This paper presents evidence based on manufacturer specifications and field measurement that the switching frequency of a Landis + Gyr smart meter SMPS is about 130 kHz. Further, that this creates a harmonic-rich signal that is readily induced in the hot legs of a 100-amp residential service entrance. Evidence from field measurement is also presented showing that this harmonic-rich switching frequency is radiated from the meter.
Studies are coming out that show these frequencies, sometimes called intermediate frequencies, from common devices can do biological harm, especially if there is direct contact between ones body and the device.
This paper also shows the current waveforms of two switching power supplies. We see harmonic distortion indicating a low power factor and a spectrum analysis of this harmonic distortion. The paper explains how these images can be used for product identification. Power factor correction of a SMPS will change any such signature and quite possibly reduce the likelihood of making a positive identification of the associated device. Power factor correction has no effect on the switching frequency or its harmonics.
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