| 摘要 |
PROBLEM TO BE SOLVED: To prevent an air conditioner from being abnormally driven to enhance reliability of the air conditioner, by detecting a phase condition of a three-phase alternating current power source supplied to the air conditioner. SOLUTION: This phase condition detector is constituted of a phase detecting part 21 for detecting the first, second and third phases of the three-phase alternating current power source, an interruption detecting part 23 for detecting a tailing edge of a pulse signal corresponding to the third phase and for recognizing the generation of interruption by the third phase to generate a count signal, a counter part 22 for counting the pulse signals corresponding to the first and second phases using the third phase as a reference, a reverse phase/open phase detecting part 24 for detecting a "normal connection" condition or "antiphase" condition and for detecting an "open phase" condition based on the counted frequency of the interruption hereinbefore, and a display part 25 for displaying an message for showing the each condition of the "antiphase" condition, the "open phase" condition or the "normal connection" condition. COPYRIGHT: (C)2004,JPO |
