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变压器磁是可以做为初级元件来处理的,这种情况多用于开关电源产品内的高频变压器。2 y, | B4 Q( S7 i
6 s9 F/ j5 S9 C1 _- \' \$ C在标准中的Table 2H中有对此种情况进行了说明。见下文(摘录于标准)
9 M6 _) [- ~8 z5 ` NThe term "conductive part" refers to an electrically conductive part that is/ G; Q7 s, L! |6 Q' d9 h! n
– not normally energized, and
' `' D# V$ K3 ?$ R* b; Y* {8 C# e8 h$ j– not connected to any of the following:) H, g0 S; y/ u: f/ P. q
• a circuit at HAZARDOUS VOLTAGE, or$ a" R- c( C6 ]2 n- [ y; T
• an ELV CIRCUIT, or
, B1 ^8 |# Q- l1 @( E8 s• a TNV CIRCUIT, or
2 `$ _& `% A1 [" ?% O• an SELV CIRCUIT, or
( _$ h8 ?4 M% P0 o4 I• a LIMITED CURRENT CIRCUIT.7 W$ [* x8 o, M- r% n) j
Examples of such a conductive part are the BODY of equipment, a transformer core, and in some cases a9 |' r3 W! \/ X
conductive screen in a transformer.
6 B7 ]: M3 l0 Q$ Q" s+ O. nIf such a conductive part is protected from a part at HAZARDOUS VOLTAGE by:2 `! h! W; G' C$ t: F
– DOUBLE INSULATION or REINFORCED INSULATION, it is termed a "double-insulated conductive part";
, S4 |) ^. \0 R+ Y) S– BASIC INSULATION plus protective earthing, it is termed an "earthed conductive part";
" w( w, x9 l$ n' R, f– BASIC INSULATION but is not earthed, that is it has no second level of protection, it is termed a "basic-insulated- `* n: c/ ~+ h
conductive part".1 \$ F6 C# p/ I" I9 Y* I
A circuit or conductive part is termed "earthed" if it is connected to a protective earthing terminal or contact in
7 t( I1 ^# M+ x4 ? Xsuch a way as to meet the requirements in 2.6 (although it will not necessarily be at earth potential). Otherwise
' t; c/ R) O! |& r) Z8 Z" h, A. f0 @7 _the circuit or conductive part is termed "unearthed". |
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