I read in !emc-pstc that Lesmeister, Glenn <[email protected]>
wrote (in <[email protected]
orp.net>) about 'EN 61000-3-3', on Fri, 31 Aug 2001:
>However, the new annex B
>that defines the test clearly indicates in the introduction (B.1) that the
>purpose of the test is to address the repeatability issues inherent in
>manually operated (presumably mechanical) switches through a statistical
>analysis. If your device does not have a switch or if it uses an electronic
>circuit to turn on the power, the test would presumably not be subject to
>the variations in question and thus you would not need to perform the test.
That is a misinterpretation. If it has a switch of any sort, you use
*that* switch. If it has no switch then 'manual switching' is not
possible. It is assumed that this applies only to very low-power
equipment, or permanently connected equipment. For other equipment,
safety standards normally require a switch.
The variations in inrush current have something to do with the switch
characteristics (that's why you must use the equipment's own switch) but
also with the epoch ('point on waveform') at which switching occurs. If
there is a mains transformer, this applies to switch-off as well as
switch-on.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Eat mink and be dreary!
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