Sensor Reheat; Steam Sensor And Digital Programmer Circuit; Thermistor - Panasonic NN-SD698S Service Manual

Explanation of the Auto Sensor Cooking process
1. During the first 10 second period there is no microwave
activity. When calculating the T2 time by using the
formula below make sure this 10 seconds is subtracted
from the T1 time. In other words, T1 time starts at the
end of the 10 second period.
2. T1 time The total amount of time it takes themicrowave
oven to switch to T2 time after the 10second period.
3. T2 time When the steam escapes from the cooking
container placed in the oven, the steam sensor detects
it and the microprocessor calculates the balance of
cooking time. This T2 time is then shown in the display
and begins counting down.
Balance of cooking time (T2 time)
The balance of cooking time which is called T2time, can
be calculated by the following formula.
T2 time (in sec.) = T1 time X K factor
NOTE:
Remember, the T1 time starts after the 10 second
period. The coefficient K is programmed into the
microprocessor memory and they are listed in the
following tables along with the P1 and P2 powers.
NOTE:
When "More" or "Less" pad is selected, the K factor
varies resulting in T2 time to be increased or decreased.
Example of calculating the T2 time
Example 1: If the T1 time is measured to be 2 minutes and
40 seconds after the 10 second period, and the Auto
program selected is Oatmeal:
T2 = T1 × K
= 2 min. and 40 sec. × 0.1
= 160sec. × 0.1
= 16 sec.
Category P1
Power
Oatmeal HIGH
P2 K Factor
Power Standard
HIGH 0.1
2.5.

Sensor reheat

Auto Sensor Reheat is a quick and easy way to reheat
refrigerated and room temperature foods.
Simply press the reheat pad. There is no need to select power
level and cooking time.
NOTE:
The Auto Sensor Reheat process is same as Auto Sensor
Cooking process.
Category P1
Power
Sensor Reheat HIGH
2.6. Steam sensor and digital
programmer circuit
In order to determine if the steam sensor function of the digital
programmer circuit is working, do the following test.
1. Place a water load (150 cc) in the oven.
2. Tap Sensor Reheat pad.
3. Tap Start pad.
4. Steam Sensor detects steam about 1.5 to 4 minutes after
the Start pad is tapped.
5. T1 time cooking automatically switches to remaining time
for cooking (T2).
6. The remaining cooking time (T2) appears in display
window. If the following cooking time appears, Steam
Sensor function is normal.
T1 TIME
1 Min. 30 Sec. ~ 4 Min.
2.7.

Thermistor

The thermistor which fixed on magnetron detects magnetron
temperature and make power down when the temperature
becomes abnormal high. A normal thermistor´s resistance
values for temperature ranges between 75-85 degree F is from
37kΩ to 57kΩ.
7
NN-SD698S / NN-ST678S / NN-ST658W
P2 K Factor
Power Standard
MEDIUM 0.3
T2 TIME (Remainingcooking time)
27 Sec. ~ 1Min.12 Sec.