC). Power relay always stay on, but PWM (Pulse Width Modulation) signal controls microwave output power.

NOTE:

The ON/OFF time ratio does not correspond with the percentage of microwave power since approximately 2 seconds are required for heating of magnetron filament.

Variable Power Cooking

POWER SETTING

OUTPUT

MANUAL MICROWAVE

 

 

POWER(%)

DUTY

 

 

APPROX.

ON(SEC)

OFF(SEC)

HIGH

P10

100%

22

0

 

P9

90%

22

0

 

P8

80%

22

0

MEDIUM-HIGH

P7

70%

22

0

MEDIUM

P6

60%

22

0

 

P5

50%

22

0

 

P4

40%

22

0

MEDIUM-LOW

P3

30%

22

0

 

P2

20%

15

7

 

P1

10%

8

14

DEFROST

P3

30%

22

0

2.2.Inverter power supply circuit

The Inverter Power Supply circuit powered from the line voltage, 120V 60Hz AC input supplies 4,000V DC to the magnetron tube, and functions in place ofthe H.V. transformer, the H.V. capacitor and H.V. diode.

1.The AC input voltage 120V 60Hz is rectified to DC voltage immediately.

2.DC voltage will be supplied to the switching devices called IGBT. These devices are switched ON-OFF by the 20 to 40 kHz PWM (pulse width modulation) signal from the microcomputer in the DPC.

3.This drives the High voltage transformer to increase voltage up to 2,000V AC.

4.Then the half-wave doubler voltage rectifier circuit, consisting of the H.V. diodes and capacitors, generates the necessary 4,000V DC needed for the magnetron.

5.Output power of the magnetron tube is always monitored by the signal output from the current transformer built into the inverter circuit.

6.This signal is fed back to the microcomputer in the DPC to determine operating conditions and output necessary to control PWM signal to the Inverter Power Supply for control of the output power.

2.3.Inverter defrost

When the Auto Control feature is selected and the Start pad is tapped:

1.The digital programer circuit determines the power level and cooking time to complete cooking and indicates the operating state in the display window. Table shows the corresponding cooking times for respective serving by categories.

Inverter Turbo Defrost

SELECTED WEIGHT

COOKING TIME

1.0 LB

5 min.00 sec.

2.When cooking time in the display window has elapsed, the oven turns off automatically by a control signal from the digital programmer circuit.

2.4.Sensor cooking

Auto sensor cooking without setting a power level or selecting a time. All that is necessary is to select an Auto Sensor Program before starting to cook.

Understanding Auto Sensor Cooking

As the food cooks, a certain amount of steam is produced. If the food is covered, this steam builds up and eventually escapes from the container. In Auto Sensor Cooking, a carefully designed instrument, called the steam sensor element, senses this escape of steam. Then, based upon the Auto Sensor Program selected, the unit will automatically determine the correct power level and the proper length of time it will take to cook the food.

NOTE:

Auto Sensor Cooking is successful with the foods and recipes found in the Auto Sensor Cooking Guide. Because of the vast differences in food composition, items not mentioned in the Cooking Guide should be prepared in the microwave oven using power select and time features. Please consult Variable Power Microwave Cookbook for procedures.

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Panasonic NN-SD698S manual Description of Operating Sequence, Variable power cooking control, Inverter power supply circuit

NN-ST658W, NN-ST678S, NN-SD698S specifications

The Panasonic NN-SD688S and NN-SD698S are two high-performance microwave ovens designed to meet the needs of modern households. With cutting-edge technology and innovative features, these models offer a convenient way to heat, cook, and defrost a variety of foods.

At the heart of both models is the Inverter Technology, which provides consistent and precise cooking power throughout the microwave's cooking time. Unlike traditional microwaves that use a turn-on, turn-off method to regulate cooking power, the inverter system delivers a steady stream of energy. This allows for evenly cooked meals, reduces the chances of overcooking, and ensures delicate items like fish and vegetables retain their texture and flavor.

Both the NN-SD688S and NN-SD698S boast a spacious 1.2 cubic feet capacity, allowing users to easily accommodate large dishes and multiple servings. The sleek and modern stainless steel design ensures these microwaves fit seamlessly into any kitchen décor, while also being easy to clean and maintain.

The microwaves come equipped with an array of smart cooking features, including the Sensor Cook function. This technology automatically detects the steam released from food and adjusts cooking time and power levels accordingly. This feature takes the guesswork out of microwave cooking, ensuring perfectly cooked meals without constant monitoring.

Another standout feature is the Keep Warm function, which helps maintain food temperature without cooking it further. This can be especially useful when preparing multiple dishes or when meals need to be served at different times.

Both models also include a variety of pre-programmed cooking options, providing quick access to commonly prepared items. With one-touch settings for popcorn, pizza, and more, users can select their desired food type and let the microwave handle the rest.

In terms of safety, Panasonic has integrated a child safety lock to prevent accidental operation, which offers peace of mind for families with young children.

In summary, the Panasonic NN-SD688S and NN-SD698S microwaves reflect the brand's commitment to innovative cooking solutions. With features such as Inverter Technology, Sensor Cook, and a sleek design, these models are perfect for those seeking efficiency, convenience, and ease of use in their kitchen appliances. Whether reheating leftovers, cooking fresh meals, or defrosting ingredients, these microwaves offer versatility and reliability, making them essential tools for any modern kitchen.