智能化真有效值数字仪表设计

Design of a New Digital Instrument

采用新型大规模单片集成电路芯片ＡＤ５３６Ａ与８０９８单片机相结合所设计的智能化真有效值数字仪表，可实现对任意波形交流信号真有效值的直接测量。仪表设计时，给ＡＤ５３６Ａ芯片外接适当的积分电容和滤波电路，可在不增加其稳定时间的情况下有效地减少其有效值直流输出信号中的纹波分量；对８０９８单片机内部Ａ／Ｄ转换器采用高稳定的参考电压可减少干扰对Ａ／Ｄ转换精度的影响。在测量精度要求较高的场合，只要作校准用的信号源具有足够的稳定度及良好的接地，就可在每次实际测量之初进行自动校准，取得当时的校准参数，通过计算校准方程获得准确的被测信号值，从而提高仪表的测量精度。

A new digital instrument based on microcontroller MCS-8098 and VLSI TRMS/DS converter is designed.The instrument can directly measure TRMS of any AC signal.In designing the instrument which is connected with an proper integrating capacitor and with a filtering circuit can obtained a direct voltage proportional to input signal,thus its measuring accuracy can be higher and the wiggle signal can be supressed,stable time of signal can be decreased.High voltage which is stable and employed in microcontroller MCS-8098 can decrease interference influence on A/D transforming accuracy.In the case of highly precise measurement,auto-calibration is made before each actual measurement.By computing calibration equation the input AC signals'S TRMS can be measured precisely.