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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!
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For conductive patterns on printed circuit boards, except at their edges, the values in the
4 P6 K/ l/ U+ H3 R. N; Ztable between parts of different potential may be reduced, as long as the peak value of the
: X% G( _* u* N! ?$ T7 ]( `; c I. ^voltage stress does not exceed:
1 F# k# K+ l6 g0 O i5 ~– 150 V per mm with a minimum distance of 0,2 mm, if protected against the deposition of dirt;
% e, Y6 E4 |8 x/ l3 P$ ~0 X– 100 V per mm with a minimum distance of 0,5 mm, if not protected against the deposition of
! P5 L$ _1 C+ n- T' j6 Zdirt.! @3 t$ ]- q6 a- s6 o5 e
When the limits mentioned above lead to higher values than those of the table, the values of. T4 M5 a, Z8 `0 s# G
the table apply.8 g+ e2 Z) d! [# {4 o" N
For peak voltages exceeding 50 V, the reduced creepage distances only apply if the Proof7 m0 D' w7 s5 @
Tracking Index (PTI) of the printed circuit board, measured as in Annex G, is greater than' f* u3 K' ~/ k6 q% B: ?4 c6 E2 ?
175.. C- p( B: I T3 Y' q
These distances may be reduced further, provided that the tool complies with the& j4 L6 X4 Q& o2 d+ ~* {
requirements of Clause 18 when the distances are short-circuited in turn.( D- g* j" F6 D
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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. ! v% L0 o3 X% V0 T
——若是防尘物沉积的,为150V/mm,但最小距离为0.2mm.& D7 Y) s& @, K0 B& A. b
——若不是防尘物沉积的,为100V/mm,但最小距离为0.5mm.
! @0 i$ P$ v$ w9 O! r 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.8 }5 B( t1 X: D4 R. m
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. |
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