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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?6 `& |+ s# d8 w: t3 ^9 m
9 h: U. r T, r2 Y7 \& `
– for audio signals of PROFESSIONAL APPARATUS, 120 V r.m.s.,5 u9 x) N! n2 {6 u* ]6 ^
– for audio signals of other than PROFESSIONAL APPARATUS, 71 V r.m.s.;
% a* U2 p4 h+ G对音频信号的限值是71Vrms或120Vrms,正常和故障情况下一样。
& C- e# i( C S5 x/ z1 cWhen determining whether a part or output TERMINAL contact is HAZARDOUS LIVE according# j L5 z0 y& X( X" m. r' X) _
to 9.1.1.1 and 11.1, the apparatus shall be operated with a sinusoidal input test signal of
! K' h# f3 k- f7 K3 R1 kHz or where applicable, another frequency corresponding to the geometric mean of the
5 ?! t4 |, P0 ?' L( I/ @/ wupper and lower –3 dB response points of the relevant amplifier part of the apparatus,! H4 x- q, T* C& L0 B
sufficient in amplitude for the apparatus to deliver the NON-CLIPPED OUTPUT POWER into its$ T7 i/ ^% H3 m" u; ^
RATED LOAD IMPEDANCE. Open-circuit output voltage is determined after the load is
0 [! S& a. N) C6 a( O [* T1 p5 j% Dremoved.
0 E" E; ~# w) y+ `; B& V3 k* X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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