标题: 变压器用在报警喇叭上是什么作用？普通的喇叭不是这样用的 [打印本页] 作者: jane@2013 时间: 2016-8-28 17:05 标题: 变压器用在报警喇叭上是什么作用？普通的喇叭不是这样用的 变压器用在报警喇叭上是什么作用？普通的喇叭不是这样用的，求大神指导，跪谢！( d7 h& K3 d) F9 l5 f8 y 作者: xhy_hard 时间: 2016-8-28 20:43
贴图出来作者: 超級狗 时间: 2016-8-30 23:17
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A typical high-impedance system is shown in Figure 1. A transformer at the power-amplifier output steps up the voltage to approximately 70 volts at full power. Each speaker has a step-down transformer that matches the 70V line to each speaker's impedance. The primaries of all the speaker transformers are paralleled across the transformer secondary on the power amplifier. * h% N2 X. r! C9 N4 i: j) V& f, h' E+ M2 [9 @, w; ? ADVANTAGES OF 70V OPERATION 5 H" x" z) Y5 H# m! @As stated before, a 70V line reduces power loss due to cable heating. That's because the speaker cable carries the audio signal as a low current. Consequently you can use smaller-gauge speaker cable, or very long cable runs, without losing excessive power. Another advantage of 70V operation is that you can more easily provide the amplifier with a matching load. Suppose you're connecting hundred of speakers to a single 8-ohm amplifier output. It can be difficult to wire the speakers in a series-parallel combination having a total impedance of 8 ohms. Also it's bad practice to run speakers in series because if one speaker fails, all the speakers in series are lost. This changes the load . K z: w! W/ o' C; timpedance seen by the power amplifier. + [2 x- G' j1 P8 u z' Z
