Relays in safety-related control systems
There are no fewer than seven ways for even a simple transistor to fail. This means that monitoring all the electronic components that may be defective in a safe electronic switching output calls for considerable effort and the use of such things as a clocked fail-safe unit and microcontrollers (Figure 1).
Relay design evolves to address new applications
Electromechanical relays are continually evolving and adapting to meet the requirements of new generations of applications. For example, longer endurance power relays are needed to address smart meter applications and devices that can withstand higher inrush current are required for inductive load applications like energy efficient lighting.