| 摘要 |
PURPOSE:To reduce noise of blower motor without sacrifice of temperature adjusting function by controlling a fan such that the variation rate when increasing air flow will be different from that when decreasing the air flow. CONSTITUTION:The differential temperature data TD1 between setting temperature data TR1 and cabin temperature data TS1 is operated then the differential temperature data TD2 between setting temperature data TR2 and cabin temperature data TS2 is operated. Thereafter, it is decided whether TD1-TD2>0, and if the answer is NO, it will mean that the difference DELTAT between TS and TR is increasing thereby a control signal is fed to drive circuit 10 to bring TS near to TR thus to increase the rotation of blower motor 3 and to increase the air flow linearly as DELTAT increases. If the answer is YES, it will mean that DELTAT is decreasing to drive the motor 3 to reduce the rotation thus to reduce the air flow in step as DELTAT decreases. Consequently, variation of air flow is not perceptible when increasing while noise reduction is clearly perceptible when decreasing. |
