Design of Range-measuring System for Breakpoint Faults in Communication Cables

摘要

This paper introduces a new method of discovering the breakpoint faults in communication cables by means of low voltage pulse reflection and the system by single-chip microcomputer 89C52. In this system, high frequency pulses are generated and the amplitude is raised with pulse wave sending circuits. The high-frequency pulse is transmitted into the cable by carrier wave through link equipments. In the course of transmitting though the cable, the pulse will be reflected at the terminal point when confronted with high-impedance. The reflective wave will be sent back to pulse receiving circuit of the system. By calculating the time period between sending and receiving of the wave, accurate position of the breakpoint can be determined. The system is simple in construction and easy to operate. It offers precise distance measurement and excellent effects.