Control circuit of fan motor and electronic device

Abstract

The application discloses a control circuit of a fan motor and electronic equipment, and the control circuit comprises a first switch unit, a first driving unit, a second switch unit and a second driving unit; in a first preset time period and a second preset time period, voltage signals input by input ends of the first switch unit and the second switch unit are opposite, in the case that the first switch unit inputs a first voltage signal, a driving unit connected with the first switch unit outputs a first output voltage, in the case that the second switch unit inputs a second voltage signal, a driving unit connected with the second switch unit outputs a second output voltage, in the case that a voltage difference between a voltage input by a positive electrode and a voltage input by a negative electrode is a positive number, the fan motor rotates forward, and in the case that the voltage difference is a negative number, the fan motor rotates reversely. The fan blowing direction is switched by forward / reverse switching of the fan, so that vibration is generated, automatic cleaning of the fan is realized, and the cleaning efficiency can be improved.

Description

Technical Field

[0001] This application belongs to the field of fan technology, and in particular relates to a control circuit and electronic equipment for a fan motor. Background Technology

[0002] Fans are common furniture. During use, due to factors such as static electricity, low-pressure adsorption effect, and environmental dust, fans tend to accumulate more and more dust over time.

[0003] However, fans on the market do not have automatic cleaning capabilities. They need to be manually disassembled and cleaned to achieve a good cleaning effect, resulting in low cleaning efficiency. Utility Model Content

[0004] This application provides a control circuit and electronic device for a fan motor, which can improve the cleaning efficiency of the fan.

[0005] In a first aspect, embodiments of this application provide a control circuit for a fan motor, the control circuit comprising:

[0006] A first switching unit, a first driving unit, a second switching unit, and a second driving unit;

[0007] The output terminal of the first switching unit is connected to the input terminal of the first driving unit, and the output terminal of the first driving unit is connected to the positive terminal of the fan motor.

[0008] The output terminal of the second switching unit is connected to the input terminal of the second driving unit, and the output terminal of the second driving unit is connected to the negative terminal of the fan motor.

[0009] When the voltage difference between the positive and negative input terminals is positive, the fan motor rotates in the forward direction; when the voltage difference is negative, the fan motor rotates in the reverse direction.

[0010] During a first preset time period, the input terminals of the first switching unit and the second switching unit respectively receive a first voltage signal and a second voltage signal. During a second preset time period, the input terminals of the first switching unit and the second switching unit respectively receive the second voltage signal and the first voltage signal. When the first voltage signal is input to the switching unit, the switching unit is turned on, and the driving unit connected to the switching unit outputs a first output voltage. When the second voltage signal is input to the switching unit, the switching unit is not turned on, and the driving unit connected to the switching unit outputs a second output voltage. Wherein, the first voltage signal is greater than the second voltage signal, and the first output voltage is greater than the second output voltage.

[0011] In some embodiments, the output terminal of the first switching unit is connected to the output terminal of the second driving unit and the negative terminal of the fan motor, respectively; the output terminal of the second switching unit is connected to the output terminal of the first driving unit and the positive terminal of the fan motor, respectively.

[0012] In some embodiments, the first switching unit includes a first resistor and a first transistor; a first end of the first resistor is connected to the gate of the first transistor, a second end of the first resistor is connected to the source of the first transistor, the drain of the first transistor is the output terminal of the first switching unit, and the node connecting the first end of the first resistor and the gate of the first transistor is the input terminal of the first switching unit; the second switching unit includes a second resistor and a second transistor; a first end of the second resistor is connected to the gate of the second transistor, a second end of the second resistor is connected to the source of the second transistor, the drain of the second transistor is the output terminal of the second switching unit, and the node connecting the second resistor and the gate of the second transistor is the input terminal of the second switching unit; when the first voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source and drain of the transistor are turned on; or, when the second voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source and drain of the transistor are not turned on; when the source and drain of the transistor are turned on, the switching unit corresponding to the transistor is turned on; when the source and drain of the transistor are not turned on, the switching unit corresponding to the transistor is not turned on.

[0013] In some embodiments, the first driving unit includes a third transistor, a third resistor, and a fourth resistor; the second driving unit includes a fourth transistor, a fifth resistor, and a sixth resistor; the input terminal of the driving unit is the first terminal of a first target resistor, the second terminal of the first target resistor is connected to the gate of the first target transistor and the first terminal of the second target resistor, the gate of the first target transistor is connected to the first terminal of the second target resistor, the source of the first target transistor is connected to the second terminal of the second target resistor and a target power supply, and the second terminal of the second target resistor is connected to the target power supply; the drain of the first target transistor is the output terminal of the driving unit; wherein, when the driving unit is the first driving unit, the first target resistor is the third resistor, the second target resistor is the fourth resistor, and the first target transistor is the third transistor; when the driving unit is the second driving unit, the first target resistor is the fifth resistor, the second target resistor is the sixth resistor, and the first target transistor is the fourth transistor; the source and drain of the first target transistor are connected, and when the first voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs the first output voltage; or, when the second voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs the second output voltage.

[0014] In some embodiments, the control circuit includes a first capacitor and a second capacitor; the first terminal of the capacitor is connected to the first terminal of the second target resistor, the gate of the second target transistor, and the second terminal of the first target resistor, respectively; the second terminal of the capacitor is connected to the second terminal of the second target resistor, the source of the second target transistor, and the target power supply, respectively; wherein, when the capacitor is the first capacitor, the second target resistor is the fourth resistor, the first target resistor is the third resistor, and the second target transistor is the third transistor; and when the capacitor is the second capacitor, the second target resistor is the sixth resistor, the first target resistor is the fifth resistor, and the second target transistor is the fourth transistor.

[0015] In some embodiments, the control circuit further includes a first diode and a second diode; the cathode of the first diode is connected to the output terminal of the first driving unit and the output terminal of the first switching unit, respectively, and the anode of the first diode is grounded; the cathode of the second diode is connected to the output terminal of the second driving unit and the output terminal of the second switching unit, respectively, and the anode of the second diode is grounded.

[0016] In some embodiments, the control circuit further includes a back electromotive force absorption circuit, which is used to absorb the back electromotive force generated by the fan motor when switching directions; the first end of the absorption circuit is connected to the output end of the first switching unit, the input end of the first driving unit, and the output end of the second driving unit, respectively; the second end of the absorption circuit is connected to the output end of the second switching unit, the input end of the second driving unit, and the output end of the first driving unit, respectively.

[0017] In some embodiments, the absorption circuit includes a third capacitor and a seventh resistor; the first terminal of the third capacitor is the first terminal of the absorption circuit, the second terminal of the third capacitor is connected to the first terminal of the seventh resistor, and the second terminal of the seventh resistor is the second terminal of the absorption circuit.

[0018] In some embodiments, the first switching unit may further include an eighth resistor, the first end of which is the input terminal of the first switching unit, and the second end of which is connected to the first terminal of the first resistor and the gate of the first transistor respectively; the second switching unit may further include a ninth resistor, the first end of which is the input terminal of the second switching unit, and the second end of which is connected to the first terminal of the second resistor and the gate of the second transistor respectively.

[0019] Secondly, embodiments of this application provide an electronic device, which includes a control circuit for a fan motor as described in any one of the first aspects.

[0020] The fan motor control circuit and electronic device of this application embodiment can, within a first preset time period, input a first voltage signal and a second voltage signal respectively to the input terminals of the first and second switching units, and within a second preset time period, input a second voltage signal and a first voltage signal respectively to the input terminals of the first and second switching units. When the first voltage signal is input to the switching unit, the switching unit is turned on, and the drive unit connected to the switching unit outputs a first output voltage; when the second voltage signal is input to the switching unit, the switching unit is not turned on, and the drive unit connected to the switching unit outputs a second output voltage; wherein, the first voltage signal is greater than the second voltage signal, and the first output voltage is greater than the second output voltage. The control circuit allows the fan to switch its blowing direction in both forward and reverse directions, thereby generating vibration and effectively removing dust accumulated on the fan blades. This application enables automatic fan cleaning without manual intervention, avoiding manual labor and improving cleaning efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the control circuit of the fan motor provided in an embodiment of this application;

[0023] Figure 2 This is a circuit diagram of the control circuit for the fan motor provided in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the fan being turned on in forward DC mode according to an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of the fan in high-frequency vibration + DC mode provided in an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the signal flow when controlling the fan motor to rotate forward, provided in an embodiment of this application.

[0027] Figure 6 This is a schematic diagram of the signal flow when controlling the fan motor to reverse, provided in an embodiment of this application. Detailed Implementation

[0028] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0029] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0030] To address the related technical problems, this application provides a control circuit and electronic device for a fan motor. The control circuit for the fan motor provided in this application is described below.

[0031] Figure 1 A schematic diagram of the control circuit for a fan motor provided in an embodiment of this application is shown. Figure 1 As shown, the control circuit of the fan motor specifically includes a first switching unit, a first driving unit, a second switching unit, and a second driving unit. The output terminal of the first switching unit is connected to the input terminal of the first driving unit, the output terminal of the first driving unit is connected to the positive terminal of the fan motor, the output terminal of the second switching unit is connected to the input terminal of the second driving unit, and the output terminal of the second driving unit is connected to the negative terminal of the fan motor.

[0032] The fan motor rotates forward when the voltage difference between the positive and negative input terminals is positive, and rotates in reverse when the voltage difference is negative. In other words, the fan motor rotates forward when the voltage difference between the output voltage of the first drive unit and the output voltage of the second drive unit is positive, and rotates in reverse when the voltage difference is negative.

[0033] During a first preset time period, the input terminals of the first switching unit and the second switching unit respectively receive a first voltage signal and a second voltage signal. During a second preset time period, the input terminals of the first switching unit and the second switching unit respectively receive a second voltage signal and a first voltage signal. When the first voltage signal is input to the switching unit, the switching unit is turned on, and the driving unit connected to the switching unit outputs a first output voltage. When the second voltage signal is input to the switching unit, the switching unit is not turned on, and the driving unit connected to the switching unit outputs a second output voltage. The first voltage signal is greater than the second voltage signal, and the first output voltage is greater than the second output voltage.

[0034] The aforementioned switching unit is either a first switching unit or a second switching unit.

[0035] The aforementioned first preset time period can be before or after the second preset time period.

[0036] The aforementioned first preset time period can be multiple first preset time periods, and the aforementioned second preset time period can be multiple second preset time periods. These multiple first preset time periods and multiple second preset time periods are divided into multiple time period groups. Each time period group includes at least one sub-time period group, and each sub-time period group includes a first preset time period and a second preset time period. Within a sub-time period group, the first preset time period is either before or after the second preset time period. The preset time period in the j-th sub-time period group is before the preset time period in the (j+1)-th time period group. The value of i ranges from 1 to M-1, where M is the number of sub-time period groups in the time period group. The preset time period in the i-th time period group is before the preset time period in the (i+1)-th time period group. The value of i ranges from 1 to N-1, where N is the number of time period groups. During the first preset time period of the i-th time period group, the input terminals of the first switching unit and the second switching unit respectively input a first voltage signal and a second voltage signal. During the second preset time period of the i-th time period group, the input terminals of the first switching unit and the second switching unit respectively input a second voltage signal and a first voltage signal. The fan can switch to high-frequency vibration + DC mode. For example, the fan generates high-frequency vibration by repeatedly switching the fan blowing direction in the forward / reverse direction at about 100Hz. After running for 2-3 seconds, it effectively removes dust accumulated on the fan blades.

[0037] The time in the above sub-time period group can be continuous, and the time in the i-th time period group and the (i+1)-th time period group can be continuous.

[0038] In one implementation, the input terminals of the first and second switching units are connected to a CPU program device, which is used to input a first voltage signal or a second voltage signal to the switching units. The first or second voltage signal can be controlled by a CPU program within the CPU program device.

[0039] In one implementation, the second voltage signal can be 0V, and in this case, the second output voltage can also be 0V. In another implementation, the first voltage signal can be a voltage value greater than 0V, such as 3.3V.

[0040] In this embodiment, by having the voltage signals input to the input terminals of the first and second switching units opposite during the first and second preset time periods, the circuit can repeatedly switch the fan motor in forward / reverse direction, thereby generating vibration and effectively removing dust from the fan blades. This application enables automatic fan cleaning, eliminating the need for manual disassembly and cleaning, thus improving fan cleaning efficiency. Furthermore, the circuit utilizes two switching units and a drive unit to achieve forward and reverse motor rotation, efficiently controlling the motor's direction of motion. Forward and reverse rotation are achieved simply by switching the states of the switching units, making operation convenient and responsive, significantly improving the flexibility of motor control. Secondly, the combination of the switching and drive units effectively isolates the control circuit from the motor's main circuit, preventing interference from high voltage and current generated during motor operation, thereby enhancing the stability and reliability of the entire system. This circuit structure is relatively simple, easy to implement and maintain, reducing system complexity and cost, and also facilitates expansion and upgrades according to actual needs, better meeting the requirements for forward and reverse motor control in different application scenarios.

[0041] In some embodiments, during a third preset time period, the input terminals of the first switching unit and the second switching unit respectively receive a first voltage signal and a second voltage signal. The aforementioned time period group may further include a third preset time period, which is after the first and second preset time periods, i.e., after the fan motor is switched between forward and reverse directions via the circuit, the fan motor controls the fan blades to rotate in the forward direction, causing the fan to switch to a forward DC operating mode. At this time, the fan generates air pressure to expel the adhering material through airflow.

[0042] For example, the fan repeatedly switches its blowing direction between forward and reverse at approximately 100Hz for 2-3 seconds to effectively remove dust from the fan blades. Then, the fan switches to a forward DC operating mode, where it generates air pressure to expel the accumulated dust forward through airflow, continuing for another 2-3 seconds. This process is then repeated alternately for approximately 10 minutes, effectively cleaning the fan surface. Specifically, this can be achieved by sequentially rotating the fan forward for 2 seconds within the first preset time period of multiple sub-time periods within a time period group, then rotating it backward for 2 seconds within the second preset time period, and then rotating it forward for 3 seconds within the third preset time period of the time period group. This process is repeated, alternating between different time periods, for approximately 10 minutes, effectively cleaning the fan surface.

[0043] In some embodiments, the output terminal of the first switching unit is connected to the output terminal of the second driving unit and the negative terminal of the fan motor, respectively, and the output terminal of the second switching unit is connected to the output terminal of the first driving unit and the positive terminal of the fan motor, respectively.

[0044] Reference Figure 2 , Figure 2 The circuit diagram of the control circuit of the fan motor provided in the embodiments of this application shows that, in some embodiments, the first switching unit includes a first resistor (R123) and a first transistor (Q11). The first end of the first resistor (R123) is connected to the gate (G) of the first transistor (Q11), the second end of the first resistor (R123) is connected to the source (S) of the first transistor (Q11), the drain (D) of the first transistor (Q11) is the output terminal of the first switching unit, and the node where the first end of the first resistor (R123) is connected to the gate of the first transistor (Q11) is the input terminal of the first switching unit.

[0045] The second switching unit includes a second resistor (R126) and a second transistor (Q12). The first end of the second resistor (R126) is connected to the gate (G) of the second transistor (Q12), and the second end of the second resistor (R126) is connected to the source (S) of the second transistor (Q12). The drain (D) of the second transistor (Q12) is the output terminal of the second switching unit, and the node where the second resistor (R126) and the gate (G) of the second transistor (Q12) are connected is the input terminal of the second switching unit.

[0046] In this configuration, the source (S) of the first transistor (Q11) is connected to the source (S) of the second transistor (Q12) and the second terminal of the second resistor (R126), respectively. The source (S) of the second transistor (Q12) is connected to the second terminal of the first resistor (R123). The source (S) of the first transistor (Q11), the source (S) of the second transistor (Q12), the second terminal of the first resistor (R123), and the second terminal of the second resistor (R126) are all grounded.

[0047] When a first voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source (S) and drain (D) of the transistor are turned on; or, when a second voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source (S) and drain (D) of the transistor are not turned on.

[0048] When the source (S) and drain (D) of a transistor are turned on, the corresponding switching unit of the transistor is turned on; when the source (S) and drain (D) of a transistor are not turned on, the corresponding switching unit of the transistor is not turned on.

[0049] The aforementioned transistor is either a first transistor (Q11) or a second transistor (Q12). The switching unit corresponding to the first transistor (Q11) is a first switching unit, and the switching unit corresponding to the second transistor (Q12) is a second switching unit. That is, when a first voltage signal is input to the input terminal of the first switching unit, the source (S) and drain (D) of the first transistor are turned on; when a first voltage signal is input to the input terminal of the second switching unit, the source (S) and drain (D) of the second transistor are turned on. Alternatively, when a second voltage signal is input to the input terminal of the first switching unit, the source (S) and drain (D) of the first transistor are not turned on; when a second voltage signal is input to the input terminal of the second switching unit, the source (S) and drain (D) of the second transistor are not turned on. When the source (S) and drain (D) of the first transistor are turned on, the first switching unit is turned on; when the source (S) and drain (D) of the first transistor are not turned on, the first switching unit is not turned on; when the source (S) and drain (D) of the second transistor are turned on, the second switching unit is turned on; when the source (S) and drain (D) of the second transistor are not turned on, the second switching unit is not turned on.

[0050] The nominal resistance value of the above resistors can be set according to requirements, and the model of the above transistors can be set according to requirements.

[0051] In some embodiments, the first driving unit includes a third transistor (Q4), a third resistor (R111), and a fourth resistor (R106), and the second driving unit includes a fourth transistor (Q2), a fifth resistor (R110), and a sixth resistor (R101).

[0052] The input terminal of the aforementioned driving unit is the first terminal of the first target resistor (R111 / R110). The second terminal of the first target resistor (R111 / R110) is connected to the gate (G) of the first target transistor (Q4 / Q2) and the first terminal of the second target resistor (R106 / R101), respectively. The gate (G) of the first target transistor (Q4 / Q2) is connected to the first terminal of the second target resistor (R106 / R101). The source (S) of the first target transistor (Q4 / Q2) is connected to the second terminal of the second target resistor (R106 / R101) and the target power supply, respectively. The second terminal of the second target resistor (R106 / R101) is connected to the target power supply. The drain (D) of the first target transistor (Q4 / Q2) is the output terminal of the driving unit.

[0053] Specifically, when the driving unit is the first driving unit, the first target resistor is the third resistor (R111), the second target resistor (R106 / R101) is the fourth resistor (R106), and the first target transistor is the third transistor (Q4); when the driving unit is the second driving unit, the first target resistor is the fifth resistor (R110), the second target resistor (R106 / R101) is the sixth resistor (R101), and the first target transistor is the fourth transistor (Q2). That is, the input terminal of the first driving unit is the first terminal of the third resistor (R111). The second terminal of the third resistor (R111) is connected to the gate (G) of the third transistor (Q4) and the first terminal of the fourth resistor (R106). The gate (G) of the third transistor (Q4) is connected to the first terminal of the fourth resistor (R106). The source (S) of the third transistor (Q4) is connected to the second terminal of the fourth resistor (R106) and the target power supply. The second terminal of the fourth resistor (R106) is connected to the target power supply. The drain (D) of the third transistor (Q4) is the output terminal of the first driving unit. The input terminal of the second driving unit is the first terminal of the fifth resistor (R110). The second terminal of the fifth resistor (R110) is connected to the gate (G) of the fourth transistor (Q2) and the first terminal of the sixth resistor (R101). The gate (G) of the fourth transistor (Q2) is connected to the first terminal of the sixth resistor (R101). The source (S) of the fourth transistor (Q2) is connected to the second terminal of the sixth resistor (R101) and the target power supply. The second terminal of the sixth resistor (R101) is connected to the target power supply. The drain (D) of the fourth transistor (Q2) is the output terminal of the second driving unit.

[0054] When the source (S) and drain (D) of the first target transistor are turned on, and a first voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs a first output voltage; or, when a second voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs a second output voltage. The first target transistor is either a third transistor (Q4) or a fourth transistor (Q2), the driving unit corresponding to the third transistor (Q4) is the first driving unit, and the driving unit corresponding to the fourth transistor (Q2) is the second driving unit.

[0055] The model of the first target transistor can be set according to requirements.

[0056] The nominal resistance values ​​of the first target resistor (R111 / R110) and the second target resistor (R106 / R101) can be set as required.

[0057] The voltage of the target power supply VDD can be set as needed.

[0058] In some embodiments, the control circuit described above includes a first capacitor (C147) and a second capacitor (C146).

[0059] The first terminal of the aforementioned capacitor (C147 / C146) is connected to the first terminal of the second target resistor (R106 / R101), the gate (G) of the second target transistor (Q4 / Q2), and the second terminal of the first target resistor (R111 / R110), respectively. The second terminal of the aforementioned capacitor (C147 / C146) is connected to the second terminal of the second target resistor (R106 / R101), the source (S) of the second target transistor (Q4 / Q2), and the target power supply, respectively.

[0060] Specifically, when the capacitor is the first capacitor (C147), the second target resistor is the fourth resistor (R106), the first target resistor is the third resistor (R111), and the second target transistor is the third transistor (Q4). When the capacitor is the second capacitor (C146), the second target resistor is the sixth resistor (R101), the first target resistor is the fifth resistor (R110), and the second target transistor is the fourth transistor (Q2).

[0061] The first capacitor (C147) and the second capacitor (C146) are used to reduce the Miller effect.

[0062] The model of the capacitors mentioned above can be set according to requirements, and the capacitance and rated voltage of the capacitors can also be set according to requirements.

[0063] In some embodiments, the control circuit further includes a first diode (D8) and a second diode (D5).

[0064] The cathode of the first diode (D8) is connected to the output terminal of the first driving unit and the output terminal of the first switching unit, respectively, and the anode of the first diode (D8) is grounded.

[0065] The negative terminal of the second diode (D5) is connected to the output terminal of the second driving unit and the output terminal of the second switching unit, respectively, and the positive terminal of the second diode (D5) is grounded.

[0066] The first diode (D8) and the second diode (D5) are used for transient protection.

[0067] The model of the diodes mentioned above can be set according to requirements.

[0068] In some embodiments, the control circuit further includes a back electromotive force absorption circuit.

[0069] The first end of the absorption circuit is connected to the output end of the first switching unit, the input end of the first driving unit, and the output end of the second driving unit, respectively.

[0070] The second end of the absorption circuit is connected to the output end of the second switching unit, the input end of the second driving unit, and the output end of the first driving unit, respectively.

[0071] The aforementioned absorption circuit is used to absorb the back electromotive force generated by the fan motor when it switches directions.

[0072] The absorption circuit described above can also be used to absorb the back electromotive force generated when the fan motor stops or starts.

[0073] In some embodiments, the control circuit described above further includes a third capacitor (C148) and a seventh resistor (R112).

[0074] The first terminal of the third capacitor (C148) is the first terminal of the absorption circuit, and the second terminal of the third capacitor (C148) is connected to the first terminal of the seventh resistor (R112).

[0075] The second terminal of the seventh resistor (R112) is the second terminal of the absorption circuit.

[0076] The model of the third capacitor (C148) can be set according to requirements, and the capacitance and rated voltage of the third capacitor (C148) can be set according to requirements.

[0077] The nominal resistance value of the seventh resistor (R112) can be set according to requirements.

[0078] In some embodiments, the first switching unit may further include an eighth resistor (R120), and the second switching unit may further include a ninth resistor (R122).

[0079] The first end of the eighth resistor (R120) is the input terminal of the first switching unit, and the second end of the eighth resistor (R120) is connected to the first end of the first resistor (R123) and the gate (G) of the first transistor (Q11). The first end of the ninth resistor (R122) is the input terminal of the second switching unit, and the second end of the ninth resistor (R122) is connected to the first end of the second resistor (R126) and the gate (G) of the second transistor (Q12).

[0080] The eighth resistor (R120) and the ninth resistor (R122) mentioned above are protective resistors.

[0081] The nominal resistance values ​​of the eighth resistor (R120) and the ninth resistor (R122) mentioned above can be set according to requirements.

[0082] In some embodiments of this application, an electronic device is also provided, which includes the control circuit of the fan motor described above.

[0083] In one implementation, the aforementioned electronic device can be a fan.

[0084] To facilitate understanding of the above control circuit, embodiments of this application provide an example using a fan based on the control circuit, see below. Figure 2 Taking the nominal resistance values ​​of R123 and R126 as 10kΩ, Q11 and Q12 as N-channel MOSFET transistors (AO3400), Q4 and Q2 as P-channel enhancement-mode field-effect transistors (AO3401), R111 and R110 as 15kΩ, R106 and R101 as 4.7kΩ, the target power supply VDD as 12V, C147 and C146 as having capacitance and rated voltage of 0.1uF and 50V respectively, the diode as a surface-mount transient voltage suppressor diode (SMAJ15A), C148 as having capacitance and rated voltage of 470nF and 25V respectively, R112 as having a nominal resistance of 1kΩ, and R120 and R122 as having a nominal resistance of 100Ω as an example, the following is a description:

[0085] Reference Figure 3 , Figure 3 This is a schematic diagram of the fan in forward DC mode provided in an embodiment of this application, as shown below. Figure 3 As shown, when the fan is in normal use, it operates in forward DC mode. In this mode, the fan works normally, and the user can use the fan functions as usual. Forward DC mode means the fan motor rotates in the forward direction.

[0086] Reference Figure 4 , Figure 4 This is a schematic diagram of a fan operating in high-frequency vibration + DC mode according to an embodiment of this application, as shown below. Figure 4 As shown, when cleaning the fan (fan unit), the fan uses a high-frequency vibration + DC mode (i.e., self-cleaning mode). At this time, the fan switches from the traditional forward DC mode to the high-frequency vibration + DC mode. The high-frequency vibration + DC mode involves repeatedly switching the fan blowing direction forward / reverse in multiple time periods, and then switching to the forward DC working mode after repeatedly switching the fan blowing direction forward / reverse. For example, the fan repeatedly switches the fan blowing direction forward / reverse at about 100Hz for 2-3 seconds, effectively removing the dust accumulated on the fan blades. The fan then switches to the forward DC working mode, at which time the fan generates wind pressure to expel the attached substances through airflow. This continues for 2-3 seconds, and then the two processes alternate repeatedly for about 10 minutes, resulting in effective cleaning of the fan surface.

[0087] like Figure 2 As shown, in_1 and in_2 are signal input terminals, and out_1 and out_2 are output terminals, which are connected to the positive and negative terminals of the fan motor.

[0088] When in_1 and in_2 are both 0V, Q11 MOS_DS and Q12 MOS_DS are not conducting (i.e., the drain and source terminals of Q11 and Q12 are not connected), there is no current in the circuit, and the fan stops.

[0089] When in_1 receives 3.3V and in_2 receives 0V, Q11 MOS_DS is turned on (i.e., the drain and source terminals of Q11 are connected), and out_1 outputs 0V. At the same time, Q4 MOS_DS is turned on (i.e., the drain and source terminals of Q4 are connected), and out_2 outputs 12V. A voltage difference of 12V is formed between out_1 and out_2, and the fan rotates in the forward direction.

[0090] Input 0V to in_1, input 3.3V to in_2, Q12 MOS_DS conducts, out_2 outputs 0V, and simultaneously Q2 MOS_DS conducts, out_1 outputs 12V. A voltage difference of -12V is formed between out_1 and out_2, causing the fan to reverse. See Table 1 below:

[0091] Table 1

[0092] In_1 In_2 out_1 out_2 direction 3.3V 0V 0V 12V Forward 0V 3.3V 12V 0V Reversal

[0093] Figure 2 Q2 and Q4 are the upper arm switching MOSFETs, Q11 and Q12 are the lower arm switching MOSFETs, C147 and C146 are gate-source capacitors used to reduce the Miller effect, and D5 and D8 are used for transient protection to prevent damage to the motor caused by excessive voltage.

[0094] Reference Figure 5 , Figure 5 This is a schematic diagram of the signal flow when controlling the fan motor to rotate forward, provided in an embodiment of this application. In forward rotation mode, the signal flow in the circuit is as follows: Figure 5 As shown by the dashed arrow in the diagram, i.e., signal path 1, R106 and R111 act as a voltage divider on the other end, as above. Figure 5 As shown, Q4 Vg (the voltage at the gate of Q4) is the voltage divider of R106 and R111, i.e. (12V*15K / (15K+4.7K)=9.13V). At this time, the voltage difference between Q4 MOS_GS (the voltage difference between the gate and source) is 2.86V, and Q4 MOS_DS (the gate and source of Q4) is turned on.

[0095] Reference Figure 6 , Figure 6 This is a schematic diagram illustrating the signal flow when controlling the fan motor to reverse, as provided in an embodiment of this application. In reverse mode, the signal flow in the circuit is as follows: Figure 6 As shown by the dashed arrow in the diagram, i.e., signal path 2, R101 and R110 act as a voltage divider at one end, as above. Figure 6As shown, Vg (the voltage at the gate of Q2) is the voltage divider of R101 and R110, i.e. (12V*15K / (15K+4.7K)=9.13V). At this time, the voltage difference between Q2 MOS_GS (the voltage difference between the gate and source) is 2.86V, and Q2 MOS_DS (the gate and source of Q2) is turned on.

[0096] C148 and R112 absorb the back electromotive force of the motor when it starts, stops, or changes direction at the output end.

[0097] R123 and R126 are pull-down resistors to prevent the circuit from malfunctioning due to level uncertainty when the resistors are not controlled (high impedance state). When R123 and R126 are pulled down simultaneously, it is equivalent to the stop control state.

[0098] In all the examples shown and described above, any specific value should be interpreted as merely exemplary and not as a limitation; therefore, other examples of exemplary embodiments may have different values.

[0099] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0100] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

[0101] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A control circuit for a fan motor, characterized by The control circuit includes: a first switching unit, a first driving unit, a second switching unit, and a second driving unit; The output terminal of the first switching unit is connected to the input terminal of the first driving unit, and the output terminal of the first driving unit is connected to the positive terminal of the fan motor. The output terminal of the second switching unit is connected to the input terminal of the second driving unit, and the output terminal of the second driving unit is connected to the negative terminal of the fan motor. When the voltage difference between the positive and negative input terminals is positive, the fan motor rotates in the forward direction; when the voltage difference is negative, the fan motor rotates in the reverse direction. During a first preset time period, the input terminals of the first switching unit and the second switching unit respectively receive a first voltage signal and a second voltage signal. During a second preset time period, the input terminals of the first switching unit and the second switching unit respectively receive the second voltage signal and the first voltage signal. When the first voltage signal is input to the switching unit, the switching unit is turned on, and the driving unit connected to the switching unit outputs a first output voltage. When the second voltage signal is input to the switching unit, the switching unit is not turned on, and the driving unit connected to the switching unit outputs a second output voltage. Wherein, the first voltage signal is greater than the second voltage signal, and the first output voltage is greater than the second output voltage.

2. The control circuit for a fan motor as set forth in claim 1, wherein The output terminal of the first switching unit is connected to the output terminal of the second driving unit and the negative terminal of the fan motor, respectively; The output terminal of the second switching unit is connected to the output terminal of the first driving unit and the positive terminal of the fan motor, respectively.

3. The control circuit for a fan motor as set forth in claim 1, wherein The first switching unit includes a first resistor and a first transistor; The first end of the first resistor is connected to the gate of the first transistor, the second end of the first resistor is connected to the source of the first transistor, the drain of the first transistor is the output of the first switching unit, and the node where the first end of the first resistor is connected to the gate of the first transistor is the input of the first switching unit. The second switching unit includes a second resistor and a second transistor; The first end of the second resistor is connected to the gate of the second transistor, the second end of the second resistor is connected to the source of the second transistor, the drain of the second transistor is the output of the second switching unit, and the node where the second resistor is connected to the gate of the second transistor is the input of the second switching unit. When the first voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source and drain of the transistor are turned on; or, when the second voltage signal is input to the input terminal of the switching unit corresponding to the transistor, the source and drain of the transistor are not turned on. When the source and drain of the transistor are turned on, the corresponding switching unit of the transistor is turned on; When the source and drain of the transistor are not conducting, the corresponding switching unit of the transistor is not conducting.

4. The control circuit for a fan motor as set forth in claim 1, wherein The first driving unit includes a third transistor, a third resistor, and a fourth resistor; the second driving unit includes a fourth transistor, a fifth resistor, and a sixth resistor. The input terminal of the driving unit is the first terminal of the first target resistor. The second terminal of the first target resistor is connected to the gate of the first target transistor and the first terminal of the second target resistor. The gate of the first target transistor is connected to the first terminal of the second target resistor. The source of the first target transistor is connected to the second terminal of the second target resistor and the target power supply. The second terminal of the second target resistor is connected to the target power supply. The drain of the first target transistor is the output terminal of the driving unit; Wherein, when the driving unit is the first driving unit, the first target resistor is the third resistor, the second target resistor is the fourth resistor, and the first target transistor is the third transistor; when the driving unit is the second driving unit, the first target resistor is the fifth resistor, the second target resistor is the sixth resistor, and the first target transistor is the fourth transistor. When the source and drain of the first target transistor are turned on, and the first voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs the first output voltage; or, when the second voltage signal is input to the input terminal of the driving unit corresponding to the first target transistor, the first target transistor outputs the second output voltage.

5. The control circuit for the fan motor according to claim 4, characterized in that, The control circuit includes a first capacitor and a second capacitor; The first terminal of the capacitor is connected to the first terminal of the second target resistor, the gate of the second target transistor, and the second terminal of the first target resistor. The second terminal of the capacitor is connected to the second terminal of the second target resistor, the source of the second target transistor, and the target power supply. Wherein, when the capacitor is the first capacitor, the second target resistor is the fourth resistor, the first target resistor is the third resistor, and the second target transistor is the third transistor; when the capacitor is the second capacitor, the second target resistor is the sixth resistor, the first target resistor is the fifth resistor, and the second target transistor is the fourth transistor.

6. The control circuit for the fan motor according to claim 2, characterized in that, The control circuit also includes a first diode and a second diode; The cathode of the first diode is connected to the output terminal of the first driving unit and the output terminal of the first switching unit, respectively, and the anode of the first diode is grounded. The negative terminal of the second diode is connected to the output terminal of the second driving unit and the output terminal of the second switching unit, respectively, and the positive terminal of the second diode is grounded.

7. The control circuit for the fan motor according to claim 2, characterized in that, The control circuit also includes a back electromotive force absorption circuit, which is used to absorb the back electromotive force generated by the fan motor when switching directions. The first end of the absorption circuit is connected to the output end of the first switching unit, the input end of the first driving unit, and the output end of the second driving unit, respectively. The second end of the absorption circuit is connected to the output end of the second switching unit, the input end of the second driving unit, and the output end of the first driving unit, respectively.

8. The control circuit for the fan motor according to claim 7, characterized in that, The absorption circuit includes a third capacitor and a seventh resistor; The first terminal of the third capacitor is the first terminal of the absorption circuit, the second terminal of the third capacitor is connected to the first terminal of the seventh resistor, and the second terminal of the seventh resistor is the second terminal of the absorption circuit.

9. The control circuit for the fan motor according to claim 3, characterized in that, The first switching unit may further include an eighth resistor, the first end of which is the input terminal of the first switching unit, and the second end of which is connected to the first end of the first resistor and the gate of the first transistor respectively. The second switching unit may further include a ninth resistor, the first end of which is the input terminal of the second switching unit, and the second end of which is connected to the first end of the second resistor and the gate of the second transistor.

10. An electronic device, characterized in that, The electronic device includes a control circuit for a fan motor as described in any one of claims 1-9.

Images