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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?3 ~2 i3 h; w. C/ s
+ ^% f( j# x( U
– for audio signals of PROFESSIONAL APPARATUS, 120 V r.m.s., }! @: i9 m* U7 B+ n' Y; N
– for audio signals of other than PROFESSIONAL APPARATUS, 71 V r.m.s.;: u, L) N7 {6 o: b4 U1 T
对音频信号的限值是71Vrms或120Vrms,正常和故障情况下一样。6 J7 _/ x3 w2 B9 q! h. G+ A3 K7 u
When determining whether a part or output TERMINAL contact is HAZARDOUS LIVE according
' l9 o8 |- x# U/ gto 9.1.1.1 and 11.1, the apparatus shall be operated with a sinusoidal input test signal of, V7 @3 r Z( {9 S. ]; N4 ^
1 kHz or where applicable, another frequency corresponding to the geometric mean of the
9 T5 w% X. _/ E6 s# ~upper and lower –3 dB response points of the relevant amplifier part of the apparatus,
8 h- H2 d3 Q. i1 x1 z, o; Tsufficient in amplitude for the apparatus to deliver the NON-CLIPPED OUTPUT POWER into its
. v9 o+ }. \1 T$ |' Z- \% VRATED LOAD IMPEDANCE. Open-circuit output voltage is determined after the load is
( s: z3 R( r2 X9 v5 y' O# ^removed.
( H, ?4 d# b! T! @0 v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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