摘要
数字多点系统是一种传输多制式移动通信信号和以太网信号,用于解决移动信号室内覆盖问题的设备。在数字多点系统中有数量庞大的远端设备分布在信号覆盖地的机房内,而机房内的温度、湿度等因素会导致设备的自激、氧化甚至短路问题,需要引入过流保护装置以提高远端设备的安全性。传统过流保护措施如保险丝、热敏电阻等具有维护困难、灵敏度和精度低等问题。本文在严密设计和大量实验的基础上,采用555定时器实现了一种"打嗝"型的过流保护装置,不仅很好地解决了上述问题,而且在设备过流状态下还具有很高的关断时间与导通时间比,进一步提高了过流保护装置的可靠性。经实验验证表明,设计是合理有效的。
Digital multicast system, a kind of devices that can transmit multi-standard communication signals and Ethernet signals,is used to solve the problem of indoor coverage. In multicast systems, there is a large number of remote equipment distributed among the areas where signals cover, and the temperature, humidity and other factors in equipment room can lead equipment to self-excitation, oxidation, and even short circuit problem. Under the circumstances, introducing in over-current protection device to improve the security of the remote device is urgently needed. Traditional over-current protection measures such as fuses or thermal resistors are difficult to maintain and the sensitivity and accuracy is rough. On the basis of rigorous design and a large number of experiments, a kind of ＂ hiccups＂ type over- current protection device is realized by using 555 timers. This newly designed devise not only solved the deficiency of traditional measures very well,but also has a very high ratio between conduction time and close time in the condition of equipment over-flow, which further improve the reliability of overcurrent protection device. It has been verified by the experiment that the design is reasonable and effective.
出处
《系统仿真技术》
2015年第3期236-241,共6页
System Simulation Technology
