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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。! Z% [' C: _& _+ a
* m5 @/ w% }" h: H% E% X) [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)/ n# d# M; V4 }/ {, Q( k+ ~
The term "conductive part" refers to an electrically conductive part that is% j1 B$ I9 h- y7 A4 i
– not normally energized, and
7 a% M* w: L0 Q6 d3 B2 q– not connected to any of the following:6 C! u" d0 `' l M3 X2 U/ R" o& }
• a circuit at HAZARDOUS VOLTAGE, or
" X* i* U2 }* {% G5 d# _: u. w( r2 u• an ELV CIRCUIT, or
( l3 L" B- m j% B" c5 @• a TNV CIRCUIT, or C1 ]- |1 F8 G
• an SELV CIRCUIT, or# w8 X8 ]+ o! g& j$ J' w
• a LIMITED CURRENT CIRCUIT.4 [$ P$ r9 W- B$ V9 Z
Examples of such a conductive part are the BODY of equipment, a transformer core, and in some cases a
# S4 O4 [$ c4 S8 H1 L) }conductive screen in a transformer.
6 A" r0 J0 _6 e$ K. `! cIf such a conductive part is protected from a part at HAZARDOUS VOLTAGE by:
T# H" s" _* o" H+ v% n" @' ^– DOUBLE INSULATION or REINFORCED INSULATION, it is termed a "double-insulated conductive part";
; _5 u8 W% U) }0 o# @– BASIC INSULATION plus protective earthing, it is termed an "earthed conductive part";5 ^$ i9 {6 C: u) P1 \# ]9 W# m
– BASIC INSULATION but is not earthed, that is it has no second level of protection, it is termed a "basic-insulated
/ A. Z4 y r- u3 W' _conductive part".
' g8 x1 @! ~, ` bA circuit or conductive part is termed "earthed" if it is connected to a protective earthing terminal or contact in H( r' U! M; A Z0 N- B( W
such a way as to meet the requirements in 2.6 (although it will not necessarily be at earth potential). Otherwise
5 L5 B: P* ^$ _/ O, Ethe circuit or conductive part is termed "unearthed". |
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