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目前通用的工业称重数显仪表与称重传感器的接口一般接以高阻抗直流电压放大器。这种接口方案虽然简单易行,但是由于采用电压传输,因此对传输线上阻抗的变化敏感,从而限制了传感器信号的传输距离。实践证明,当传感器的传输线路在10m范围以内时,其线路的阻抗变化可以忽略,但是当传感器信号需要长线传输时,其直流放大器的设计必须考虑抗长线干扰的能力,否则将要通过信号调理器,以V/I变换的方法完成传感器由零至满量程输出0～10mA或4～20mA的直流恒电流信号,达到传感器输出信号远距离变送的目的。据此,本文提出一种具有极强的长线
At present, the common industrial weighing digital display interface with the load cell is generally connected to a high impedance DC voltage amplifier. Although this interface scheme is simple and easy, it is sensitive to the change of impedance on the transmission line due to the voltage transmission, thus limiting the transmission distance of the sensor signal. Practice has proved that when the sensor’s transmission line within the 10m range, the impedance change of the line can be ignored, but when the sensor signal needs long-term transmission, the design of the DC amplifier must consider the ability to resist long-term interference, or through the signal conditioner , V / I transform method to complete the sensor from zero to full scale output DC current of 0 ~ 10mA or 4 ~ 20mA constant current signal to achieve the purpose of long-distance transmission sensor output. Accordingly, this paper proposes a very strong long-term