Patent ID: 8477057

Claim:
A method for sensing AC voltage, comprising: providing a voltage sensing circuit in communication with an AC power source; rectifying an AC signal from the AC power source with rectifier circuitry of the voltage sensing circuit; applying a first voltage to an analog-to-digital (A-to-D) converter circuit, wherein the first voltage is across a second resistive element of a first half cycle voltage divider comprising a first resistive element and the second resistive element and in communication with a positive DC output of the rectifier circuitry; applying a second voltage to the A-to-D converter circuit, wherein the second voltage is across a fourth resistive element of a second half cycle voltage divider comprising a third resistive element and the fourth resistive element and in communication with a negative DC output of the rectifier circuitry, wherein the first half cycle voltage divider and the second half cycle voltage divider share a common ground; converting the first voltage and the second voltage to a first digital voltage value and second digital voltage value respectively; and analyzing the first digital voltage value and the second digital voltage value by a processor to determine a voltage of the AC power source.