Reliability Testing Of Electromagnetic Relay For IoT Enabled Devices

Abstract

A smart device is said to have “intelligence” in everyday appliances (viz. fans, TVs, washer, cars, etc.). These appliances can communicate over network to deliver service to the user. In IoT (Internet of Things) [1] devices like smart switches, relays are used to allow remote wireless control to the circuit loads such as lighting and door control applications, also in residential applications like fans and TVs, etc. These devices have critical components like Microcontroller, power devices like MOSFET / IGBT and relay. As devices are becoming smart and digital; the main switching component like relay usage becoming more important as compared to traditional devices. In traditional devices like switch, it can be operated through manually to make on / off operations. In smart switch, the on / off operations increased a lot as it can be operated through voice command & mobile app with scene creation, timer scheduling features in addition to manual operations. This increases the switching on/ off duty cycle of the switching component mainly relay. For this increased in duty cycles it is necessary to understand more about relay construction, physics of failure to meet the required reliability. Currently the reliability is assessed at system level that does not capture the failure mechanisms of the critical components like relay. This paper identifies different failure modes / mechanisms of relay and proposes robust reliability test plans to verify them. Based on this study the recommendations for enhancing the reliability of relay are also developed.