菜鸟上电路求分析

flywinder

9 s3 S/ _7 t% e( n' o) H6 I菜鸟上电路求分析：这个是个反响放大电路么,电容是什么作用呢

reval

世纪难题。除非IC内部已经有相关电路。可以不用外围，否则的话，应该是不小心吧？

skatecom

坐等高手解析

liangjiatian

围观一下

jacklee_47pn

等待  非常有名氣的提行官---超級狗   開棺驗屍。    ^_^

zlpkcnm

等待大圣{:soso_e129:}

flywinder

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reval 发表于 2013-4-8 12:26
+ e1 |. J8 P- o) }& q$ j% m世纪难题。除非IC内部已经有相关电路。可以不用外围，否则的话，应该是不小心吧？

如果正相输入端串个电容或电阻接地呢

超級狗

Values of IB range from 60 fA (about one electron every three microseconds) in the AD549 electrometer, to tens of microamperes in some high speed op amps. Op amps with simple input structures using bipolar junction transistors (BJT) or FET long-tailed pair have bias currents that flow in one direction. More complex input structures (bias-compensated and current feedback op amps) may have bias currents that are the difference between two or more internal current sources, and may flow in either direction.
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Bias current is a problem to the op amp user because it flows in external impedances and produces voltages, which add to system errors. Consider a non-inverting unity gain buffer driven from a source impedance of 1 MΩ. If IB is 10 nA, it will introduce an additional 10 mV of error. This degree of error is not trivial in any system.
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Or, if the designer simply forgets about IB and uses capacitive coupling, the circuit won't work—at all! Or, if IB is low enough, it may work momentarily while the capacitor charges, giving even more misleading results. The moral here is not to neglect the effects of IB, in any op amp circuit. The same admonition goes for in-amp circuits.

超級狗

Audio Signal 轉 Impulse Signal ???
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後面是想去觸發什麼東西？？？
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flywinder

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超級狗 发表于 2013-4-8 16:28
  \/ ~+ A# K: R( w/ G$ ~Audio Signal 轉 Impulse Signal ???

* e, ^* |' b* q0 ?# j後面是想去觸發什麼東西？？？

9 |0 j' I% V/ ]4 A3 E音频信号转脉冲信号？ 输出接的是耳机接口，输入是右声道模拟信号
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超級狗

那就如二樓說的，IC7 是什麼型號？有 Internal Pull-Down 嗎？
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{:soso_e132:}

flywinder

超級狗 发表于 2013-4-8 17:19
  r; M% _! j2 L/ ?, ~% n那就如二樓說的，IC7 是什麼型號？有 Internal Pull-Down 嗎？

NJM2740,里面集成了2个运放，一个左声道，一个右声道

xin_515

貌似是一个低通滤波器吧。

flywinder

超級狗 发表于 2013-4-8 17:19
4 x  z5 p* c/ H5 Q! x7 {那就如二樓說的，IC7 是什麼型號？有 Internal Pull-Down 嗎？

嗯，第一张图是我重新只画了一个运放的，那我给你上一张完整的

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zn383462925

第一个电容隔直，第二个电容和电阻组成低通滤波。。。可以用公式计算的！