How is "time delay" defined in control systems?

In control systems, "time delay" refers to the duration it takes for an output to respond to a change in input. This is crucial for system analysis and design because time delays can significantly affect system performance, stability, and responsiveness. For instance, if an input signal changes, the time delay indicates how long it will take before the system's output reflects that change. Understanding this concept is essential for troubleshooting and optimizing control systems, as excessive time delays can lead to poor control response, overshoot, and stability issues.

The other options, while related to specific aspects of control systems, do not capture the broader definition of time delay. The reading time of a sensor, communication delays, or the time for power stabilization each represent different characteristics within a control system but do not define the overarching concept of time delay as it pertains to input-output response. This understanding is foundational for anyone working with control systems, particularly for diagnosing issues or improving system design.