Page 120 - Power Electronics Handbook

EMCstandards 113
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a.c. supply ==c1 sw

Load
1 -$
a.c. supply sw
I

(b)

I 0

a.c. supply sw
1

IC)

1
a.c. supply
I

(d)
prrrc 4.8 Modidicstionr to the basic filter arrangements: (a) basic Ltype; (b) and (e) L-type;
(4 %-type

and the capacitors must have low series inductance. The filter should be
endosed in a screened box, which is connected to the wall of the shielded
enclosure, so that interference s@& cannot become coupled from the
noisy side to the quiet side of the system.

4.6 EMC standards
Most countries have their own standards organisations which regulate their
RFI policies, examples of these being the BSI in the UK, the FCC in the
USA, and the VDE in West Otrmany. The military also have their own
requirements, referred to as MIL-STD and DEF standards, although the
needs of commercial and military equipment are Merent. The military
require that their equipment continue to perform in battlefield conditions,
whilst commercial interests centre on the need to protect radio, television,
telecommunication and domestic systems.