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你所说的使用220V但电流限制0.7mA是哪类的产品?在IEC 60950-1标准的LCC章节定义中,电压并不是最终决定因素,而是需要考量该电压的环境就是:与LCC电路的连接须符合Clause 2.4.3前提下,该LCC电路的分类和测量方式下不超过Clause 2.4.2规定限值的,才是人体可以直接触摸的。
* G* S8 V* v" c- E注:要考虑测量时使用2000欧无感电阻、考虑电压的频率、还有该电路的电容量这些必不可少的因素。* ?. Q1 s9 b/ @) W: k
6 p/ X3 u4 v# k7 U2.4 Limited current circuits2 p3 v/ ~- K9 T- D* f
2.4.2 Limit values
! G C' o+ @$ d) x lFor frequencies not exceeding 1 kHz, the steady-state current drawn through a non-inductive5 F) s( C. O; ?# y( V. T
resistor of 2 000 Ω ± 10 % connected between any two parts of a LIMITED CURRENT CIRCUIT, or
1 o5 n$ D- E- \; |9 abetween any such part and earth (see 1.4.9), shall not exceed 0,7 mA peak, or 2 mA d.c.' i0 W4 S: E$ }# `
For frequencies above 1 kHz, the limit of 0,7 mA is multiplied by the value of the frequency in
( ^; i9 z: s0 z5 }" J* hkilohertz but shall not exceed 70 mA peak.2 {3 m6 q' t) h" r/ g) X
Alternatively, it is permitted to use the measuring instruments of Annex D instead of the noninductive; J1 Q) h# Z' Q3 s" b
resistor of 2 000 Ω ± 10 % mentioned above.
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% v- Y- @( x; Q2 \2 n+ b( v2.4.3 Connection of limited current circuits to other circuits
( X, k2 Q5 U/ |! G! F. vLIMITED CURRENT CIRCUITS are permitted to be supplied from or connected to other circuits,4 N' w! w7 W V" g# I
provided that the following conditions are met:
; a3 H# c5 ]( f0 V− the LIMITED CURRENT CIRCUIT meets the limits of 2.4.2 under normal operating conditions;9 t& W8 C6 T/ T t3 Z% o! S
− the LIMITED CURRENT CIRCUIT continues to meet the limits of 2.4.2 in the event of a single4 G' F y3 B' [/ p& t
failure of any component or insulation in the LIMITED CURRENT CIRCUIT, or of any component
/ r8 z O) D Q+ y' E3 j- y+ a, yor insulation in t he other circuit to which it is connected.
3 i0 u; e; \7 k* @8 x. zIf a LIMITED CURRENT CIRCUIT is connected to one or more other circuits, the LIMITED CURRENT
( G0 O( |* h7 F s+ u1 e( xCIRCUIT is that part which complies with the requirements of 2.4.1.
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* p, M3 b! e# b) F在IEC 60950-1的限流电路(也就是LCC)的一般适用情形:
' N( k# `9 ?3 P: h/ F6 ^( c某种高电压输出的电路,该电路在设计上能保证在正常和单一故障条件下,从电路流出的电流都是非危险的电流。通俗的讲法是,该电路虽然电压高但人是可以直接触摸的。 |
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