| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an alarm unit that can improve accuracy of failure diagnosis of a buzzer. <P>SOLUTION: An alarm unit 1 causes a buzzer 40 to output an audible alarm to indicate an abnormal condition when the abnormal condition is detected. The alarm unit 1 comprises: a failure diagnosis unit 22 for determining that the buzzer 40 is defect when a voltage applied to the buzzer 40 is equal to or less than a threshold; and a threshold setting unit 23 for reducing the threshold in accordance with a reduced battery voltage. In addition, the threshold setting unit 23 sets the threshold in accordance with battery voltage information immediately before determination of failure of the buzzer 40 by the failure diagnosis unit 22. <P>COPYRIGHT: (C)2013,JPO&INPIT |
