Hello from San Diego:
Classifying products according to EN 61000-3-2 is
not straight-forward.
A product with the "special waveshape" (i.e., the
waveshape created by a rectifier-capacitor circuit
of a switching-mode or linear power supply) is
Class D.
A product with input current waveform having the
"special waveshape" is not likely comply with the
Class D limits. So, the product must be changed
such that its input current waveform is outside
the "special waveshape," in which case the class
changes to Class A.
The Class D exemption for low-power products (i.e.,
75 W initially and 50 W later) is an exemption
from Class D. The low-power products must comply
with Class A. (Since the Class A limits are
absolute, low-power products readily comply with
the limits regardless of waveshape.)
EN 61000-3-2 is really a strange standard in its
construction. It establishes Class D with limits.
But, for all practical purposes, a product with
input current waveform of the "special waveshape"
cannot meet the Class D limits! The limits
essentially outlaw Class D (i.e., rectifier-
capacitor input) products!
The standard might just as well have simply said
that the products (except low-power products)
having the "special waveform" are not permitted.
Best regards,
Rich
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