TWI579685B - Fan system and fan control method - Google Patents

Description

Fan system and fan control method

The present invention relates to a fan system and a fan control method, and more particularly to a fan system and a fan control method capable of maintaining a three-legged fan at a low voltage.

To start the fan, you need to input a starting voltage. When the fan is started, the voltage that keeps the fan running can be substantially lower than the starting voltage. However, conventionally, in order to enable the fan to continue to operate continuously after being turned on, the circuit design will make the minimum supply voltage supplied to the fan not lower than the starting voltage, thereby avoiding a situation in which the fan does not rotate. For a three-pin (3 pin) fan, since the fan speed can only be controlled by the input voltage, if the input voltage must always be higher than the starting voltage, the fan can only run at high speed, which may bring Noise that can cause user confusion.

In order to solve the above problems, the present invention provides a fan system and a fan control method capable of maintaining a three-legged fan at a low voltage.

The fan system of the present invention comprises: a three-pin fan having a starting voltage; a starting circuit for outputting a first voltage greater than or equal to the starting voltage; and a basic input/output system, the output is lower than the starting a second voltage of the voltage; and a switching device that, when the fan is operating normally, the second The pressure is supplied to the three-legged fan, and when a trigger signal is received, the first voltage is switched to the three-legged fan.

According to an embodiment of the invention, the fan system is installed in a computer system, and the trigger signal is a power-on signal sent when the computer system is turned on. According to an embodiment of the invention, the position of the three-legged fan is used to detect the rotation speed of the three-legged fan, and the trigger signal is output when the fan speed is not detected. According to an embodiment of the invention, the startup voltage is 3.6V and the second voltage is greater than 2V.

According to an embodiment of the invention, the switching device includes: a diode connected to the voltage output end of the basic input/output system, a cathode connected to the power pin of the three-pin fan; and a switching element connected to the The cathode of the diode is between the voltage output of the startup circuit.

The fan control method of the present invention is for controlling a three-pin fan, comprising: providing a first time greater than or equal to a starting voltage of the three-pin fan when the system for mounting the three-pin fan is powered on Voltage to the tripod fan; and when the fan is running, providing a second voltage less than the startup voltage to the tripod fan.

According to an embodiment of the present invention, the fan control method further includes: providing the first voltage to the three-legged fan when detecting that the fan is stopped; and providing the second voltage to when detecting that the fan is running The three-legged fan.

According to an embodiment of the invention, in the fan control method, the starting voltage is 3.6V, and the second voltage system is greater than 2V.

As described above, the fan system and the fan control method according to various embodiments of the present invention provide a running voltage of a three-pin fan lower than a starting voltage, It can reduce the noise caused by the high fan speed and provide a comfortable working environment for users. Moreover, in response to the above-mentioned operating voltage lower than the starting voltage, the three-pin fan is provided, and the possibility that the fan will stop cannot be eliminated. In order to prevent the three-pin fan from being activated when the stop state is stopped, the present invention is further turned on or detected. When the fan has no speed, switch the power pin of the three-pin fan to a power supply voltage greater than or equal to the starting voltage, and restart the fan by short-term power supply from other lines. Therefore, the three-legged fan of the present invention can maintain operation at a low voltage, and can resume operation through another circuit that supplies a high voltage even when the fan is stopped, thereby maintaining a good state of the product that uses the fan for heat dissipation. The fan system and the fan control method of the present invention simultaneously solve the problem of noise and possible stop of operation.

1‧‧‧Fan system

10‧‧‧Three-legged fan (fan)

20‧‧‧Starting circuit

30‧‧‧Basic Input Output System (BIOS)

40‧‧‧Switching device

D‧‧‧ diode

OUT‧‧‧ output

S‧‧‧ trigger signal

SW‧‧ switch

V1‧‧‧ first voltage

V2‧‧‧second voltage

Fig. 1 is a schematic view showing the basic configuration of a fan system of the present invention.

Fig. 2 is a flow chart showing a fan control method according to a first embodiment of the present invention.

Fig. 3 is a flow chart showing a fan control method according to a second embodiment of the present invention.

Fig. 4 is a flow chart showing a fan control method according to a third embodiment of the present invention.

Fig. 5 is a view showing an embodiment of the switching device of Fig. 1.

Embodiments of the present invention will be described below with reference to the drawings. Fig. 1 is a schematic view showing the basic configuration of a fan system of the present invention.

As shown in FIG. 1, the fan system 1 of the present invention includes: three-legged position A fan (or simply a fan) 10, a starter circuit 20, a basic input/output system (hereinafter referred to as BIOS) 30, and a switching device 40. The three-pin fan 10 has a power pin, a ground pin, and a rotational reading pin. The three-legged fan 10 has a starting voltage Vs, which is the lowest voltage (for example, 3.6 V) at which the three-legged fan 10 can be operated from the stop. The speed of the three-pin fan can only be controlled by controlling the voltage of the input power pin. The higher the input voltage, the higher the fan speed. The startup circuit 20 outputs a first voltage V1 (for example, 5 V) greater than or equal to the startup voltage Vs for starting the stopped three-legged fan 10. The BIOS 30 outputs a second voltage V2 (for example, 2 to 3 V) that is less than the startup voltage Vs, so that the three-pin fan is kept running at a low speed. The switching device 40 selectively supplies one of the first voltage V1 and the second voltage V2 to the power pin of the three-pin fan 10.

The technical feature of the present invention is that the voltage for starting the three-pin fan 10 and the voltage for controlling the operation of the three-pin fan 10 are separated and controlled, and thus the power supply voltage is supplied from the BIOS only, so that the voltage must always be high. The limit of the starting voltage Vs. Based on this design concept, a trigger signal S is needed to control the switching device 40, so that the switching device 40 switches the voltage output to the power pin of the three-pin fan 10 from the second voltage V2 to the first according to the trigger signal S. A voltage V1.

According to an embodiment of the present invention, the case where the three-legged fan 10 needs to be supplied with the first voltage V1 is when the system is turned on. The fan system 1 is installed, for example, in a personal computer. When the personal computer is turned on, the three-legged fan 10 needs to be activated to provide a three-pin fan installation object (which may be a CPU, a display card, or a motherboard). Cooling function. In this case, the trigger signal S may be a power-on signal when the personal computer is turned on (for example, generated by the user pressing the power button) Pulse signal).

Fig. 2 is a flow chart showing a fan control method according to a first embodiment of the present invention. As shown in Fig. 2, in step S201, the user presses the power button of the host (e.g., personal computer) to which the fan system of the present invention is installed to turn on the host. At step S202, the host issues a power-on signal. In step S203, when the switching device 40 receives the power-on signal as the trigger signal S, it switches to supply the first voltage V1 of the startup voltage Vs supplied by the startup circuit 20 to the power pin of the three-pin fan 10. To start the fan. In step S204, the switching device 40 determines whether the power-on signal is still received (the length of the power-on signal can be customized according to the designer of the device), and if the power-on signal is still received, the first voltage V1 is maintained, and if the power-on signal is not received, Indicates that the host has been turned on (the three-pin fan 10 has also been activated), then proceeds to step S205 to switch to supply the second voltage V2 supplied by the BIOS 30 below the startup voltage Vs to the power pin of the three-pin fan 10 to The fan is operated at a low speed to reduce the noise generated when the fan is running.

According to another embodiment of the present invention, the case where the three-legged fan 10 needs to be supplied with the first voltage V1 is when the fan is stopped. Since the voltage supplied by the three-legged fan 10 of the present invention during normal operation is lower than the starting voltage, the fan is still stopped due to the resistance of the external environment, etc., in order to avoid the shortage of the second voltage V2 supplied by the BIOS 30. To start the fan again, it is necessary to detect whether the fan is stopped. If the fan stops, a trigger signal S is issued to switch the first voltage V1 to restart the fan.

Fig. 3 is a flow chart showing a fan control method according to a second embodiment of the present invention. As shown in Fig. 3, in step S301, the fan 10 is powered by the second voltage V2 supplied from the BIOS 30 lower than the startup voltage Vs. in In step S302, the rotational speed of the fan is read from the rotational speed of the three-legged fan 10. In step S303, it is determined whether the fan 10 is rotating according to the rotational speed signal, and if no rotational speed signal is received, the fan 10 is in a stopped state. In step S303, if it is found that the fan is still rotating, the process returns to step S302 to continue detecting the rotation speed of the fan 10. On the other hand, if it is found that the fan is not rotating, the process proceeds to step S304. In step S304, the fan is not rotated to output the trigger signal S to the switching device 40, and the switching device is switched to supply the first voltage V1 of the starting voltage Vs supplied by the starting circuit 20 to the power pin of the three-pin fan 10. Bit, to restart the fan. After a predetermined time that can be designed, the process proceeds to step S305. In step S305, the switching device 40 switches to supply the second voltage V2 lower than the startup voltage Vs supplied from the BIOS 30 to the power pin of the three-pin fan 10, operates the fan at a low rotation speed, and returns to step S302 to read again. Take the speed of the fan 10. According to the above-described flow, it is possible to surely avoid the case where the fan does not rotate after an unexpected stop.

Further, according to another embodiment of the present invention, the three-legged fan 10 can be supplied with the first voltage V1 both at the time of the above-described power-on and when the fan is abnormally stopped. Thereby, the advantages of the above two embodiments can be satisfied at the same time.

Fig. 4 is a flow chart showing a fan control method according to a third embodiment of the present invention. As shown in Fig. 4, in step S401, the user presses the power button of the host on which the fan system of the present invention is installed to turn on the host. At step S402, the host issues a power-on signal. In step S403, when the switching device 40 receives the power-on signal as the trigger signal S, it switches to supply the first voltage V1 of the startup voltage Vs supplied by the startup circuit 20 to the power pin of the three-pin fan 10. To start the fan. In step S404, the switching device 40 determines whether the power-on signal is still received (the length of the power-on signal can be customized according to the designer of the device), if still After receiving the power-on signal, the first voltage V1 is maintained. If the power-on signal is not received, indicating that the host has been powered on (the three-pin fan 10 has also been activated), the process proceeds to step S405, where the BIOS 30 is supplied with a lower than the startup voltage. The second voltage V2 of Vs is supplied to the power pin of the three-pin fan 10, and the fan is operated at a low rotational speed. After the host booting process is completed, the process proceeds to step S406, and the rotational speed of the fan is read from the rotational speed of the three-legged fan 10. In step S407, it is determined whether the fan 10 is rotating according to the rotational speed signal, and if no rotational speed signal is received, the fan 10 is in a stopped state. In step S407, if it is found that the fan is still rotating, the process returns to step S406 to continue detecting the rotation speed of the fan 10. On the other hand, if it is found that the fan is not rotating, the process proceeds to step S408. In step S408, the absence of rotation of the fan causes the trigger signal S to be output to the switching device 40, causing the switching device to switch to supply the first voltage V1 to the power pin of the three-pin fan 10, thereby restarting the fan. After a predetermined time that can be designed, the process proceeds to step S409. In step S409, the switching device 40 switches back to the second voltage V2 to supply the power pin of the three-pin fan 10, operates the fan at a low rotational speed, and returns to step S406 to read the rotational speed of the fan 10 again.

Fig. 5 is a view showing an embodiment of the switching device 40 of Fig. 1. As shown in FIG. 5, the switching device 40 includes: a diode D connected to the second voltage V2 outputted by the BIOS 30, the cathode connected to the output terminal OUT of the switching device 40, and a switching element SW connected to the starting circuit The first voltage V1 outputted by 20 is between the output terminal OUT of the switching device 40. When there is no trigger signal S input, the switch SW is opened, so that the output terminal OUT outputs the second voltage V2; when the trigger signal S is input, the switch SW is closed to make the first voltage V1 output from the output terminal OUT. At this time, since the first voltage V1 is greater than the second voltage V2, the diode D is in a reverse biased state and is not turned on. The above configuration is only one of the switching devices 40 In a simple embodiment, the present invention is not limited to the above embodiment, and the switching device is implemented by, for example, other switching devices such as MOSFETs, relays, and jumps.

According to the above embodiment, the fan system and the fan control method of the present invention can reduce the noise caused by the high fan speed by providing the operating voltage of the three-pin fan lower than the starting voltage, thereby providing a user with more comfortable. working environment. Moreover, in response to the above-mentioned operating voltage lower than the starting voltage, the three-pin fan is provided, and the possibility that the fan will stop cannot be eliminated. In order to prevent the three-pin fan from being activated when the stop state is stopped, the present invention is further turned on or detected. When the fan has no speed, switch the power pin of the three-pin fan to a power supply voltage greater than or equal to the starting voltage, and restart the fan by short-term power supply from other lines. Therefore, the three-legged fan of the present invention can maintain operation at a low voltage, and can resume operation through another circuit that supplies a high voltage even when the fan is stopped, thereby maintaining a good state of the product that uses the fan for heat dissipation. The fan system and the fan control method of the present invention simultaneously solve the problem of noise and possible stop of operation.

The embodiments of the present invention are described in detail above, but the present invention is not limited to the above-described embodiments, and the present invention includes various modifications and changes as long as it conforms to the gist of the invention described in the claims.

1‧‧‧Fan system

10‧‧‧Three-legged fan (fan)

20‧‧‧Starting circuit

30‧‧‧Basic Input Output System (BIOS)

40‧‧‧Switching device

S‧‧‧ trigger signal

Claims (8)

A fan system comprising: a three-pin fan having a starting voltage; a starting circuit for outputting a first voltage greater than or equal to the starting voltage; and a basic input/output system for outputting a second lower than the starting voltage And a switching device that supplies the second voltage to the three-pin fan when the fan is in normal operation, and switches the first voltage to the three-pin fan when receiving a trigger signal. The fan system of claim 1, wherein the fan system is installed in a computer system, and the trigger signal is a power-on signal sent when the computer system is powered on. The fan system of claim 1, wherein the one-legged position of the three-legged fan is used to detect the speed of the three-legged fan, and the trigger signal is output when the fan speed is not detected. The fan system of claim 1, wherein the starting voltage is 3.6V and the second voltage is greater than 2V. The fan system of claim 1, wherein the switching device comprises: a diode, an anode connected to the voltage output end of the basic input/output system, and a cathode connected to the power pin of the three-pin fan; And a switching element connected between the cathode of the diode and the voltage output end of the starting circuit. A fan control method for controlling a three-pin fan includes: providing a first voltage greater than or equal to a starting voltage of the three-pin fan to the third when the system for mounting the three-pin fan is powered on a pin fan; and when the fan is running, providing a second voltage less than the starting voltage to the tripod fan. The fan control method of claim 6, further comprising: providing the first voltage to the three-legged fan when detecting that the fan is stopped; and providing the second when detecting that the fan is running Voltage to the three-legged fan. The fan control method of claim 6, wherein the starting voltage is 3.6V, and the second voltage system is greater than 2V.