Final answer:
Voltage monitors or voltage detectors are devices that monitor AC or DC voltages and emit an audible signal and display the voltage level on a meter when the voltage goes out of specification. They play a crucial role in maintaining system integrity, especially in AC circuits where they can help filter out noise.
Step-by-step explanation:
The electronic devices in question are designed to monitor voltages and provide an output if the voltage is outside a specified range. These devices are known as voltage monitors or voltage detectors. They are commonly used in various types of electrical and electronic systems to ensure that the voltage levels remain within safe or functional limits.
Voltage monitors typically feature an audible alert, such as a "click", to signal that a change in voltage has occurred. Additionally, they display the voltage level via a digital or analog meter. This helps technicians and engineers quickly identify and troubleshoot potential issues with the electrical system. For instance, during the study of Alternating-Current (AC) circuits, which involve voltages that vary in a sinusoidal manner, these devices can be critical for monitoring and recording these variations accurately.
In practical applications, voltage monitors might be used to track electrical signals from various sources, such as audio signals from a microphone or atmospheric data from radar systems. These signals often come with unwanted noise or frequencies, which need to be filtered out to maintain signal integrity. RC filters are an example of a component that can be used with AC circuits to remove unwanted frequencies and reduce noise.