一种新型多功能智能型直流电压表的设计

Design of New Type Multi-Function Intelligent DC Voltmeter

介绍了一款测量范嗣为750～750V且在该范围自动换挡，精度为0．5级直流电压表；设计中把测量信号调理为单片机A／D转换所要求的范同，单片机对信号进行处理，数码管显示，按键设置报警范围，并可进行校表，设计了RS485通信接口与上位机通信，并把测量范同的测量值变送成420mA电流输出，设置了两路继电器报警输出。

This article describes a measurement range of --750V--750V automatic shifting in the range, accuracy 0. 5 DC voltmeter. The design of the measurement signal conditioning to requ!red range for single--chip A / D, single chip for signal processing, digital display, keys can be set up alarm range and school table, RS485 communication interface is designed to communicate with PC and the measured value is transmitter into a 4 20mA current output, set the two--way relay alarm output.