Fan rotational speed controlling circuit
A circuit for controlling rotational speed of a fan includes a sensor, a first chipset, and a second chipset. The sensor detects an ambient temperature and generates a corresponding temperature signal. The first chipset provides a pulse-width modulation signal to the fan for driving the fan, and receives a rotational speed signal from the fan. The second chipset defines a controlling relationship between the rotational speed of the fan and the temperature. The controlling relationship is that the temperature is partitioned into a plurality of temperature ranges and each of the temperature ranges corresponds to a rotational speed range. The temperature signal is transmitted from the sensor to the second chipset via the first chipset. The second chipset determines a rotational speed range according to the controlling relationship, and controls the first chipset to adjust the pulse-width modulation signal until the actual rotational speed of the fan is in the rotational speed range.
Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd. Hon Hai Precision Industry Co., Ltd.
Y Y F
Y10S Y02B F04D
additional additional inventional
Ting Qiu
Huang Hu