| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarity detector of an AC power supply for reliably detecting three polarities and for easily connecting each terminal of the AC power supply and electric equipment. SOLUTION: In the polarity detector of the AC power supply, a voltage detection circuit is provided for detecting each voltage among three terminals of a hot terminal, a cold terminal, and an earth terminal, and polarity is detected by determining whether the connection state among respective terminals of the AC power supply and electric equipment is normal or abnormal, based on the detection result of the voltage detection circuit. The voltage detection circuit comprises, for example. a series circuit of a resistor, and a display lamp connected among three terminals. Additionally, the detection voltage among three terminals by the voltage detection circuit is processed by a matrix circuit, thus automatically determining whether a connection state is normal or abnormal and interrupting the power supply. COPYRIGHT: (C)2005,JPO&NCIPI
|
