| CPC H05K 7/20209 (2013.01) [G06F 1/20 (2013.01); H05K 7/20136 (2013.01); G06F 2200/201 (2013.01)] | 14 Claims |
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1. A smart cooling fan system, being disposed in a housing case of an electronic device, and comprising:
at least one first cooling fan, being disposed in the housing case, and being installed on or near at least one electronic chip; wherein the at least one first cooling fan has a rotations per minute (RPM) signal outputting terminal and a pulse width modulation (PWM) signal inputting terminal;
at least one first temperature sensor, being disposed in the housing case for sensing a first temperature of the at least one electronic chip;
at least one second cooling fan, being disposed in the housing case, and being used for exhausting a hot air produced in the housing case or feeding an external air into the housing case; wherein the at least one second cooling fan also has a RPM signal outputting terminal and a PWM signal inputting terminal;
at least one second temperature sensor, being disposed in the housing case for sensing a second temperature of an inner space of the housing case; and
a microcontroller, having a memory and being selected from a group consisting of complex programmable logic device (CPLD) and field programmable gate array (FPGA), and being coupled to the at least one first temperature sensor, the at least one second temperature sensor, the RPM signal outputting terminal and the PWM signal inputting terminal of the at least one first cooling fan, and the RPM signal outputting terminal and the PWM signal inputting terminal of the at least one second cooling fan;
wherein the memory stores a plurality of lookup tables, and the plurality of lookup tables comprising:
three first lookup tables, wherein one of the three first lookup tables records, corresponding to the at least one first cooling fan, a plurality of first volumetric flow rates and a plurality of first fan rotation speed corresponding to the plurality of first volumetric flow rates, and one of the three first lookup tables records, corresponding to the at least one second cooling fan, a plurality of second volumetric flow rates and a plurality of second fan rotation speed corresponding to the plurality of second volumetric flow rates;
a second lookup table, recording L number of first duty cycle analog values and L number of first temperature values corresponding to the L number of first duty cycle analog values, L being a positive integer; and
a third lookup table, recording M number of second duty cycle analog values and M number of second temperature values corresponding to the M number of second duty cycle analog values, M being a positive integer;
wherein during a normal operation of the at least one first cooling fan and the at least one second cooling fan, the microcontroller receiving a first immediate rotation speed of the at least one first cooling fan and a second immediate rotation speed of the at least one second cooling fan;
wherein after receiving a data of the first temperature sensed by the at least one first temperature sensor, the microcontroller finding out one of the L number of first duty cycle analog values corresponding to the first temperature value from the second lookup table, and then generating and transmitting, according to the first duty cycle analog value, a first PWM signal with a first duty cycle to the PWM signal inputting terminal of the at least one first cooling fan, thereby controlling the at least one first cooling fan to produce a first airflow with a one of the plurality of first volumetric flow rates;
wherein after receiving a data of the second temperature sensed by the at least one second temperature sensor, the microcontroller finding out one of the M number of second duty cycle analog values corresponding to the second temperature value from the third lookup table, and then generating and transmitting, according to the second duty cycle analog value, a second PWM signal with a second duty cycle to the PWM signal inputting terminal of the at least one second cooling fan, thereby controlling the at least one second cooling fan to produce a second airflow with one of the plurality of second volumetric flow rates.
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