Convection Cooking Control - Panasonic NN-CF770M CPH Service Manual

4.6.

Convection cooking control

The digital programmer circuit controls the ON-OFF time of the
heater in order to control oven cavity temperature.
1. After selecting desired
Convection/Grill Convection (the range of selected oven
temp is 100°C-250°C) and pressing [Start] button, a high
level signal comes out of the micro computer and applies to
power relay (RY6).
2. When RY6 are switched to ON, power source voltage is
applied to the convection heater, and the heaters turn on.
3. The digital programmer circuit senses the oven cavity
temperature through oven temp sensor (thermistor). When
the oven temperature reaches the set temperature, DPC
stops supplying high level signal to the power relay, and the
heater turn off.
4. After the convection heater turn off, the oven temperature
will continue increasing for a while and then decrease.
When the oven temperature drops below the set
temperature, the digital programmer circuit senses the
signal and starts supplying a high level signal to RY6 again.
NOTE:
a. If only convection heater works, convection motor
would rotate for over 1 minute after cooking to cool
oven and electric components.
b. After convection cooking, fan motor rotates for 1~6
minutes to cool oven and electric components.
oven cavity temperature of
9
NN-CF770M