Patent ID: 7446538
Filing Date: 2008-11-04
Classification: H02H

Abstract:
1. A device for identifying an arrangement of an alternating current (AC) power supply, comprising: a first voltage detecting circuit coupled to a ground line and a hot line of the AC power supply, receiving a first input signal from the hot line of the AC power supply for detecting a voltage level thereof to generate a first detect signal; a second voltage detecting circuit coupled to the ground line and a neutral line of the AC power supply, receiving a second input signal from the neutral line of the AC power supply and detecting a voltage level thereof to generate a second detect signal; and a comparison logic circuit coupled to the first and second voltage detecting circuits, receiving the first and second detect signals to generate first and second identification signals according to the first and second detect signals, indicating the arrangement of the AC power supply, wherein combination of low level first detect signal and high level second detect signal, low level first detect signal and low level second detect signal, and high level first detect signal and low level second detect signal indicate the arrangement of the AC power supply being single-phase two-wire, single- phase three-wire, and inverted single-phase two wire arrangements respectively.