Development And Application Of Multi-channel Testing Equipment For Electrical Performance Of Connectors

The electrical performance of electrical connectors in electronic equipment plays a very important role in the normal operation of the equipment.The electrical properties of the connectors,the insulation resistance and contact resistance are particularly important two performance indicators.In the application environment,the connector insulation aging and lower insulation resistance will cause electrical leakage or short circuit accident;and the corrosive film is formed on electrical contacts by the environment,the contact resistance increases,which will cause the connector overheating and cause accidents.In the environmental research of connectors,it is often necessary to carry out accelerated experiments in a temperature and humidity chamber,and the insulation resistance and the contact resistance of the connectors need to be monitored in real time.In addition,multiple samples need to be tested in parallel.Aiming at the demand of scientific research,this paper designs a set of multi-channel testing equipment of electrical performance for online monitoring and real-time display of insulation resistance and electrical contact resistance curves of multiple connectors in environmental experiments.In this paper,by the analysis of the research needs of the experimental equipment,the design range of the key parameters was determined.And design the hardware circuit to control and test,and write software with interactive interface to facilitate the control of the entire process and data acquisition,which was followed by hardware and software debugging and testing of key indicators.Finally,the equipment was used to monitor the insulation resistance and contact resistance of the standard comb-type circuit board and Type B USB connector in a temperature humidity bias(THB)environment.According to the needs of experimental research,this dissertation divides the testing equipment into two systems,hardware and software.The hardware system includes seven modules,namely an insulation resistance measurement module,a contact resistance measurement module,a relay array module which is connected to tested samples,an upper computer module,a sample connection module,an external power supply and a heat dissipation module.The software system includes five modules,namely the communication module with the hardware system,the instruction release module of the control system,the human-machine interaction module,the data storage module and the data display module.The device can measure the insulation resistance and contact resistance of up to 30 samples in turn and display the characteristic curves in real time during the experiments.Insulation resistance range is 103? to 1011??accuracy of 5;contact resistance range is 1m? to 20?,accuracy of 5;single measurement duration is 5 seconds;single measurement interval is 1 second;a single experiment can store up to 106 measurement data per channel.The device can choose the electrical parameters and the sample channels to be measured,and can set different external voltage regulator,constant current source and other auxiliary equipment parameters.It can switch display full resistance curves of the experiment to the latest 50 rounds of measurement curve.All experimental data can be saved to the specified Excel document for later experimental analysis and data collation.The device was used to study the change of insulation resistance of the comb-shaped circuit board during electrochemical migration under the conditions of THB.The insulation resistance and the contact resistance of the USB connectors were measured in real time at THB.