Motor control circuit and DC brush motor device

Abstract

The embodiment of the utility model provides a motor control circuit and a direct-current brush motor device, and the circuit comprises a power interface which comprises a positive electrode end and a negative electrode end; the positive end of the power interface is coupled to the first end of the motor through a rotating speed adjusting unit, and the negative end of the power interface is coupled to the second end of the motor through a switch element. A main control chip; the chip adjusting end is coupled with an adjusting circuit and is used for receiving the rotating speed information of the motor output by the adjusting circuit; the control end of the chip is coupled with the control end of the rotating speed adjusting unit through a first resistor; the chip feedback end is coupled to the other end of the rotating speed adjusting unit through a feedback circuit; the chip power supply end is coupled with a power supply circuit. Through cooperative work of the rotating speed adjusting unit and the main control chip, high-precision dynamic adjustment of the rotating speed of the motor is realized. And the system can keep stable rotating speed output under the conditions of starting, operation or load change.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of motor control, and in particular to a motor control circuit and a DC brush motor device. BACKGROUND

[0002] In modern industrial automation, household appliances and consumer electronics, motors are widely used as power sources. In order to achieve effective control of the running state of the motor (especially the speed), traditional solutions usually rely on mechanical or analog speed regulating devices such as slide rheostat, potentiometer, etc. However, these traditional methods have problems such as slow response speed, low precision, easy to be affected by environmental factors, etc., and are difficult to integrate into complex control systems. With the development of microelectronic technology and digital signal processing technology, intelligent motor control schemes based on master control chips have emerged. This kind of system can set the working parameters of the motor through software programming, and monitor the state of the motor in real time using feedback mechanism, so as to realize more accurate and stable speed control. In addition, digital control also provides higher flexibility and expandability, which is convenient for communication connection with other devices or network. However, the existing motor control system based on master control chip still faces some challenges. For example, in some cases, due to the lack of effective feedback mechanism or the inaccuracy of the regulation strategy, there is a certain deviation between the actual speed and the expected value. SUMMARY

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present disclosure is to provide a motor control circuit and a DC brush motor device to solve the problems in the related art.

[0004] The first aspect of the present disclosure provides a motor control circuit for controlling the speed of a motor, comprising:

[0005] A power interface includes a positive terminal and a negative terminal; the positive terminal of the power interface is coupled to a first end of the motor via a speed regulating unit, and the negative terminal of the power interface is coupled to a second end of the motor via a switching element;

[0006] A master control chip includes a chip regulating terminal, a chip control terminal, a chip feedback terminal and a chip power supply terminal; the chip regulating terminal is coupled to a regulating circuit for receiving the speed information of the motor output by the regulating circuit; the chip control terminal is coupled to the control terminal of the speed regulating unit via a first resistor for controlling the on / off of the speed regulating unit according to the speed information; the chip feedback terminal is coupled to the other end of the speed regulating unit via a feedback circuit for detecting the conduction state of the speed regulating unit; and the chip power supply terminal is coupled to a power supply circuit.

[0007] In the embodiments of the first aspect, the regulating circuit comprises:

[0008] a tunable resistor, one end of the tunable resistor being coupled to a reference power supply, the other end of the tunable resistor being grounded, a tunable end of the tunable resistor being coupled to the chip adjustment end, the chip adjustment end generating the rotation speed information according to a resistance value of the tunable resistor.

[0009] In an embodiment of the first aspect, the feedback circuit comprises:

[0010] a second resistor, one end of the second resistor being coupled to an output end of the power supply circuit, the other end of the second resistor being coupled to the first end of the motor via a third resistor, a voltage division point between the second resistor and the third resistor leading to the chip feedback end.

[0011] In an embodiment of the first aspect, the master control chip further comprises a protection end, the protection end being coupled to the switching element via a protection circuit; the protection circuit comprises:

[0012] a fourth resistor, one end of the fourth resistor being grounded, the other end of the fourth resistor being coupled to the negative end via a fifth resistor, the fourth resistor and the fifth resistor leading to the protection end, the protection end receiving a level signal, the master control chip determining an on-off state of the switching element based on the level signal being high or high-low level change, so as to set the off switching element to on.

[0013] In an embodiment of the first aspect, the protection circuit further comprises:

[0014] a first capacitor, the first capacitor being connected in parallel with the fourth resistor.

[0015] In an embodiment of the first aspect, the power supply circuit comprises at least one of the following elements:

[0016] a voltage stabilizing diode, a positive electrode of the voltage stabilizing diode being coupled to the negative end, a negative electrode of the voltage stabilizing diode being coupled to the positive end;

[0017] a storage capacitor, the storage capacitor being connected in parallel with the voltage stabilizing diode, a positive electrode of the storage capacitor being coupled to the chip power supply end, a negative electrode of the storage capacitor being grounded;

[0018] a first diode, a positive electrode of the first diode being coupled to the negative electrode of the storage capacitor, a negative electrode of the first diode being coupled to the negative end via a sixth resistor.

[0019] In an embodiment of the first aspect, the master control chip further comprises a current detection end, the current detection end being coupled to the rotation speed adjustment unit via a current detection circuit, the current detection circuit being coupled to a current sampling point between the positive end and the first end of the motor.

[0020] In an embodiment of the first aspect, the current detection circuit comprises a seventh resistor and an eighth resistor.

[0021] One end of the seventh resistor is coupled to the current detection end, and the other end of the seventh resistor is coupled to the positive end and one end of the eighth resistor via the eighth resistor, and the other end of the eighth resistor is coupled to the first end of the motor via the speed regulation unit.

[0022] In an embodiment of the first aspect, the speed regulation unit comprises a bidirectional thyristor.

[0023] The second aspect of the present disclosure provides a direct current brush motor device, wherein the device comprises the motor control circuit according to any one of the above.

[0024] The present disclosure has the following advantages: through the cooperative work of the speed regulation unit and the main control chip, high-precision dynamic regulation of the motor speed is realized. No matter in the case of starting, running or load change, the system can maintain stable speed output. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A structural block diagram of a motor control circuit in an embodiment of the present disclosure is shown.

[0026] Figure 2 A circuit schematic diagram of a motor control circuit in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0027] The embodiments of the present disclosure are described below through specific and concrete examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the messages disclosed in the present disclosure. The present disclosure can also be implemented or applied in different specific embodiments, and the details in the present disclosure can be modified or changed according to different views and applications without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0028] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in various different forms, and is not limited to the embodiments described herein.

[0029] In the description of the present disclosure, the expressions "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. mean that the particular feature, structure, material or characteristic following the expressions are included in at least one embodiment or example of the present disclosure. Also, the expressions can include a particular feature, structure, material or characteristic in combination with one or more of the other features, structures, materials or characteristics in any one or more embodiments or examples. In addition, the different embodiments or examples of the present disclosure and the features of the different embodiments or examples can be combined and combined with each other, if not mutually exclusive.

[0030] In addition, the terms "first", "second", etc. are used only to indicate a purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "a group" is two or more, unless specifically limited.

[0031] In order to clearly illustrate the present disclosure, devices irrelevant to the description are omitted, and the same reference numerals are given to the same or similar constituent elements throughout the description.

[0032] Throughout the description, when it is said that a device is "connected" to another device, it includes not only the case of "direct connection", but also the case of "indirect connection" in which other elements are placed therebetween. In addition, when it is said that a device "includes" a certain constituent element, unless specifically stated to the contrary, other constituent elements are not excluded, but it means that other constituent elements can also be included.

[0033] Although the terms first, second, etc. are used herein to refer to various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first interface and a second interface, etc. are indicated. Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", mean the presence of the stated features, steps, operations, elements, modules, items, kinds and / or groups, but do not exclude the presence or addition of one or more other features, steps, operations, elements, modules, items, kinds and / or groups. The terms "or" and "and / or" as used herein are to be interpreted as inclusive, or meaning either or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". This definition applies only when a combination of elements, functions, steps or operations are in some way specifically called out in a claim.

[0034] The technical terms used herein are for reference only to specific embodiments and are not intended to limit the scope of this disclosure. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in this specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0035] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the message of the present disclosure, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0036] In related technologies, speed regulation relies on simple mechanical devices (such as pulleys and gears) or basic electronic components (such as resistors and capacitors), which make it difficult to achieve high-precision dynamic regulation. Especially under complex operating conditions, the motor's response speed and stability cannot be fully guaranteed.

[0037] To address the aforementioned shortcomings, one embodiment of this disclosure provides a motor control circuit for controlling the motor speed. Through the coordinated operation of a speed regulation unit and a main control chip, high-precision dynamic adjustment of the motor speed is achieved. The system maintains a stable speed output regardless of startup, operation, or load changes.

[0038] exist Figure 1 In this embodiment, the motor control circuit includes:

[0039] The power interface 200 includes a positive terminal 201 and a negative terminal 202; the positive terminal 201 of the power interface 200 is coupled to a first end of the motor 100 via a speed adjustment unit 300, and the negative terminal 202 of the power interface 200 is coupled to a second end of the motor 100 via a switching element 400.

[0040] Specifically, in some embodiments, the speed regulation unit 300 is used to dynamically adjust the speed of the motor 100 according to system requirements, ensuring that the motor 100 can operate stably at different speeds or under different demands. The switching element 400 controls the on / off state of the motor 100 circuit, thereby enabling the switching of starting and stopping the motor 100.

[0041] The main control chip 500 includes a chip adjusting end 501, a chip control end 502, a chip feedback end 503, and a chip power supply end 504. The chip adjusting end 501 is coupled with an adjusting circuit 600, and is used to receive the rotating speed information of the motor 100 output by the adjusting circuit 600. The chip control end 502 is coupled with the control end of the rotating speed adjusting unit 300 via a first resistor R1, and is used to control the on / off of the rotating speed adjusting unit 300 according to the rotating speed information. The chip feedback end 503 is coupled with another end of the rotating speed adjusting unit 300 via a feedback circuit 700, and is used to detect the conduction state of the rotating speed adjusting unit 300. The chip power supply end 504 is coupled with a power supply circuit 800.

[0042] Specifically, the adjusting circuit 600 outputs the rotating speed information required by the motor 100 according to the actual demand, so as to ensure that the system can flexibly adjust the rotating speed of the motor 100 according to different application scenarios. At the same time, the main control chip 500 detects the conduction state of the rotating speed adjusting unit 300 in real time through the chip feedback end 503, so as to ensure the stable operation of the system.

[0043] Optionally, in some embodiments, the adjusting circuit 600 includes a voltage divider circuit. Figure 2 In an embodiment, the adjusting circuit 600 includes:

[0044] The adjustable resistor RV1 has one end coupled with a reference power supply, and the other end grounded. The adjustable end of the adjustable resistor RV1 is coupled with the chip adjusting end 501, and the chip adjusting end 501 generates the rotating speed information according to the resistance value of the adjustable resistor RV1.

[0045] Specifically, in some embodiments, the main control chip 500 calculates the current resistance value by reading the voltage difference between the two ends of the adjustable resistor RV1. According to the pre-set mapping relationship, the main control chip 500 converts the resistance value into corresponding rotating speed information. The user can adjust the resistance value of the adjustable resistor RV1 in a manual or automatic manner, so as to change the rotating speed setting of the motor 100. For example, in the manual mode, the user can directly rotate the knob of the adjustable resistor RV1; in the automatic mode, the main control chip 500 can automatically adjust the resistance value according to the pre-set program. In Figure 2 In an embodiment, a third capacitor C3 is further provided, one end of the third capacitor C3 is coupled with the chip adjusting end 501, and the other end of the third capacitor C3 is grounded. The third capacitor C3 is used for filtering.

[0046] Optionally, in some embodiments, the rotating speed adjusting unit 300 includes a bidirectional thyristor. Figure 2 In an embodiment, the rotating speed adjusting unit 300 includes a bidirectional thyristor.

[0047] Optionally, in Figure 2 In an embodiment, the feedback circuit 700 comprises:

[0048] A second resistor R2, one end of the second resistor R2 is coupled to the output end of the power supply circuit 800, the other end of the second resistor R2 is coupled to the first end of the motor 100 via a third resistor R3, and a voltage dividing point between the second resistor R2 and the third resistor R3 leads to the chip feedback end 503.

[0049] Specifically, in some embodiments, the bidirectional thyristor is a bidirectional triggered semiconductor device that can be turned on or off in two half cycles of alternating current. By changing the conduction time (i.e. conduction angle) of the bidirectional thyristor, the root mean square value of the input voltage of the motor 100 can be adjusted, thereby controlling the speed of the motor 100. The second resistor R2 and the third resistor R3 constitute a voltage dividing circuit for detecting the conduction state of the bidirectional thyristor. When the bidirectional thyristor is turned on, current flows through the second resistor R2 and the third resistor R3, forming a voltage dividing point between them. The main control chip 500 reads the voltage value of the voltage dividing point through the chip feedback end 503, thereby determining the actual conduction state of the bidirectional thyristor. The main control chip 500 detects the conduction state of the bidirectional thyristor in real time through the chip feedback end 503, ensuring stable operation of the system. If an abnormal condition (such as a deviation of the conduction angle from the set value) is detected, the main control chip 500 will immediately adjust the control signal to restore the normal conduction state.

[0050] Optionally, in Figure 2 In an embodiment, the main control chip 500 further comprises a protection end 505 coupled to the switching element 400 via a protection circuit; the protection circuit comprises:

[0051] A fourth resistor R4, one end of the fourth resistor R4 is grounded, the other end of the fourth resistor R4 is coupled to the negative terminal 202 via a fifth resistor R5, and the fourth resistor R4 and the fifth resistor R5 lead to the protection end 505, the protection end 505 receives a level signal, and the main control chip 500 determines the on-off state of the switching element 400 based on whether the level signal is high or changes from high to low, so as to set the disconnected switching element 400 to be turned on.

[0052] Specifically, in some embodiments, the fourth resistor R4 and the fifth resistor R5 constitute a voltage dividing circuit for detecting the on-off state of the switch element 400. When the switch element 400 is turned on, the protection terminal 505 of the master control chip 500 is led out through the voltage dividing point between the fourth resistor R4 and the fifth resistor R5. When the plug is connected to the socket, the master control chip 500 detects the level signal through the protection terminal 505, and if a square wave signal is detected, it indicates that the switch is in the on state. At this time, the master control chip 500 sends a start signal to the speed regulation unit 300 through the chip control terminal 502 to ensure that the motor 100 will not start immediately, preventing accidental injury. Then, the master control chip 500 waits for the user to manually turn on the switch again to start the motor 100. If a low level or a high level that does not reach the preset voltage value is detected, it indicates that the switch is in the off state, and at this time the motor 100 is not allowed to start. Only when the master control chip 500 detects a high level signal above the preset voltage value, the motor 100 will start when the switch element 400 is turned on again. This ensures that in any case, the motor 100 will only start after confirming that the switch element 400 has been properly turned on, improving safety. The main function of the protection unit is to prevent the switch from being in the off state when the plug is connected, thereby avoiding the motor 100 from starting immediately and injuring people. By detecting the level signal, the master control chip 500 can intelligently determine the state of the switch element 400, ensuring that the motor 100 will not start immediately when the plug is inserted.

[0053] Optionally, in Figure 2 In an embodiment, the protection circuit further comprises:

[0054] A first capacitor C1 is connected in parallel with the fourth resistor R4 for filtering high-frequency noise.

[0055] Optionally, in Figure 2 In an embodiment, the power supply circuit 800 comprises at least one of the following elements:

[0056] A voltage stabilizing diode DW1 has its positive electrode coupled to the negative terminal 202 and its negative electrode coupled to the positive terminal 201.

[0057] An energy storage capacitor CV1 is connected in parallel with the voltage stabilizing diode DW1, and the positive electrode of the energy storage capacitor CV1 is coupled to the chip power supply terminal 504, and the negative electrode of the energy storage capacitor CV1 is grounded.

[0058] A first diode D1 has its positive electrode coupled to the negative electrode of the energy storage capacitor CV1, and its negative electrode is coupled to the negative terminal 202 via a sixth resistor R6.

[0059] Specifically, in some embodiments, the role of the voltage stabilizing diode DW1 is to maintain the power supply voltage within a stable range, preventing voltage fluctuations from affecting the normal operation of the master chip 500 and other circuit elements. The role of the first diode D1 is to prevent reverse current from flowing into the power supply interface 200, protecting the circuit from damage. The sixth resistor R6 is used to limit the current, ensuring the safe operation of the first diode D1. The energy storage capacitor CV1 is charged when the power supply voltage is stable, and discharged when the power supply voltage is temporarily reduced or power is off for a short time, ensuring that the master chip 500 receives continuous power supply. A second capacitor C2 is also provided in parallel with the voltage stabilizing diode DW1 for filtering.

[0060] Optionally, in Figure 2 In an embodiment, the master chip 500 further includes a current detection terminal 506, which is coupled to the speed regulation unit 300 via a current detection circuit, and the current detection circuit is coupled to a current sampling point between the positive terminal 201 and the first end of the motor 100.

[0061] Optionally, in Figure 2 In an embodiment, the current detection circuit includes a seventh resistor R7 and an eighth resistor R8.

[0062] One end of the seventh resistor R7 is coupled to the current detection terminal 506, and the other end of the seventh resistor R7 is coupled to the positive terminal 201 and one end of the eighth resistor R8 via the eighth resistor R8. The other end of the eighth resistor R8 is coupled to the first end of the motor 100 via the speed regulation unit 300.

[0063] Specifically, in some embodiments, when the motor 100 is running, the current flows through the path formed by the seventh resistor R7 and the eighth resistor R8. Since the voltage drop across the resistor is proportional to the current, the master chip 500 can calculate the current of the motor 100 by measuring the voltage difference across the seventh resistor R7. The master chip 500 monitors the current of the motor 100 in real time through the current detection terminal 506, ensuring that the motor 100 can operate stably under different load conditions. If an abnormal situation (such as excessive or insufficient current) is detected, the master chip 500 will take immediate measures, such as adjusting the conduction angle of the speed regulation unit 300 or triggering an alarm, to protect the motor 100 and the system from damage. A fourth capacitor C4 is also provided in parallel with the eighth resistor R8 for filtering.

[0064] In yet another embodiment of the present disclosure, a direct current brush motor device is provided, which includes the motor control circuit of any one of the above.

[0065] The above embodiments are only illustrative of the principles of the present disclosure and its effects, and are not intended to limit the present disclosure. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present disclosure shall be covered by the protection scope of the present disclosure.

Claims

1. A motor control circuit for controlling the speed of a motor, characterized in that, include: A power interface includes a positive terminal and a negative terminal; the positive terminal of the power interface is coupled to a first end of the motor via a speed regulation unit, and the negative terminal of the power interface is coupled to a second end of the motor via a switching element. The main control chip includes a chip adjustment terminal, a chip control terminal, a chip feedback terminal, and a chip power supply terminal. The chip adjustment terminal is coupled to an adjustment circuit and is used to receive the motor speed information output by the adjustment circuit. The chip control terminal is coupled to the control terminal of the speed adjustment unit via a first resistor and is used to control the on / off state of the speed adjustment unit according to the speed information. The chip feedback terminal is coupled to the other end of the speed adjustment unit via a feedback circuit and is used to detect the conduction state of the speed adjustment unit. The chip power supply terminal is coupled to a power supply circuit.

2. The motor control circuit according to claim 1, characterized in that, The regulating circuit includes: An adjustable resistor is provided, with one end of the adjustable resistor coupled to a reference power supply and the other end grounded. The adjustable end of the adjustable resistor is coupled to the adjustment terminal of the chip, and the adjustment terminal of the chip generates the rotation speed information based on the resistance value of the adjustable resistor.

3. The motor control circuit according to claim 1, characterized in that, The feedback circuit includes: The second resistor has one end coupled to the output terminal of the power supply circuit, and the other end coupled to the first terminal of the motor via a third resistor. The voltage divider point between the second resistor and the third resistor is led out to the feedback terminal of the chip.

4. The motor control circuit according to claim 1, characterized in that, The main control chip further includes a protection terminal, which is coupled to the switching element via a protection circuit; the protection circuit includes: A fourth resistor, one end of which is grounded, and the other end of which is coupled to the negative terminal via a fifth resistor. A protection terminal is led out between the fourth resistor and the fifth resistor. The protection terminal receives a level signal. The main control chip determines the on / off state of the switching element based on the level signal being high or changing between high and low levels, so as to set the off switching element to on.

5. The motor control circuit according to claim 4, characterized in that, The protection circuit also includes: The first capacitor is connected in parallel with the fourth resistor.

6. The motor control circuit according to claim 1, characterized in that, The power supply circuit includes at least one of the following components: A Zener diode, wherein the positive terminal of the Zener diode is coupled to the negative terminal, and the negative terminal of the Zener diode is coupled to the positive terminal; An energy storage capacitor is connected in parallel with the Zener diode. The positive terminal of the energy storage capacitor is coupled to the power supply terminal of the chip, and the negative terminal of the energy storage capacitor is grounded. A first diode, the positive terminal of which is coupled to the negative terminal of the energy storage capacitor, and the negative terminal of the first diode is coupled to the negative terminal via a sixth resistor.

7. The motor control circuit according to claim 1, characterized in that, The main control chip also includes a current detection terminal, which is coupled to the speed regulation unit via a current detection circuit. The current detection circuit is coupled to a current sampling point located between the positive terminal and the first terminal of the motor.

8. The motor control circuit according to claim 7, characterized in that, The current detection circuit includes: a seventh resistor and an eighth resistor; One end of the seventh resistor is coupled to the current detection terminal, and the other end of the seventh resistor is coupled to the positive terminal and one end of the eighth resistor via the eighth resistor. The other end of the eighth resistor is coupled to the first terminal of the motor via the speed adjustment unit.

9. The motor control circuit according to claim 1, characterized in that, The speed regulation unit includes a bidirectional thyristor.

10. A DC brushed motor device, characterized in that, Includes the motor control circuit as described in any one of claims 1-9.

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