Patent ID: 8659301

Claim:
A device that detects an overvoltage condition caused by a broken service neutral line or another overvoltage anomaly comprising: a rectifier circuit placed between the neutral connection and active line connection of a power line such that the output is a positive voltage with a peak value approximately equal to the maximum magnitude of the input voltage, a capacitor to hold the voltage output of the rectifier circuit at approximately a constant value near the peak voltage, a DC voltage source of a predetermined-value, a voltage divider network such that the voltage across a given resistive section of the network is equal to or greater than a predetermined value when the voltage output of the rectifier circuit is equal to or greater than a predetermined maximum safe value, a device for comparing the DC voltage source value to the voltage across the given section of the voltage divider network, an output from the comparing device that will be a unique signal depending on whether the voltage across the given section of the voltage divider network is greater than or less than the predetermined DC voltage source used as a reference, wherein the device for comparing the DC voltage to the voltage across the given section of the voltage divider network is a comparator that outputs a high voltage signal supplied by its high voltage rail when the voltage across the given section of the voltage divider network is higher than the DC voltage and outputs a low voltage signal when the DC voltage is higher than the voltage across the given section of the voltage divider network, and wherein the DC voltage simultaneously provides the high voltage rail for the comparator.