CN100435468C - Fan control device and method - Google Patents

Abstract

A fan control device receives an external start signal, and includes a rotational speed control module and a driving module. The rotation speed control module comprises a starting control unit, a control unit and a control unit, wherein the starting control unit receives a starting signal and generates a starting rotation speed control signal according to the starting signal; and a speed control unit, which receives the initial signal and generates a speed control signal according to the initial signal after a specific time; the driving module receives the initial rotation speed control signal and controls the initial rotation speed of the fan according to the initial rotation speed control signal, and receives the rotation speed control signal and controls the rotation speed of the fan according to the rotation speed control signal. The invention also provides a fan control method applicable to the fan control device.

Description

Fan control device and method

technical field

The present invention relates to a fan control device and its control method, in particular to a control device capable of controlling the fan's initial rotational speed and its control method.

Background technique

Most electronic systems are equipped with a fan for heat dissipation, so as to prevent some components in the electronic system from overheating and malfunctioning. Generally speaking, in order to control the fan in the electronic system, most of them have a fan control device to provide the electronic system to control the fan speed through the fan control device, so that the fan can match the actual operating conditions of the electronic system And adjust the speed of the fan. For example, when a fan is used in a computer system, when the CPU usage ratio of the computer system is high, the heat energy generated by it is relatively high. At this time, the computer system can use the fan control device to Increase the speed of the fan to meet cooling requirements. Conversely, when the central processing unit is in an idle state, the rotational speed of the fan can be relatively reduced to save energy.

Please refer to FIG. 1 and FIG. 2 , which are respectively a block diagram and a circuit diagram of a conventional fan control device. The conventional fan control device 1 includes a rotational speed control module 11 and a driving module 12 (generally speaking, the driving module 12 is a driving chip). The rotational speed control module 11 has a power supply terminal and a signal input terminal, the power supply terminal is used to connect an external voltage source V, the signal input terminal receives a target rotational speed control signal 101 sent by a computer system 10, and according to The target speed control signal 101 generates a speed control signal 102 . The drive module 12 controls the speed of a fan 2 according to the speed control signal 102 . Generally speaking, the voltage of the speed control signal 102 is inversely proportional to the speed of the fan 2 , that is, the lower the voltage of the speed control signal 102 , the faster the speed of the fan 2 . In addition, as shown in FIG. 2 , the speed control module 11 mainly includes a transistor 111 , a plurality of resistors 112 and a capacitor 113 . The base of the transistor 111 is used as an input terminal to receive the target speed control signal, and the collector of the transistor 111 is electrically connected to the voltage source V to provide the operating voltage of the fan control device 1 .

However, when the conventional fan control device 1 is started, the voltage of the voltage source V has been provided to the collector of the transistor 111. If the computer system 10 is still performing initialization, the target speed control signal cannot be provided. 101 to control the fan 2, the transistor 111 is turned off, so that the rotational speed control signal 102 is a low voltage signal, and the rotational speed of the fan 2 reaches the maximum rotational speed at this time, causing excessive noise and excessive current at startup.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a fan control device and a control method thereof.

To achieve the above purpose, the fan control device of the present invention receives an external start signal, and the fan control device includes a speed control module and a drive module; wherein, the speed control module includes: a start control unit , which receives an initial signal, and generates an initial rotational speed control signal according to the initial signal; and a rotational speed control unit, which receives the initial signal, and generates a rotational speed control signal according to the initial signal after a specific time; the The driving module receives the initial rotational speed control signal and controls the initial rotational speed of the fan according to the initial rotational speed control signal, and receives the rotational speed control signal and controls the rotational speed of the fan according to the rotational speed control signal.

To achieve the above object, the fan control method of the present invention is used to control a fan, comprising the following steps: providing a start control unit, using the start control unit to receive a start signal, and using the start control unit to generate a start signal according to the start signal An initial rotational speed control signal; providing a rotational speed control unit, using the rotational speed control unit to receive the initial signal, and using the rotational speed control unit to generate a rotational speed control signal according to the initial signal after a certain period of time; and providing a drive module , using the drive module to control the fan according to the initial speed control signal, and using the drive module to control the fan according to the speed control signal.

To sum up, the fan control device and method of the present invention controls the initial rotational speed of the fan through the initial rotational speed control signal so that the initial rotational speed of the fan will not be too fast, so as to solve the problem of existing fan control The speed of the fan cannot be controlled at the moment when the device is started, which causes the problem of noise caused by the excessive speed of the fan, and also avoids the problem of excessive current at the moment of start-up.

In order to further illustrate the above-mentioned purpose, structural features and effects of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a block diagram of an existing fan control device;

Fig. 2 is the circuit diagram of existing fan control device;

3 is a block diagram of a fan control device according to a preferred embodiment of the present invention;

4 is a circuit diagram of a fan control device according to a preferred embodiment of the present invention;

FIG. 5 is a circuit diagram of an equivalent circuit of the fan control device in FIG. 4;

FIG. 6 is a schematic diagram of the fan speed in FIG. 4;

7 is a circuit diagram of a fan control device according to another preferred embodiment of the present invention;

FIG. 8 is a schematic diagram of the characteristic curve of the first switching element in this embodiment; and

FIG. 9 is a schematic diagram of the fan speed in FIG. 7 .

Detailed ways

A fan control device and a control method thereof according to preferred embodiments of the present invention will be described below with reference to related drawings.

Please refer to FIG. 3 , which is a block diagram of a fan control device according to a preferred embodiment of the present invention. The fan control device 3 of this embodiment is used in conjunction with a computer system 4, and the computer system 4 controls the rotation speed of a fan 5 through the fan control device 3 to meet heat dissipation requirements. Because when the computer system 4 and the fan control device 3 are started, although the computer system 4 needs to perform an initialization action, the initial speed of the fan 5 can be controlled by the fan control device 3, so that the fan 5 can be set at a specific speed. Rotational speed. After a certain period of time, and after the initialization of the computer system 4 is completed, a target speed control signal 91 , such as a pulse width modulation signal (Pulse Width Modulation Signal) can be sent to the fan control device 3 . The fan control device 3 controls the speed of the fan 5 according to the target speed control signal 91 .

The fan control device 3 of this embodiment starts to act after receiving an external start signal. Here, the start signal is a voltage (hereinafter referred to as the voltage) provided by an external voltage source V. Activate the fan control device 3 . Wherein, the fan control device 3 includes a speed control module 31 and a driving module 32 .

The speed control module 31 has a start control unit 311 and a speed control unit 312 . The starting control unit 311 and the rotational speed control unit 312 are connected to the voltage source V respectively. When the fan control device 3 starts, after the start control unit 311 and the speed control unit 312 receive the voltage, the start control unit 311 generates an initial speed control signal 92 to the drive module 32, after a certain time , the speed control unit 312 generates a speed control signal 93 to the driving module 32 .

The driving module 32 has a signal input terminal Vth, which receives the initial speed control signal 92 or the speed control signal 93, and controls the speed of the fan 5 when it is just started (hereinafter referred to as hereinafter) according to the initial speed control signal 92 is the initial rotational speed) or the rotational speed of the fan 5 is controlled according to the rotational speed control signal 93 .

Here, the driving module 32 can be a driving chip. Generally speaking, the voltages of the initial rotational speed control signal 92 and the rotational speed control signal 93 are inversely proportional to the rotational speed of the fan 5, that is, when the voltages of the initial rotational speed control signal 92 and the rotational speed control signal 93 are lower , the faster the rotational speed of the fan 5 is, on the contrary, when the voltages of the initial rotational speed control signal 92 and the rotational speed control signal 93 are higher, the rotational speed of the fan 5 is slower.

Please also refer to FIG. 4 , which is a circuit diagram of a fan control device according to a preferred embodiment of the present invention. Wherein, the startup control unit 311 has a first switch element Q1, a first resistor R1, a first capacitor C1, and a second resistor R2. Wherein, the first switch element Q1 in this embodiment is a transistor or other electronic elements with a switch function.

A source S of the first switching element Q1 is electrically connected to the voltage source V to receive the start signal. And a first end of the first resistor R1 is electrically connected to the source S of the first switching element Q1 , and a second end is electrically connected to the gate G of the first switching element Q1 .

A first end of the first capacitor C1 is electrically connected to the gate G of the first switching element Q1, and a second end of the capacitor C1 is grounded. A first end of the second resistor R2 is electrically connected to the drain D of the first switch element Q1, and a second end of the second resistor R2 is electrically connected to the signal input end Vth of the driving module 32, for to generate the initial rotational speed control signal 92 .

The speed control unit 312 has a third resistor R3 , a second switch element Q2 , a fourth resistor R4 , a fifth resistor R5 and a second capacitor C2 . Wherein, the second switch element Q2 in this embodiment is a transistor or other electronic elements with switch function.

A first end of the third resistor R3 is electrically connected to the voltage source V to receive the start signal. The collector C of the second switching element Q2 is electrically connected to a second terminal of the third resistor R3.

A first end of the fourth resistor R4 is electrically connected to the base B of the second switching element Q2, and a second end is electrically connected to the first end of the third resistor. A first end of the fifth resistor R5 is electrically connected to the collector C of the second switching element Q2, and a second end is electrically connected to a first end of the second capacitor C2. And the first end of the second capacitor C2 is electrically connected to the signal input end Vth of the driving module 32 to generate the speed control signal, and the base B of the second switching element Q2 is electrically connected to the computer system 4 to receive The target rotational speed signal 91 .

The control method of the fan control device 3 is as follows: at a first time T1, the computer system 4 and the fan control device 3 are started, and at this time the computer system 4 cannot provide the target speed signal 91 to the fan control for initialization. device 3, and the fan control device 3 receives the voltage of the voltage source V and starts to act. Since the base B of the second switching element Q2 does not receive the target speed signal 91 , the second switching element Q2 is turned off, and the source S of the first switching element Q1 receives the voltage and turns on.

Please refer to FIG. 5 and FIG. 6 at the same time, which are schematic diagrams of the equivalent circuit of the fan control device 3 in FIG. 4 and the fan speed respectively. At the first time T1, the rotational speed control unit 312 can be equivalent to an equivalent voltage source Vd and an equivalent resistor Rd. At this time, the start control unit 311 generates the start speed control signal to the signal input terminal Vth of the driving module 32 .

at this time, Where V is the voltage source, Vd is the equivalent voltage source, Rd is the equivalent resistor, and R2 is the second resistor.

The drive module 32 controls the initial rotational speed of the fan 5 according to the initial rotational speed control signal 92, and the user only needs to adjust the ratio between the second resistor R2 and the equivalent resistor Rd (that is, to adjust the initial rotational speed The voltage value of the control signal), the initial rotational speed of the fan 5 can be adjusted.

In addition, at the first time T1, the first capacitor C1 starts charging, and after a specific time (this specific time is the charging time of the first capacitor C1, the capacity of the first capacitor C1 can be selected according to the user's needs) value, to determine the length of the specific time), at a second time T2, when the voltage difference between the first capacitor C1 and the voltage source V reaches a specific voltage difference, the first switching element Q1 is turned off.

At this time, if the computer system 4 has not completed the initialization action at the second time T2 and cannot provide the target speed control signal 91 to the base of the second switching element Q2, then the second switching element Q2 and the Since the first switching elements Q1 are all turned off, the signal input terminal Vth of the driving module 32 receives a low voltage, and the driving module 32 drives the fan 5 to operate at the maximum speed.

On the contrary, if the computer system 4 has completed the initialization action at the second time T2, it can provide the target speed control signal 91 to the base of the second switching element Q2, and the second switching element Q2 is turned on at this time. , the first switch element Q1 is in the off state, so the speed control unit 312 generates the speed control signal 93 to the drive module 32 according to the target speed control signal 91, so that the drive module 32 controls the speed according to the speed control signal 93 The speed of fan 5.

As mentioned above, it can be known that the fan control device 3 controls the initial rotation speed of the fan 5 through the start control unit 311 to avoid the problem that the initial rotation speed of the fan 5 is too fast, which causes the problem of excessive current at the start-up moment of the fan 5 .

In addition, the rotational speed control unit 312 further has a sixth resistor R6 and a seventh resistor R7, a first end of the sixth resistor R6 is electrically connected to the second end of the fourth resistor R4, and the first end of the sixth resistor R6 is electrically connected to the second end of the fourth resistor R4. A first end of the seven resistor R7 is electrically connected to the second end of the sixth resistor R6, so the half-speed control signal 94 can be provided to the half-speed signal input terminal RMI of the driving module 32 at the first time T1 , so that the driving module 32 can control the minimum speed of the fan 5 according to the half-speed control signal 94 .

In addition, in one embodiment, the rotational speed control unit 312 can also be a voltage source and a resistor, which are like the equivalent voltage source Vd and an equivalent resistor Rd shown in FIG. This will not be repeated.

In addition, please refer to FIG. 7 , which is a circuit diagram of a fan control device according to another preferred embodiment of the present invention.

The fan control device of this embodiment is different from the fan control device 3 in FIG. 4 in that the start control unit 311' further has an eighth resistor R8, a first end of which is electrically connected to the first resistor R1. The second end of the second end is electrically connected to the first end of the first capacitor C1.

When the fan control device is activated, the voltage difference between the gate G and the source S of the first switching element Q1 $\mathrm{Vgs}=V\×\left(\frac{R8}{R1+R8}\right),$ Where V is the voltage source, R8 is the eighth resistor, and R1 is the first resistor. In this embodiment, the ratio between the first resistor R1 and the eighth resistor R8 can be adjusted so that Vgs is a larger voltage difference, such as -3V.

Please also refer to the characteristic curve of the first switching element Q1 in FIG. 8 , when the first capacitor C1 is charged, Vgs rises slowly and a current Id passing through the first switching element Q1 drops at a slower rate ( As shown in FIG. 8 ), it means that the current passing through the driving module 32 can be controlled so that the voltage of the signal input terminal Vth of the driving module 32 drops slowly, so that the driving module 32 The voltage of Vth controls the speed of the fan 5 to increase slowly, so as to achieve the effect of soft-start (as shown in FIG. 9 ).

To sum up, according to the fan control device and method of the present invention, it controls the initial speed of the fan through the initial speed control signal, so that the initial speed of the fan will not be too fast, so as to solve the problem of starting up the existing fan control device. The speed of the fan cannot be controlled in an instant, which causes the problem of noise caused by excessive fan speed, and also avoids the problem of excessive current at the moment of startup.

Although the present invention has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, and other modifications can be made without departing from the spirit of the present invention. Various equivalent changes or substitutions, therefore, as long as the changes and modifications to the above embodiments are within the spirit of the present invention, they will all fall within the scope of the claims of the present application.

Claims (20)

1. fan control device is characterized in that comprising:

One rotating speed control die set comprises:

One start-up control unit, it receives an initial signal, and produces an initial speed controling signal according to this initial signal; And

One rotary speed controling unit, it receives this initial signal, and produces a speed controling signal through a special time according to this initial signal;

And

One drives module, and it receives this initial speed controling signal and according to this initial speed controling signal, controlling the initial rotating speed of this fan, and receives this speed controling signal and according to this speed controling signal, to control the rotating speed of fan.

2. fan control device as claimed in claim 1 is characterized in that:

This start-up control unit includes one first switch element, this rotary speed controling unit includes a second switch element, when this first switch element is opened and this second switch element when closing, this start-up control unit produces this initial speed controling signal, and close and this second switch element when opening when this first switch element, this this rotary speed controling unit produces this speed controling signal.

3. fan control device as claimed in claim 1 is characterized in that:

This rotary speed controling unit receives this initial signal and also produces half speed control system signal according to this initial signal, and this driving module is controlled the minimum speed of this fan according to this Half Speed control signal.

4. fan control device as claimed in claim 3 is characterized in that: this initial speed controling signal, this speed controling signal and this Half Speed control signal are respectively a voltage signal.

5. fan control device as claimed in claim 1 is characterized in that: this rotary speed controling unit produces this speed controling signal according to this initial signal and a rotating speed of target control signal.

6. fan control device as claimed in claim 5 is characterized in that: this rotating speed of target control signal is a pulse width modulation signal.

7. fan control device as claimed in claim 6 is characterized in that: this rotating speed of target control signal is provided by a computer system.

8. fan control device as claimed in claim 1 is characterized in that: this start-up control unit comprises:

One first switch element, it receives this initial signal;

One first resistor, one first end is electrically connected this first switch element;

One first capacitor, one first end are electrically connected one second end of this first resistor; And

One second resistor, one first end is electrically connected this first switch element, and one second end produces this initial speed controling signal.

9. fan control device as claimed in claim 8 is characterized in that: this first switch element is a transistor, and its source electrode receives this initial signal.

10. fan control device as claimed in claim 8 is characterized in that: this start-up control unit also comprises one the 8th resistor, and one first end is electrically connected this second end of this first resistor, and one second end is electrically connected this first end of this first capacitor.

11. fan control device as claimed in claim 8 is characterized in that: this special time is to decide according to the charging interval of this first capacitor.

12. fan control device as claimed in claim 8 is characterized in that: this rotary speed controling unit comprises:

One voltage source, it is electrically connected this second end of this second resistor; And

One resistor, it is electrically connected this voltage source.

13. as claim 1 or 8 described fan control devices, it is characterized in that: this rotary speed controling unit comprises:

One the 3rd resistor, one first termination is received this initial signal;

One second switch element, it is electrically connected one second end of the 3rd resistor;

One the 4th resistor, one first end is electrically connected this second switch element;

One the 5th resistor, one first end is electrically connected this second switch element;

One second capacitor, one first end are electrically connected one second end of the 5th resistor, and produce this speed controling signal;

One the 6th resistor, one first end are electrically connected one second end of the 4th resistor; And

One the 7th resistor, one first end are electrically connected one second end of the 6th resistor.

14. fan control device as claimed in claim 13, wherein this second switch element is a transistor.

15. fan control device as claimed in claim 1, wherein this initial signal is an initial voltage.

16. fan control device as claimed in claim 1, wherein this driving module is a driving wafer.

17. a control method for fan in order to control a fan, is characterized in that comprising the following steps:

One start-up control unit is provided, utilizes this start-up control unit to receive an initial signal, and utilize this start-up control unit to produce an initial speed controling signal according to this initial signal;

One rotary speed controling unit is provided, utilizes this rotary speed controling unit to receive this initial signal, and utilize this rotary speed controling unit to produce a speed controling signal according to this initial signal through a special time; And

Provide one to drive module, utilize this driving module to control this fan according to this initial speed controling signal, and utilize this driving module to control this fan according to this speed controling signal.

18. control method for fan as claimed in claim 17 is characterized in that: further comprising the steps of:

Utilize this rotary speed controling unit to accept a rotating speed of target control signal; And

According to this rotating speed of target control signal and this initial signal, utilize this rotary speed controling unit to produce this speed controling signal.

19. control method for fan as claimed in claim 17 is characterized in that: further comprising the steps of:

Utilize this rotary speed controling unit to produce half speed control system signal according to this initial signal.

20. control method for fan as claimed in claim 17 is characterized in that: this initial signal is an initial voltage.

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