TWI690801B - Detection circuit and method thereof - Google Patents

Abstract

A detection circuit for detecting a fan device is plugged in or not includes a tachometer pin, a negative power source, a judgement unit and a processing unit. The negative power source is used to provide a negative voltage on the tachometer pin. When a speed signal pin of the fan connected to the tachometer pin, the negative voltage is used to enable a clamping circuit of the fan such that the clamping circuit clamps the negative voltage on the tachometer pin to a first level. The judgement unit is used to determine whether the negative voltage on the tachometer pin is clamped to the first level. The processing unit outputs an enable signal when the judgement unit determining that the negative voltage on the tachometer pin is clamped to the first level. Wherein, the enable signal is used to cause a driving circuit to output a driving voltage to drive the fan in rotation.

Description

Detection circuit and method

The invention relates to detection technology, in particular to a detection circuit and method for detecting whether a fan device is inserted.

With the rapid development of electronic technology, the operating frequency of electronic equipment is getting higher and higher, resulting in more and more heat generated by heating elements inside the electronic equipment. In order to avoid problems such as damage to electronic equipment due to excessive temperature, the fan device is generally installed on the board and the chassis in the electronic equipment to achieve the heat dissipation effect.

Generally speaking, the electronic equipment in operation does not allow the user to install or replace the fan without powering off the entire system. Therefore, before installing or replacing the fan, the user needs to cut off the power of the entire system of the electronic device before installing or replacing.

In one embodiment, a detection circuit for detecting whether a fan device is inserted includes a fan speed pin, a negative power supply, a judgment unit, and a processing unit. The fan speed pin is used to couple the speed signal end of the fan device. The negative power supply is used to provide a negative voltage to the fan speed pin. Moreover, when the speed signal end of the fan device is connected to the fan speed pin, the negative voltage is used to enable the clamping circuit of the fan device, so that the clamp circuit clamps the negative voltage on the fan speed pin to the first level . The judging unit is used to judge whether the negative voltage on the fan speed pin is clamped to the first level. The processing unit outputs an enable signal when the judgment unit judges that the negative voltage on the fan speed pin is clamped to the first level. The enabling signal is used to cause the driving circuit to output a driving voltage to drive the fan device to rotate.

In one embodiment, a detection method for detecting whether a fan device is inserted includes: using a negative power supply to provide a negative voltage to a fan speed pin, wherein the fan speed pin is used to couple the speed signal terminal of the fan device, And when the speed signal end of the fan device is connected to the fan speed pin, the negative voltage is used to enable the clamping circuit of the fan device, so that the clamp circuit clamps the negative voltage of the fan speed pin to the first level; The judging unit judges whether the negative voltage on the fan speed pin is clamped to the first level; and when the judging unit judges that the negative voltage on the fan speed pin is clamped to the first level, it outputs an enable signal, in which the enable The signal is used to cause the driving circuit to output a driving voltage to drive the fan device to rotate.

In order to make the above objects, features, and advantages of the embodiments of the present invention more obvious and understandable, the following description will be made in detail in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of an embodiment of a detection circuit. Please refer to FIG. 1, the detection circuit 100 is coupled to the driving circuit 200. The detection circuit 100 can be used to detect whether the fan device 300 is inserted, and only cause the drive circuit 200 to output a driving voltage Vd to drive the fan device 300 to rotate when it is detected that the fan device 300 is inserted, to prevent the fan device 300 from being generated when it is inserted The instantaneous large current damages the fan device 300 or the system. In an embodiment, the fan device 300 may include a fan 310 and a driver 320, and the driver 320 is coupled to the fan 310. The driver 320 is used to drive the fan 310 to operate, and the driver 320 can drive the fan 310 according to the driving voltage Vd.

In one embodiment, both the detection circuit 100 and the driving circuit 200 are disposed on the machine board and are coupled to the connection ports on the machine board. The fan device 300 may further include a connection port 330, and the connection port 330 is coupled to the driver 320. Here, the type of the connection port 330 corresponds to the type of the connection port on the board, and the fan 310 can be coupled to the detection circuit 100 and the driving circuit 200 because the connection port 330 is connected to the connection port on the board. Therefore, the detection circuit 100 can determine whether the fan device 300 is inserted by detecting whether the connection port 330 of the fan device 300 is connected to the connection port on the machine board.

In one embodiment, the detection circuit 100 may include a fan speed pin 111, a negative power supply 120, a determination unit 130, and a processing unit 140. In addition, the detection circuit 100 may further include a first switch module SW1 and a second switch module SW2. The first switch module SW1 is coupled between the fan speed pin 111 and the negative power supply 120. The second switch module SW2 is coupled between the fan speed pin 111 and the determination unit 130. Moreover, the processing unit 140 is coupled to the first switch module SW1, the second switch module SW2, and the determination unit 130.

The fan speed pin 111 of the detection circuit 100 can be coupled to the connection port 330 of the fan device 300. In an embodiment, the connection port 330 of the fan device 300 may include a speed signal terminal 331, a power signal terminal 332, and a ground signal terminal 333. The rotation speed signal terminal 331 is used to output a rotation speed signal S1 about the rotation speed of the fan 310 from the fan device 300. The power signal terminal 332 is used to couple the driving voltage Vd. Moreover, the ground signal terminal 333 is used for coupling to the ground voltage GND. In some embodiments, the ground voltage GND is a reference voltage, such as zero voltage. However, the present invention is not limited to this. In another embodiment, as shown in FIG. 2, the connection port 330 of the fan device 300 may further include a speed control terminal 334, and the speed control terminal 334 is used to receive the speed control signal PWM . Here, the fan speed pin 111 of the detection circuit 100 is used to connect with the speed signal terminal 331 of the port 330.

The first switch module SW1 is controlled by the processing unit 140, and can turn on or off the electrical connection between the negative power supply 120 and the fan speed pin 111 according to the control of the processing unit 140. In addition, the second switch module SW2 is controlled by the processing unit 140, and can electrically connect or disconnect the electrical connection between the determining unit 130 and the fan speed pin 111 according to the control of the processing unit 140.

The processing unit 140 can detect whether the fan device 300 is inserted according to the detection method of any embodiment of the present invention (ie, detect whether the speed signal terminal 331 of the fan device 300 is connected to the fan speed pin 111), and detect The fan device 300 outputs the enable signal SE only when it is inserted to cause the drive circuit 200 to output the drive voltage Vd.

FIG. 3 is a schematic flowchart of an embodiment of a detection method. Please refer to FIGS. 1 to 3. In an embodiment of the detection method, the processing unit 140 may first enable the first switch module SW1 to turn on the electrical property between the negative power supply 120 and the fan speed pin 111 link. Moreover, the processing unit 140 can enable the second switch module SW2 to electrically connect the conduction determination unit 130 and the fan speed pin 111. In some embodiments, the processing unit 140 can enable the first switch module SW1 and the second switch module SW2 synchronously, so that the negative power supply 120 and the determination unit 130 can be electrically connected to the fan speed pin 111 simultaneously.

Here, the negative power supply 120 is used to provide a negative voltage V1. Therefore, the processing unit 140 can use the negative power supply 120 to provide the negative voltage V1 to the fan speed pin 111 by enabling the first switch module SW1 (step S10). Moreover, the processing unit 140 can use the determination unit 130 to determine whether the negative voltage V1 on the fan speed pin 111 is clamped to the first level by enabling the second switch module SW2 (step S20), and then according to the fan Whether the negative voltage V1 on the speed pin 111 is clamped to the first level to know whether the speed signal terminal 331 of the fan device 300 is connected to the fan speed pin 111.

In one embodiment, the fan device 300 further includes a clamp circuit 340, and the clamp circuit 340 is coupled between the speed signal terminal 331 and the ground signal terminal 333. Here, when the speed signal terminal 331 of the fan device 300 is connected to the fan speed pin 111 of the detection circuit 100, the negative voltage V1 on the fan speed pin 111 can enable the clamp circuit 340, so that the clamp circuit 340 will The negative voltage V1 on the fan speed pin 111 is clamped to the first level.

In some embodiments, the clamping circuit 340 may be, but not limited to, a diode, such as a general diode, a Zener diode, and/or other electronic components suitable for clamping. Here, the magnitude of the negative voltage V1 provided by the negative power supply 120 can be any value sufficient to enable the clamping circuit 340 to perform the clamping operation, and the first level is the clamping generated by the clamping circuit 340 after being enabled Voltage. Therefore, the magnitude of the negative voltage V1 and the magnitude of the first level required by the negative power supply 120 may be different according to the implementation of the clamping circuit 340. For example, when the clamp circuit 340 is a diode and its turn-on voltage is approximately between 0.5 volts and 0.7 volts, the negative voltage V1 provided by the negative power supply 120 only needs to be coupled to the ground voltage GND (because the clamp circuit 340 is coupled The difference between the speed signal terminal 331 and the ground signal terminal 333 may exceed the turn-on voltage of the clamping circuit 340, for example, the negative voltage V1 provided by the negative power supply 120 may be between -1 volts (V) To -3 volts. Therefore, when the negative voltage V1 turns on the clamping circuit 340, the clamping circuit 340 can clamp the negative voltage V1 on the fan speed pin 111 to approximately -0.5 volts to -0.7 volts, but the present invention does not Limited.

In one embodiment of step S20, the determining unit 130 may compare the negative voltage V1 on the fan speed pin 111 with the reference voltage VREF to determine whether the negative voltage V1 on the fan speed pin 111 is clamped to the first level Bit. When the comparison result of the determining unit 130 is that the difference between the negative voltage V1 on the fan speed pin 111 and the reference voltage VREF is greater than a preset threshold, the determining unit 130 may determine the negative voltage V1 clamp on the fan speed pin 111 Position to the first level, and generates an output signal S2 to the processing unit 140. When the comparison result of the determining unit 130 is that the difference between the negative voltage V1 on the fan speed pin 111 and the reference voltage VREF is less than or equal to the preset threshold, the determining unit 130 can determine the negative value on the fan speed pin 111 The voltage V1 is not clamped to the first level, and the output signal S2 is not generated.

In some embodiments, the magnitude of the reference voltage VREF and the magnitude of the negative voltage V1 provided by the negative power supply 120 are substantially equal. In addition, the preset threshold can be zero, but the invention is not limited to this.

In some embodiments, the judgment unit 130 can be implemented by a comparator. For example, an input terminal of the comparator may be coupled to the second switch module SW2 to be electrically connected to the fan speed pin 111 via the second switch module SW2. The other input of the comparator is coupled to the reference voltage VREF. Moreover, the output terminal of the comparator is coupled to the processing unit 140 to generate an output signal S2 to the processing unit 140 when determining that the negative voltage V1 on the fan speed pin 111 is clamped to the first level.

In one embodiment of the detection method, the processing unit 140 can know whether the fan device 300 is inserted according to whether the output signal S2 is received. When the processing unit 140 receives the output signal S2, it indicates that the speed signal terminal 331 of the fan device 300 is connected to the fan speed pin 111 (that is, the fan device 300 is plugged in). At this time, the processing unit 140 can output the enable signal SE to the driver The circuit 200 (step S30), so that the drive circuit 200 outputs the drive voltage Vd (step S40).

In some embodiments, the driving circuit 200 may output the driving voltage Vd to the fan device 300 through the fan power pin 112 for coupling the power signal terminal 332 of the fan device 300. When the processing unit 140 does not receive the output signal S2, it means that the speed signal terminal 331 of the fan device 300 is not connected to the fan speed pin 111 (that is, the fan device 300 is not inserted), then the processing unit 140 does not output the enable signal SE And return to step S10 to restart the detection process. Moreover, the driving circuit 200 may not output the driving voltage Vd through the fan power pin 112 because the enabling signal SE is not received. In this way, the detection circuit 100 can ensure that the driving circuit 200 outputs the driving voltage Vd only when the fan device 300 is inserted, so as to avoid the generation of instantaneous large current.

In one embodiment, the detection circuit 100 can be integrated into a chip with an integrated circuit process, and the fan speed pin 111 is a pin on the chip. The driving circuit 200 is manufactured in another chip by an integrated circuit process, and the fan power pin 112 is a pin on the other chip. Moreover, the two chips can transmit signals through additional wiring, such as the transmission of the enable signal SE. However, the present invention is not limited to this. In another embodiment, the detection circuit 100 may further include a fan power pin 112 and a driving circuit 200. In other words, the detection circuit 100 and the driving circuit 200 can be integrated into the same chip in an integrated circuit process, and the fan speed pin 111 and the fan power pin 112 are both pins on the chip.

In an embodiment, the detection circuit 100 may further include a detection unit 150, a lifting power supply 160, a rotation speed detection unit 170, a third switch module SW3, and a fourth switch module SW4. The detection unit 150 is coupled to the driving circuit 200. The third switch module SW3 is coupled between the fan speed pin 111 and the lifting power supply 160. The fourth switch module SW4 is coupled between the fan speed pin 111 and the speed detection unit 170. Moreover, the processing unit 140 is coupled to the third switch module SW3, the fourth switch module SW4, and the detection unit 150.

The third switch module SW3 is controlled by the processing unit 140 and can turn on or off the electrical connection between the lifting power supply 160 and the fan speed pin 111 according to the control of the processing unit 140. The fourth switch module SW4 is controlled by the processing unit 140, and can turn on or off the electrical connection between the speed detecting unit 170 and the fan speed pin 111 according to the control of the processing unit 140. Moreover, the lifting power supply 160 is used to provide a lifting voltage V2. In some embodiments, the boost voltage V2 may be, but not limited to, 3.3 volts.

In one embodiment of the detection method, the processing unit 140 can use the detection unit 150 to detect whether the driving voltage Vd output by the driving circuit 200 reaches the turn-on voltage (step S50). When the detection unit 150 detects that the driving voltage Vd reaches the start-up voltage, the detection unit 150 may output the start-up signal S3 to the processing unit 140. When the detecting unit 150 does not detect that the driving voltage Vd reaches the starting voltage, the detecting unit 150 does not output the starting signal S3. In some embodiments, the starting voltage may be 12 volts, but this case is not limited to this. The starting voltage may be any voltage value sufficient to drive the fan 310 of the fan device 300 to rotate normally.

In an embodiment of the detection method, after the processing unit 140 receives the start-up signal S3, the processing unit 140 may disable the first switch module SW1 according to the start-up signal S3 to disconnect the negative power supply 120 from the fan speed The electrical connection between the pins 111, and the second switch module SW2 is disabled according to the start signal S3 to disconnect the electrical connection between the determination unit 130 and the fan speed pin 111 (step S60). In addition, the processing unit 140 can enable the third switch module SW3 to provide the boosted voltage V2 to the fan speed pin 111 using the lift power supply 160 (step S70), thereby enabling the fan device 300 to be connected to the fan speed via The speed signal terminal 331 of the pin 111 uses the raised voltage V2 to generate a speed signal S1 on the fan speed pin 111. Moreover, the processing unit 140 can enable the fourth switch module SW4 to use the rotation speed detection unit 170 to detect the rotation speed signal S1 on the fan rotation speed pin 111 (step S80).

In some embodiments, steps S70 and S80 can be executed synchronously, but the invention is not limited to this.

In one embodiment, the fan device 300 may further include a speed signal generating circuit 350. The speed signal generating circuit 350 is coupled to the speed signal terminal 331 and the ground signal terminal 333. The speed signal generating circuit 350 can pull the boosted voltage V2 on the fan speed pin 111 to the ground at a corresponding pull-down frequency according to the driving frequency of the driver 320 to the fan 310 through the speed signal terminal 331, so as to use the fan speed pin 111 The speed signal S1 is generated. Therefore, when the driving frequency of the driver 320 is faster, the pull-down frequency of the rotation speed signal generating circuit 350 is faster, and the frequency of the rotation speed signal S1 is also faster, which means that the rotation speed of the fan 310 is faster.

In some embodiments, the speed signal generating circuit 350 may include a signal generating unit 351 and a control unit 352. The signal generating unit 351 is coupled between the speed signal terminal 331 and the ground signal terminal 333, and is connected in parallel to the clamping circuit 340. The control unit 352 is coupled to the control end of the signal generating unit 351 so that the signal generating unit 351 can generate the speed signal S1 through the speed signal terminal 331 according to the control of the control unit 352. In some embodiments, the signal generating unit 351 can be implemented using transistors. In addition, the control unit 352 can be implemented using control logic, but the invention is not limited thereto.

FIG. 4 is a schematic flowchart of an embodiment after step S80 in FIG. 3. Please refer to FIG. 1 to FIG. 4. In one embodiment of the detection method, after the step S80 is executed, the processing unit 140 can further use the detection unit 150 to detect whether the driving voltage Vd output by the driving circuit 200 is lower than Turn-on voltage (step S90). Here, the detection unit 150 can generate a non-reaching signal S4 to the processing unit 140 when detecting that the driving voltage Vd output by the driving circuit 200 is lower than the starting voltage. When the detection unit 150 does not detect that the driving voltage Vd output by the driving circuit 200 is lower than the turn-on voltage, the under-reaching signal S4 is not generated.

In an embodiment of the detection method, when the processing unit 140 receives the under-signal S4, the processing unit 140 may disable the third switch module SW3 according to the under-signal S4 to disconnect the lifting power 160 and the fan speed The electrical connection between the pins 111, and the fourth switch module SW4 is disabled according to the non-reaching signal S4 to disconnect the electrical connection between the speed detection unit 170 and the fan speed pin 111 (step S100). Here, the fan device 300 can stop generating the speed signal S1 on the fan speed pin 111 through the speed signal terminal 331 because the fan speed pin 111 does not provide the boost voltage V2. In addition, the processing unit 140 can re-energize the electrical connection between the negative power supply 120 and the fan speed pin 111 (ie, enable the first switch module SW1) according to the under-signal S4 and the electrical unit between the determination unit 130 and the fan speed pin 111 Is connected (ie, the second switch module SW2 is enabled), so that the negative power supply 120 can be electrically connected to the fan speed pin 111 again, and the determination unit 130 is also electrically connected to the fan speed pin 111 again (step S110).

In this way, the negative power supply 120 can re-provide the negative voltage V1 to the fan speed pin 111, and the determination unit 130 can re-determine whether the negative voltage V1 on the fan speed pin 111 is clamped to the first level. At this time, when the judging unit 130 judges that the negative voltage V1 on the fan speed pin 111 is clamped to the first level, it means that the fan device 300 is still in the inserted state, so the processing unit 140 can return to step S90 to continuously observe the driving Voltage Vd. When the determining unit 130 determines that the negative voltage V1 on the fan speed pin 111 is not clamped to the first level, it means that the fan device 300 has been removed (ie, the speed signal terminal 331 is not connected to the fan speed pin 111), so The processing unit 140 can return to step S10 to restart the detection process.

FIG. 5 is a schematic diagram of another embodiment of the detection method. Please refer to FIG. 1 to FIG. 5. In an embodiment of the detection method, the processing unit 140 can further determine whether the fan device 300 rotates normally according to the detection result D1 of the rotation speed detection unit 170 (step S120 ). When the processing unit 140 determines that the fan device 300 is not rotating normally according to the detection result D1, the processing unit 140 may disconnect the electrical connection between the lifting power supply 160 and the fan speed pin 111 (ie, disable the third switch module SW3) And the electrical connection between the speed detection unit 170 and the fan speed pin 111 (ie, the fourth switch module SW4 is disabled), and the electrical connection between the negative power supply 120 and the fan speed pin 111 is re-energized (ie, the first is enabled The switch module SW1) and the determination unit 130 are electrically connected to the fan speed pin 111 (that is, the second switch module SW2 is enabled), so that the negative power supply 120 can be electrically connected to the fan speed pin 111 again, and the determination The unit 130 is also electrically connected to the fan speed pin 111 again (step S130). Here, the abnormal rotation may be that the rotation speed does not reach the normal range (for example, the detection result D1 indicates that the level of the rotation speed signal S1 changes slowly) or not rotating (for example, the detection result D1 indicates the rotation speed signal There is no change in the level of S1), but it is not limited to this.

In this way, the negative power supply 120 can re-provide the negative voltage V1 to the fan speed pin 111, and the determination unit 130 can re-determine whether the negative voltage V1 on the fan speed pin 111 is clamped to the first level. At this time, when the determining unit 130 determines that the negative voltage V1 on the fan speed pin 111 is clamped to the first level, it indicates that the fan device 300 has an abnormal condition, so the processing unit 140 may generate an error warning E1 (step S140) to the system Circuit (not shown). After the fan device 300 is removed by the user, the processing unit 140 clears the error warning E1. When the determination unit 130 determines that the negative voltage V1 on the fan speed pin 111 is not clamped to the first level, it means that the fan device 300 has been removed, so the processing unit 140 can return to step S10 to restart the detection process.

In some implementations, the error alert E1 can prompt the user through a display method. For example, an error message appears in the screen display of the display. However, the invention is not limited to this. In other implementations, the error alert E1 can also prompt the user through sound effects. For example, a buzzer, horn, etc. sound to alert the user.

In one embodiment, the detection circuit 100 may further include a ground pin 113. The ground pin 113 is used for coupling to the ground voltage GND. Moreover, when the fan device 300 is inserted, the ground pin 113 can be connected to the ground signal terminal 333 of the fan device 300.

In an embodiment, the detection circuit 100 may further include a rotation speed output unit 180, and the rotation speed output unit 180 is coupled to the processing unit 140. Here, the processing unit 140 can calculate and generate a speed output D2 indicating the speed of the fan device 300 according to the speed signal S1 on the fan speed pin 111, and the processing unit 140 returns the speed output D2 through the speed output unit 180 To the system circuit (not shown).

In one embodiment, the speed control signal PWM can be output by the driving circuit 200 to the speed control end 334 of the fan device 300 through the PWM control pin 114 to adjust the speed of the fan device 300.

In one embodiment, the fan device 300 further includes a voltage regulator circuit 360. The voltage stabilizing circuit 360 is coupled between the power signal terminal 332 and the speed signal generating circuit 350, and can convert the driving voltage Vd received from the power signal terminal into various internal components in the fan device 300 (such as the driver 320 and the speed signal generation) Circuit 350, etc.) required voltage.

In summary, the embodiments of the present invention provide a detection circuit and a detection method for determining a fan device by detecting whether a negative voltage on a fan speed pin used to couple the speed signal end of the fan device is clamped Whether it is plugged in, and only after the fan device is plugged in, the drive circuit is driven to output a driving voltage to drive the fan device, so as to avoid instantaneous large current when the fan device is plugged in and damage the fan device or the system. In addition, even if the user plugs the port of the fan device into the wrong pin, a current loop will not be generated and the fan will be prevented from being damaged.

The embodiments of the present invention are disclosed as above, but they are not intended to limit the scope of the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, the protection scope of the present invention shall be deemed as defined by the appended patent application scope.

100: detection circuit

111: Fan speed pin

112: Fan power pin

113: Ground pin

114: PWM control pin

120: negative power supply

130: Judgment unit

140: processing unit

150: detection unit

160: Raise the power

170: speed detection unit

200: drive circuit

300: fan unit

310: fan

320: drive

330: port

331: Speed signal end

332: Power signal terminal

333: Ground signal terminal

340: Clamp circuit

350: Speed signal generating circuit

351: Signal generation unit

352: control unit

360: Voltage regulator circuit

D1: detection result

E1: Error warning

GND: ground voltage

PWM: Speed control signal

S1: Speed signal

S2: output signal

S3: Starting signal

S4: Not reached signal

SE: enable signal

SW1: the first switch module

SW2: second switch module

SW3: third switch module

SW4: fourth switch module

V1: negative voltage

V2: Lifting voltage

Vd: driving voltage

VREF: reference voltage

180: speed output unit

D2: Speed output

334: Speed control end

S10~S140: Steps

FIG. 1 is a schematic diagram of an embodiment of a detection circuit. FIG. 2 is a schematic diagram of another embodiment of the detection circuit. FIG. 3 is a schematic flowchart of an embodiment of a detection method. FIG. 4 is a schematic flowchart of an embodiment after step S80 in FIG. 3. FIG. 5 is a schematic diagram of another embodiment of the detection method.

100: detection circuit

111: Fan speed pin

112: Fan power pin

113: Ground pin

114: PWM control pin

120: negative power supply

130: Judgment unit

140: processing unit

150: detection unit

160: Raise the power

170: speed detection unit

200: drive circuit

300: fan unit

310: fan

320: drive

330: port

331: Speed signal end

332: Power signal terminal

333: Ground signal terminal

340: Clamp circuit

350: Speed signal generating circuit

351: Signal generation unit

352: control unit

360: Voltage regulator circuit

D1: detection result

E1: Error warning

GND: ground voltage

PWM: Speed control signal

S1: Speed signal

S2: output signal

S3: Starting signal

S4: Not reached signal

SE: enable signal

SW1: the first switch module

SW2: second switch module

SW3: third switch module

SW4: fourth switch module

V1: negative voltage

V2: Lifting voltage

Vd: driving voltage

VREF: reference voltage

180: speed output unit

D2: Speed output

334: Speed control end

Claims (10)

A detection circuit for detecting whether a fan device is inserted, the detection circuit includes: a fan speed pin for coupling a speed signal terminal of the fan device; a negative power supply for providing a negative voltage To the fan speed pin, and when the speed signal end of the fan device is connected to the fan speed pin, the negative voltage is used to enable a clamping circuit of the fan device, so that the clamping circuit The negative voltage on the fan speed pin is clamped to a first level; a judgment unit is used to judge whether the negative voltage on the fan speed pin is clamped to the first level; and a processing unit, The judging unit judges that the negative voltage on the fan speed pin is clamped to the first position to output a consistent energy signal on time, wherein the enabling signal is used to cause a driving circuit to output a driving voltage to drive the fan device to rotate And wherein the processing unit does not output the enable signal when the judgment unit determines that the negative voltage on the fan speed pin is not clamped to the first level, and wherein the drive circuit does not receive the enable signal The drive voltage is not output. The detection circuit as described in item 1 of the patent application range, wherein the determination unit determines the negative when the difference between the negative voltage on the fan speed pin and a reference voltage is greater than a preset threshold The voltage is clamped to this first level. The detection circuit described in item 1 of the patent application scope further includes: a fan power pin for coupling a power signal terminal of the fan device; and the driving circuit, coupled to the fan power pin, And used to output the driving voltage through the fan power pin according to the enable signal. The detection circuit as described in item 1 of the patent application scope further includes: a detection unit for detecting whether the driving voltage reaches the turn-on voltage and generates a turn-on signal when the turn-on voltage is reached; Boosting power to provide a boosting voltage; and a rotation speed detection unit to detect a rotation speed signal; wherein the processing unit further disconnects the negative power supply and the fan rotation speed pin according to the starting signal And the electrical connection between the judging unit and the fan speed pin, and the electrical connection between the lifting power supply and the fan speed pin and the electrical connection between the speed detection unit and the fan speed pin Connection, wherein when the fan device receives the boost voltage through the speed signal terminal, the fan device further uses the boost voltage to generate the speed signal on the fan speed pin. The detection circuit as described in item 4 of the patent application scope, wherein the detection unit further generates a non-reaching signal when detecting that the driving voltage does not reach the turn-on voltage, and the processing unit breaks according to the non-reaching signal Turn on the electrical connection of the lifting power supply and the fan speed pin and the electrical connection of the tachometer and the fan speed pin, and turn on the electrical connection of the negative power supply and the fan speed pin and the The electrical connection between the determination unit and the fan speed pin. The detection circuit as described in item 4 of the patent application range, wherein the processing unit further determines whether the fan device rotates normally according to the detection result of the rotation speed detection unit, and when it is determined that the fan device does not rotate normally, the processing unit Disconnect the electrical connection between the lifting power supply and the fan speed pin and the electrical connection between the speed detection unit and the fan speed pin, and turn on the electrical power of the negative power supply and the fan speed pin The connection and the electrical connection between the determination unit and the fan speed pin, so that the determination The unit performs the judgment again. When the judgment unit judges that the negative voltage on the fan speed pin is clamped to the first level again, the processing unit generates an error warning. A detection method for detecting whether a fan device is inserted, the detection method includes: using a negative power supply to provide a negative voltage to a fan speed pin, wherein the fan speed pin is used to couple the fan device A speed signal terminal, when the speed signal terminal of the fan device is connected to the fan speed pin, the negative voltage is used to enable a clamp circuit of the fan device, so that the clamp circuit connects the fan speed pin Clamp the negative voltage on the first level; use a judgment unit to judge whether the negative voltage on the fan speed pin is clamped to the first level; when the judgment unit judges the fan speed pin When the negative voltage is clamped to the first level, a consistent energy signal is output, wherein the enabling signal is used to cause a driving circuit to output a driving voltage to drive the fan device to rotate; and when the judgment unit judges the fan speed When the negative voltage on the pin is not clamped to the first level, the enable signal is not output, and the drive circuit does not output the drive voltage when the enable signal is not received. The detection method as described in item 7 of the patent application scope, wherein the step of determining whether the negative voltage on the fan speed pin is clamped to the first level includes: comparing the negative voltage on the fan speed pin And a reference voltage; and when the difference between the negative voltage on the fan speed pin and the reference voltage is greater than a preset threshold, it is determined that the negative voltage is clamped to the first level. The detection method described in item 7 of the patent application scope further includes: The driving circuit is used to output the driving voltage through a fan power pin according to the enabling signal, wherein the fan power pin is used to couple to a power signal terminal of the fan device. The detection method as described in item 7 of the patent application scope further includes: detecting whether the driving voltage reaches the turn-on voltage with a detecting unit, and the detecting unit detects that the driving voltage reaches the turn-on voltage Generate a turn signal at the time; disconnect the electrical connection between the negative power supply and the fan speed pin and the electrical connection between the determination unit and the fan speed pin according to the start signal; use a lifting power supply to provide a lift The voltage is on the fan speed pin, so that the fan device generates a speed signal on the fan speed pin via the speed signal terminal using the boost voltage; and a speed detection unit detects the speed signal.

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