|
有没有人知道如下条款中说提到的电压梯度的峰值如何检测?有没有实例说明怎么将这个条款应用到线路板上呢?谢谢!. \- Z5 f7 q9 W Z
( W5 N" I$ s: F, U* M28.1
. z+ e0 |8 p: Z& c3 Q9 ?For conductive patterns on printed circuit boards, except at their edges, the values in the
4 |% z- Y( g$ e$ v) Ztable between parts of different potential may be reduced, as long as the peak value of the! G- k1 |6 g% i2 ~1 o/ f3 K
voltage stress does not exceed:
% R, L E: n$ r3 E' r) w– 150 V per mm with a minimum distance of 0,2 mm, if protected against the deposition of dirt;
8 E# M J. U( P/ d C– 100 V per mm with a minimum distance of 0,5 mm, if not protected against the deposition of
6 {4 w& E; ?0 F+ `5 n0 G. g( `dirt.$ d$ s. T, S! b" Q0 P6 {
When the limits mentioned above lead to higher values than those of the table, the values of. m! C% t3 N: W9 [' h$ Z3 l" E
the table apply.+ Q0 y9 [1 {% m, J! M% V
For peak voltages exceeding 50 V, the reduced creepage distances only apply if the Proof7 G/ M! n# d# ~/ y1 z8 _0 `2 v$ l
Tracking Index (PTI) of the printed circuit board, measured as in Annex G, is greater than
0 V$ l- C5 s$ |+ ]. i175.4 P' V) c [/ g8 U6 }
These distances may be reduced further, provided that the tool complies with the
7 ?; s5 ^$ P) g/ P- O0 vrequirements of Clause 18 when the distances are short-circuited in turn.( F! M+ F, v! ~- w/ u
8 T* `. O1 N4 Y& F
对印刷电路板上的导电图形,其边棱除外,只要电压梯度的峰值没有超过下述值,表中关于不同极性部件间的值可以减小.
4 U( Q2 h. L! e' H ——若是防尘物沉积的,为150V/mm,但最小距离为0.2mm.
: H) @1 W- u" e9 | ——若不是防尘物沉积的,为100V/mm,但最小距离为0.5mm.
6 Q! S4 e* q. c 对峰值电压超过150V的情况,只有印刷电路板的耐漏电起痕指数(PTI)按照附录G进行测量时超过175,减小的爬电距离规定才适用.( R& v9 g+ V2 _& K. d# S
只要当这些距离轮流短路时,器具符合19章的要求,这些距离可以进一步的减小. |
|