Panasonic NE-1027 - 3 Schematic Diagram; 4 Description of Operating Sequence; Variable Power Cooking Control (NE-1037)

4.1. Variable power cooking
control (NE-1027)
The vari-power controller controls the ON-OFF time of the vari-
power switch to vary the output power of the microwave oven
from "100" to "1000". The vari-power controller is a part of the
timer assembly. The timer assembly consists of timer motor,
timer switch, vari-power switch and the combination of gears,
cam and actuater lever.
One complete cycle of the vari-power controller is 26 seconds,
in which the vari-power switch is turned "on" or "off" by the cam
rotation is the 26 ± 2 second period.
By controlling the timing of the vari-power switch "on" period,
the power AC supplied to the high voltage transformer is
interrupted intermittently so that the average output power of
the microwave oven is varied.
Table shows the timing chart of vari-power switch operation in
respect to the power setting on the control panel.
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.
OUTPUT ON-OFF TIME OF
POWERSETTING POWER(W)A
PPROX.
VARI-POWER SWITCH
(Mechanical timer model)
ON(SEC) OFF(SEC)
1000 1000 26 0
600 600 20 6
440 440 15 11
DEFROST 340 10 16
250 250 8 18
100 100 4 22
4.2. Variable power cooking
control (NE-1037)
The coil of power relay B (RY1) is 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 relay B
contacts in order to vary the output power of the microwave
oven from "Low" to "High" power. One complete ON and OFF
cycle of power relay B is 22 seconds. The relation between
indications on the control panel and the output of the
microwave oven is as shown in table.
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.
*OUTPUT ON-OFF TIME OF
POWER SETTING POWER(W) POWER RELAY B (RY1)
APPROX. ON(SEC) OFF(SEC)
HIGH 1000 22 0
MEDIUM 500 11 11
DEFROST 340 8 14
*IEC-705-88 test procedure.
Specifications Subject to change without notice
4 DESCRIPTION OF OPERATING SEQUENCE
11
NE-1027 / NE-1037