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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。
) o3 U. s2 x, n9 g8 _8 @2 d
5 [ g: R9 q7 ]& Q! L' X+ b# p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)" \! \; g7 N y" l+ `! Z
The term "conductive part" refers to an electrically conductive part that is
, U! w$ P, |1 |# t– not normally energized, and
* ^& i# D1 \+ d– not connected to any of the following:
; Q; Y7 L( A0 B7 A. R• a circuit at HAZARDOUS VOLTAGE, or) J1 x' Q p9 k! Y
• an ELV CIRCUIT, or
( v4 P2 x! @0 z5 y9 c• a TNV CIRCUIT, or
1 B! N( Z* Y& }, M• an SELV CIRCUIT, or7 C) b) v- F# ]. v* g
• a LIMITED CURRENT CIRCUIT.# B: h" O1 i# E, Q" \/ B' T
Examples of such a conductive part are the BODY of equipment, a transformer core, and in some cases a
4 T; ?, K5 {1 \/ _conductive screen in a transformer.% b: f: m/ C3 j I
If such a conductive part is protected from a part at HAZARDOUS VOLTAGE by:+ Z! f4 I0 j+ B1 ^) T
– DOUBLE INSULATION or REINFORCED INSULATION, it is termed a "double-insulated conductive part";
1 _& M1 V3 B |3 w% [, ^– BASIC INSULATION plus protective earthing, it is termed an "earthed conductive part";
9 v w& k# Q5 n% z7 W3 t" O7 ^– BASIC INSULATION but is not earthed, that is it has no second level of protection, it is termed a "basic-insulated
) t: o; F+ l& b$ B: | ]: econductive part".
1 M& F6 j3 J8 o# I8 h& h& J! ]A circuit or conductive part is termed "earthed" if it is connected to a protective earthing terminal or contact in/ f/ M& A6 Q& I' A1 K
such a way as to meet the requirements in 2.6 (although it will not necessarily be at earth potential). Otherwise
6 D8 J, u8 x0 P# D+ Q3 d4 Fthe circuit or conductive part is termed "unearthed". |
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