Analysis On Reliability And Contact Bonding For Sealed Electromagnetic Relay

The sealed electromagnetic relay is one of main electronic components in national defense electronic system. It can transmit signal, execute control and distribute power for system etc. The sealed relay's reliability affects directly reliability of the whole national defense electronic system. With the development of national space technology, the application fields of sealed electromagnetic relay are growing and the amount is increasing. So it requires more and more to quantity of sealed electromagnetic relay.In the past, it did not carry into system analysis to failure mode of sealed electromagnetic relay. So the reliability design for sealed electromagnetic relay fell behind correspondingly and correction of failure mode lack systemic theory foundation. The systemic theory analysis of sealed electromagnetic relay is presented by using the reliability analysis method of FMECA and FTA, weak points of the design are found out, and corresponding corrective actions are given, so the reliability of sealed electromagnetic relay is improved.Firstly, the FMECA table of sealed electromagnetic relay is established, The table included failure mode, failure reason, failure effect, detection measure and correction action etc. Taking a certain type of sealed electromagnetic relay as an example, CA analysis is carried out, and critical failure modes are obtained. Secondly, weak links of the design were found out by building fault tree and executing FTA qualitative analysis. The corrective actions are suggested in design, producing and applying to improve quality and reliability of sealed electromagnetic relay. Lastly, contact bonding of sealed electromagnetic relay is analyzed, the mathematical model of starting melting current is built in heat steady condition, and contact arcing time and effect factors of cold welding are analyzed. Basing contact parameters characteristic of sealed electromagnetic relay, theory analyzed and calculated contact bonding features, and contrasted and validated results by simulation analysis.The research puts forward reliability analysis method of sealed electromagnetic relay, and gives corrective actions in design, which provides reference foundation for improving reliability and life of sealed electromagnetic relay.