数字多用表中,电阻的测量通常采用什么来实现

本系统设计了一个基于AT89S52单片机控制的语音播报数字多用表.它是一种价格便宜和操作简单、自动显示和播报测量数据结果、体积更小、功能强大、便于携带的语音播报数字多用表.要求能够准确测量一定范围内的电阻、电容、电感、电流及电压各参数,可以在LED上显示出来且同时通过显示和语音播报的方式将测量结果告诉用户,从而减小了因视觉误差而带来的读数误差,进一步提高了仪表的测量精确度,具有一定的智能性.系统原理是通过将测量参数R、L、C、I、V等经过频率转换电路,将对应的参数值转换成相应的频率,再通过AT89S52单片机的T0口对此频率进行采样计数,经过单片机内部处理后将频率恢复成实际数据值,在LED数码显示管上显示,并通过ISD1420语音芯片播报出来.通常的仪表测量是通过谐振法、电桥法或是伏安法来测量数据,在测量时误差比较大,而本设计采用将预测参数转换成相应频率后再处理、恢复出数据,测量误差比较小,从而提高了仪表的精确度.
This system design a AT89S52 SCM control based on the speech broadcast DMMS.It is a kind of cheap and simple,automatic display and the measurement data results,smaller,powerful,easy to carry the speech broadcast DMMS.Requirement can be measured accurately must be within the scope of the resistor,capacitor,inductor,current and voltage parameters,can be in LED display and also on display and speech broadcast by way of measuring results will tell the user,thus reduce for visual error brought the readings,and further improve the instrument error of measurement accuracy,has some of the intelligent.System principle is measured parameters by R,L,C,I,V,after frequency conversion circuit,the corresponding parameter value will be converted into the frequency,again through the mouth AT89S52 SCM T0 this frequency sampling count,through internal processing chip after frequency back into a real data in value,LED digital display,and through the XianShiGuan ISD1420 chips out of the speech.The instrument measurement is usually by resonance method,bridge or voltammetry method to measure data in its measurement error,is fairly large,and this design USES the forecasting parameters will be converted into the frequency again after the treatment,recovering the data,and the measurement error are small,so as to improve the accuracy of the instrument.