基于dsPIC的4～20mA两线制恒流源的设计  

Design of Two-wire 4～20mA Constant-Current Source Based on dsPIC

作　　者：吕振彬 袁企乡 徐玮 徐昕 

机构地区：[1]上海航天计算机技术研究所,上海201109

出　　处：《计算机测量与控制》2016年第1期310-312,共3页Computer Measurement &Control

摘　　要：我国新一代运载火箭动力测发控系统等效器中,需采用数十路4～20mA电流源模拟配气台压力变送器信号,对设备输出精度、集成度、可靠性等指标提出较高要求;文章提出一种基于dsPIC数字信号控制器控制18路PWM输出、低通滤波实现D/A转换、最终实现了两线制4～20mA电流输出的方法,并对该设计的理论基础及软硬件实现进行分析;该方案具备技术先进、输出精度高、可靠性好、高度集成化、外围电路少、软件控制简捷等优点,由于具有上述优点,在技术上已经处于国内领先状态,现在经过在我国新一代运载火箭长征六号动力测发控系统等效器中得到了成功应用。In the equivalent device of dynamic test and launch control system of new generation launch vehicle, tens of 4 to 20 mA current sources are used to simulate air pressure transmitter of distributing device. This proposes higher requirements to output precision, integration degree, reliability and so on. This paper proposes a method which uses dsPIC digital signal controller to control PWM output and low-pass filter to achieve D/Aconverter, finally two-wire 4 to 20mA current output is realized. In this paper, the design theoretical foundation as well as hardware and software realization are analyzed. This scheme has advantages of advanced technology, high output accuracy, reliability, high integration, less peripheral circuits, simple software control, ect. It has been successfully applied in equivalent device of CZ-6 new generation launch vehicle dynamic test and launch control system.

关 键 词：PWM 低通滤波 恒流源4~20mA 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]