Sensor Reheat; Steam Sensor And Digital Programmer Circuit; Convection Cooking Control - Panasonic NN-C784MF 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
Frozen MEDIUM-HIGH
Vegetables
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
P2 K Factor
Power Standard
LOW 0.1
P2 K Factor
Power Standard
MEDIUM-HIGH 0.2
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.

Convection Cooking Control

The digital programmer circuit controls the ON-OFF time of the
heater in order to control oven cavity temperature.
1. After the [Start] pad is tapped with the desired Bake/Broil
program set, an 12V DC singal comes out of the digital
programmer circuit and is applied to coil of power relay
(RY4).
2. When the contacts of power relay RY4 close, power source
voltage is applied to the heater and the heater turns on.
3. When the oven temperature reaches the set temperature,
the digital programmer circuit senses the temperature
through oven temp sensor and stops supplying and 12V DC
signal to the coil of power relay RY4 and the heater turns
off.
4. After the heater turns off, the oven temperature will
continue increasing a while and then decrease as shown in
Figure. When the oven temperature drops below the set
temperature, the digital programmer circuit senses the
signal and starts supplying an 12V DC signal to the coil of
power relay again.
7
NN-C784MF
T2 TIME (Remainingcooking time)
27 Sec. ~ 1Min.12 Sec.