基于脉宽调制原理的模拟信号长距离传输方案研究  

Research on Long-Distance Transmission Scheme of Analog Signal Based on Pulse Width Modulation Principle

作　　者：杜卯春 何利 邹强 DU Maochun;HE Li;ZOU Qiang(Hunan AEROSPACE MAGNET and MAGNETO Co.,Ltd.,Changsha 410200,China)

机构地区：[1]湖南航天磁电有限责任公司,湖南长沙410200

出　　处：《传感器世界》2022年第9期27-32,共6页Sensor World

摘　　要：文章提出了一种基于脉宽调制原理的模拟信号传输方案。传感器输出的模拟信号经发送端的电压-脉宽调制电路处理后生成一路方波信号,且占空比与模拟信号幅值成正比。该方波经差分总线驱动器转换为一组互为反向的PWM信号,该种差分信号更便于长距离传输。接收端将差动信号还原为一路方波后,设计特定带宽的滤波器可将方波信号还原为模拟信号,供模数转换器采集。文章设计了详细的电路拓扑和元件选型,对传输机理进行了仿真验证并制造样机进行实验。实验结果表明,该传输方案可有效地传输模拟信号,阶跃信号传输延时小于28μs。An analog signal transmission scheme based on pulse width modulation is proposed. The analog signal output by the sensor is processed by the voltage-pulse width modulation circuit at the transmitter end, and a square wave signal is generated, and the duty cycle is proportional to the analog signal amplitude. The square wave is changed into a group of reverse PWM signals by diferential bus driver, which is more convenient for long-distance transmission. After the receiver restores the diferential signal to a square wave, a filter with a specific bandwidth is designed to restore the square wave signal to an analog signal for the adc to collect. In the paper, the circuit topology and component selection are designed in detail, and the transmission principle is simulated, and a prototype is manufactured to carry out experiments. Experimental results show that the transmission scheme can efectively transmit analog signals, and step signal transmission delay is less than 28 μs.

关 键 词：脉宽调制 差分信号传输 传感器 低通滤波 模拟信号 RS-485 

分 类 号：TM93[电气工程—电力电子与电力传动]