RPM controller using drive profiles

摘要

A control circuit for controlling the rotational speed of a fan may include a memory element to store operating data corresponding to an operational profile of the fan defined by RPM (revolutions per minute) versus temperature, with the operating data comprising a respective temperature value and a respective RPM value for each respective operating point representing a change in slope of a function that corresponds to the operational profile of the fan. A processing unit may receive a present temperature value, retrieve the operating data from the storage unit, and identify a pair of consecutive operating points corresponding to the present temperature. The processing unit may calculate a desired RPM value corresponding to the present temperature value by performing linear interpolation between the pair of consecutive operating points, and provide the desired RPM value to a closed-loop fan controller to control the fan according to the desired RPM value.

主权项

1. A control circuit for controlling the rotational speed of a fan, the control circuit comprising:
a storage unit to store operating data corresponding to an operational profile of the fan defined by an RPM (revolutions per minute) versus temperature function (RTPF), wherein the operating data comprises a respective temperature value and a respective RPM value for each respective operating point representing a change in slope of the RTPF, wherein each pair of consecutive operating points defines a respective temperature slot; and a processing unit configured to:
communicate with the storage unit to retrieve the operating data;receive a present temperature value indicative of a present temperature reading;calculate a desired RPM value, wherein a corresponding operating point is identified when the present temperature value matches one of the respective temperature values of the stored operating points, and the desired RPM value is set to the respective RPM value corresponding to the matching one of the respective temperature values; select a matching temperature slot when the present temperature value does not match any of the respective temperature values of the stored operating points, wherein a pair of consecutive operating points corresponding to the present temperature value is identified, wherein the present temperature value is greater than a lower respective temperature value of the pair of consecutive operating points that defines the matching temperature slot, and lower than a higher respective temperature value of the pair of consecutive operating points that defines the matching temperature slot;calculate a desired RPM value according to a specified algorithm and the pair of consecutive operating points that defines the matching temperature slot; and output the desired RPM value.