Signal relays are devices commonly used to control the flow of electrical current in a wide range of applications, from simple household appliances to complex industrial systems. Their simple design has made them an essential component for safely and reliably controlling circuits remotely. Signal relays are typically tasked with switching current of 2 A or less at voltage ratings between 5 and 30 VDC, which is why they are often called “low signal relays.”
The CUI Insights blog post 
, “An Introduction to Signal Relays” explains the basic operation and specifications of signal relays in more detail. It also discusses the differences between signal relays, power relays, and solid-state relays, while covering the steps for selecting a signal relay and its typical applications.
see more information