A Voltage Fault Detector (VFD) is an electrical component that monitors multiple voltage inputs for overvoltages
and undervoltages. In simple design, voltage fault detectors detect fault conditions on voltage inputs that are monitored and show the faults
ona display. There are also intelligent VFD devices that provide detailed information
about the type of fault. Depending on the design, voltage fault detectors can monitor over 30 voltage inputs, with each individual input showing its good/bad status. Some voltage fault detectors have a clock input for the time base, which can be used to set the multiplex frequency, which is determined by the sampling rate of the AD converters (ADC).