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2. “对音频信号,在故障条件下不要超过正常工作条件下的限值”意思是指 音频信号的故障限值依然是交流35V(峰值)或直流60V,而不是 交流70V(峰值)和直流120V;是吗?为什么会这样呢?) f. ~5 b3 u* M, |% L0 |3 P, L. `9 F
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– for audio signals of PROFESSIONAL APPARATUS, 120 V r.m.s.,
* ?5 B. N) K1 q" H$ U– for audio signals of other than PROFESSIONAL APPARATUS, 71 V r.m.s.;6 @% x: {" W3 i8 ^& g
对音频信号的限值是71Vrms或120Vrms,正常和故障情况下一样。9 R) Q* S& F. k; e/ _3 L0 L8 G
When determining whether a part or output TERMINAL contact is HAZARDOUS LIVE according
" G9 y3 [8 C; R! @) V: I0 ~to 9.1.1.1 and 11.1, the apparatus shall be operated with a sinusoidal input test signal of5 B7 F, T9 \. c; J) u
1 kHz or where applicable, another frequency corresponding to the geometric mean of the! @+ G' T8 A/ M, | k
upper and lower –3 dB response points of the relevant amplifier part of the apparatus,2 J# l9 h9 O3 f
sufficient in amplitude for the apparatus to deliver the NON-CLIPPED OUTPUT POWER into its1 m2 n2 v3 T0 c2 f' x: z5 O
RATED LOAD IMPEDANCE. Open-circuit output voltage is determined after the load is( e, e* S) `) |2 X$ E# A
removed.
/ N5 j* _, [) r2 ^原因如上,标准4.2.4提到判断输出端子是否危险带电时,音频设备要输出非削波输出功率而不是正常工作条件下定义的1/8非削波输出功率。因此规定正常和故障情况下音频端子的危险电压限值是相同的。 |
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