Relays are essential components in various electrical and electronic systems, serving as switches that control the flow of current to different parts of a circuit. One of the critical specifications for relays is their voltage rating, which determines their ability to safely handle the electrical potential without causing damage. Understanding the concept of relay voltage ratings is crucial for selecting the right relay for a specific application, ensuring that the relay performs reliably without failing prematurely or posing a safety risk. In this article, we will delve into the two primary voltage ratings of a relay： coil voltage and contact voltage, and explore their significance in real-world applications.