验钞用半导体磁头信号处理电路的特性

The Signal-Processing-Circuit's Characteristic of Semiconducting Magnetic Head Used for Detection of Paper Currency

研究了验钞用半导体锑化铟 (InSb)磁头的信号处理电路的噪声、电压特性和频率特性。结果表明 :为得到满意的信噪比 ,磁头的工作电压应大于 4V ;磁头输出的信号电压在 2 .4 97～2 5 0 3V范围内 ,电路的放大倍数保持不变 ;并找到半导体磁头的动态特性随工作频率升高而变差的一个重要原因。

A result has been obtained that the semiconducting magnetic head (SMH) must work at the bias voltage of 4?V or more for a usable signal-to-noise ration with 8 times. It has been observed that the voltage gain of the SMH's signal-processing-circuit does not change when the SMH's output voltage varies between 2.497?V and 2.503?V,and why the SMH's dynamic characteristic goes down following its working frequency going up.