Study And Test On Coil’s Time Constant Of Electromagnetic Relay

The relay is an electrical appliances for automatic control. It works according to theparticular input signal action and has a wide range of applications in a variety of control systems.In order to improve the reliability and security of these systems, we should make a high efficient,objective and full-scale test before the relays leave factories. At present many industries who userelays are strict with their performance, quality, quantity and variety, so the development of therelays has strong potential and prospect. The main objective is to test the performance andparameters of the relays. Testing on the coil’s time constant of electromagnetic relay is of greatsignificance for the performance studies.This paper presents a study and test on the time constant of the DC relay. First we measurethe value of the coil’s inductance through the vector analysis. Then use the value of theinductance to find out the time constant τ. At last, we can compare the value with the one got bythe test system. The design proposal for high speed data acquisition and test system for the timeconstant of DC relay based on LabVIEW is described. Advantech PCL-818HG is used as thehardware platform of the system, which uses interrupt triggering to acquire the data and the resultis shown in graph. The system is proved to work well and it can accomplish high speed dataacquisition and real-time graph display through the test. The data will be saved in Excel fileswhich is good for data review. It has a friendly user interface.The test system for the time constant of DC relay is proved to work reliably, and the result isconsistent with the one worked out by the vector analysis.