Fan type identification apparatus and method
Systems, methods, apparatuses for fan type identification are disclosed. A predetermined pulse width modulation duty cycle is used to obtain a sequence of fan speeds from a fan over a time period. A fan type of the fan is determined based on the sequence of fan speeds.
1. A computing device comprising:
a controller coupled to a fan and configured to:
use a predetermined pulse width modulation duty cycle to obtain a sequence of fan speeds from the fan over a time period; and
determine a fan type of the fan based on each of the fan speeds within the sequence of fan speeds.
2. The computing device of claim 1 , wherein the sequence of fan speeds is obtained over a start-up time of the fan.
3. The computing device of claim 2 , wherein the sequence of fan speeds varies non-linearly over the start-up time.
4. The computing device of claim 1 , wherein the controller is further configured to set the predetermined pulse width modulation duty cycle at a value lower than that of an operational pulse width modulation range.
5. The computing device of claim 4 , wherein the predetermined pulse width modulation duty cycle is set at below 10% duty cycle.
6. The computing device of claim 1 , wherein the controller is further configured to:
determine a plurality of fan speed samples from the sequence of fan speeds, each of the fan speed samples corresponding to a different sampling time; and
assign a corresponding code element to each of the fan speed samples, in which the corresponding code element is one of a plurality of code elements, wherein each of the plurality of code elements corresponds to one of a plurality of ranges of fan speeds.
7. The computing device of claim 6 , wherein the controller further comprises:
a memory storing a library of fan types, the controller being further configured to:
form a code using the corresponding code elements; and
use the code to look up a corresponding fan type in the library of fan types.
8. The computing device of claim 6 , wherein the controller is further configured to form a code by combining the corresponding code elements in a sequence.
9. A method of fan type identification, the method comprising:
using a predetermined pulse width modulation duty cycle to obtain a sequence of fan speeds from a fan over a time period; and
determining a fan type of the fan based on each of the fan speeds within the sequence of fan speeds.
10. The method of claim 9 further comprising obtaining the sequence of fan speeds over a start-up time of the fan.
11. The method of claim 10 , wherein the sequence of fan speeds varies non-linearly over the start-up time.
12. The method of claim 9 further comprising setting the predetermined pulse width modulation duty cycle at a duty cycle lower than a duty cycle within an operational pulse width modulation range.
13. The method of claim 12 , wherein the predetermined pulse width modulation duty cycle is set at below 10% duty cycle.
14. The method of claim 9 further comprising:
determining a plurality of fan speed samples from the sequence of fan speeds, each of the fan speed samples corresponding to a different sampling time; and
assigning a code element to each of the fan speed samples, in which the assigned code element is one of a plurality of code elements, wherein each of the plurality of code elements corresponds to one of a plurality of ranges of fan speeds.
15. The method of claim 14 further comprising:
forming a code using the assigned code elements; and
using the code to look up a corresponding fan type in a library of fan types.
16. The method of claim 14 further comprising forming a code by combining the assigned code elements in a sequence in order of the sampling time, in which the code corresponds to a fan type.