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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。7 e1 t" N* V! t8 [
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。" w8 n; M$ |3 P' f }, `
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2.4 Limited current circuits
( Q5 g' r$ L) K) J3 y% {- C2.4.2 Limit values& K8 r6 M3 B$ b
For frequencies not exceeding 1 kHz, the steady-state current drawn through a non-inductive1 W# `9 p% F4 f; u' q
resistor of 2 000 Ω ± 10 % connected between any two parts of a LIMITED CURRENT CIRCUIT, or& Z4 C1 j8 F3 K3 d \1 W3 Y5 [
between any such part and earth (see 1.4.9), shall not exceed 0,7 mA peak, or 2 mA d.c.
. E* `; N6 i) J* RFor frequencies above 1 kHz, the limit of 0,7 mA is multiplied by the value of the frequency in
/ r R Z7 t1 B( e% W( Lkilohertz but shall not exceed 70 mA peak.
& v9 M, j7 w% ~ i4 d1 A2 P9 j JAlternatively, it is permitted to use the measuring instruments of Annex D instead of the noninductive- J( D9 C6 V* M4 D6 T% Q1 ~
resistor of 2 000 Ω ± 10 % mentioned above./ P# a% V P4 L& x ?4 j; Q9 G: Q! C% R
。。。
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2.4.3 Connection of limited current circuits to other circuits
B1 y, C8 T* y# u( ^5 s. yLIMITED CURRENT CIRCUITS are permitted to be supplied from or connected to other circuits,
0 i s x, F* v, wprovided that the following conditions are met:
9 v `2 ] w' r− the LIMITED CURRENT CIRCUIT meets the limits of 2.4.2 under normal operating conditions;& w. |8 _5 c4 ~7 I8 }6 A# u( L$ V
− the LIMITED CURRENT CIRCUIT continues to meet the limits of 2.4.2 in the event of a single; w" w" k" P4 s% b9 y, g
failure of any component or insulation in the LIMITED CURRENT CIRCUIT, or of any component3 U0 z- ]6 @$ N% b/ ^; G1 b
or insulation in t he other circuit to which it is connected./ a+ D) {+ g+ h7 h8 H, t; ?6 _8 I
If a LIMITED CURRENT CIRCUIT is connected to one or more other circuits, the LIMITED CURRENT
% j, m- {) n5 m5 CCIRCUIT is that part which complies with the requirements of 2.4.1.
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在IEC 60950-1的限流电路(也就是LCC)的一般适用情形:
1 T2 j( E [7 ~- P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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