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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。, O _* b$ a/ v' a$ y0 a6 N; U
- _& V J1 z7 j k8 R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); z, ?: A. z* J+ a; R# u" {
The term "conductive part" refers to an electrically conductive part that is) C# S6 ]/ Y& N& F: m$ B& L8 A3 x# Y j
– not normally energized, and
6 P0 u2 U: ?6 Z# ?; ~# r– not connected to any of the following: h; _( \2 p6 R/ u9 v
• a circuit at HAZARDOUS VOLTAGE, or
, l+ O' s" d+ }8 F+ L" ^• an ELV CIRCUIT, or
3 k. U6 y+ ^; p5 ]0 Z; \, c# O/ ?• a TNV CIRCUIT, or, A3 N' {/ R m8 s: z0 Y2 a l
• an SELV CIRCUIT, or6 n3 k- v2 j9 P0 A
• a LIMITED CURRENT CIRCUIT.
$ ]# ?5 i* q. Y, E9 ]3 v% K; N% JExamples of such a conductive part are the BODY of equipment, a transformer core, and in some cases a' i+ d2 h/ q, H9 z3 v
conductive screen in a transformer.
' q( v; a4 l# `) w& o+ lIf such a conductive part is protected from a part at HAZARDOUS VOLTAGE by:
' O9 @4 ~$ f& b; R( ^– DOUBLE INSULATION or REINFORCED INSULATION, it is termed a "double-insulated conductive part";
3 v0 @! n# D$ Y- h N– BASIC INSULATION plus protective earthing, it is termed an "earthed conductive part";
' o( }$ ]: B2 ^) w, q– BASIC INSULATION but is not earthed, that is it has no second level of protection, it is termed a "basic-insulated
: S7 a/ P- U B& c, zconductive part".3 {6 E1 j( J1 B
A circuit or conductive part is termed "earthed" if it is connected to a protective earthing terminal or contact in
, g$ I' R0 V. _$ N; Gsuch a way as to meet the requirements in 2.6 (although it will not necessarily be at earth potential). Otherwise, U- r. z* `; k. S) a: |
the circuit or conductive part is termed "unearthed". |
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