| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a blower for a septic tank provided with a watch device which does not require a crystal oscillator, a battery, a display part, a time- setting part, or the like, and can get accurate time. SOLUTION: A radio-frequency receiver integrated circuit 20 receives radio- frequency information sent from the Ministry of Posts and Telecommunications and supplies a controlling part 13 with the time information at a prescribed interval. The controlling part 13 in which a starting time for backward washing is preliminarily registered can judge if the starting time for backward washing has come based on the information on the preliminarily registered starting time. When the controlling part 13 judges that the starting time for backward washing has come, it sends a driving signal to a thyristor 21 and actuates the drive circuit of a change-over valve 4. Then, the change-over valve 4 is switched to the side of the backward washing aeration, and the backward washing aeration is executed.</p> |
