Research On Reliability And Transient Break Detection Of Electrical Connector

Nowadays, with the quick development of trunk line multiple unit trains and subway, computer network which has kinds of electric appliance connector and connectors are used on trains in every country widely.On one side, these connectors optimize the control technology of trains, make the communication of trains conveniently on some extent and upgrade the whole performance of trains.So they play an important part in the trunk line multiple unit trains and subway.But on the other side,the faults of these electric connectors will lead to severe accident to trains.so it is important to research on the reliability on of electric connectors.This paper first introduces the basic knowledge of reliability which includes reliability characteristic quantity and reliability analysis of system.This paper chose a braking circuit system to analyse its reliability.Usually, a complex circuit system is made up of kinds of subsystems which are made up of kinds of modules and components, so the reliability of subsystems can be acquired by the reliability of the modules and components and last the reliability of system can be acquired by the subsystem. First, Based on the theory of reliability, the reliability of single connector and relay can be estimated. Second, the reliabiliy of circuit subsystems which can be seemed as series system and parallel system are acquired by analysing them step by step, and finally the reliabiliy of the braking circuit can be gained.In the research, a test system which combines the hardware circuit system to PC and can transmit the test results between the hardware circuit and PC has be designed to check the faults of the electric connectors.The lower computer hardware circuit which can display the results of test by seven-segment digitron is made up of AT89S52 singlechip microcomputer and basic TTL circuit.The singlechip microcomputers are divided into two types,one type is called parameter singlechips which are used to set the value of parameters and to control the signal of self-checking, the other is called test singlechips which are used to detect the failure of the connectors, to save the test results and transmit them to the PC.In addition, the design used Keil C to programme the two kinds singlechips.The theory of failure detection is to use the method of comparing the electric resistance value caused by transient break circuit to the standdard value to judge if the circuit has failure,and use the high frequency pulse-counting method to detect the time of transient break.This paper has detailed introduce the modules of hardware circuit which includes constant current power module,power module,transient break detection module,self-checking module, annunciator module. Upper computer which was programmed by Visual C++6.0 is based on Windows XP operating system, combined with ODBC, it can operate ACCESS database.The upper computer operating interfaces was optimized by Lab View virtual controller and the results of detection can imaged by OpenGL.The process of upper computer is that,firt. it must modify the parameters which include baud rate and COM ports etc.,second,it receives the detection data from lower computers which can display as a sheet or an image after it has sent an instruction,last,it can save the data which comes from lower computer, look up the historical data, statistics and analysis which lines has fault.Combined with Keil C.this paper still use Proteus to simulate and debug the lower computer hardware.The virtual COM ports was used to simulate the communication of upper and lower computers.before the communication,it must programme the MSComm controller in the upper computer operating interfaces.The virtual COM port plays the function as a communication channels and has the same function as a physical COM pot in PC.