Mains harmonics input current levels for a five step stairstep current waveform?

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Flyback

Well-Known Member
Hello,

Rearding Class C regulatory limits for mains harmonic currents (EN61000-3-2)…..is it possible for a mains input current to a ~150W offline product to pass Class C regulations when it has no more than five steps in a “stairstep” mains input current waveform?
Attached is the LTspice simulation of a “product” which produces a five stage “stairstep” mains input current waveform. If you run the FFT on the input current waveform, you will see that it fails Class C regulations for Mains harmonic current levels.

(The excel doc shows that it fails)
What I am asking is…… is it ever possible for a five step “stairstep” mains current to ever pass Class C harmonic regulations?

Page 7 of the following shows the Class C mains harmonic current limits….
**broken link removed**
(EN61000-3-2)
 

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  • Five stage stairstep input current.jpg
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  • Five Stair step current waveform.asc
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  • Five stage stairstep current.zip
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