CN219452473U - Fan control circuit and heat dissipation device - Google Patents
Fan control circuit and heat dissipation device Download PDFInfo
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- CN219452473U CN219452473U CN202320579400.7U CN202320579400U CN219452473U CN 219452473 U CN219452473 U CN 219452473U CN 202320579400 U CN202320579400 U CN 202320579400U CN 219452473 U CN219452473 U CN 219452473U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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Abstract
The application belongs to the technical field of electronic circuits, and relates to a fan control circuit and heat dissipating equipment, wherein the fan control circuit comprises: a main control circuit and a driving circuit; the first end of the main control circuit is connected with the fan, and the driving circuit is respectively connected with the second end of the main control circuit and the fan; the main control circuit is used for receiving a temperature signal related to a heat generating object, and outputting a corresponding pulse control signal to the fan according to the temperature signal so as to control the rotating speed of the fan; the driving circuit is used for driving the fan to run according to the driving control signal output by the second end of the main control circuit. According to the scheme, the main control circuit is matched with the driving circuit, the fan rotating speed is regulated in multiple stages according to the corresponding pulse control signals output by the temperature signals, the problem that the fan control precision is low due to the mode of regulating the rotating speed by the gear is solved, the regulating range of the fan rotating speed is enlarged, and the accuracy of fan control is improved.
Description
Technical Field
The present disclosure relates to electronic circuits, and particularly to a fan control circuit and a heat dissipating device.
Background
A fan is an electric appliance that accelerates air circulation by driving blades to rotate, and in many cases, the fan may be used to radiate heat to a heat-generating object.
In the related art, the rotation speed of the fan is generally controlled by a gear adjusting mode, however, the rotation speed adjusting range is small by a gear adjusting mode for controlling the rotation speed of the fan, so that the control accuracy of the fan is low.
Disclosure of Invention
In order to solve or partially solve the problems in the related art, the present application provides a fan control circuit and a heat dissipating device, where the fan control circuit can achieve accurate control of a fan through improvement of a circuit structure.
A first aspect of the present application provides a fan control circuit, the circuit comprising: a main control circuit and a driving circuit;
the first end of the main control circuit is connected with the fan, and the driving circuit is respectively connected with the second end of the main control circuit and the fan;
the main control circuit is used for receiving a temperature signal related to a heat generating object, outputting a pulse control signal corresponding to the temperature signal to the fan according to the temperature signal so as to control the rotating speed of the fan; wherein the duty cycle of the effective signal in the pulse control signal is positively correlated with the temperature value in the temperature signal;
the driving circuit is used for driving the fan to run according to a driving control signal output by the second end of the main control circuit.
According to the fan control circuit provided by the application, the main control circuit comprises a controller and a switch piece;
the first end of the controller is connected with the switch piece, the switch piece is connected with a circuit between the fan and a fan power supply, and the second end of the controller is connected with the driving circuit;
the controller is used for outputting a pulse control signal corresponding to the temperature signal according to the temperature signal, and the switch piece is used for switching on or switching off the connection between the fan and the fan power supply according to the pulse control signal.
According to the fan control circuit provided by the application, the driving circuit comprises a driver and a first resistive element;
the driver is connected with the fan, one end of the first resistive element is connected with the driver, and the other end of the first resistive element is connected with the second end of the main control circuit.
According to the fan control circuit provided by the application, the driver is also connected with the third end of the main control circuit;
the driver is further configured to output a specific level signal to a third terminal of the main control circuit when a current flowing through the fan exceeds a preset threshold, and the main control circuit is further configured to control the fan to be powered off according to the specific level signal.
According to the fan control circuit provided by the application, the fan control circuit further comprises a first protection circuit, wherein the first protection circuit is used for conducting surge voltage input into the fan to the ground;
the first protection circuit comprises a first diode and/or a second diode;
one end of the first diode is connected with the first end of the fan, one end of the second diode is connected with the second end of the fan, and the other end of the first diode and the other end of the second diode are grounded.
According to the fan control circuit provided by the application, the fan control circuit further comprises a second protection circuit, wherein the second protection circuit is used for conducting reverse electromotive force in a circuit between the driving circuit and the fan to the ground;
the second protection circuit comprises at least one third diode, one end of the at least one third diode is connected to a circuit between the driving circuit and the fan, and the other end of the at least one third diode is grounded.
According to the fan control circuit provided by the application, the fan control circuit further comprises a third protection circuit, wherein the third protection circuit is used for limiting the current flowing through the driving circuit;
the third protection circuit comprises at least one second resistive element, the at least one second resistive element is connected in series to form a series branch, one end of the series branch is connected with the driving circuit, and the other end of the series branch is grounded.
According to the fan control circuit provided by the application, the fan control circuit further comprises a power supply circuit, wherein the power supply circuit is used for supplying power to the main control circuit and the driving circuit;
the power supply circuit comprises a first power supply sub-circuit and a second power supply sub-circuit;
the first power supply electronic circuit is connected with the main control circuit, and the second power supply electronic circuit is connected with the driving circuit.
According to the fan control circuit provided by the application, the first power supply circuit comprises a first power supply, a third resistive element and a fourth resistive element;
the first power supply is connected with the fourth end of the main control circuit, one end of the third resistive element is connected with the fourth end of the main control circuit, the other end of the third resistive element is connected with the third end of the main control circuit, one end of the fourth resistive element is connected with the first end of the main control circuit, and the other end of the fourth resistive element is grounded.
According to the fan control circuit provided by the application, the second power supply electronic circuit comprises a second power supply and a voltage dividing component, one end of the voltage dividing component is connected with the second power supply, and the other end of the voltage dividing component is connected with the driving circuit.
A second aspect of the present application provides a heat dissipating device comprising a fan and any of the fan control circuits described above.
The technical scheme that this application provided can include following beneficial effect:
the fan control circuit is simple in structure, and can output corresponding pulse control signals to carry out multistage adjustment on the fan rotating speed according to temperature signals through the matching of the main control circuit and the driving circuit, so that the adjusting range of the fan rotating speed is enlarged, and the accuracy of fan control is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
The foregoing and other objects, features and advantages of the application will be apparent from the following more particular descriptions of exemplary embodiments of the application as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the application.
Fig. 1 is a schematic diagram of a fan control circuit according to an embodiment of the present disclosure;
FIG. 2 is another schematic diagram of a fan control circuit according to an embodiment of the present disclosure;
FIG. 3 is another schematic diagram of a fan control circuit according to an embodiment of the present disclosure;
FIG. 4 is another schematic diagram of a fan control circuit according to an embodiment of the present disclosure;
FIG. 5 is another schematic diagram of a fan control circuit according to an embodiment of the present disclosure;
FIG. 6 is another schematic diagram of a fan control circuit shown in an embodiment of the present application;
FIG. 7 is another schematic diagram of a fan control circuit shown in an embodiment of the present application;
fig. 8 is another structural schematic diagram of a fan control circuit shown in an embodiment of the present application;
fig. 9 is another structural schematic diagram of the fan control circuit shown in the embodiment of the present application;
fig. 10 is a schematic structural view of a heat dissipating device shown in an embodiment of the present application;
reference numerals:
100: fan control circuit, 101: master circuit, 102: drive circuit, 103: a fan;
201: controller, 202: switch piece, 203: fan power supply, 204: driver, 205: a first resistive element;
301: first protection circuit, 3011: first diode, 3012: a second diode;
401: second protection circuit 4011: a third diode;
501: third protection circuit, 5011: a second resistive element;
601: power supply circuit, 6011: a first power supply electronic circuit;
701: first power supply, 702: third resistive element, 703: fourth resistive element, 704: second power supply, 705: a voltage dividing assembly;
801: filter circuit, 8011: a capacitive element.
Detailed Description
Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, a first message may also be referred to as a second message, and similarly, a second message may also be referred to as a first message, without departing from the scope of the present application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present application, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.
Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected or detachably connected or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.
The embodiment relates to the technical field of electronic circuits, and particularly can be applied to a fan control scene, in the related art, the rotating speed of a fan is generally regulated in a gear regulating mode, and the regulating mode has fewer controllable points of the rotating speed of the fan and has lower control precision.
In view of the above problems, embodiments of the present application provide a fan control circuit capable of realizing accurate control of a fan through improvement of a circuit structure.
The following describes in detail the technical solutions of the fan control circuit and the heat dissipating device provided in the embodiments of the present application with reference to fig. 1 to 10.
Fig. 1 is a schematic diagram of a fan control circuit according to an embodiment of the present application.
Referring to fig. 1, a fan control circuit provided in an embodiment of the present application specifically includes: a main control circuit 101 and a driving circuit 102;
the first end of the main control circuit 101 is connected with the fan 103, and the driving circuit 102 is respectively connected with the second end of the main control circuit 101 and the fan 103;
the main control circuit 101 is configured to receive a temperature signal related to a heat generating object, and output a pulse control signal corresponding to the temperature signal to the fan 103 according to the temperature signal, so as to control a rotation speed of the fan 103; wherein the duty cycle of the effective signal in the pulse control signal is positively correlated with the temperature value in the temperature signal;
the driving circuit 102 is configured to drive the fan 103 to operate according to a driving control signal output from the second end of the main control circuit 101.
In this embodiment, the main control circuit 101 may be connected with an external temperature acquisition device, the temperature acquisition device may acquire a temperature signal related to a heat generating object, the temperature signal is transmitted to the main control circuit 101, the main control circuit 101 receives the temperature signal, and then outputs a corresponding pulse control signal to the fan 103, and the fan control circuit is driven by the driving circuit 102, so that multistage adjustment of the rotation speed of the fan 103 may be implemented.
In some embodiments, referring to fig. 2, the master circuit 101 specifically includes a controller 201 and a switch 202;
the first end of the controller 201 is connected with the switch element 202, the switch element 202 is connected with a circuit between the fan 103 and the fan power supply 203, and the second end of the controller 201 is connected with the driving circuit 102;
the controller 201 is configured to output a pulse control signal corresponding to the temperature signal according to the temperature signal, and the switching element 202 is configured to switch on or off the connection of the fan 103 and the fan power supply 203 according to the pulse control signal.
In this embodiment, the controller 201 may cooperate with the switching element 202 to control the rotation speed of the fan 103, where the switching element 202 controls the rotation of the fan 103 by mainly switching on or off the connection between the fan 103 and the fan power supply 203, that is, the switching element 202 may control the rotation of the fan 103 by controlling the power on or off of the fan 103.
The pulse control signal may be determined by a voltage signal output from the first end of the controller 201, in which the first end of the controller 201 mainly outputs two voltage signals, one is a high voltage signal, such as a voltage signal of 5V, and the other is a low voltage signal, such as a voltage signal of 0V; different kinds of voltage signals can control the switch 202 to perform different actions, for example, a high voltage signal can control the switch 202 to be opened, a low voltage signal can control the switch 202 to be closed, and whether the fan 103 rotates or not can be further controlled by the opening and closing state of the switch 202.
The effective signal in the pulse control signal refers to a voltage signal that can control the rotation of the fan 103, and the duty cycle of the effective signal in the entire pulse control signal will affect the rotation speed of the fan 103, specifically, the higher the duty cycle of the effective signal, the higher the rotation speed of the fan 103.
In the practical application process, in order to realize that the rotation speed of the fan 103 can adapt to the temperature of the heat generating object, the duty ratio of the effective signal in the pulse control signal and the temperature value in the temperature signal can be calibrated in advance, so that after the controller 201 receives the temperature signal related to the heat generating object, the pulse control signal corresponding to the temperature value can be determined according to the temperature value in the temperature signal, and the controller 201 can output the pulse control signal to the switch element 202, and then adjust the rotation speed of the fan 103 through the opening and closing action of the switch element 202.
It should be noted that, in this embodiment, the controller 201 may use a single-chip microcomputer, for example, an MCU (Micro Controller Unit, micro control unit) may be used, fig. 9 shows that the micro control unit U2 has a first end of PWMOUT pin, the PWMOUT pin may output a pulse control signal to the switch element 202, a second end of the micro control unit U2 has an OUT1 pin, the OUT1 pin may output a driving control signal to the driving circuit 102, and the micro control unit U2 also has an AD2 pin, where the AD2 pin may receive a temperature signal input by an external temperature collecting device.
In this embodiment, the switching element 202 may be a transistor, such as a MOS transistor, fig. 9 also shows a MOS transistor D4, a source of the MOS transistor D4 is connected to the fan 103, a gate of the MOS transistor D4 is connected to the first end of the controller 201, the power VCC2 in fig. 9 represents a fan power supply, a drain of the MOS transistor D4 is connected to the power VCC2, and the power VCC2 in this embodiment may be a power supply with a supply voltage of 12V.
According to the method, the fan rotating speed can be adjusted in multiple stages through the pulse control signals, and compared with a gear adjusting mode, the method is more in controllable point positions and higher in control precision.
In some embodiments, referring to fig. 2, the driving circuit 102 may specifically include a driver 204 and a first resistive element 205;
the driver 204 is connected to the fan 103, one end of the first resistive element 205 is connected to the driver 204, and the other end of the first resistive element 205 is connected to the second end of the main control circuit 101.
In this embodiment, the driver 204 is mainly used for driving the fan 103 to operate, the first resistive element 205 is mainly used for providing an enabling signal for the driver 204 to operate, and the driver 204 is specifically connected to the controller 201. In the practical application process, the driver 204 may use a driving chip with an overcurrent protection function, see fig. 9, and in this embodiment, the chip U1 with a model SGM2521AYTDC8G/TR is used to implement the overcurrent protection and driving functions in the fan operation process, and the device J1 in fig. 9 represents the fan.
In this embodiment, the first resistive element 205 may adopt a current limiting resistor, referring to fig. 9, where the current limiting resistor R1 represents the first resistive element, the ENUV pin of the chip U1 is connected to the current limiting resistor R1, and the current limiting resistor R1 is also connected to the OUT1 pin of the micro control unit U2; the ENUV pin of chip U1 is active after a voltage greater than 1.43V is achieved.
In an exemplary embodiment, the driver 204 is also connected to a third terminal of the master circuit 101;
the driver 204 is further configured to output a specific level signal to the third terminal of the main control circuit 101 when the current flowing through the fan 103 exceeds a preset threshold, and the main control circuit 101 is further configured to control the fan 103 to be powered off according to the specific level signal.
Referring to fig. 2, in this embodiment, the driver 204 may be specifically connected to the third terminal of the controller 201 in the main control circuit 101, where the driver 204 may provide an over-current protection function for the operation of the fan 103.
Specifically, when the current flowing through the fan 103 exceeds the preset threshold, the driver 204 outputs a specific level signal, in this embodiment, outputs a low level signal, the voltage collected by the third terminal of the controller 201 is 0V, the controller 201 sends a control signal through the first terminal to control the switch 202 to be turned off, and simultaneously, the second terminal of the controller 201 outputs a low level signal to make the voltages at both ends of the fan 103 be 0V, so as to control the fan 103 to be powered off, and stop the fan 103 from rotating.
Still taking the driver 204 as an example, the chip U1 with the model SGM2521AYTDC8G/TR is used as the driver 204, referring to fig. 9, the nFLT pin of the chip U1 is connected with the AD1 pin of the micro-control unit U2, when the fan J1 is locked or the current flowing through the fan J1 exceeds the preset threshold value due to other reasons, the nFLT pin of the chip U1 outputs a specific level signal, in this embodiment, the nFLT pin of the chip U1 outputs a low level signal, correspondingly, the voltage signal collected by the AD1 pin of the micro-control unit U2 is 0V, the micro-control unit U2 rapidly turns off the MOS transistor D4 through the PWMOUT pin, and meanwhile, the OUT1 pin outputs a low level signal, at this time, the voltages at both ends of the fan J1 are all 0V, and the fan J1 stops rotating, thereby effectively protecting the fan J1 and other devices in the circuit.
In this embodiment, the driver 204 cooperates with the main control circuit 101 to realize an overcurrent protection function, so that the fan can be controlled to stop in time when the current flowing through the fan is too large, so as to avoid damage of various devices in the circuit due to the too large current, and improve the safety and stability of the operation of the circuit.
In some embodiments, referring to fig. 3, the fan control circuit further includes a first protection circuit 301, the first protection circuit 301 being configured to conduct a surge voltage input to the fan 103 to ground;
the first protection circuit 301 includes a first diode 3011 and/or a second diode 3012;
one end of the first diode 3011 is connected to a first end of the fan 103, one end of the second diode 3012 is connected to a second end of the fan 103, and the other end of the first diode 3011 and the other end of the second diode 3012 are grounded.
Considering that the fan 103 is an external interface of the fan control circuit, external surge voltage is easily conducted to the fan control circuit through the fan, which easily causes damage to the fan control circuit. For this reason, the present embodiment provides at least one diode at the driving signal input of the fan 103 to prevent the surge voltage from damaging the fan control circuit.
Fig. 3 shows a case where the first protection circuit 301 includes a first diode 3011 and a second diode 3012, see fig. 9, where the diode D2 in fig. 9 represents the first diode, the diode D3 represents the second diode, and TVS (Transient Voltage Suppression ) diodes may be used for both the first diode and the second diode in this embodiment, and the diode D2 in fig. 9 is connected to the first end of the fan J1, and the diode D3 is connected to the second end of the fan J1.
After the first diode 3011 and the second diode 3012 are arranged, surge voltage entering the fan control circuit through input is conducted to the ground through the first diode 3011 and the second diode 3012, so that damage to later-stage circuit devices is avoided, and the operation safety of the fan control circuit is further improved.
In some embodiments, referring to fig. 4, the fan control circuit further includes a second protection circuit 401, where the second protection circuit 401 is configured to conduct the back electromotive force in the line between the driving circuit 102 and the fan 103 to the ground;
the second protection circuit 401 includes at least one third diode 4011, one end of the at least one third diode 4011 is connected to a line between the driving circuit 102 and the fan 103, and the other end of the at least one third diode 4011 is grounded.
Considering that the fan 103 is an inductive device, a reverse electromotive force is easily generated at the output end at the moment of turning off the fan 103, and the reverse electromotive force may have a certain influence on the circuit device driving the fan 103 to operate in the fan control circuit, for this reason, the embodiment is provided with at least one third diode 4011, and the third diode 4011 can timely release the reverse electromotive force generated at the moment of turning off the fan 103, thereby ensuring the operation safety of the fan control circuit.
In this embodiment, a third diode 4011 is provided, referring to fig. 9, the diode D1 in fig. 9 represents a third diode, the diode D1 may be a freewheeling diode, and the arrangement of the diode D1 may consume the reverse electromotive force generated in the moment of turning off the fan J1 in a continuous current manner, thereby protecting the components in the fan control circuit from being damaged, and further improving the operation safety of the fan control circuit.
In some embodiments, referring to fig. 5, the fan control circuit further includes a third protection circuit 501, the third protection circuit 501 being configured to limit the current flowing through the driving circuit 102;
the third protection circuit 501 includes at least one second resistive element 5011, where the at least one second resistive element 5011 is connected in series to form a series branch, one end of the series branch is connected to the driving circuit 102, and the other end of the series branch is grounded.
In order to avoid the driving circuit 102 from being burned out due to excessive current, the present embodiment further provides at least one second resistive element 5011 in the fan control circuit, where the second resistive element 5011 is mainly used for limiting the current flowing through the driving circuit 102, and specifically, in the present embodiment, the second resistive element 5011 is connected to the driver in the driving circuit 102 for limiting the current flowing through the driver, thereby protecting the driver from safe operation.
In this embodiment, a second resistive element 5011 is provided, referring to fig. 9, a current limiting resistor R4 in fig. 9 represents the second resistive element, one end of the current limiting resistor R4 is connected to the ILIM pin of the chip U1, the other end of the current limiting resistor R4 and the GND pin of the chip U1 are grounded, and the current limiting resistor R4 may be a resistor with a resistance value of 150kΩ, and in this embodiment, an overcurrent value of the chip U1 may be set to be 1.454A.
By setting the current limiting resistor R4, the chip U1 can be prevented from being burnt due to overlarge current flowing through the chip U1, so that the working safety of the fan control circuit is further improved.
In some embodiments, referring to fig. 6, the fan control circuit further comprises a power supply circuit 601, the power supply circuit 601 being configured to supply power to the main control circuit 101 and the driving circuit 102;
the power supply circuit 601 includes a first power supply sub-circuit 6011 and a second power supply sub-circuit 6012;
the first power supply sub-circuit 6011 is connected to the main control circuit 101, and the second power supply sub-circuit 6012 is connected to the driving circuit 102.
In this embodiment, the power supply part includes two parts, namely, a first power supply sub-circuit 6011 for supplying power to the main control circuit 101 and a second power supply sub-circuit 6012 for supplying power to the driving circuit 102, and specifically, the first power supply sub-circuit 6011 mainly supplies power to the controller in the main control circuit 102 and the second power supply sub-circuit 6012 mainly supplies power to the driver in the driving circuit 102, so that stable operation of the driving circuit 102 and the main control circuit 101 is ensured.
In an exemplary embodiment, referring to fig. 7, a first power supply circuit 6011 includes a first power supply 701, a third resistive element 702, and a fourth resistive element 703;
the first power supply 701 is connected to the fourth terminal of the master circuit 101, one end of the third resistive element 702 is connected to the fourth terminal of the master circuit 101, the other end of the third resistive element 702 is connected to the third terminal of the master circuit 101, one end of the fourth resistive element 703 is connected to the first terminal of the master circuit 101, and the other end of the fourth resistive element 703 is grounded.
In this embodiment, the first power supply 701 mainly supplies power to the controller in the main control circuit 101, and since the controller may use a single chip microcomputer, in this embodiment, the first power supply 701 may use a dc power supply with a power supply voltage range of 2.7V to 5.5V, and in this embodiment, the first power supply 701 uses a dc power supply with a power supply voltage of 5V. The third resistive element 702 can be a pull-up resistor of the controller, the fourth resistive element 703 can be a pull-down resistor of the controller, and meanwhile, the third resistive element 702 and the fourth resistive element 703 also have the function of current limiting, so that the safe operation of the controller can be further ensured.
Referring to fig. 9, a power supply VCCIN represents a first power supply, the power supply VCCIN is a 5V dc power supply, the power supply VCCIN may be connected to a fourth terminal of the controller, VCCQ pins of the micro control unit U2 are connected to the power supply VCCIN in fig. 9, a resistor R5 represents a third resistive element in fig. 9, one terminal of the resistor R5 is connected to VCCQ pins of the micro control unit U2, and the other terminal of the resistor R5 is connected to an AD1 pin of the micro control unit U2; in fig. 9, a resistor R6 represents a fourth resistive element, one end of the resistor R6 is connected to the source of the MOS transistor D4, and the other end of the resistor R6 is grounded.
By matching the first power supply 701, the third resistive element 702 and the fourth resistive element 703, the power is supplied to the controller, and meanwhile, the input and output of the controller can be more stable, so that the operation stability of the fan control circuit is improved.
In an exemplary embodiment, referring to fig. 7, the second power supply circuit 6012 includes a second power supply 704 and a voltage dividing assembly 705, one end of the voltage dividing assembly 705 is connected to the second power supply 704, and the other end of the voltage dividing assembly 705 is connected to the driving circuit 102.
In this embodiment, the second power supply 704 is mainly used for supplying power to the driver, and the voltage dividing component 705 is mainly used for sharing the voltage of the power supply line connected to the driver, so as to ensure that the driver can obtain a voltage that is stable and meets the operation requirement.
The voltage divider 705 specifically includes a fifth resistive element and a sixth resistive element, where the fifth resistive element and the sixth resistive element are voltage dividing resistors, one end of the fifth resistive element is connected to the second power source, the other end of the fifth resistive element is connected to the driver, one end of the sixth resistive element is connected to a line where the fifth resistive element is connected to the driver, and the other end of the sixth resistive element is grounded, and in addition, the fifth resistive element is also connected to the fifth end of the controller.
Referring to fig. 9, the power VCC1 represents a second power supply, the power VCC1 may be connected to an input pin of the driver, IN fig. 9, the power VCC1 is connected to an IN pin of the chip U1, the selectable voltage range of the power VCC1 is 4.5V to 24V, IN this embodiment, the power VCC1 with a supply voltage of 12V is selected, and the chip U1 outputs an effective voltage after the ENUV pin obtains a voltage greater than 1.43V.
In fig. 9, a resistor R2 represents a fifth resistive element, a resistor R3 represents a sixth resistive element, the resistor R2 is connected to an OVP pin of the chip U1, the OVP pin of the chip U1 is an overvoltage protection pin, and when the voltage of the input OVP pin exceeds 1.39V, the chip U1 turns off the output; in addition, the resistor R2 is also connected with the AD3 pin of the micro control unit U2, the SS pin of the chip U1 is also connected with the capacitor C1, and the capacitor C1 can provide a rising time control function for the output power supply of the chip U1.
Through the cooperation of the second power supply 704 and the voltage dividing component 705, the safe and stable operation of the driver can be ensured while the driver is powered, and the operation stability of the fan control circuit is further improved.
In some embodiments, referring to fig. 8, the fan control circuit further comprises a filter circuit 801, the filter circuit 801 comprising at least one capacitive element 8011;
one end of the at least one capacitive element 8011 is connected to a circuit between the driving circuit 102 and the fan 103, and the other end of the at least one capacitive element 8011 is grounded.
In this embodiment, the ac component in the voltage output from the driving circuit 102 can be filtered by at least one capacitive element 8011, so as to ensure that the voltage output from the driving circuit 102 is smoother, and the capacitive element 8011 can be a filter capacitor. Referring to fig. 9, two capacitive elements are provided in this embodiment, namely, a capacitor C2 and a capacitor C3 in fig. 9, one end of each of the capacitor C2 and the capacitor C3 is connected to a circuit of the OUT pin of the chip U1 connected to the fan J1, and the other ends of the capacitor C2 and the capacitor C3 are grounded.
The arrangement of the filter circuit 801 in this embodiment can make the dc voltage between the driving circuit 102 and the fan 103 smoother, thereby improving the stability of the operation of the fan 103.
Referring to fig. 9, the working principle of the fan control circuit provided in this embodiment is specifically as follows:
when the power supply VCC1 outputs 12V power supply voltage, the power supply VCCIN outputs 5V power supply voltage, after the ENUV pin of the chip U1 obtains a 5V voltage signal, the OUT pin is output effectively, and the 1 pin of the fan J1 obtains a 12V voltage signal;
when the PWMOUT pin of the micro-processing unit U2 outputs a voltage signal of 5V, the MOS triode D4 is opened, the 2 pin of the fan J1 obtains a voltage signal of 12V, and thus, the two ends of the fan J1 obtain the same voltage signal, and the fan J1 cannot rotate;
when the PWMOUT pin of the micro-processing unit U2 outputs a voltage signal of 0V, the MOS triode D4 is closed, the 2 pin of the fan J1 obtains the voltage signal of 0V, so that the voltage signals obtained at two ends of the fan J1 are different, a certain voltage difference exists, and the fan J1 rotates;
therefore, in this embodiment, by controlling the duty ratio of the 0V voltage signal in the voltage signal output by the PWMOUT pin of the micro-processing unit U2, the fan rotation speed can be precisely controlled, that is, the fan rotation speed can be controlled by controlling the duty ratio of the effective signal in the pulse control signal output by the main control circuit.
The AD2 pin of the micro-processing unit U2 receives a temperature signal sent by external temperature acquisition equipment, when the temperature value in the received temperature signal is higher, for example, the temperature value is higher than a first temperature threshold, the duty ratio of a 0V voltage signal in a voltage signal output by the PWMOUT pin of the micro-processing unit U2 can be properly adjusted, and the rotating speed of the fan J1 can be improved; when the temperature value in the temperature signal received by the AD2 pin of the micro-processing unit U2 is lower, for example, the temperature value is lower than the second temperature threshold, the duty ratio of the 0V voltage signal in the voltage signal output by the PWMOUT pin of the micro-processing unit U2 can be properly reduced, so that the rotation speed of the fan J1 can be reduced.
In the practical application process, the duty ratio of the 0V voltage signal in the voltage signal and different temperature values in the temperature signal can be calibrated in advance to obtain the corresponding relation between the temperature values and the duty ratio, so that after the micro-processing unit U2 receives the temperature signal, the pulse control signal corresponding to the temperature signal can be directly determined according to the temperature values in the temperature signal.
When the fan J1 works normally, the voltage signal of 5V is obtained from the AD1 pin of the micro-processing unit U2, and when the current flowing through the fan J1 is too large due to the locked rotor of the fan J1 or other reasons, for example, the current flowing through the fan J1 exceeds a preset current threshold, the nFLT pin of the chip U1 outputs a low-level signal, so that the voltage signal of 0V is obtained from the AD1 pin of the micro-processing unit U2, the MOS triode D4 is quickly turned off by the micro-processing unit U2 through the PWMOUT pin, meanwhile, the low-level signal is output from the OUT1 pin, so that the voltage signal of 0V is obtained from both ends of the fan J1, and the fan J1 stops rotating, thereby effectively protecting the fan J1 and other devices.
When the power voltage output by the power supply VCC1 exceeds 16.5V, the voltage division of the resistor R2 and the resistor R3 exceeds 1.39V, at the moment, the chip U1 is closed to output, and meanwhile, the OUT pin outputs a low-level signal, so that the two ends of the fan simultaneously obtain a voltage signal of 0V, the fan J1 stops rotating, and the fan J1 can be effectively protected.
In summary, the fan control circuit provided in this embodiment not only can perform multistage adjustment on the rotation speed of the fan by the main control circuit according to the corresponding pulse control signal output by the temperature signal, so as to achieve an accurate control function of the fan, but also can achieve protection functions such as surge protection, overvoltage protection, overcurrent protection, and the like by setting up each protection circuit, so that safe and stable operation of the fan can be ensured.
Corresponding to the embodiment of the application function implementation method, the application further provides heat dissipation equipment and corresponding embodiments.
Fig. 10 shows a heat dissipating device provided in an embodiment of the present application.
Referring to fig. 10, the heat dissipating device provided in the embodiment of the present application may specifically include: the fan 103 and the fan control circuit 100 are connected to the fan 103 and the fan control circuit 100.
The running process of the fan 103 can be controlled through the fan control circuit 100, the rotating speed of the fan 103 can be regulated in multiple stages, meanwhile, the running stability and safety of the fan 103 can be guaranteed, and the fan 103 is matched with the fan control circuit 100, so that the safe output of the heat radiation device can be stable and reliable, and a better heat radiation effect can be achieved.
It can be appreciated that the heat dissipating device in this embodiment may be a device that needs to dissipate heat in real time, such as a vehicle controller in the autopilot field, a power supply device, and the like, which is easy to generate heat during operation.
The structure and the operation principle of the fan control circuit in the heat dissipating device of the above embodiment have been described in detail in the above embodiments related to the fan control circuit, and will not be described in detail here.
The aspects of the present application have been described in detail hereinabove with reference to the accompanying drawings. In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments. Those skilled in the art will also appreciate that the acts and modules referred to in the specification are not necessarily required in the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application may be sequentially adjusted, combined and pruned according to actual needs, and the modules in the apparatus of the embodiment of the present application may be combined, divided and pruned according to actual needs.
The embodiments of the present application have been described above, the foregoing description is exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (11)
1. A fan control circuit, comprising: a main control circuit and a driving circuit;
the first end of the main control circuit is connected with the fan, and the driving circuit is respectively connected with the second end of the main control circuit and the fan;
the main control circuit is used for receiving a temperature signal related to a heat generating object, outputting a pulse control signal corresponding to the temperature signal to the fan according to the temperature signal so as to control the rotating speed of the fan; wherein the duty cycle of the effective signal in the pulse control signal is positively correlated with the temperature value in the temperature signal;
the driving circuit is used for driving the fan to run according to a driving control signal output by the second end of the main control circuit.
2. The fan control circuit of claim 1, wherein the master control circuit comprises a controller and a switch;
the first end of the controller is connected with the switch piece, the switch piece is connected with a circuit between the fan and a fan power supply, and the second end of the controller is connected with the driving circuit;
the controller is used for outputting a pulse control signal corresponding to the temperature signal according to the temperature signal, and the switch piece is used for switching on or switching off the connection between the fan and the fan power supply according to the pulse control signal.
3. The fan control circuit of claim 1, wherein the drive circuit comprises a driver and a first resistive element;
the driver is connected with the fan, one end of the first resistive element is connected with the driver, and the other end of the first resistive element is connected with the second end of the main control circuit.
4. The fan control circuit of claim 3, wherein the driver is further coupled to a third terminal of the main control circuit;
the driver is further configured to output a specific level signal to a third terminal of the main control circuit when a current flowing through the fan exceeds a preset threshold, and the main control circuit is further configured to control the fan to be powered off according to the specific level signal.
5. The fan control circuit of claim 1, further comprising a first protection circuit for conducting a surge voltage input to the fan to ground;
the first protection circuit comprises a first diode and/or a second diode;
one end of the first diode is connected with the first end of the fan, one end of the second diode is connected with the second end of the fan, and the other end of the first diode and the other end of the second diode are grounded.
6. The fan control circuit of claim 1, further comprising a second protection circuit for conducting back electromotive force in a line between the drive circuit and the fan to ground;
the second protection circuit comprises at least one third diode, one end of the at least one third diode is connected to a circuit between the driving circuit and the fan, and the other end of the at least one third diode is grounded.
7. The fan control circuit of claim 1, further comprising a third protection circuit for limiting current flowing through the drive circuit;
the third protection circuit comprises at least one second resistive element, the at least one second resistive element is connected in series to form a series branch, one end of the series branch is connected with the driving circuit, and the other end of the series branch is grounded.
8. The fan control circuit of claim 1, further comprising a power supply circuit for powering the main control circuit and the drive circuit;
the power supply circuit comprises a first power supply sub-circuit and a second power supply sub-circuit;
the first power supply electronic circuit is connected with the main control circuit, and the second power supply electronic circuit is connected with the driving circuit.
9. The fan control circuit of claim 8, wherein the first power supply circuit comprises a first power supply, a third resistive element, and a fourth resistive element;
the first power supply is connected with the fourth end of the main control circuit, one end of the third resistive element is connected with the fourth end of the main control circuit, the other end of the third resistive element is connected with the third end of the main control circuit, one end of the fourth resistive element is connected with the first end of the main control circuit, and the other end of the fourth resistive element is grounded.
10. The fan control circuit of claim 8, wherein the second power supply circuit comprises a second power supply and a voltage dividing assembly, one end of the voltage dividing assembly is connected with the second power supply, and the other end of the voltage dividing assembly is connected with the driving circuit.
11. A heat dissipating device comprising a fan and a fan control circuit as claimed in any one of claims 1 to 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320579400.7U CN219452473U (en) | 2023-03-22 | 2023-03-22 | Fan control circuit and heat dissipation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320579400.7U CN219452473U (en) | 2023-03-22 | 2023-03-22 | Fan control circuit and heat dissipation device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219452473U true CN219452473U (en) | 2023-08-01 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320579400.7U Active CN219452473U (en) | 2023-03-22 | 2023-03-22 | Fan control circuit and heat dissipation device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219452473U (en) |
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2023
- 2023-03-22 CN CN202320579400.7U patent/CN219452473U/en active Active
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