电压变送器的研制.doc

电压变送器的研制 摘 要 电量变送器是将交流信号线性变为直流信号的一个装置。本文就研究了一种基于对数反对数原理的交流电压变送器，介绍了研究背景和设计要求，并阐述了该变送器的组成、特点和功能。 该变送器主要设计包括变送器主电路和供电电路。主电路包括取样单元、真有效值变换单元、信号调理单元、电流输出单元。为了将100V的交流信号转换成比较小的交流信号，我们采用电流互感器传递电压信号的方式，在加上反相放大器共同组成采样单元。而真有效值变换单元主要是利用对数反对数原理的AD536芯片实现的。与此同时为将AD536输出的信号进行调理我们还设计了信号调理电路，并最终输出我们想要的电压值，其包括同相放大器、有源滤波器和反相加法器。电流输出单元则是实现对4-20mA电流的输出。 供电电路包括电源变压器、整流电路、滤波电路、稳压电路。电源变压器采用的是中间抽头的变压器，并与桥式整流电路相连；而滤波电路采用无源滤波的形式，最终与7812和7912进行稳压处理的稳压电路相连。 本文的最后还对电压变送器电路的调试做了细致介绍。 关键词　电压变送器；AD536；调试；有效值 Development of voltage converter Abstract The AC power signal transmitter is linear DC signal into a device. This paper studies a number of objections based on the principle of the AC voltage the number of transmitters, Describes the background and design requirements, and explains the composition of the transmitter, features and functions. The main transmitter design includes the main circuit and power supply circuit transmitter. Main circuit: sampling unit, True RMS conversion unit, signal conditioning unit, the current output unit. Sampling unit main function is to capture and amplify signals. To the 100V voltage signal into a current signal, and amplification, we use current transformers, inverting amplifier, and follower together constitute the sampling unit. True RMS conversion unit is mainly used against the number of number theory AD536 chip. Signal conditioning circuit is mainly to AD536 output signal conditioning, the final output voltage value we want, including inverting amplifier, active filter and the summing inverter. Current output unit is mainly to achieve the 4-20mA current output. Power supply circuit: power transformer, rectifier, filter circuit, voltage regulator circuit. Power transformer primary center tap is used in transformers. Rectifier circuit through the bridge rectifier circuit. The filter circuit with passive filtering. Voltage regulator voltage regulator using Office 7812 and 7912 were years. Finally, this article voltage transmitter circuit of the electromagnet