Overcurrent protection devices, drive control circuits and motor components

Abstract

The embodiment of the present invention provides an overcurrent protection device, a drive control circuit and a motor assembly, wherein the overcurrent protection device includes: a sampling circuit for connecting the positive pole of a power supply and a drive circuit; a mirror current source circuit connected to the sampling circuit; a detection circuit connected to the mirror current source circuit, and the mirror current source circuit can control whether the detection circuit is turned on according to the sampling value of the sampling circuit; and a control circuit connected to the detection circuit; wherein, when the detection circuit is turned on, the detection circuit sends a conduction signal to the control circuit, so that the control circuit sends an overcurrent warning signal according to the conduction signal. A smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor. The volume of the sampling resistor can also be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of overcurrent protection, and in particular, to an overcurrent protection device, a drive control circuit, and a motor assembly. Background Art

[0002] At present, overcurrent detection circuits are generally used in power device protection for motor drives, overcurrent protection for switching power supplies, battery power management, etc. The purpose is to prevent power devices from failing due to thermal breakdown caused by large currents, thereby cutting off abnormally large current conduction circuits and protecting power devices.

[0003] An economical and low-cost current detection method generally uses the voltage generated by the current flowing through the resistor to detect the current. In the related technology, the resistor is placed between the drive circuit and the ground. This method is called low-end current detection.

[0004] However, if there is a problem with the motor winding and leakage occurs, the current flowing from the positive end of the power supply may flow directly back to GND without passing through the current sampling resistor, which may cause overcurrent but not be detected. Moreover, if the current sampling resistor fails or burns out, the voltage at the positive end of the power supply will be directly applied to the overcurrent detection circuit and the drive circuit of the power tube, causing large-scale burning of electronic components at the control end.

[0005] In addition, if a relatively large current is to be detected, a resistor with a relatively large rated power is required, which causes greater heat generation and occupies a larger area of ​​the PCB board. Summary of the invention

[0006] The embodiments of the present invention are intended to solve at least one of the technical problems existing in the prior art.

[0007] To this end, a first aspect of an embodiment of the present invention provides an overcurrent protection device.

[0008] A second aspect of an embodiment of the present invention provides a drive control circuit.

[0009] A third aspect of an embodiment of the present invention provides a motor assembly.

[0010] In view of this, according to the first aspect of an embodiment of the present invention, an overcurrent protection device is provided, the overcurrent protection device comprising: a sampling circuit, used to connect the positive pole of a power supply and a driving circuit; a mirror current source circuit, connected to the sampling circuit; a detection circuit, connected to the mirror current source circuit, the mirror current source circuit can control whether the detection circuit is turned on according to the sampling value of the sampling circuit; a control circuit, connected to the detection circuit; wherein, when the detection circuit is turned on, the detection circuit sends a conduction signal to the control circuit, so that the control circuit sends an overcurrent warning signal according to the conduction signal.

[0011] The overcurrent protection device provided by the embodiment of the present invention includes a sampling circuit, a mirror current source circuit, a detection circuit and a control circuit. Specifically, the sampling circuit is connected to the positive electrode of the power supply and the drive circuit, the mirror current source circuit is connected to the sampling circuit, the detection circuit is connected to the mirror current source circuit, and the control circuit is connected to the detection circuit. That is to say, the overcurrent protection device is arranged between the positive electrode of the power supply and the drive circuit, that is, high-end current detection.

[0012] By setting the overcurrent protection device between the positive pole of the power supply and the drive circuit, compared with the related art in which the overcurrent detection circuit is set between the drive circuit and the ground, because the total current flows out from the positive pole of the power supply, there will be no shunt situation that exists in low-end current detection, ensuring effective detection of large currents and improving the accuracy of current detection.

[0013] In addition, since the overcurrent protection device itself can withstand the high-end common-mode voltage, even if the sampling resistor of the sampling circuit fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device prevents large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit with the overcurrent protection device and extends the service life of each power device in the drive circuit.

[0014] The mirror current source circuit can control whether the detection circuit is turned on according to the sampling value of the sampling circuit. For example, when the sampling value of the sampling circuit is less than the preset sampling value, that is, a smaller current flows out from the positive pole of the power supply, the mirror current source circuit generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit cannot be turned on, and the detection module of the detection circuit cannot detect the voltage signal or current signal.

[0015] When the sampling value of the sampling circuit is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the drive circuit, the container causes the power device on the drive circuit to undergo thermal breakdown and fail. The mirror current source circuit generates a large voltage difference. The large voltage difference can turn on the detection circuit, so that the detection module can detect the voltage signal or current signal and send a conduction signal to the control circuit. The control circuit sends an overcurrent warning signal according to the conduction signal, thereby cutting off the drive signal, that is, no current flows into the drive circuit, and the power device on the drive circuit is prevented from burning.

[0016] In addition, by controlling the conduction state of the detection circuit through a mirror current source circuit, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0017] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0018] In practical applications, the sampling circuit includes a sampling resistor, the mirror current source circuit includes two PNP transistors with the same parameters, and the bases of the two transistors are connected. The detection circuit includes a PNP transistor, that is, the conduction state of the PVP transistor is controlled by the mirror current source circuit.

[0019] In addition, the overcurrent protection device provided according to the above technical solution of the present invention also has the following additional technical features:

[0020] In a possible technical solution, when the sampling value is less than a preset sampling value, the mirror current source circuit outputs a first voltage difference to cut off the detection circuit; when the sampling value is greater than or equal to the preset sampling value, the mirror current source circuit outputs a second voltage difference to turn on the detection circuit; wherein the first voltage difference is less than the second voltage difference.

[0021] In this technical solution, when the sampling value of the sampling circuit is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the mirror current source circuit generates a first voltage difference, wherein the first voltage difference is small, or the first voltage difference is zero, so that the detection circuit cannot be turned on, and the detection module of the detection circuit cannot detect the voltage signal or the current signal.

[0022] When the sampling value of the sampling circuit is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the driving circuit, the container causes the power device on the driving circuit to undergo thermal breakdown and fail, and the mirror current source circuit generates a second voltage difference, wherein the second voltage difference is greater than the first voltage difference. The larger second voltage difference can turn on the detection circuit, so that the detection module can detect the voltage signal or the current signal and send a conduction signal to the control circuit. The control circuit sends an overcurrent warning signal according to the conduction signal, thereby cutting off the driving signal, that is, no current flows into the driving circuit, thereby preventing the power device on the driving circuit from burning out.

[0023] In addition, by controlling the conduction state of the detection circuit through a mirror current source circuit, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0024] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0025] In a possible technical solution, the sampling circuit includes a sampling resistor, and the sampling resistor is used to connect the positive electrode of the power supply and the driving circuit.

[0026] In this technical solution, the sampling circuit includes a sampling resistor, that is, the voltage generated by the current flowing through the sampling resistor is used to detect the current. Furthermore, the sampling resistor is connected between the positive electrode of the power supply and the drive circuit. Compared with the related art in which the resistor is set between the drive circuit and the ground, because the total current flows out from the positive electrode of the power supply, there will be no shunt situation that exists in low-end current detection, ensuring effective detection of large currents and improving the accuracy of current detection.

[0027] In addition, since the overcurrent protection device itself can withstand the high-end common-mode voltage, even if the sampling resistor fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device prevents large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit with the overcurrent protection device and extends the service life of each power device in the drive circuit.

[0028] In a possible technical solution, the mirror current source circuit includes a first branch and a second branch, wherein the first branch is connected to the positive pole of the power supply and the sampling resistor, the first branch is provided with a first switch element, the second branch is connected to the sampling resistor and the driving circuit, and is connected in parallel with the first branch, the second branch is provided with a second switch element, the second switch element is connected to the first switch element, and the detection circuit is connected to the first branch and the second branch.

[0029] In this technical solution, it is defined that the mirror current source circuit includes two parallel first branches and second branches, the first branch is connected to the positive pole of the power supply and the sampling resistor, the second branch is connected to the sampling resistor and the driving circuit, and a first switch element is provided on the first branch, a second switch element is provided on the second branch, the first switch element is connected to the second switch element, and the detection circuit is connected to the first branch and the second branch.

[0030] It can be understood that when the sampling value of the sampling circuit is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the first switch element and the second switch element are closed, so that the mirror current source circuit produces a smaller voltage difference, or the voltage difference produced is zero, so that the detection circuit cannot be turned on, and the detection module of the detection circuit cannot detect the voltage signal or the current signal.

[0031] When the sampling value of the sampling circuit is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the drive circuit, the container causes the power device on the drive circuit to undergo thermal breakdown and fail. At this time, the first switch is closed and the second switch is disconnected, so that the mirror current source circuit produces a large voltage difference. The large voltage difference can turn on the detection circuit, so that the detection module can detect the voltage signal or current signal and send a conduction signal to the control circuit. The control circuit sends an over-current warning signal according to the conduction signal, thereby cutting off the drive signal, that is, no current flows into the drive circuit, thereby preventing the power device on the drive circuit from burning.

[0032] In addition, by controlling the conduction state of the detection circuit through a mirror current source circuit, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0033] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0034] In practical applications, the first switch element and the second switch element are two PNP transistors with the same parameters, and the bases of the two PNP transistors are connected to form a mirror current source circuit.

[0035] In a possible technical solution, the mirror current source circuit also includes a first resistor and a second resistor, wherein the first resistor is arranged on the first branch and connected to the first switch element, and the second resistor is arranged on the second branch and connected to the second switch element; the resistance value of the first resistor is the same as the resistance value of the second resistor.

[0036] In this technical solution, it is defined that the mirror current source circuit also includes a first resistor and a second resistor, the first resistor is arranged on the first branch, and the second resistor is arranged on the second branch. By respectively arranging resistors on the two branches, a current limiting function can be achieved, thereby improving the anti-interference ability of the overcurrent protection device.

[0037] The resistance value of the first resistor is the same as the resistance value of the second resistor, so that the mirror current source circuit can accurately control the on-off of the detection circuit to achieve large current detection.

[0038] In a possible technical solution, the mirror current source circuit also includes a third resistor and a fourth resistor, wherein the third resistor is arranged on the first branch, the third resistor is connected to the positive pole of the power supply and the first switch element, and the fourth resistor is arranged on the second branch, the fourth resistor is connected to the sampling resistor and the second switch element; the resistance value of the third resistor is the same as the resistance value of the fourth resistor, the resistance value of the third resistor is smaller than the resistance value of the first resistor; and / or the resistance value of the fourth resistor is smaller than the resistance value of the second resistor.

[0039] In this technical solution, it is defined that the mirror current source circuit also includes a third resistor and a fourth resistor.

[0040] Specifically, the third resistor is arranged on the first branch, and the fourth resistor is arranged on the second branch, so as to further improve the anti-interference capability of the overcurrent protection device.

[0041] In addition, the resistance value of the third resistor is the same as the resistance value of the fourth resistor, and the third resistor is smaller than the first resistor, and the fourth resistor is smaller than the second resistor. Therefore, while realizing large current detection, it prevents the opening and closing state of the second switch component from being affected by excessive voltage division of the fourth resistor, further improving the accuracy of large current detection by the overcurrent protection device and extending the service life of each power device in the driving circuit.

[0042] In a possible technical solution, the detection circuit includes a third switch element and a detection module, wherein:

[0043] The third switch is connected to the first branch and the second branch, and the detection module is connected to the third switch; when the third switch is turned on, the detection module sends a turn-on signal to the control circuit, so that the control circuit sends an overcurrent warning signal according to the turn-on signal.

[0044] In this technical solution, it is defined that the detection circuit includes a third switch and a detection module. Specifically, the third switch is connected to the first branch and the second branch, and the detection module is connected to the third switch.

[0045] When the sampling value of the circuit is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the mirror current source circuit generates a smaller voltage difference, or the generated voltage difference is zero, and the third switch is disconnected, so that the detection circuit cannot be turned on, and the detection module of the detection circuit cannot detect the voltage signal or current signal.

[0046] When the sampling value of the sampling circuit is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the drive circuit, the container causes the power device on the drive circuit to thermally break down and fail. The mirror current source circuit generates a large voltage difference. The large voltage difference can close the third switch and turn on the detection circuit, so that the detection module can detect the voltage signal or current signal and

[0047] A conduction signal is sent to the control circuit, and the control circuit sends an over-current warning signal according to the conduction signal, thereby cutting off the drive signal, that is, no current flows into the drive circuit anymore, preventing the power devices on the drive circuit from burning out.

[0048] In practical applications, the third switch element is a PNP transistor, the base of which is connected to the second branch, and the emitter of which is connected to the first branch.

[0049] In a possible technical solution, the first switch element is a PNP type transistor; and / or the second switch element is a PNP type transistor; and / or the third switch element is a PNP type transistor.

[0050] In this technical solution, the first switch element, the second switch element and the third switch element are PNP type triodes, which can be specifically configured according to actual needs, and have a simple structure and are easy to operate.

[0051] According to a second aspect of the present invention, there is provided a drive control circuit, comprising an overcurrent protection device as provided by any of the above technical solutions, thereby having all the beneficial technical effects of the overcurrent protection device, which will not be described in detail herein.

[0052] Furthermore, the drive control circuit also includes a power supply and a drive circuit, wherein the overcurrent protection device is connected to the positive pole of the power supply and the drive circuit.

[0053] The drive control circuit provided by the embodiment of the present invention includes an overcurrent protection device, a power supply and a drive circuit. Specifically, by setting the overcurrent protection device between the positive pole of the power supply and the drive circuit, compared with the related art in which the overcurrent detection circuit is set between the drive circuit and the ground, because the total current flows out from the positive pole of the power supply, there will be no shunt situation that exists in low-end current detection, thereby ensuring effective detection of large currents and improving the accuracy of current detection.

[0054] In addition, since the overcurrent protection device itself can withstand the high-end common-mode voltage, even if the sampling resistor of the sampling circuit fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device prevents large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit with the overcurrent protection device and extends the service life of each power device in the drive circuit.

[0055] According to a third aspect of the present invention, there is provided a motor assembly, comprising a drive control circuit as provided by any of the above technical solutions, thereby having all the beneficial technical effects of the drive control circuit, which will not be elaborated herein.

[0056] Furthermore, the motor assembly also includes a motor, and the drive control circuit is configured to control the operation of the motor.

[0057] Additional aspects and advantages according to the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0059] Figure 1 A schematic structural diagram of an overcurrent protection device according to an embodiment of the present invention is shown;

[0060] Figure 2 A specific structural schematic diagram of an overcurrent protection device according to an embodiment of the present invention is shown.

[0061] in, Figure 1 and Figure 2 The corresponding relationship between the reference numerals and the component names is as follows:

[0062] 100 overcurrent protection device, 110 sampling circuit, 120 mirror current source circuit, 121 first branch, 122 first switch element, 123 second branch, 124 second switch element, 125 first resistor, 126 second resistor, 127 third resistor, 128 fourth resistor, 130 detection circuit, 131 third switch element, 132 detection module, 140 control circuit. DETAILED DESCRIPTION

[0063] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0064] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0065] Refer to the following Figure 1 and Figure 2 The overcurrent protection device 100, the drive control circuit and the motor assembly provided according to some embodiments of the present invention are described.

[0066] In one embodiment according to the present application, Figure 1 and Figure 2 As shown, an overcurrent protection device 100 is proposed, and the overcurrent protection device 100 includes: a sampling circuit 110, which is used to connect the positive pole of the power supply and the driving circuit; a mirror current source circuit 120, which is connected to the sampling circuit 110; a detection circuit 130, which is connected to the mirror current source circuit 120, and the mirror current source circuit 120 can control whether the detection circuit 130 is turned on according to the sampling value of the sampling circuit 110; a control circuit 140, which is connected to the detection circuit 130; wherein, when the detection circuit 130 is turned on, the detection circuit 130 sends a turn-on signal to the control circuit 140, so that the control circuit 140 sends an overcurrent warning signal according to the turn-on signal.

[0067] The overcurrent protection device 100 provided in the embodiment of the present invention includes a sampling circuit 110, a mirror current source circuit 120, a detection circuit 130 and a control circuit 140. Specifically, the sampling circuit 110 is connected to the positive electrode of the power supply and the drive circuit, the mirror current source circuit 120 is connected to the sampling circuit 110, the detection circuit 130 is connected to the mirror current source circuit 120, and the control circuit 140 is connected to the detection circuit 130. In other words, the overcurrent protection device 100 is set between the positive electrode of the power supply and the drive circuit, that is, high-end current detection.

[0068] By setting the overcurrent protection device 100 between the positive pole of the power supply and the drive circuit, compared with the related art in which the overcurrent detection circuit is set between the drive circuit and the ground, because the total current flows out from the positive pole of the power supply, there will be no shunt situation that exists in low-end current detection, thereby ensuring effective detection of large currents and improving the accuracy of current detection.

[0069] In addition, since the overcurrent protection device 100 itself can withstand the high-end common-mode voltage, even if the sampling resistor of the sampling circuit 110 fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device 100 prevents a large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit 140 with the overcurrent protection device 100 and extends the service life of each power device in the drive circuit.

[0070] The mirror current source circuit 120 can control whether the detection circuit 130 is turned on according to the sampling value of the sampling circuit 110. For example, when the sampling value of the sampling circuit 110 is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the mirror current source circuit 120 generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.

[0071] When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the driving circuit, the container causes the power device on the driving circuit to undergo thermal breakdown and fail. The mirror current source circuit 120 generates a large voltage difference. The large voltage difference can turn on the detection circuit 130, so that the detection module 132 can detect the voltage signal or current signal and send a conduction signal to the control circuit 140. The control circuit 140 sends an overcurrent warning signal according to the conduction signal, thereby cutting off the driving signal, that is, no current flows into the driving circuit, thereby preventing the power device on the driving circuit from burning out.

[0072] In addition, by controlling the conduction state of the detection circuit 130 through the mirror current source circuit 120, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0073] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0074] In practical applications, the sampling circuit 110 includes a sampling resistor, the mirror current source circuit 120 includes two PNP transistors with the same parameters, and the bases of the two transistors are connected. The detection circuit 130 includes a PNP transistor, that is, the conduction state of the PVP transistor is controlled by the mirror current source circuit 120.

[0075] On the basis of the above embodiment, further, when the sampling value is less than the preset sampling value, the mirror current source circuit 120 outputs a first voltage difference to cut off the detection circuit 130; when the sampling value is greater than or equal to the preset sampling value, the mirror current source circuit 120 outputs a second voltage difference to turn on the detection circuit 130; wherein the first voltage difference is less than the second voltage difference.

[0076] In this embodiment, when the sampling value of the sampling circuit 110 is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the mirror current source circuit 120 generates a first voltage difference, wherein the first voltage difference is small, or the first voltage difference is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.

[0077] When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the driving circuit, the container causes the power device on the driving circuit to undergo thermal breakdown and fail. The mirror current source circuit 120 generates a second voltage difference, wherein the second voltage difference is greater than the first voltage difference. The larger second voltage difference can turn on the detection circuit 130, so that the detection module 132 can detect the voltage signal or the current signal and send a conduction signal to the control circuit 140. The control circuit 140 sends an overcurrent warning signal according to the conduction signal, thereby cutting off the driving signal, that is, no current flows into the driving circuit, thereby preventing the power device on the driving circuit from burning out.

[0078] In addition, by controlling the conduction state of the detection circuit 130 through the mirror current source circuit 120, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0079] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0080] like Figure 2 As shown, based on the above embodiment, further, the sampling circuit 110 includes a sampling resistor, and the sampling resistor is used to connect the positive electrode of the power supply and the driving circuit.

[0081] In this embodiment, the sampling circuit 110 includes a sampling resistor, that is, the voltage generated by the current flowing through the sampling resistor is used to detect the current. Furthermore, the sampling resistor is connected between the positive electrode of the power supply and the drive circuit. Compared with the related art in which the resistor is set between the drive circuit and the ground, because the total current flows out from the positive electrode of the power supply, there will be no shunt situation existing in low-end current detection, ensuring effective detection of large currents and improving the accuracy of current detection.

[0082] In addition, since the overcurrent protection device 100 itself can withstand the high-end common-mode voltage, even if the sampling resistor fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device 100 prevents large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit 140 with the overcurrent protection device 100 and extends the service life of each power device in the drive circuit.

[0083] like Figure 2 As shown, on the basis of the above embodiment, further, the mirror current source circuit 120 includes a first branch 121 and a second branch 123, wherein the first branch 121 is connected to the positive electrode of the power supply and the sampling resistor, the first branch 121 is provided with a first switch element 122, the second branch 123 is connected to the sampling resistor and the driving circuit, and is connected in parallel with the first branch 121, the second branch 123 is provided with a second switch element 124, the second switch element 124 is connected to the first switch element 122, and the detection circuit 130 is connected to the first branch 121 and the second branch 123.

[0084] In this embodiment, the mirror current source circuit 120 is defined to include two parallel first branches 121 and second branches 123, the first branch 121 is connected to the positive electrode of the power supply and the sampling resistor, the second branch 123 is connected to the sampling resistor and the driving circuit, and a first switch element 122 is provided on the first branch 121, a second switch element 124 is provided on the second branch 123, the first switch element 122 is connected to the second switch element 124, and the detection circuit 130 is connected to the first branch 121 and the second branch 123.

[0085] It can be understood that when the sampling value of the sampling circuit 110 is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the first switch element 122 and the second switch element 124 are closed, so that the mirror current source circuit 120 produces a smaller voltage difference, or the voltage difference produced is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.

[0086] When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the drive circuit, the container causes the power device on the drive circuit to thermally break down and fail. At this time, the first switch 122 is closed and the second switch 124 is disconnected, so that the mirror current source circuit 120 generates a large voltage difference. The large voltage difference can turn on the detection circuit 130, so that the detection module 132 can detect the voltage signal or current signal and send a conduction signal to the control circuit 140. The control circuit 140 sends an over-current warning signal according to the conduction signal, thereby cutting off the drive signal, that is, no current flows into the drive circuit, thereby preventing the power device on the drive circuit from burning.

[0087] In addition, by controlling the conduction state of the detection circuit 130 through the mirror current source circuit 120, compared with the related art in which no mirror current source circuit is provided, a smaller sampling resistor can be used to detect currents of the same magnitude, thereby greatly reducing the power consumed by the sampling resistor, especially when detecting large currents, reducing the heating of the sampling resistor and extending the service life of the sampling resistor.

[0088] Moreover, the volume of the sampling resistor can be reduced, thereby reducing the area occupied by the sampling resistor on the PCB board and improving the space utilization rate of the PCB board.

[0089] In practical applications, the first switch element 122 and the second switch element 124 are two PNP transistors with the same parameters, and the bases of the two PNP transistors are connected to form the mirror current source circuit 120 .

[0090] like Figure 2 As shown, on the basis of the above embodiment, further, the mirror current source circuit 120 also includes a first resistor 125 and a second resistor 126, wherein the first resistor 125 is arranged on the first branch 121, and the first resistor 125 is connected to the first switch element 122, and the second resistor 126 is arranged on the second branch 123, and the second resistor 126 is connected to the second switch element 124; the resistance value of the first resistor 125 is the same as the resistance value of the second resistor 126.

[0091] In this embodiment, it is defined that the mirror current source circuit 120 also includes a first resistor 125 and a second resistor 126. The first resistor 125 is arranged on the first branch 121, and the second resistor 126 is arranged on the second branch 123. By respectively arranging resistors on the two branches, a current limiting function can be achieved, thereby improving the anti-interference ability of the overcurrent protection device 100.

[0092] The resistance value of the first resistor 125 is the same as the resistance value of the second resistor 126 , so that the mirror current source circuit 120 can accurately control the on and off of the detection circuit 130 to achieve large current detection.

[0093] like Figure 2 As shown, on the basis of the above embodiment, further, the mirror current source circuit 120 also includes a third resistor 127 and a fourth resistor 128, wherein the third resistor 127 is arranged on the first branch 121, the third resistor 127 is connected to the positive electrode of the power supply and the first switch element 122, the fourth resistor 128 is arranged on the second branch 123, the fourth resistor 128 is connected to the sampling resistor and the second switch element 124; the resistance value of the third resistor 127 is the same as the resistance value of the fourth resistor 128, the resistance value of the third resistor 127 is less than the resistance value of the first resistor 125; and / or the resistance value of the fourth resistor 128 is less than the resistance value of the second resistor 126.

[0094] In this embodiment, it is defined that the mirror current source circuit 120 also includes a third resistor 127 and a fourth resistor 128. Specifically, the third resistor 127 is arranged on the first branch 121, and the fourth resistor 128 is arranged on the second branch 123, so as to further improve the anti-interference capability of the overcurrent protection device 100.

[0095] In addition, the resistance value of the third resistor 127 is the same as the resistance value of the fourth resistor 128, and the third resistor 127 is smaller than the first resistor 125, and the fourth resistor 128 is smaller than the second resistor 126. Therefore, while realizing large current detection, it prevents the fourth resistor 128 from affecting the opening and closing state of the second switch 124 due to excessive voltage division, further improving the accuracy of the overcurrent protection device 100 in large current detection and extending the service life of each power device in the driving circuit.

[0096] like Figure 2 As shown, on the basis of the above embodiment, further, the detection circuit 130 includes a third switch element 131 and a detection module 132, wherein the third switch element 131 is connected to the first branch 121 and the second branch 123, and the detection module 132 is connected to the third switch element 131; when the third switch element 131 is turned on, the detection module 132 sends a conduction signal to the control circuit 140, so that the control circuit 140 sends an over-current warning signal according to the conduction signal.

[0097] In this embodiment, it is defined that the detection circuit 130 includes a third switch element 131 and a detection module 132. Specifically, the third switch element 131 is connected to the first branch 121 and the second branch 123, and the detection module 132 is connected to the third switch element 131. When the sampling value of the sampling circuit 110 is less than the preset sampling value, that is, a smaller current flows out from the positive electrode of the power supply, the mirror current source circuit 120 generates a smaller voltage difference, or the generated voltage difference is zero, and the third switch element 131 is disconnected, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.

[0098] When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a large current flows out from the positive electrode of the power supply. If the current flows to the drive circuit, the container causes the power device on the drive circuit to thermally break down and fail. The mirror current source circuit 120 generates a large voltage difference. The large voltage difference can close the third switch 131 and the detection circuit 130 is turned on, so that the detection module 132 can detect the voltage signal or the current signal and send a conduction signal to the control circuit 140. The control circuit 140 sends an over-current warning signal according to the conduction signal, thereby cutting off the drive signal, that is, no current flows into the drive circuit, thereby preventing the power device on the drive circuit from burning.

[0099] In practical applications, the third switch element 131 is a PNP transistor, the base of which is connected to the second branch 123 , and the emitter of which is connected to the first branch 121 .

[0100] In a specific embodiment, further, the first switch element 122 is a PNP type transistor; and / or the second switch element 124 is a PNP type transistor; and / or the third switch element 131 is a PNP type transistor.

[0101] In this embodiment, the first switch element 122, the second switch element 124 and the third switch element 131 are PNP type transistors, which can be specifically configured according to actual needs, have a simple structure and are easy to operate.

[0102] According to a second aspect of the present invention, a drive control circuit 140 is provided, comprising an overcurrent protection device 100 as provided in any of the above embodiments, and thus having all the beneficial technical effects of the overcurrent protection device 100, which will not be described in detail herein.

[0103] Furthermore, the drive control circuit 140 also includes a power supply and a drive circuit, wherein the overcurrent protection device 100 is connected to the positive electrode of the power supply and the drive circuit.

[0104] The drive control circuit 140 provided in the embodiment of the present invention includes an overcurrent protection device 100, a power supply and a drive circuit. Specifically, by setting the overcurrent protection device 100 between the positive pole of the power supply and the drive circuit, compared with the related art in which the overcurrent detection circuit is set between the drive circuit and the ground, because the total current flows out from the positive pole of the power supply, there will be no shunt situation that exists in low-end current detection, thereby ensuring effective detection of large currents and improving the accuracy of current detection.

[0105] In addition, since the overcurrent protection device 100 itself can withstand the high-end common-mode voltage, even if the sampling resistor of the sampling circuit 110 fails or burns out, it will not cause the drive circuit part to burn out. Therefore, while the overcurrent protection device 100 prevents a large current from flowing through the drive circuit and causing the power device to fail due to thermal breakdown, it further ensures the safe use of the drive control circuit 140 with the overcurrent protection device 100 and extends the service life of each power device in the drive circuit.

[0106] According to a third aspect of the present invention, there is provided a motor assembly, comprising a drive control circuit 140 as provided in any of the above embodiments, and thus having all the beneficial technical effects of the drive control circuit 140, which will not be elaborated herein.

[0107] Furthermore, the motor assembly also includes a motor, and the drive control circuit 140 is configured to control the operation of the motor.

[0108] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0109] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means 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 invention. In this specification, the schematic representation of the above terms does 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.

[0110] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An overcurrent protection device, characterized in that: include: A sampling circuit, used for connecting the positive electrode of the power supply and the driving circuit; A mirror current source circuit connected to the sampling circuit; A detection circuit connected to the mirror current source circuit, wherein the mirror current source circuit can control whether the detection circuit is turned on according to a sampling value of the sampling circuit; A control circuit connected to the detection circuit; Wherein, when the detection circuit is turned on, the detection circuit sends a turn-on signal to the control circuit, so that the control circuit sends an overcurrent warning signal according to the turn-on signal; When the sampling value is less than the preset sampling value, the mirror current source circuit outputs a first voltage difference to cut off the detection circuit; When the sampling value is greater than or equal to the preset sampling value, the mirror current source circuit outputs a second voltage difference to turn on the detection circuit; wherein the first voltage difference is less than the second voltage difference; The sampling circuit comprises: A sampling resistor, the sampling resistor is used to connect the positive electrode of the power supply and the driving circuit; The mirror current source circuit comprises: A first branch, connected to the positive electrode of the power supply and the sampling resistor, wherein the first branch is provided with a first switch; a second branch connected to the sampling resistor and the driving circuit and connected in parallel with the first branch, the second branch being provided with a second switch element, the second switch element being connected to the first switch element, and the detection circuit being connected to the first branch and the second branch; The mirror current source circuit also includes: A first resistor is provided on the first branch, and the first resistor is connected to the first switch; A second resistor is provided on the second branch, and the second resistor is connected to the second switch; Wherein, the resistance value of the first resistor is the same as the resistance value of the second resistor; When the sampling value of the sampling circuit is greater than or equal to the preset sampling value, the first switch is closed and the second switch is opened, so that the mirror current source circuit generates the second voltage difference, which can turn on the detection circuit; The first switch element and the second switch element are two PNP transistors with the same parameters, and the bases of the two PNP transistors are connected.

2. The overcurrent protection device according to claim 1, characterized in that: The mirror current source circuit also includes: A third resistor is provided on the first branch, and the third resistor is connected to the positive electrode of the power supply and the first switch; a fourth resistor, disposed on the second branch, the fourth resistor being connected to the sampling resistor and the second switch; The resistance value of the third resistor is the same as the resistance value of the fourth resistor, and the resistance value of the third resistor is smaller than the resistance value of the first resistor; and / or the resistance value of the fourth resistor is smaller than the resistance value of the second resistor.

3. The overcurrent protection device according to claim 1, characterized in that: The detection circuit comprises: a third switch element, connected to the first branch and the second branch; A detection module connected to the third switch element; Wherein, when the third switch is turned on, the detection module sends a turn-on signal to the control circuit, so that the control circuit sends an over-current warning signal according to the turn-on signal.

4. The overcurrent protection device according to claim 3, characterized in that: The first switch element is a PNP transistor; and / or The second switch element is a PNP transistor; and / or The third switch element is a PNP transistor.

5. A drive control circuit, characterized in that: include: The overcurrent protection device according to any one of claims 1 to 4; power supply; The overcurrent protection device is connected to the positive pole of the power supply and the driving circuit.

6. A motor assembly, characterized in that: include: The drive control circuit as claimed in claim 5; The motor is configured to control the operation of the motor.

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