Postout Of Communication Cable Break Monitoring System Design

In the information society of today, the optic cable as an information carrier in the national economy became play an increasingly important role. The damaged of optic cable will cause large enormous lost. So at this stage it is urgent to need an automation optic cable breakage monitoring system. A complete monitor system should include three aspects, the cable fiber core automatic monitoring; optic cable sheath insulation resistance automatic monitoring; joint box flooded automatic monitoring. What optical cable used for the transmission of data is optical fiber, according to the experience of experts, insulating layer of fiber optic cable and connector boxes of damaged water is the main reason for fiber damage. The monitor of cable insulation layer damage and the flood of joint box is very important to the cable maintenance.At present the key to weigh the defect of cable insulation layer is to measure the resistance of cable insulation layer. Now the major domestic method is that use artificial get every joint box and measure insulation resistance, but it is time-consuming effort and can not do real-time forecast. Cable damaged situation on-line monitoring system is used to detect a cable insulation resistance and the humidity of joint box automatically. Radiation company of Britain is the only who have a similar product, but it is too high for the engineer used, and it isn't suit for large-scale use in domestic. Cable damage situation on-line monitor system can measure optic cable insulation resistance and then afford measurement data to monitoring centre. Then monitoring centre estimate the dilapidated conditions of the optic cable for early judgement.Monitoring systems include three part include insulation resistance measurement, control, and data transmission. This paper will research high-voltage generation circuit used for measure insulation resistance, insulating layer discharge circuit, the sampling circuit, the relay trigger control circuit of power on stage, the interface circuit for processor control system. In this paper the design indicators harsh circuit designed by the large-scale use of separation rather than integrate circuit. During the circuit design process I usually use EDA software Pspice which take greatly facilitate for the design of the circuit. After debug, the circuit generate 250V voltage used for insulation resistance measurement by 26V system power supply voltage. Relay control circuit of power on stage which make relay trigger under the normal current and voltage in provision circumstances of relay. And control by the processor after power supply of the system work. The remain circuits are working properly satisfy the design requirements.