| 摘要 |
PROBLEM TO BE SOLVED: To provide a detecting device capable of accurately and stably detecting the fan life without misdetection, and widely applied regardless of the frequency of switching on and off of a power source. SOLUTION: This detecting device comprises a timer 6 starting its counting by inputting a rotating speed decrease signal 101 output from a comparing circuit 4, and outputting a count pulse 102 of a selected count time, a protective circuit 5 inputting the rotating speed decrease signal 101, and outputting an alarm signal 103 with a protection time on the basis of the count pulse 102, a rotating speed decrease pulse generating circuit 8 inputting the rotating speed decrease signal 101, and outputting one decrease pulse 104 every output, and a counting circuit 9 counting the decrease pulse generated within a period of a monitor pulse 105, and generating an advance alarm signal 106, when the number of decrease pulses reaches a reference number. COPYRIGHT: (C)2004,JPO
|
