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4． IEC 60335-1中什么是电子开关？
: w B- [* T6 S- s% M4 i2 q/ yNote:
$ g* x8 O$ V2 R' ]( y4.1 60335-1中提到电子开关涉及的测试最主要就是19.11.4, 当然这个要和off position (3.8.2)一起考虑才有意义。- v2 R7 P/ a4 I r$ P v& q
4.2 单纯地看待电子开关的话，请参看61058-1 table 15会很清楚：SSD without electrical contacts, SSD with serial contacts, SSD with parrel contacts, SSD with serial and parrllel contacts, 电子开关可以是半导体元件通断电实现off position, 或者是控制机械触点实现（例如继电器）: i: F0 x8 ^) {2 B( K/ H% n
4.3 24.1.3和Annex H也得看看。
: w1 o* d9 x1 s( R" d
/ m- T5 B- Q) T6 A8 R. o" u8 Z5． 关于IEC60335-1 cl 16关于泄漏电流加倍的讨论。
" s3 o+ n U: LNote: 这个问题在IEC TC 61 Chairman D.R.Johns写的IEC 60335 interpretation 里面有比较清晰的解释.9 F: @6 i2 D# }: z% I
If the appliance is functionally switched off by a single-pole disconnection, then one end is left
9 |- N. y% |6 iconnected to the supply since the appliance is only functionally off. The leakage current . p/ K8 w" a8 h0 U, L' v: l) x
distribution in the functionally off position can be as shown in figure A (格式问题，图贴不上来） and the nett leakage current will be Ix, where Ix is the leakage current per unit length of the insulation.
1 j, I ?+ u# O& aWhen the appliance is tested according to the method detailed in 16.2, the leakage current distribution will be as shown in figure A (格式问题，图贴不上来）and the nett leakage current will be Ix. / v! F8 o0 ]. P. S) f
: R, i) b1 _2 JWhen the appliance is on the leakage current distribution will be as shown in figure B (格式问题，图贴不上来）and the nett leakage current will be Ix/2 (since the appliance neutral is normally at or near earth potential).
# e! b7 E+ Z' f9 {8 b# U, a9 j) [, w" I- J5 |8 d! g* _
If the appliance is switched off by an all pole disconnection switch or by withdrawal of a plug + r1 Z1 O# a7 L( n6 L
then one end is not left connected to the supply when the appliance is off and the leakage ) m3 r E/ |$ e/ y( f% t) j
current in the off position will be zero. The leakage current value measured during the test of
+ R; G% q5 i b4 G9 o8 G# r& G! E16.2 will be twice the mean value experienced by the insulation in practice.
6 X& h' Z5 M+ ~3 |; q
9 e9 M/ K4 T8 }# M' @) kIt is therefore, permissible to double the limit and still achieve the same level of safety as in the case where the appliance is switched off by a single pole disconnection switch. |
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发表于 2009-4-11 01:26
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