Motor control circuit and overcurrent protection control method

Abstract

The invention belongs to the technical field of motor driving, and particularly relates to a motor control circuit and an overcurrent protection control method, and the motor control circuit comprises the components of a first control circuit of which the input end is connected with a first pin for receiving a first control signal and the output end is connected with a first electrode; the input end of the second control circuit is connected with the second pin for receiving a second control signal, and the output end of the second control circuit is connected with the second electrode; the overcurrent protection circuit is respectively connected with the first control circuit, the second control circuit and the motor driving chip; the first control circuit and the second control circuit can control forward rotation and reverse rotation of the motor according to the first control signal and the second control signal respectively; the overcurrent protection circuit can output a control signal to the motor driving chip when the motor is in a forward / reverse rotation state so as to control the working state of the motor according to the control signal. According to the scheme, the working state of the motor can be controlled according to the current in the forward / reverse rotation control circuit, motor overcurrent is avoided, and the motor is protected.

Description

Technical Field

[0001] The present application belongs to the field of motor drive technology, and specifically relates to a motor control circuit and an overcurrent protection control method. Background Art

[0002] At present, many motor application circuits directly use motor driver chips, such as A4950, DRV8870, DRV8872, AT8870, etc. The advantage of directly using motor driver chips is that it eliminates the trouble of developing motor drive circuits, such as overcurrent protection, undervoltage protection, short-circuit protection, and current limiting settings.

[0003] However, when these motor driver chips are used, the motor directly provides a control signal to control the motor's operation, but this circuit has disadvantages; for example, the motor can only rotate in a single direction, and no overcurrent protection circuit is set. When the motor current exceeds the limit, the motor driver chip cannot identify the fault in time, resulting in motor damage. Summary of the Invention

[0004] The purpose of this application is to provide a motor control circuit and an overcurrent protection control method, which can realize the forward and reverse rotation of the motor, and the motor driver chip can timely identify the current of the motor during forward and reverse rotation, and control the working state of the motor according to the motor current, which is safe and reliable as a whole.

[0005] In a first aspect, the present application provides a motor control circuit connected between a power supply pin of a motor driver chip and a motor, the motor control circuit comprising:

[0006] a first control circuit, wherein an input end of the first control circuit is connected to a first pin of the motor driving chip for receiving a first control signal, and an output end of the first control circuit is connected to a first electrode of the motor;

[0007] a second control circuit, wherein an input end of the second control circuit is connected to the second pin of the motor driving chip for receiving a second control signal, and an output end of the second control circuit is connected to the second electrode of the motor;

[0008] an overcurrent protection circuit, the overcurrent protection circuit being connected to the first control circuit, the second control circuit, and the motor drive chip respectively;

[0009] Wherein, the first control circuit and the second control circuit are capable of controlling the forward rotation and the reverse rotation of the motor according to the first control signal and the second control signal respectively;

[0010] The overcurrent protection circuit can output a control signal to the motor driving chip when the motor is in a forward rotation state / reverse rotation state, and the motor driving chip can control the working state of the motor according to the control signal.

[0011] In an exemplary embodiment of the present application, when the motor is in a forward rotation state: the first control signal is at a high level, and the second control signal is at a low level;

[0012] When the motor is in a reverse state: the first control signal is at a low level, and the second control signal is at a high level.

[0013] In an exemplary embodiment of the present application, the first control circuit and the second control circuit each include a first switch tube, a second switch tube, a first resistor, a third switch tube, a fourth switch tube, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a fifth switch tube, and a sixth switch tube;

[0014] The first switch tube, wherein the control end of the first switch tube is connected to the first pin / the second pin for receiving the first control signal / the second control signal, the first end of the first switch tube is connected to the control end of the second switch tube, and the second end of the first switch tube is grounded;

[0015] The second switch tube, wherein the first end of the second switch tube is connected to the first power signal, and the second end of the second switch tube is connected to the first end of the first resistor, the control end of the third switch tube, and the control end of the fourth switch tube;

[0016] the first resistor, wherein a second end of the first resistor is grounded;

[0017] the third switch tube, wherein a first end of the third switch tube is connected to the first end of the second resistor, and a second end of the third switch tube is grounded;

[0018] The second resistor, wherein the second end of the second resistor is connected to the first end of the third resistor and the control end of the fifth switch tube;

[0019] The third resistor, wherein the second end of the third resistor is connected to the second power signal and the first end of the fifth switch tube;

[0020] The fourth switch tube, wherein a first end of the fourth switch tube is connected to the third power signal, and a second end of the fourth switch tube is connected to the fourth resistor;

[0021] The fourth resistor, wherein the second end of the fourth resistor is connected to the control end of the sixth switch tube and the first end of the fifth resistor;

[0022] the fifth resistor, wherein the second end of the fifth resistor is connected to the first end of the sixth switch tube, the first end of the sixth resistor, and the overcurrent protection circuit;

[0023] the sixth resistor, wherein a second end of the sixth resistor is grounded;

[0024] The fifth switching tube, the second end of the fifth switching tube is connected to the second end of the sixth switching tube and the first electrode / the second electrode of the motor.

[0025] In an exemplary embodiment of the present application, when the motor is in the forward rotation state: the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the first control circuit are turned on, and the fourth switch tube and the sixth switch tube in the first control circuit are turned off; the fourth switch tube and the sixth switch tube in the second control circuit are turned on, and the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the second control circuit are turned off;

[0026] When the motor is in the reverse state: the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the first control circuit are turned off, and the fourth switch tube and the sixth switch tube in the first control circuit are turned on; the fourth switch tube and the sixth switch tube in the second control circuit are turned off, and the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the second control circuit are turned on.

[0027] In an exemplary embodiment of the present application, when the motor is in the forward rotation state, the first control circuit outputs a high-level signal to the first electrode of the motor, and the second control circuit outputs a low-level signal to the second electrode of the motor;

[0028] When the motor is in the reverse state, the first control circuit outputs a low-level signal to the first electrode of the motor, and the second control circuit outputs a high-level signal to the second electrode of the motor.

[0029] In an exemplary embodiment of the present application, the overcurrent protection circuit includes a comparator, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor;

[0030] a comparator, wherein a power input terminal of the comparator is connected to a fourth power signal, a first terminal of the seventh resistor, and a first terminal of the eighth resistor, and a power output terminal of the comparator is grounded; the comparator includes a first comparison module for detecting a current flowing through the sixth resistor in the first control circuit and a second comparison module for detecting a current flowing through the sixth resistor in the second control circuit;

[0031] The positive phase input terminal of the first comparison module is connected to the second end of the fifth resistor, the first end of the sixth switch tube and the first end of the sixth resistor in the first control circuit, the negative phase input terminal of the first comparison module is connected to the second end of the eighth resistor and the first end of the ninth resistor, the output terminal of the first comparison module is connected to the second end of the seventh resistor and the motor driving chip, and the second end of the ninth resistor is grounded;

[0032] The positive phase input terminal of the second comparison module is connected to the second end of the fifth resistor, the first end of the sixth switch tube and the first end of the sixth resistor in the second control circuit, the negative phase input terminal of the second comparison module is connected to the second end of the eleventh resistor and the first end of the twelfth resistor, the output terminal of the second comparison module is connected to the second end of the tenth resistor and the motor drive chip, the first end of the tenth resistor and the first end of the eleventh resistor are connected to the fifth power supply signal, and the second end of the twelfth resistor is grounded.

[0033] In an exemplary embodiment of the present application, the overcurrent protection circuit further includes a power supply circuit for powering the comparator, the power supply circuit including a thirteenth resistor, a first capacitor, and a second capacitor;

[0034] The first end of the thirteenth resistor is connected to the sixth power supply signal, the second end of the thirteenth resistor is connected to the seventh power supply signal, the first end of the first capacitor and the first end of the second capacitor, and the second end of the first capacitor and the second end of the second capacitor are both grounded.

[0035] In an exemplary embodiment of the present application, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all triodes, and the fifth switch tube and the sixth switch tube are both metal oxide semiconductor field effect transistors.

[0036] A second aspect of the present application provides an overcurrent protection control method, using any of the motor control circuits described above, the control method comprising:

[0037] Obtaining a current value flowing through the second control circuit / the first control circuit when the motor is in a forward rotation state / reverse rotation state;

[0038] Comparing the obtained current value with a preset current value, if the current value is less than or equal to the preset current value, outputting a low-level signal to the motor driver chip to drive the motor to operate normally; if the current value is greater than the preset current value, outputting a high-level signal to the motor driver chip, and obtaining a duration T1 of outputting the high-level signal to the motor driver chip;

[0039] Comparing the obtained duration T1 with the preset time T2;

[0040] If the duration T1 of outputting the high-level signal to the motor driver chip is less than or equal to the preset time T2, the motor operates normally; if the duration T1 of outputting the high-level signal to the motor driver chip is greater than the preset time T2, the motor stops operating.

[0041] In another exemplary embodiment of the present application, both the first control circuit and the second control circuit include a sixth resistor, and a control method for obtaining a current value flowing through the second control circuit / the first control circuit when the motor is in a forward rotation state / reverse rotation state includes:

[0042] Obtain a current value flowing through the sixth resistor in the second control circuit / the first control circuit when the motor is in a forward rotation state / reverse rotation state.

[0043] The present application includes a motor control circuit and an overcurrent protection control method, which have the following beneficial effects:

[0044] The first control signal and the second control signal are used to control the output levels of the first control circuit and the second control circuit, respectively, thereby controlling the motor to be in a forward rotation state or a reverse rotation state, so that the motor has two rotation directions and a variety of rotation directions. In addition, the motor control circuit also includes an overcurrent protection circuit. This overcurrent protection circuit can detect the current signal in the second control circuit or the current value in the first control circuit when the motor is in the forward rotation state or the reverse rotation state, respectively, and compare the current value with a preset current value. If the current value does not exceed the preset current value, it outputs a low-level signal to the motor driver chip, and the motor driver chip controls the motor to operate normally according to the low-level signal. If the current value exceeds the preset current value, it outputs a high-level signal to the motor driver chip and obtains the duration T1 of the overcurrent protection circuit outputting the high-level signal to the motor driver chip. If the duration T1 is less than or equal to the preset time T2, the motor driver chip controls the motor to rotate normally; if the duration T1 is greater than the preset time T2, the motor driver chip controls the motor to stop rotating. In other words, the motor driver chip can control the operating state of the motor according to the current value in the control circuit during forward rotation or reverse rotation, and can provide safe and reliable protection for the motor when the motor overcurrent occurs.

[0045] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0046] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0048] Figure 1 A circuit connection diagram of an electrode control circuit provided in an embodiment of the present application is shown.

[0049] Figure 2 A circuit connection diagram of the first control circuit provided in an embodiment of the present application is shown.

[0050] Figure 3 A circuit connection diagram of the second control circuit provided in an embodiment of the present application is shown.

[0051] Figure 4 A circuit connection diagram of an overcurrent protection circuit provided in an embodiment of the present application is shown.

[0052] Figure 5 A circuit connection diagram of a charging circuit of an overcurrent protection circuit provided in an embodiment of the present application is shown.

[0053] Figure 6 A flow chart of an overcurrent protection control method under forward rotation of a motor provided in an embodiment of the present application is shown.

[0054] Figure 7 A flow chart of the overcurrent protection control method under motor reversal provided in an embodiment of the present application is shown.

[0055] Description of reference numerals:

[0056] 100, motor control circuit; 110, first control circuit; 120, second control circuit;

[0057] 130, overcurrent protection circuit; 131, comparator; 131a, first comparison module; 131b, second comparison module; 132, seventh resistor; 133, eighth resistor; 134, ninth resistor; 135, tenth resistor; 136, eleventh resistor; 137, twelfth resistor; 138, power supply circuit; 1381, thirteenth resistor; 1382, first capacitor; 1383, second capacitor;

[0058] 141. First switching tube; 142. Second switching tube; 143. First resistor; 144. Third switching tube; 145. Fourth switching tube; 146. Second resistor; 147. Third resistor; 148. Fourth resistor; 149. Fifth resistor; 1410. Sixth resistor; 1411. Fifth switching tube; 1412. Sixth switching tube; D1. First control signal; D2. Second control signal; V1. First power signal; V2. Second power signal; V3. Third power signal; V4. Fourth power signal; V5. Fifth power signal; V6. Sixth power signal; V7. Seventh power signal; 210. First electrode; 220. Second electrode. DETAILED DESCRIPTION

[0059] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0060] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0061] In this application, unless otherwise specified or limited, terms such as "assembly" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0062] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0063] The present invention provides a motor control circuit 100, which can be used in products with DC motors, such as household washing machines and air conditioners. The motor control circuit 100 is connected between the power pins of a motor driver chip and the motor. The power pins of the motor driver chip output a control signal to the motor control circuit 100, which the motor receives to determine its operating state.

[0064] Among them, see Figure 1 As shown, the motor control circuit 100 includes a first control circuit 110, a second control circuit 120 and an overcurrent protection circuit 130. The first control signal D1 and the second control signal D2 respectively control the level signals output by the first control circuit 110 and the second control circuit 120 to achieve forward rotation and reverse rotation of the motor.

[0065] For example, see Figure 2 As shown, the input end of the first control circuit 110 is connected to the first pin of the motor driver chip for receiving the first control signal D1, that is, the motor driver chip outputs the first control signal D1 to the input end of the first control circuit 110 through the first pin, and the output end of the first control circuit 110 is connected to the first electrode 210 of the motor.

[0066] See also Figure 3 As shown, the input end of the second control circuit 120 is connected to the second pin of the motor driver chip for receiving the second control signal D2, that is, the motor driver chip outputs the second control signal D2 to the input end of the second control circuit 120 through the second pin, and the output end of the second control circuit 120 is connected to the second electrode 220 of the motor.

[0067] Among them, when the first control circuit 110 outputs a high-level signal to the first electrode 210 of the motor under the action of the first control signal D1, and the second control circuit 120 outputs a low-level signal to the second electrode 220 of the motor under the action of the second control signal D2, the motor is in the forward rotation state.

[0068] On the contrary, when the first control circuit 110 outputs a low-level signal to the first electrode 210 of the motor under the action of the first control signal D1, and the second control circuit 120 outputs a high-level signal to the second electrode 220 of the motor under the action of the second control signal D2, the motor is in a reverse state.

[0069] That is, the first control signal D1 and the second control signal D2 are used to control the level signals output by the first control circuit 110 and the second control circuit 120 respectively, so as to realize the forward and reverse rotation of the motor, ensuring that the motor no longer rotates in a single direction but in multiple directions.

[0070] See also Figure 1 As shown, the overcurrent protection circuit 130 is connected to the first control circuit 110, the second control circuit 120, and the motor driver chip, respectively. The overcurrent protection circuit 130 can output a control signal to the motor driver chip when the motor is in the forward rotation state or the reverse rotation state. This control signal can be a level signal described below. The motor driver chip controls the operating state of the motor based on the control signal (level signal) output by the overcurrent protection circuit 130.

[0071] For example, if the control signal (level signal) output by the overcurrent protection circuit 130 is a low-level signal, the motor driver chip controls the motor to rotate normally. If the control signal (level signal) output by the overcurrent protection circuit 130 is a high-level signal, the motor driver chip further obtains the time T1 during which the overcurrent protection circuit 130 transmits the high-level signal to the motor driver chip, and compares the obtained time T1 with the preset time T2. If the maintained time T1 is greater than the preset time T2, the motor driver chip controls the motor to stop rotating; if the maintained time T1 is less than or equal to the preset time T2, the motor driver chip controls the motor to rotate normally.

[0072] That is, the overcurrent protection circuit 130 can obtain the current in the first control circuit 110 / the second control circuit 120, and when the current exceeds the preset value, the motor driver chip immediately controls the motor to stop rotating, which is safe, reliable and versatile.

[0073] It is worth mentioning that in this application, the forward and reverse rotation of the motor can be controlled by controlling the first control circuit 110 and the second control circuit 120 respectively through two pins on the motor driver chip, reducing the space occupied by the control circuit on the chip and saving chip resources.

[0074] In the examples of this application, see Figure 1 and Figure 2As shown, the first control circuit 110 includes a first switch tube 141, a second switch tube 142, a first resistor 143, a third switch tube 144, a fourth switch tube 145, a second resistor 146, a third resistor 147, a fourth resistor 148, a fifth resistor 149 and a sixth resistor 1410, a fifth switch tube 1411 and a sixth switch tube 1412.

[0075] The first switch tube 141 has a control end connected to the first pin of the motor driver chip for receiving a first control signal D1 . The first end of the first switch tube 141 is connected to the control end of the second switch tube 142 , and the second end of the first switch tube 141 is grounded.

[0076] The second switch tube 142 has a first end connected to the first power signal V1 , and a second end connected to the first end of the first resistor 143 , the control end of the third switch tube 144 , and the control end of the fourth switch tube 145 .

[0077] The first resistor 143 has a second end connected to the ground.

[0078] The third switch tube 144 has a first end connected to the first end of the second resistor 146 , and a second end of the third switch tube 144 is grounded.

[0079] The second resistor 146 has a second end connected to the first end of the third resistor 147 and the control end of the fifth switch tube 1411 .

[0080] The third resistor 147 has a second end connected to the second power signal V2 and a first end of the fifth switch 1411 .

[0081] The fourth switch tube 145 has a first terminal connected to the third power signal V3 , and a second terminal connected to the fourth resistor 148 .

[0082] The fourth resistor 148 has a second end connected to the control end of the sixth switch tube 1412 and a first end of the fifth resistor 149 .

[0083] The fifth resistor 149 has a second end connected to the first end of the sixth switch tube 1412 , the first end of the sixth resistor 1410 , and the overcurrent protection circuit 130 .

[0084] The sixth resistor 1410 has a second end connected to the ground.

[0085] The fifth switching tube 1411 has a second end connected to the second end of the sixth switching tube 1412 and the first electrode 210 of the motor.

[0086] It is worth mentioning that in the embodiments of the present application, Figure 3 As shown, the second control circuit 120 employs the same circuit structure as the first control circuit 110; that is, the second control circuit 120 also includes a first switch 141, a second switch 142, a first resistor 143, a third switch 144, a fourth switch 145, a second resistor 146, a third resistor 147, a fourth resistor 148, a fifth resistor 149, a sixth resistor 1410, a fifth switch 1411, and a sixth switch 1412. The control terminal of the first switch 141 receives the second control signal D2. The circuit connections between the switches and resistors in the second control circuit 120 are the same as those in the first control circuit 110 and will not be further described here. The second control circuit 120 outputs a level signal to the second electrode 220 of the motor.

[0087] Among them, the first switch tube 141 and the third switch tube 144 in the first control circuit 110 and the second control circuit 120 are both NPN-type transistors, that is, their collectors and emitters are both N-type semiconductors, and their bases are P-type semiconductors; the second switch tube 142 and the fourth switch tube 145 in the first control circuit 110 and the second control circuit 120 are both PNP-type transistors, that is, their collectors and emitters are both P-type semiconductors, and their bases are N-type semiconductors.

[0088] Each of the first switching transistor 141, the second switching transistor 142, the third switching transistor 144, and the fourth switching transistor 145 includes two voltage-dividing resistors. The resistance values of these two voltage-dividing resistors can be 10kΩ and 4kΩ, respectively. One end of the 10kΩ resistor is connected to the emitter and the other end is connected to the base; one end of the 4kΩ resistor is connected to the 10kΩ resistor and the base. Of course, these voltage-dividing resistors can also use resistors of other resistance values.

[0089] Furthermore, the fifth and sixth switching transistors 1411 and 1412 in the first and second control circuits 110 and 120 can be high-current metal-oxide-semiconductor field-effect transistors (MOS) or relays. This is because the DC motor's initial startup current is very high. Using ordinary transistors to control the motor's power supply could easily damage the transistors. Therefore, high-current MOS transistors or relays are used to protect the motor control circuit 100.

[0090] In the embodiment of the present application, the first power signal V1, the second power signal V2 and the third power signal V3 can be powered by a 12V power supply, or can be powered by a power supply with other voltage values.

[0091] In the embodiment of the present application, when the motor is in the forward rotation state, the first control signal D1 outputs a high-level signal and the second control signal D2 outputs a low-level signal; at this time, the first switch tube 141, the second switch tube 142, the third switch tube 144, and the fifth switch tube 1411 in the first control circuit 110 are turned on, and the fourth switch tube 145 and the sixth switch tube 1412 in the first control circuit 110 are turned off. The first control signal D1 is transmitted to the first electrode 210 of the motor through the first switch tube 141, the second switch tube 142, the third switch tube 144, and the fifth switch tube 1411, and the first electrode 210 is a high-level signal; the fourth switch tube 145 and the sixth switch tube 1412 in the second control circuit 120 are turned on, and the first switch tube 141, the second switch tube 142, the third switch tube 144, and the fifth switch tube 1411 in the second control circuit 120 are turned off, and the second electrode 220 is a low-level signal.

[0092] When the motor is in the reverse state, the first control signal D1 outputs a low-level signal and the second control signal D2 outputs a high-level signal. At this time, the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the first control circuit 110 are turned off, the fourth switch 145 and the sixth switch 1412 in the first control circuit 110 are turned on, and the first electrode 210 is a low-level signal. The fourth switch 145 and the sixth switch 1412 in the second control circuit 120 are turned off, and the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the second control circuit 120 are turned on. The second control signal D2 is transmitted to the second electrode 220 of the motor through the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411, and the second electrode 220 is a high-level signal.

[0093] Among them, the first resistor 143 in the first control circuit 110 and the second control circuit 120 can control only one of the third switch tube 144 and the fourth switch tube 145 to be turned on, and the other is in the off state, so as to avoid the short circuit problem between the first control circuit 110 and the second control circuit 120; wherein, the resistance value of this first resistor 143 can be selected according to the specific embodiment.

[0094] It is worth mentioning that the first end of the fourth switch tube 145 is connected to the second power signal V2, and the second power signal V2 passes through the two voltage divider resistors in the fourth transistor and then passes through the first resistor 143 to be grounded, thereby realizing the conduction of the fourth switch tube 145.

[0095] Furthermore, when the motor is in the forward rotation state, the first control circuit 110 transmits a high-level signal to the first electrode 210 of the motor, and the second control circuit 120 transmits a low-level signal to the second electrode 220 of the motor. When the motor is in the reverse rotation state, the first control circuit 110 transmits a low-level signal to the first electrode 210 of the motor, and the second control circuit 120 transmits a high-level signal to the second electrode 220 of the motor. This achieves forward and reverse rotation of the motor and prevents the motor from rotating in a single direction.

[0096] For further information, see Figure 4 As shown, the overcurrent protection circuit 130 includes a comparator 131 , a seventh resistor 132 , an eighth resistor 133 , a ninth resistor 134 , a tenth resistor 135 , an eleventh resistor 136 and a twelfth resistor 137 ;

[0097] The power input terminal of the comparator 131 is connected to the fourth power signal V4, the first end of the seventh resistor 132, and the first end of the eighth resistor 133, and the power output terminal of the comparator 131 is grounded. The comparator 131 includes a first comparison module 131a for detecting the current flowing through the sixth resistor 1410 in the first control circuit 110 and a second comparison module 131b for detecting the current flowing through the sixth resistor 1410 in the second control circuit 120. The first comparison module 131a and the second comparison module 131b are capable of comparing the acquired current value with a preset current value and outputting the comparison result to the motor driver chip. The motor driver chip controls the operating state of the motor based on the comparison result.

[0098] like Figure 4 As shown, the first comparison module 131a includes a positive phase input terminal (+), a negative phase input terminal (-), and an output terminal. The positive phase input terminal of the first comparison module 131a is connected to the second end of the fifth resistor 149, the first end of the sixth switch tube 1412, and the first end of the sixth resistor 1410 in the first control circuit 110, and is used to obtain the current value I1 flowing through the sixth resistor 1410; the negative phase input terminal of the first comparison module 131a is connected to the second end of the eighth resistor 133 and the first end of the ninth resistor 134 to input a preset current value I; the output terminal of the first comparison module 131a is connected to the second end of the seventh resistor 132 and the motor driver chip to transmit the signal after comparing the current value I1 with the preset current value I to the motor driver chip. The motor driver chip controls the operating state of the motor according to the signal output by the first comparison module 131a. In addition, the second end of the ninth resistor 134 is grounded.

[0099] Please continue to see Figure 4As shown, the second comparison module 131b also includes a positive input terminal (+), a negative input terminal (-), and an output terminal. The positive input terminal of the second comparison module 131b is connected to the second terminal of the fifth resistor 149, the first terminal of the sixth switch tube 1412, and the first terminal of the sixth resistor 1410 in the second control circuit 120, and is used to obtain the current value I2 flowing through the sixth resistor 1410. The negative input terminal of the second comparison module 131b is connected to the second terminal of the eleventh resistor 136 and the first terminal of the twelfth resistor 137 to input a preset current value I. The output terminal of the second comparison module 131b is connected to the second terminal of the tenth resistor 135 and the motor driver chip to transmit the signal after comparing the current value I2 with the preset current value I to the motor driver chip. The motor driver chip controls the operating state of the motor according to the signal output by the first comparison module 131a. The first terminal of the tenth resistor 135 and the first terminal of the eleventh resistor 136 are connected to the fifth power signal V5, and the second terminal of the twelfth resistor 137 is grounded.

[0100] It should be noted that the preset current value I in the first control circuit 110 can be adjusted by adjusting the resistance values of the eighth resistor 133 and the ninth resistor 134; and the preset current value I in the second control circuit 120 can be adjusted by adjusting the resistance values of the eleventh resistor 136 and the twelfth resistor 137.

[0101] In the examples of this application, see Figure 5 As shown, the comparator 131 further includes a power supply circuit 138, which includes a thirteenth resistor 1381, a first capacitor 1382, and a second capacitor 1383; the first end of the thirteenth resistor 1381 is connected to the sixth power supply signal V6, the second end of the thirteenth resistor 1381 is connected to the seventh power supply signal V7, the first end of the first capacitor 1382, and the first end of the second capacitor 1383, and the second end of the first capacitor 1382 and the second end of the second capacitor 1383 are both grounded.

[0102] The sixth power signal V6 may be a 5V voltage.

[0103] It should be noted that the working principle of the overcurrent protection circuit 130 is as follows:

[0104] When the motor is in the forward rotation state, the first control signal D1 and the second control signal D2 are high-level and low-level signals, respectively, and are transmitted to the first control circuit 110 and the second control circuit 120, respectively, to control the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the first control circuit 110 to be turned on, and the fourth switch 145 and the sixth switch 1412 in the first control circuit 110 to be turned off. The fourth switch 145 and the sixth switch 1412 in the second control circuit 120 are controlled to be turned on, and the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the second control circuit 120 to be turned off. At this time, the non-inverting input terminal of the second comparison module 131b in the overcurrent protection circuit 130 obtains the current value I2 of the sixth resistor 1410 in the second control circuit 120, compares the obtained current value I2 with the preset current value I, obtains a comparison signal, and transmits the comparison signal to the motor driver chip. If the comparison signal is a low-level signal, the motor driver chip controls the normal operation of the motor; if the comparison signal is a high-level signal, the motor driver chip obtains the time T1 for the second comparison module 131b to transmit the high-level signal to it, and compares the time T1 for the second comparison module 131b to transmit the high-level signal to the motor driver chip with the preset time T2 in the motor driver chip. If the time T1 is less than or equal to the preset time T2, the motor driver chip controls the normal operation of the motor; if the time T1 is greater than the preset time T2, the motor driver chip controls the motor to stop rotating.

[0105] Accordingly, when the motor is in the reverse state, the first control signal D1 and the second control signal D2 are low-level and high-level signals, respectively, which are transmitted to the first control circuit 110 and the second control circuit 120, respectively, to control the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the first control circuit 110 to be turned off, and the fourth switch 145 and the sixth switch 1412 in the first control circuit 110 to be turned on. The fourth switch 145 and the sixth switch 1412 in the second control circuit 120 are controlled to be turned off, and the first switch 141, the second switch 142, the third switch 144, and the fifth switch 1411 in the second control circuit 120 to be turned on. At this time, the positive input terminal of the first comparison module 131a in the overcurrent protection circuit 130 obtains the current value I1 of the sixth resistor 1410 in the first control circuit 110, compares the obtained current value I1 with the preset current value I, obtains a comparison signal, and transmits the comparison signal to the motor driver chip. If the comparison signal is a low-level signal, the motor driver chip controls the normal operation of the motor; if the comparison signal is a high-level signal, the motor driver chip obtains the time T1 for which the first comparison module 131a transmits the high level to it, and compares the time T1 for the first comparison module 131a to transmit the high level to the motor driver chip with the preset time T2 in the motor driver chip. If the time T1 is less than or equal to the preset time T2, the motor driver chip controls the normal operation of the motor; if the time T1 is greater than the preset time T2, the motor driver chip controls the motor to stop rotating.

[0106] The embodiment of the present application also provides an overcurrent protection control method, which uses any of the above motor control circuits 100, such as Figure 6 and Figure 7 As shown, this overcurrent protection control method includes:

[0107] Step S100 , obtaining the current value flowing through the second control circuit 120 / the first control circuit 110 when the motor is in a forward rotation state / a reverse rotation state.

[0108] When the motor is in the forward rotation state, the non-inverting input terminal of the second comparison module 131b obtains the current value I2 flowing through the sixth resistor 1410 in the second control circuit 120. When the motor is in the reverse rotation state, the non-inverting input terminal of the first comparison module 131a obtains the current value I1 flowing through the sixth resistor 1410 in the first control circuit 110.

[0109] Step S200: comparing the acquired current value with a preset current value.

[0110] When the motor is in forward rotation, the current value I2 obtained by the positive phase input terminal of the second comparison module 131b is compared with the preset current value I at the negative phase input terminal of the second comparison module 131b. If the current value I2 obtained by the positive phase input terminal is less than or equal to the preset current value I at the negative phase input terminal, the output terminal of the second comparison module 131b outputs a low-level signal to the motor driver chip to control the normal operation of the motor. If the current value I2 obtained by the positive phase input terminal is greater than the preset current value I at the negative phase input terminal, the output terminal of the second comparison module 131b outputs a high-level signal to the motor driver chip.

[0111] When the motor is in reverse rotation, the current value I1 obtained at the positive phase input terminal of the first comparison module 131a is compared with the preset current value I at the negative phase input terminal of the first comparison module 131a. If the current value I1 obtained at the positive phase input terminal is less than or equal to the preset current value I at the negative phase input terminal, the output terminal of the first comparison module 131a outputs a low-level signal to the motor driver chip to control the normal operation of the motor. If the current value I1 obtained at the positive phase input terminal is greater than the preset current value I at the negative phase input terminal, the output terminal of the first comparison module 131a outputs a high-level signal to the motor driver chip.

[0112] Step S300 : When outputting a high-level signal to the motor driver chip, obtaining a duration T1 of outputting the high-level signal to the motor driver chip.

[0113] When the motor is in forward rotation, the motor driving chip automatically obtains the duration T1 of the high level signal output by the second comparison module 131 b to the motor driving chip.

[0114] When the motor is in reverse rotation, the motor driving chip automatically obtains the duration T1 of the high level signal output by the first comparison module 131 a to the motor driving chip.

[0115] Step S400: Compare the acquired duration T1 with the preset time T2.

[0116] When the motor is in forward rotation, if the duration T1 of the high-level signal output by the second comparison module 131b to the motor driver chip is less than or equal to the preset time T2, the motor driver chip controls the motor to operate normally. If the duration T1 of the high-level signal output by the second comparison module 131b to the motor driver chip is greater than the preset time T2, the motor driver chip controls the motor to stop rotating.

[0117] When the motor is in reverse rotation, if the duration T1 of the high-level signal output by the first comparison module 131a to the motor driver chip is less than or equal to the preset time T2, the motor driver chip controls the motor to operate normally. If the duration T1 of the high-level signal output by the first comparison module 131a to the motor driver chip is greater than the preset time T2, the motor driver chip controls the motor to stop rotating.

[0118] That is to say, through this overcurrent protection control method, when the motor driver chip identifies that the current in the motor control circuit 100 exceeds the limit, it can promptly control the motor to stop rotating and protect the motor. It has safer and more reliable properties and is highly versatile.

[0119] In the description of this specification, the reference terms "some embodiments", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0120] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent application.

Claims

1. A motor control circuit, characterized in that: Connected between the power supply pin of the motor driver chip and the motor, the motor control circuit includes: a first control circuit, wherein an input end of the first control circuit is connected to a first pin of the motor driving chip for receiving a first control signal, and an output end of the first control circuit is connected to a first electrode of the motor; a second control circuit, wherein an input end of the second control circuit is connected to the second pin of the motor driving chip for receiving a second control signal, and an output end of the second control circuit is connected to the second electrode of the motor; an overcurrent protection circuit, the overcurrent protection circuit being connected to the first control circuit, the second control circuit, and the motor drive chip respectively; Wherein, the first control circuit and the second control circuit are capable of controlling the forward rotation and the reverse rotation of the motor according to the first control signal and the second control signal respectively; The overcurrent protection circuit can output a control signal to the motor driving chip when the motor is in a forward rotation state / reverse rotation state, and the motor driving chip can control the working state of the motor according to the control signal.

2. The motor control circuit according to claim 1, wherein: When the motor is in a forward rotation state: the first control signal is at a high level, and the second control signal is at a low level; When the motor is in a reverse state: the first control signal is at a low level, and the second control signal is at a high level.

3. The motor control circuit according to claim 2, wherein: The first control circuit and the second control circuit each include a first switching tube, a second switching tube, a first resistor, a third switching tube, a fourth switching tube, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a fifth switching tube, and a sixth switching tube; The first switch tube, wherein the control end of the first switch tube is connected to the first pin / the second pin for receiving the first control signal / the second control signal, the first end of the first switch tube is connected to the control end of the second switch tube, and the second end of the first switch tube is grounded; The second switch tube, wherein the first end of the second switch tube is connected to the first power signal, and the second end of the second switch tube is connected to the first end of the first resistor, the control end of the third switch tube, and the control end of the fourth switch tube; the first resistor, wherein a second end of the first resistor is grounded; the third switch tube, wherein a first end of the third switch tube is connected to the first end of the second resistor, and a second end of the third switch tube is grounded; The second resistor, wherein the second end of the second resistor is connected to the first end of the third resistor and the control end of the fifth switch tube; The third resistor, wherein the second end of the third resistor is connected to the second power signal and the first end of the fifth switch tube; The fourth switch tube, wherein a first end of the fourth switch tube is connected to the third power signal, and a second end of the fourth switch tube is connected to the fourth resistor; The fourth resistor, wherein the second end of the fourth resistor is connected to the control end of the sixth switch tube and the first end of the fifth resistor; the fifth resistor, wherein the second end of the fifth resistor is connected to the first end of the sixth switch tube, the first end of the sixth resistor, and the overcurrent protection circuit; the sixth resistor, wherein a second end of the sixth resistor is grounded; The fifth switching tube, wherein the second end of the fifth switching tube is connected to the second end of the sixth switching tube and the first electrode / the second electrode of the motor.

4. The motor control circuit according to claim 3, characterized in that: When the motor is in the forward rotation state: the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the first control circuit are turned on, and the fourth switch tube and the sixth switch tube in the first control circuit are turned off; the fourth switch tube and the sixth switch tube in the second control circuit are turned on, and the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the second control circuit are turned off; When the motor is in the reverse state: the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the first control circuit are turned off, and the fourth switch tube and the sixth switch tube in the first control circuit are turned on; the fourth switch tube and the sixth switch tube in the second control circuit are turned off, and the first switch tube, the second switch tube, the third switch tube, and the fifth switch tube in the second control circuit are turned on.

5. The motor control circuit according to claim 3 or 4, characterized in that: When the motor is in the forward rotation state, the first control circuit outputs a high-level signal to the first electrode of the motor, and the second control circuit outputs a low-level signal to the second electrode of the motor; When the motor is in the reverse state, the first control circuit outputs a low-level signal to the first electrode of the motor, and the second control circuit outputs a high-level signal to the second electrode of the motor.

6. The motor control circuit according to claim 3, characterized in that: The overcurrent protection circuit includes a comparator, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor; a comparator, wherein a power input terminal of the comparator is connected to a fourth power signal, a first terminal of the seventh resistor, and a first terminal of the eighth resistor, and a power output terminal of the comparator is grounded; the comparator includes a first comparison module for detecting a current flowing through the sixth resistor in the first control circuit and a second comparison module for detecting a current flowing through the sixth resistor in the second control circuit; The positive phase input terminal of the first comparison module is connected to the second end of the fifth resistor, the first end of the sixth switch tube and the first end of the sixth resistor in the first control circuit, the negative phase input terminal of the first comparison module is connected to the second end of the eighth resistor and the first end of the ninth resistor, the output terminal of the first comparison module is connected to the second end of the seventh resistor and the motor driving chip, and the second end of the ninth resistor is grounded; The positive phase input terminal of the second comparison module is connected to the second end of the fifth resistor, the first end of the sixth switch tube and the first end of the sixth resistor in the second control circuit, the negative phase input terminal of the second comparison module is connected to the second end of the eleventh resistor and the first end of the twelfth resistor, the output terminal of the second comparison module is connected to the second end of the tenth resistor and the motor drive chip, the first end of the tenth resistor and the first end of the eleventh resistor are connected to the fifth power supply signal, and the second end of the twelfth resistor is grounded.

7. The motor control circuit according to claim 6, characterized in that: The overcurrent protection circuit further includes a power supply circuit for supplying power to the comparator, the power supply circuit including a thirteenth resistor, a first capacitor and a second capacitor; The first end of the thirteenth resistor is connected to the sixth power supply signal, the second end of the thirteenth resistor is connected to the seventh power supply signal, the first end of the first capacitor and the first end of the second capacitor, and the second end of the first capacitor and the second end of the second capacitor are both grounded.

8. The motor control circuit according to claim 3, wherein: The first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all triodes, and the fifth switch tube and the sixth switch tube are both metal oxide semiconductor field effect transistors.

9. An overcurrent protection control method, characterized in that: Using the motor control circuit according to any one of claims 1 to 8, the control method includes: Obtaining a current value flowing through the second control circuit / the first control circuit when the motor is in a forward rotation state / reverse rotation state; Comparing the obtained current value with a preset current value, if the current value is less than or equal to the preset current value, outputting a low-level signal to the motor driver chip to drive the motor to operate normally; if the current value is greater than the preset current value, outputting a high-level signal to the motor driver chip, and obtaining a duration T1 of outputting the high-level signal to the motor driver chip; Comparing the obtained duration T1 with the preset time T2; If the duration T1 of outputting the high-level signal to the motor driver chip is less than or equal to the preset time T2, the motor operates normally; if the duration T1 of outputting the high-level signal to the motor driver chip is greater than the preset time T2, the motor stops operating.

10. The overcurrent protection control method according to claim 9, characterized in that: The first control circuit and the second control circuit both include a sixth resistor, and the control method for obtaining the current value flowing through the second control circuit / the first control circuit when the motor is in a forward rotation state / a reverse rotation state includes: Obtain a current value flowing through the sixth resistor in the second control circuit / the first control circuit when the motor is in a forward rotation state / reverse rotation state.

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