| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cooling fan control unit capable of preventing a decrease of rotational frequency of a cooling fan due to aging. <P>SOLUTION: A cooling fan 10 for cooling equipment includes a voltage supply circuit 35 including a plurality of resistance elements R1, R2 connected to a cooling fan 10, for changing a drive voltage to be supplied to the cooling fan 10 depending on the number of the resistance elements. A voltage detection circuit 40 for detecting whether or not a drive voltage to be supplied by the voltage supply circuit 35 has reached a predetermined voltage to be set beforehand. A CPU50 reduces the number of the resistance elements connected to the cooling fan 10 and increases the drive voltage to be supplied to the cooling fan 10, when it is detected by the voltage detection circuit 40 that the voltage detection circuit 40 has reached the predetermined voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT |
