Red Seal Instrumentation and Control Technician Practice Exam

What is the main objective of signal filtering in control systems?

1. To amplify the desired signal

2. To remove unwanted noise and enhance the desired signal

3. To convert analog signals to digital

4. To regulate the system's power supply

The correct answer is: To remove unwanted noise and enhance the desired signal

The main objective of signal filtering in control systems is to remove unwanted noise and enhance the desired signal. In many control applications, signals can be contaminated with various forms of noise due to electrical interference, environmental factors, or inherent limitations of sensors and measurement devices. Filtering is a process that selectively allows the desired signal components to pass through while attenuating or eliminating the noise, which leads to a clearer and more accurate representation of the actual signal being measured or controlled. This enhancement of the desired signal is crucial for effective control system performance, as it improves the reliability and accuracy of signal measurements, enhancing the system's overall efficiency. Effective filtering techniques can be implemented through various methods, including low-pass, high-pass, band-pass, and notch filters, each serving specific purposes based on the frequency characteristics of the noise and the desired signal. Amplifying the desired signal, converting analog signals to digital formats, and regulating the system's power supply are important processes in control systems but do not directly address the specific aim of filtering. Therefore, these choices are not the primary focus of signal filtering.