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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。
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: X3 g+ u6 z# c2 Q/ k3 h. w( G- L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)
8 m3 R' \5 \" ]# x$ D$ c; \7 z$ xThe term "conductive part" refers to an electrically conductive part that is( r0 w$ G$ C& ^) `
– not normally energized, and, N0 \' l4 B3 ~" R) S
– not connected to any of the following:, Q9 [% W' [ w r& A
• a circuit at HAZARDOUS VOLTAGE, or
6 W. b$ g. B, @2 W• an ELV CIRCUIT, or, Z. z. F( C* I( M/ b
• a TNV CIRCUIT, or- l5 T& X* v: F6 _% S6 i
• an SELV CIRCUIT, or
4 C' k9 l4 A( Q1 J2 j$ L' h# a• a LIMITED CURRENT CIRCUIT.; g% L$ e) E! F6 p( [
Examples of such a conductive part are the BODY of equipment, a transformer core, and in some cases a/ Q |/ O. X( a# L# O6 B
conductive screen in a transformer.
1 t! F; C9 o6 H, eIf such a conductive part is protected from a part at HAZARDOUS VOLTAGE by:
; t) [6 f/ K; }: T– DOUBLE INSULATION or REINFORCED INSULATION, it is termed a "double-insulated conductive part";
' H" M I% }! [8 I* v* p) \2 \1 Q– BASIC INSULATION plus protective earthing, it is termed an "earthed conductive part";
' I* N2 O, J2 |/ k7 K1 w– BASIC INSULATION but is not earthed, that is it has no second level of protection, it is termed a "basic-insulated% u' {; `7 |/ L& o, v
conductive part".
8 \" c2 W: v: `/ yA circuit or conductive part is termed "earthed" if it is connected to a protective earthing terminal or contact in! a/ R3 ] x E( S$ V
such a way as to meet the requirements in 2.6 (although it will not necessarily be at earth potential). Otherwise
, u) b$ X' [# C9 R/ L. d' Wthe circuit or conductive part is termed "unearthed". |
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