craigyu 发表于 2012-11-5 17:58

这是标准条款，也不是Y电容都是保护阻抗的，要跨接可接触安全和危险部件间的
protective impedance
impedance connected between live parts and accessible conductive parts of class II
constructions so that the current, in normal use and under likely fault conditions in the
appliance, is limited to a safe value

22.42 Protective impedance shall consist of at least two separate components. If any one
of the components is short-circuited or open-circuited, the values specified in 8.1.4 shall not
be exceeded.
Component impedances shall be unlikely to change significantly during the lifetime of the
appliance.
Compliance is checked by inspection and by measurement and if necessary, for resistors and
capacitors by the following tests.
Resistors are checked by the test of 14.1 a) in IEC 60065 and capacitors are checked by the
tests for class Y capacitors in IEC 60384-14 appropriate to the rated voltage of the
appliance.

山炮 发表于 2012-11-5 21:23

这问题，今年的安规网年会上家电标准的讲师讲过了，专心看女生的我都听到了，你们在干什么哟?

wanaut 发表于 2012-11-6 08:51

要先判断是否必须符合这个要求，然后才判断是否符合要求，两者的关系要分清

liuyingcai 发表于 2012-11-12 22:38

大家分析的好，我也长进了。

silvira 发表于 2012-12-9 10:56

曾经跟一家测试机构打过交道，我家的产品是带触摸屏的，开关电源变压器供电，变压器单独测试，初次级绕组不满足加强绝缘要求，测试机构要我在两级之间垮接串联两个满足14472的Y2电容，说是这样就可以把次级输出电路不视为带电部件，满足8.1.4条的要求。现在看看标准还有些疑问，保护阻抗不是用在二类结构上吗？变压器已经不满足二类结构了，这样垮2个Y电容还有意义吗？

lanxiao121 发表于 2012-12-10 10:49

马蹄 发表于 2012-11-1 11:36 static/image/common/back.gif
阻抗降压的原理就是简单的电工学的东西，额定电压下，电阻越大，电流越小，保护阻抗用高值电阻或电容（一 ...

很有道理

lds08080808 发表于 2017-9-25 09:29

求保护阻抗相关电路

rlandg 发表于 2017-9-25 11:07

路过，学习了:)

lotte_528 发表于 2017-9-26 16:45

最简单的保护阻抗电路例子： 接触式试电笔

jtt1471025811 发表于 2023-3-25 10:51

前来学习
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