Description Of Operating Sequence - Panasonic NE-C1153 Service Manual

6 DESCRIPTION OF OPERATING SEQUENCE

6.1. Variable power cooking control (MICROWAVE)
The coil of power relays are energized intermittently by the digital programmer circuit, when the oven is set at any power selection
except for High power position. The digital programmer circuit controls the ON-OFF time of power relays contacts in order to vary
the output power of the microwave oven.
The relation between indications on the control panel and the output of the microwave oven is as shown.
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.
6.2. Convection cooking control
The digital programmer circuit controls the ON-OFF time of convection heater in order to control the oven cavity temperature, see
table and figure.
1. The digital programmer circuit generates the power relay control signals at a specific timing.
2. When the oven reaches the selected temperature, the digital programmer circuit senses the temperature through oven temp
sensor and stops supplying 18V DC to the power relays resulting in turn off convection heaters. After the heaters have been
turned off, the oven temperature will continue to increase a while then decrease as shown in figure.
3. When the oven temperature drops below the selected temperature, the digital programmer circuit senses the oven temperature
and starts supplying 18V DC to the coils of power relays alternately.
NOTE:
After convection process, if oven temerature is higher than predetermind temperature, the fan motor will operate for
5 minutes at maximum speed to cool the electric components of the oven.
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NE-C1153 / NE-C1153C