Specifications

B-field Exposure From Induction Cooking Appliances 25
Figure 18: Time-domain signals of the alternating magnetic field generated by ap-
pliance 2. Graphs a) and b) correspond to the heat settings 4 and P. The fundamental signal
frequencies are, respectively, 52.1 kHz and 21.2 kHz. The signal rms-value increases approxi-
mately by a factor of 2.5 for heat settings from 4 to P. Graphs c) and d) correspond to the heat
settings 4 and P and show a signal envelope with a frequency of 100 Hz that remains constant
for all heat settings; d) also shows a 50 Hz component. Graphs e) and f) correspond to the heat
settings 1 and 4. For heat settings 1 to 4, the signal is pulse-width modulated, with a frequency
of 0.5 Hz.
Discussion The two built-in appliances and the portable appliance present similar character-
istics. The signal rms-value increases with the heat setting for all three appliances. As shown
in Figures 17 a) and b), 18 a) and b) and 19 a) and b), the rms-value increases approximately
by a factor of 5, 2.5 and 4 when the heat setting varies from the lowest to the highest values,
for appliances 1, 2 and 3, respectively. At the opposite, the frequency of the signal decreases
when the heat setting increases (see Table 5). Figures 17 a) and b), 18 a) and b), and 19 a)
and b) also show that the shape of the signal changes for different heat settings. For all three
appliances, the signal shape is a triangle at the lowest heat setting and changes into a sinusoidal
at the highest heat setting. Figures 17 c and d), 18 c) and d), and 19 c and d) display the
signals envelopes. The envelope frequency (100 Hz, 100 Hz and 300 Hz for appliances 1, 2 and 3,