| CPC F04D 27/004 (2013.01) [F04D 25/16 (2013.01); G05B 15/02 (2013.01); H03K 7/08 (2013.01)] | 13 Claims |
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1. A fan driving method, comprising:
driving a first fan according to a first driving signal, and driving a second fan according to a second driving signal;
obtaining a first rotating speed signal from the first fan, and obtaining a second rotating speed signal from the second fan, wherein the first rotating speed signal has a first phase, and the second rotating speed signal has a second phase;
comparing a difference between the second phase and the first phase to obtain a detection phase difference when determining that the first phase is unstable; and
selectively increasing or decreasing a duty cycle of the second driving signal according to the detection phase difference to adjust the second phase to maintain a preset phase difference with the first phase,
wherein the first rotating speed signal has a first frequency, the second rotating speed signal has a second frequency, and the fan driving method further comprises:
determining whether the first frequency maintains stable;
comparing a difference between the second frequency and the first frequency to obtain a detection frequency difference when determining that the first frequency is unstable; and
increasing or decreasing the duty cycle of the second driving signal selectively to change the second frequency toward the first frequency according to the detection frequency difference.
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