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60950的2.1.1.7写到:2 ]' C# O# M" |2 \& F
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No test for shock hazard is required unless the nominal voltage of the MAINS SUPPLY exceeds 42,4 V peak or 60 V d.c.4 j" {. U8 f( ]/ \
就是输入超过SELV的就要去考虑电容放电,这是条件一;
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Equipment is considered to comply if any capacitor having a marked or nominal capacitance exceeding 0,1 uF and in circuits connected to the MAINS SUPPLY has a means of discharge resulting in a time constant not exceeding: 1 s for PLUGGABLE EQUIPMENT TYPE A;* X2 y; K8 R4 _9 I
NOTE During an interval equal to one time constant, the voltage will have decayed to 37 % of its original value.
; C& H2 O0 H' K" |; W条件二,如果输入电容(一般看前面跨接L/N的X电容)超过0.1uF的话,针对PLUGGABLE EQUIPMENT TYPE A(非工业插头)产品,它的放电时间常数不能超过1S;
8 ~; N$ g2 T$ d" K5 c9 K这个放电时间常数计算比较复杂,一般情况都是通过测试去判定,1S内plug端的电压(240VrmsX1.4.1=340Vpeak)下降到初始电压的37%(125.8Vpeak)就pass了。 |
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