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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?
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6 `1 }& x6 C- m% d– for audio signals of PROFESSIONAL APPARATUS, 120 V r.m.s.,
' @2 B/ B, c i' X2 R6 c U$ M( C– for audio signals of other than PROFESSIONAL APPARATUS, 71 V r.m.s.;
7 Y0 }9 j7 J$ F, J对音频信号的限值是71Vrms或120Vrms,正常和故障情况下一样。5 b' {, u) z- K* w( r
When determining whether a part or output TERMINAL contact is HAZARDOUS LIVE according6 [" W: @0 f) f. n6 k7 @$ |
to 9.1.1.1 and 11.1, the apparatus shall be operated with a sinusoidal input test signal of
1 E/ l+ Z- z4 z, c4 A6 ]1 kHz or where applicable, another frequency corresponding to the geometric mean of the# _2 J: a: M0 g. h0 k( W5 x
upper and lower –3 dB response points of the relevant amplifier part of the apparatus,. `1 g# e6 j% i7 Z0 K' h; `
sufficient in amplitude for the apparatus to deliver the NON-CLIPPED OUTPUT POWER into its5 m* o$ q3 x$ v3 h. v6 L; C
RATED LOAD IMPEDANCE. Open-circuit output voltage is determined after the load is
2 E! w. l" I* S+ c, }. z/ H2 J5 xremoved.- Z/ l3 ?/ e, q# R6 G$ X$ Q% [
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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