Method and apparatus for searching electromagnetic disturbing source and non-contact voltage probe apparatus therefor

An apparatus for searching for an electromagnetic interference source, comprising:

• a plurality of non-contact voltage probes respectively connected in non-contact relationships with a plurality of cables connected to pieces of electronic equipment;
• a plurality of non-contact current probes respectively connected in non-contact relationships with the plurality of cables;
• means for inputting therein a voltage and a current of the electromagnetic interference source both measured by voltage and current probes connected to the same cable of said plurality of cables and calculating an effective component of energy of each electromagnetic interference source;
• and
• means for specifying an invading route of each electromagnetic interference source from a direction in which a calculated energy flows.

An apparatus for searching for an electromagnetic interference source, comprising:

• means for measuring, in a time domain, waveforms of a voltage v(t) and a current i(t) of the electromagnetic interference source developed in each of cables connected to electronic equipment;
• means for recording measured waveforms of voltage and current therein;
• means for converting the measured waveforms of voltage and current into waveforms of a voltage and a current in a frequency domain respectively;
• means for calculating energy for each frequency, based on the voltage and current waveforms in the frequency domain;
• and
• means for displaying the calculated energy for each frequency in the form of positive and negative polarities of the energy and a magnitude thereof so as to correspond to coordinates indicative of each frequency.