US-20260129791-A1 - COOLING SYSTEM AND METHOD OF FAN CONTROL

US20260129791A1US 20260129791 A1US20260129791 A1US 20260129791A1US-20260129791-A1

Abstract

A method of fan control is to be implemented by a main controller, and a fan controller electrically connected to the main controller to drive a plurality of fans. The method includes: by the main controller, generating a plurality of fan control signals and transmitting, using time-division multiplexing (TDM), a TDM control signal that includes the fan control signals to the fan controller, the fan control signals corresponding respectively to the fans and being in a form of pulse-width modulation (PWM) signals; by the fan controller, in response to receipt of the TDM control signal, demultiplexing the TDM control signal to obtain the fan control signals, and generating a plurality of driving signals based respectively on the fan control signals, the driving signals being in the form of PWM signals; and by the fan controller, transmitting the driving signals respectively to the fans to drive the fans to rotate accordingly.

Inventors

WEN-HSIEN LAI

Assignees

IN WIN DEVELOPMENT INC.

Dates

Publication Date: 20260507
Application Date: 20250219
Priority Date: 20241105

Claims (15)

1 . A method of fan control, the method to be implemented by a main controller and a fan controller that is electrically connected to the main controller to drive a plurality of fans, the plurality of fans being electrically connected to the fan controller, the method comprising: by the main controller, generating a plurality of fan control signals and transmitting, using time-division multiplexing (TDM), a TDM control signal that includes the plurality of fan control signals to the fan controller, the plurality of fan control signals corresponding respectively to the plurality of fans and being in a form of pulse-width modulation (PWM) signals; by the fan controller, in response to receipt of the TDM control signal, demultiplexing the TDM control signal thus received to obtain the plurality of fan control signals, and generating a plurality of driving signals based respectively on the plurality of fan control signals, the plurality of driving signals being in the form of PWM signals; and by the fan controller, transmitting the plurality of driving signals respectively to the plurality of fans to drive the plurality of fans to rotate accordingly.
2 . The method as claimed in claim 1 , wherein transmitting the TDM control signal to the fan controller includes the main controller, within a signal cycle of the TDM control signal, sequentially transmitting the plurality of fan control signals and a control-end signal that follows the plurality of fan control signals, the control-end signal being in a form of a PWM signal and having a duty cycle of less than twenty percent; and wherein demultiplexing the TDM control signal includes the fan controller determining the signal cycle of the TDM control signal based on the control-end signal in order to obtain the plurality of fan control signals.
3 . The method as claimed in claim 1 , further comprising: by the fan controller, receiving a plurality of tachometer signals respectively from the plurality of fans, the plurality of tachometer signals corresponding respectively to current rotating speeds of the plurality of fans; and by the fan controller, generating a plurality of fan speed signals, which are in a form of pulse wave signals, based respectively on the plurality of tachometer signals thus received, and transmitting, using the TDM, a TDM speed signal that includes the plurality of fan speed signals to the main controller.
4 . The method as claimed in claim 3 , further comprising: by the main controller, in response to receipt of the TDM speed signal from the fan controller, demultiplexing the TDM speed signal to obtain the plurality of fan speed signals, and determining pulse wave frequencies respectively of the plurality of fan speed signals to obtain the current rotating speeds of the plurality of fans.
5 . The method as claimed in claim 3 , wherein transmitting the TDM speed signal to the main controller includes the fan controller determining the current rotating speeds of the plurality of fans based respectively on the plurality of tachometer signals, adding a constant value to a highest one of the current rotating speeds of the plurality of fans thus determined to produce an end-point value, converting the end-point value into a speed-end signal that is in a form of a pulse wave signal, and within a signal cycle of the TDM speed signal, sequentially transmitting the plurality of fan speed signals and the speed-end signal that follows the plurality of fan speed signals to the main controller.
6 . The method as claimed in claim 3 , wherein in generating the plurality of fan speed signals, for each of the plurality of fans, when the current rotating speed of the fan becomes higher, a frequency of the fan speed signal that is correspondingly generated becomes higher.
7 . The method as claimed in claim 1 , wherein in generating the plurality of driving signals based respectively on the plurality of fan control signals, each of the plurality of driving signals has a duty cycle that is same as a duty cycle of the respective one of the plurality of fan control signals.
8 . A cooling system comprising: a main controller; a fan controller electrically connected to said main controller; and a plurality of fans electrically connected to said fan controller, wherein said main controller is configured to generate a plurality of fan control signals, and transmit, using time-division multiplexing (TDM), a TDM control signal that includes the plurality of fan control signals to said fan controller, the plurality of fan control signals corresponding respectively to said plurality of fans and being in a form of PWM signals, wherein said fan controller is configured to, in response to receipt of the TDM control signal, demultiplex the TDM control signal thus received to obtain the plurality of fan control signals, and generate a plurality of driving signals based respectively on the plurality of fan control signals, the plurality of driving signals being in the form of PWM signals, and wherein said fan controller is further configured to transmit the plurality of driving signals respectively to said plurality of fans to drive said plurality of fans to rotate accordingly.
9 . The cooling system as claimed in claim 8 , wherein said main controller is configured to, when transmitting the TDM control signal to said fan controller, within a signal cycle of the TDM control signal, sequentially transmit the plurality of fan control signals and a control-end signal that follows the plurality of fan control signals, the control-end signal being in a form of a PWM signal and having a duty cycle of less than twenty percent; and wherein said fan controller is configured to, when demultiplexing the TDM control signal, determine the signal cycle of the TDM control signal based on the control-end signal in order to obtain the plurality of fan control signals.
10 . The cooling system as claimed in claim 8 , wherein said fan controller is further configured to receive respectively from said plurality of fans a plurality of tachometer signals that correspond respectively to current rotating speeds of said plurality of fans, generate a plurality of fan speed signals based respectively on the plurality of tachometer signals thus received, and transmit, using the TDM, a TDM speed signal that includes the plurality of fan speed signals to said main controller, the plurality of fan speed signals being in a form of pulse wave signals.
11 . The cooling system as claimed in claim 10 , wherein said main controller is further configured to, in response to receipt of the TDM speed signal from said fan controller, demultiplex the TDM speed signal to obtain the plurality of fan speed signals, and determine pulse wave frequencies respectively of the plurality of fan speed signal to obtain the current rotating speeds of said plurality of fans.
12 . The cooling system as claimed in claim 10 , wherein said fan controller is configured to, when transmitting the TDM speed signal to said main controller, determine the current rotating speeds of said plurality of fans based respectively on the plurality of tachometer signals, add a constant value to a highest one of the current rotating speeds of said plurality of fans thus determined to produce an end-point value, convert the end-point value into a speed-end signal that is in a form of a pulse wave signal, and within a signal cycle of the TDM speed signal, sequentially transmit the plurality of fan speed signals and the speed-end signal that follows the plurality of fan speed signals to said main controller.
13 . The cooling system as claimed in claim 10 , wherein for each of said plurality of fans, when the current rotating speed of said fan becomes higher, a frequency of the fan speed signal that is correspondingly generated becomes higher.
14 . The cooling system as claimed in claim 8 , wherein each of the plurality of driving signals has a duty cycle that is same as a duty cycle of the respective one of the plurality of fan control signals.
15 . The cooling system as claimed in claim 8 , further comprising a motherboard that includes said main controller, and a control board that includes said fan controller and that is electrically connected to said motherboard.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Taiwanese Invention Patent Application No. 113142359, filed on Nov. 5, 2024, the entire disclosure of which is incorporated by reference herein. FIELD The disclosure relates to a cooling system and a method of fan control, and more particularly to a cooling system with multiple fans and a method for controlling multiple fans. BACKGROUND In recent years, as the operating speed and performance of central processing units (CPUs) significantly advance, the amount of waste heat generated during operations of the CPUs rises. Modern CPUs heavily rely on conventional cooling systems to dissipate the waste heat, ensuring that the CPUs operate within a permissible temperature range. Additionally, components within a computer chassis, such as graphics cards, memory, and hard drives, also generate waste heat, and are increasing in number. Therefore, installing the conventional cooling systems within the computer chassis has become a common approach to achieving heat dissipation. Referring to FIG. 1, a conventional cooling system 900 is installed in a computer (not shown), and includes a motherboard 91, a fan hub 92, and a plurality of fans 93 that are electrically connected to the fan hub 92. The fans 93 are mounted in different areas of the computer. The motherboard 91 outputs a driving signal to the fans 93 through the fan hub 92 to drive the fans 93 to rotate at the same speed according to the driving signal. However, each area of the computer has a different temperature rise condition, but the motherboard 91 can only output the driving signal that controls all the fans 93 to rotate at the same time and at the same speed. Therefore, the conventional cooling system 900 is unable to adjust rotating speeds of the fans 93 separately based on the temperature rise conditions respectively of different areas of the computer, which may cause a waste of power. SUMMARY Therefore, an object of the disclosure is to provide a method of fan control and a cooling system that can alleviate at least one of the drawbacks of the prior art. According to an aspect of the disclosure, the method of fan control is to be implemented by a main controller, and a fan controller that is electrically connected to the main controller to drive a plurality of fans. The fans are electrically connected to the fan controller. The method includes: by the main controller, generating a plurality of fan control signals and transmitting, using time-division multiplexing (TDM), a TDM control signal that includes the fan control signals to the fan controller, the fan control signals corresponding respectively to the fans and being in a form of pulse-width modulation (PWM) signals; by the fan controller, in response to receipt of the TDM control signal, demultiplexing the TDM control signal thus received to obtain the fan control signals, and generating a plurality of driving signals based respectively on the fan control signals, the driving signals being in the form of PWM signals; and by the fan controller, transmitting the plurality of driving signals respectively to the fans to drive the fans to rotate accordingly. According to another aspect of the disclosure, the cooling system includes a main controller, a fan controller and a plurality of fans. The fan controller is electrically connected to the main controller. The fans are electrically connected to the fan controller. The main controller is configured to generate a plurality of fan control signals, and transmit, using TDM, a TDM control signal that includes the fan control signals to the fan controller. The fan control signals correspond respectively to the fans and are in a form of PWM signals. The fan controller is configured to, in response to receipt of the TDM control signal, demultiplex the TDM control signal thus received to obtain the fan control signals, and generate a plurality of driving signals based respectively on the fan control signals, where the driving signals are in the form of PWM signals. The fan controller is further configured to transmit the driving signals respectively to the fans to drive the fans to rotate accordingly. BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment(s) with reference to the accompanying drawings. It is noted that various features may not be drawn to scale. FIG. 1 is a schematic diagram of a conventional cooling system. FIG. 2 is a schematic diagram of a cooling system according to an embodiment of the disclosure. FIG. 3 is a signal timing diagram illustrating a frame of a time-division multiplexing (TDM) control signal within a signal cycle thereof. FIG. 4 is a flow chart illustrating a fan driving procedure of an embodiment of the disclosure. FIG. 5 is a signal timing diagram illustrating a frame of a TDM speed signal within a signal cycle thereof. FIG. 6 is a flow chart il