Motor driving circuit, driving method and electric equipment

Abstract

The invention discloses a motor driving circuit, a driving method and electric equipment. The motor driving circuit comprises a driving module and a current limiting module. The driving module is connected with the motor and used for driving the motor to work; and the current limiting module is connected in series in a driving loop where the driving module and the motor are connected, and the current limiting module is used for delayed conduction in a starting stage of the motor and conduction of a body diode of the current limiting module in a turn-off period so as to reduce current in the driving loop. According to the technical scheme of the embodiment of the invention, the starting current of the motor can be reduced, the reliability based on motor equipment is improved, the service life of a motor power supply is prolonged, and the user experience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a motor drive circuit, a drive method and an electric device. Background Art

[0002] At present, electric devices using brushed DC motors generally use lithium batteries or dry batteries as power supply. At the moment when the brushed motor starts, since the resistance of small brushed motors is usually relatively small, the starting current is very large, resulting in insufficient battery power supply capacity, which in turn causes voltage drop, reducing the battery's endurance and power supply stability. Summary of the invention

[0003] The present invention provides a motor drive circuit, a drive method and an electric device, which can reduce the starting current of the motor, improve the reliability of the motor device, increase the service life of the motor power supply and improve the user experience.

[0004] According to one aspect of the present invention, there is provided a motor driving circuit, comprising: a driving module and a current limiting module;

[0005] The driving module is connected to the motor, and the driving module is used to drive the motor to work;

[0006] The current limiting module is connected in series in a driving circuit connecting the driving module and the motor. The current limiting module is used to delay conduction during the motor startup phase and conduct its own body diode during the shutdown period to reduce the current in the driving circuit.

[0007] Optionally, the driving module includes an H-bridge driving circuit, and the current limiting module includes a first MOS transistor, which is reversely connected between the H-bridge driving circuit and ground.

[0008] Optionally, the H-bridge driving circuit includes: a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a first resistor, a second resistor, a first switch unit and a second switch unit;

[0009] The first end of the first resistor is respectively connected to the control electrode of the third MOS tube, the control electrode of the fifth MOS tube, and the second end of the second switch unit; the first end of the second resistor is respectively connected to the control electrode of the second MOS tube, the control electrode of the fourth MOS tube, and the second end of the first switch unit; the first electrode of the second MOS tube, the first electrode of the third MOS tube, the second end of the first resistor, and the second end of the second resistor are all connected to a power supply; the second electrode of the second MOS tube is respectively connected to the second electrode of the fourth MOS tube and the first end of the motor; the second electrode of the third MOS tube is respectively connected to the second electrode of the fifth MOS tube and the second end of the motor; the first electrode of the fourth MOS tube and the first electrode of the fifth MOS tube are both connected to the first electrode of the first MOS tube; the first end of the first switch unit is grounded; the control end of the first switch unit is connected to a first control signal; the first end of the second switch unit is grounded; the control end of the second switch unit is connected to a second control signal; and the control electrode of the first MOS tube is connected to a third control signal.

[0010] Optionally, the first switch unit includes: a first switch tube and a third resistor; the second switch unit includes: a second switch tube and a fourth resistor;

[0011] The second electrode of the first switch tube is respectively connected to the control electrode of the second MOS tube, the control electrode of the fourth MOS tube, and the first end of the second resistor, the first electrode of the first switch tube is grounded, the control electrode of the first switch tube is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first control signal; the second electrode of the second switch tube is respectively connected to the control electrode of the third MOS tube, the control electrode of the fifth MOS tube, and the first end of the first resistor, the first electrode of the second switch tube is grounded, the control electrode of the second switch tube is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second control signal.

[0012] Optionally, the current limiting module includes a sixth MOS tube, and the sixth MOS tube is reversely connected between the driving module and the ground; the driving module includes: a seventh MOS tube;

[0013] The control electrode of the seventh MOS tube is connected to the fourth control signal, the first electrode of the seventh MOS tube is connected to the first electrode of the sixth MOS tube, the second electrode of the seventh MOS tube is connected to the first end of the motor, the second end of the motor is connected to the power supply, the second electrode of the sixth MOS tube is grounded, and the control electrode of the sixth MOS tube is connected to the fifth control signal.

[0014] According to another aspect of the present invention, there is provided a motor driving method, comprising:

[0015] In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on, and the body diode of the current limiting module is turned on during the shutdown period.

[0016] Optionally, the driving module includes an H-bridge driving circuit, the current limiting module includes a first MOS transistor, and the first MOS transistor is reversely connected between the H-bridge driving circuit and ground;

[0017] In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on. The body diode of the current limiting module is turned on during the shutdown period, including:

[0018] The H-bridge driving circuit is controlled to be turned on to drive the motor to work, and the first MOS tube is controlled to be turned on with a delay. When the first MOS tube is not turned on, the body diode of the first MOS tube itself is turned on.

[0019] Optionally, the current limiting module includes a sixth MOS tube, and the sixth MOS tube is reversely connected between the driving module and the ground; the driving module includes: a seventh MOS tube;

[0020] In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on. The body diode of the current limiting module is turned on during the shutdown period, including:

[0021] The seventh MOS tube is controlled to be turned on to drive the motor to work, and the sixth MOS tube is controlled to be turned on with a delay. During the period when the sixth MOS tube is not turned on, the body diode of the sixth MOS tube itself is turned on.

[0022] Optionally, the motor driving method further includes:

[0023] Detecting whether the motor starts normally;

[0024] If yes, controlling the current limiting module to be turned on;

[0025] If not, increase the delay time;

[0026] When the delayed on time reaches the preset time, the alarm mode is triggered.

[0027] According to another aspect of the present invention, there is provided an electric device, comprising the motor drive circuit provided by any one of the above embodiments.

[0028] The technical solution of the embodiment of the present invention is to set a current limiting module, and the current limiting module is connected in series in the driving circuit connecting the driving module and the motor. During the motor starting stage, the current limiting module is in a cut-off state, but the body diode of the current limiting module itself is in a conducting state, and a forward voltage drop is generated through the body diode, thereby reducing the voltage when the motor starts, and then the starting current of the motor can be reduced. It can avoid the problem of insufficient power supply capacity of the power supply due to the large starting current during the motor starting stage, and can improve the endurance of the motor power supply and the stability of the power supply. At the same time, it can avoid the problem of the motor not being able to work normally due to the low energy of the power supply, thereby improving the reliability of the motor-based equipment and improving the user experience.

[0029] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the structure of a motor drive circuit provided according to an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the structure of another motor driving circuit provided according to an embodiment of the present invention;

[0033] Figure 3 A timing diagram provided according to an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of the structure of another motor driving circuit provided according to an embodiment of the present invention;

[0035] Figure 5 Another timing diagram provided according to an embodiment of the present invention;

[0036] Figure 6 A flowchart of a motor driving method provided according to an embodiment of the present invention;

[0037] Figure 7 A flowchart of another motor driving method provided according to an embodiment of the present invention;

[0038] Figure 8A flowchart of another motor driving method provided according to an embodiment of the present invention;

[0039] Fig. 9 The figure is a schematic diagram of the structure of an electric device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] Figure 1 FIG. 1 is a schematic diagram of a motor drive circuit according to an embodiment of the present invention. Figure 1 The motor driving circuit includes a driving module 10 and a current limiting module 20; the driving module 10 is connected to the motor M1, and the driving module 10 is used to drive the motor M1 to work; the current limiting module 20 is connected in series in the driving circuit connecting the driving module 10 and the motor M1, and the current limiting module 20 is used to delay conduction during the startup phase of the motor M1, and conduct its own body diode during the shutdown period to reduce the current in the driving circuit.

[0043] The motor M1 can be specifically understood as a brushed motor.

[0044] Specifically, during the startup phase of the motor M1, the current limiting module 20 is in the cut-off state and the body diode of the current limiting module 20 itself is in the on state. At this time, the voltage in the drive circuit is reduced by the forward voltage drop of the body diode itself, thereby reducing the voltage when the motor M1 is started, and further reducing the current when the motor M1 is started.

[0045] The technical solution of the embodiment of the present invention is to set a current limiting module, and the current limiting module is connected in series in the driving circuit connecting the driving module and the motor. During the motor starting stage, the current limiting module is in a cut-off state, but the body diode of the current limiting module itself is in a conducting state, and a forward voltage drop is generated through the body diode, thereby reducing the voltage when the motor starts, and then the starting current of the motor can be reduced. It can avoid the problem of insufficient power supply capacity of the power supply due to the large starting current during the motor starting stage, and can improve the endurance of the motor power supply and the stability of the power supply. At the same time, it can avoid the problem of the motor not being able to work normally due to the low energy of the power supply, thereby improving the reliability of the motor-based equipment and improving the user experience.

[0046] Figure 2 FIG. 1 is a schematic diagram of another motor driving circuit according to an embodiment of the present invention. Figure 2 On the basis of the above embodiment, optionally, the driving module 10 includes an H-bridge driving circuit 11, and the current limiting module 20 includes a first MOS tube Q1, which is reversely connected between the H-bridge driving circuit 11 and the ground.

[0047] Specifically, by reversely connecting the first MOS tube Q1 between the H-bridge drive circuit 11 and the ground, when the current limiting module 20 is in the cut-off state and the body diode of the current limiting module 20 is in the on state during the startup phase of the motor M1, the forward voltage drop generated on the body diode can reduce the current of the drive circuit.

[0048] Continue to refer Figure 2Optionally, the H-bridge driving circuit 11 includes: a second MOS tube Q2, a third MOS tube Q3, a fourth MOS tube Q4, a fifth MOS tube Q5, a first resistor R1, a second resistor R2, a first switch unit 12 and a second switch unit 13; the first end of the first resistor R1 is respectively connected to the control electrode of the third MOS tube Q3, the control electrode of the fifth MOS tube Q5, and the second end of the second switch unit 13, the first end of the second resistor R2 is respectively connected to the control electrode of the second MOS tube Q2, the control electrode of the fourth MOS tube Q4, and the second end of the first switch unit 12, the first electrode of the second MOS tube Q2, the first electrode of the third MOS tube Q3, the second end of the first resistor R1 is connected to the first electrode of the second resistor R2 Both ends are connected to the power supply VCC, the second electrode of the second MOS tube Q2 is respectively connected to the second electrode of the fourth MOS tube Q4 and the first end of the motor M1, the second electrode of the third MOS tube Q3 is respectively connected to the second electrode of the fifth MOS tube Q5 and the second end of the motor M1, the first electrode of the fourth MOS tube Q4 and the first electrode of the fifth MOS tube Q5 are both connected to the first electrode of the first MOS tube, the first end of the first switch unit 12 is grounded, the control end of the first switch unit 12 is connected to the first control signal REV, the first end of the second switch unit 13 is grounded, the control end of the second switch unit 13 is connected to the second control signal FWD0, and the control electrode of the first MOS tube Q1 is connected to the third control signal Delay0.

[0049] The power supply VCC can be provided by a battery. The first resistor R1 and the second resistor R2 are used for current limiting. The first switch unit 12 is used to turn on or off according to the level of the first control signal REV, so that the second MOS tube Q2 or the fourth MOS tube Q4 is turned on or off. Exemplarily, when the level of the first control signal REV is high, the first switch unit 12 is turned on, so that the second MOS tube Q2 is turned on and the fourth MOS tube Q4 is turned off; when the level of the first control signal REV is low, the first switch unit 12 is turned off, so that the second MOS tube Q2 is turned off and the fourth MOS tube Q4 is turned on. The second switch unit 13 is used to turn on or off according to the level of the second control signal FWD0, so that the third MOS tube Q3 or the fifth MOS tube Q5 is turned on or off. Exemplarily, when the level of the second control signal FWD0 is high, the second switch unit 13 is turned on, so that the third MOS tube Q3 is turned on and the fifth MOS tube Q5 is turned off; when the level of the second control signal FWD0 is low, the second switch unit 13 is turned off, so that the third MOS tube Q3 is turned off and the fifth MOS tube Q5 is turned on. And the first control signal REV and the second control signal FWD0 are not low or high at the same time. The first MOS tube Q1 is turned off when the third control signal Delay0 is low, and is turned on when the third control signal Delay0 is high. Through this setting, the battery power can be fully utilized, thereby improving the battery life and working stability.

[0050] Figure 3 A timing diagram is provided according to an embodiment of the present invention, specifically for driving Figure 2 Circuit structure. Combined with Figure 2 and Figure 3Specifically, in the starting phase of the motor M1 (phase t1), the level of the second control signal FWD0 is high, the level of the first control signal REV is low, and the level of the third control signal Delay0 is low. At this time, the first switch unit 12 is in the off state, so that the fourth MOS tube Q4 is turned on; the second switch unit 13 is in the on state, so that the third MOS tube Q3 is turned on; at the same time, since the first MOS tube Q1 is in the off state, but the body diode of the first MOS tube Q1 itself is in the on state, a forward voltage drop is generated on the body diode, for example, the forward voltage drop can be 0.7V-1V. In turn, the starting current of the motor M1 can be reduced. At this time, the motor M1 is in the first action state (for example, the motor M1 is in forward rotation). Exemplarily, when the voltage of the power supply is 3V-4.2V, the forward voltage drop generated on the body diode is about 1V. At this time, the voltage at the moment of starting the motor M1 is about 2V-3.2V, so that the starting current of the motor M1 is reduced by 1 / 3-1 / 2. It can be understood that the duration of the t1 phase is the delayed on time of the first MOS tube Q1. The delayed on time can be 10ms-30ms. During the delayed on phase of the first MOS tube Q1, the motor M1 is in a stable operation phase.

[0051] In the rated operation stage of the motor (stage t2), the level of the second control signal FWD0 is high, the level of the first control signal REV is low, and the level of the third control signal Delay0 is high. At this time, the voltage of the first pole of the first MOS tube Q1 is about 1V, and the first MOS tube Q1 is in the on state, thereby short-circuiting its own body diode. At this time, the on-state voltage drop is about 0V, so that the voltage across the motor M1 is increased to the power supply voltage VCC, the first MOS tube Q1 remains in the on state, the motor voltage is restored to 3V-4.2V, and the motor M1 enters the rated working state.

[0052] In the next startup phase (t3 phase), the level of the second control signal FWD0 is low, the level of the first control signal REV is high, and the level of the third control signal Delay0 is low. At this time, the first switch unit 12 is in the on state, so that the second MOS tube Q2 is turned on; the second switch unit 13 is in the off state, so that the fifth MOS tube Q5 is turned on; so that the motor M1 is in the second action state (for example, the motor M1 is in reverse). The subsequent process of reducing the starting current of the motor M1 is the same as when the motor M1 is in the first action state, and will not be repeated here. Similarly, the t4 phase is the stage where the next motor enters the rated working state.

[0053] Combination Figure 2Optionally, the first switch unit 12 includes: a first switch tube Q6 and a third resistor R3; the second switch unit 13 includes: a second switch tube Q7 and a fourth resistor R4; the second electrode of the first switch tube Q6 is respectively connected to the control electrode of the second MOS tube Q2, the control electrode of the fourth MOS tube Q4, and the first end of the second resistor R2, the first electrode of the first switch tube Q6 is grounded, the control electrode of the first switch tube Q6 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the first control signal REV; the second electrode of the second switch tube Q7 is respectively connected to the control electrode of the third MOS tube Q3, the control electrode of the fifth MOS tube Q5, and the first end of the first resistor R1, the first electrode of the second switch tube Q7 is grounded, the control electrode of the second switch tube Q7 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected to the second control signal FWD0.

[0054] The third resistor R3 and the fourth resistor R4 are used for current limiting.

[0055] Specifically, when the level of the first control signal REV is high, the first switch tube Q6 is turned on, and when the level of the first control signal REV is low, the first switch tube Q6 is turned off. When the level of the second control signal FWD0 is high, the second switch tube Q7 is turned on, and when the level of the second control signal FWD0 is low, the second switch tube Q7 is turned off.

[0056] Figure 4 FIG. 1 is a schematic diagram of another motor driving circuit according to an embodiment of the present invention. Figure 4 On the basis of the above embodiments, optionally, the current limiting module 20 includes a sixth MOS transistor Q8, which is reversely connected between the driving module 10 and the ground; the driving module 10 includes: a seventh MOS transistor Q9; the control electrode of the seventh MOS transistor Q9 is connected to the fourth control signal FWD1, the first electrode of the seventh MOS transistor Q9 is connected to the first electrode of the sixth MOS transistor Q8, the second electrode of the seventh MOS transistor Q9 is connected to the first end of the motor M1, the second end of the motor M1 is connected to the power supply VCC, the second electrode of the sixth MOS transistor Q8 is grounded, and the control electrode of the sixth MOS transistor Q8 is connected to the fifth control signal Delay1.

[0057] Figure 5 Another timing diagram provided according to an embodiment of the present invention is specifically used for driving Figure 4 Circuit structure. Combined with Figure 4 and Figure 5Specifically, in the startup phase of the motor M1 (phase t1), the level of the fourth control signal FWD1 is high, and the level of the fifth control signal Delay1 is low. At this time, the seventh MOS tube Q9 is turned on. At the same time, since the sixth MOS tube Q8 is in the cut-off state, but the body diode of the sixth MOS tube Q8 itself is in the on state, a forward voltage drop is generated on the body diode, thereby reducing the starting current of the motor M1. At this time, the motor M1 is in the on state. It can be understood that the duration of the t1 phase is the delayed on time of the sixth MOS tube Q8. Exemplarily, the delayed on time can be 10ms-30ms. During the delayed on phase of the sixth MOS tube Q8, the motor M1 is in a stable operation phase.

[0058] In the rated operation stage of the motor (stage t2), the level of the fourth control signal FWD1 is high, and the level of the fifth control signal Delay1 is high. At this time, the voltage of the first electrode of the sixth MOS tube Q8 is about 1V. At this time, the sixth MOS tube Q8 is in the on state, thereby short-circuiting its own body diode. At this time, the on-state voltage drop is about 0V, so that the voltage across the motor M1 is increased to the power supply voltage VCC, the sixth MOS tube Q8 remains in the on state, the motor voltage is restored to 3V-4.2V, and the motor enters the rated working state.

[0059] In the motor off phase (phase t3 ), the level of the fourth control signal FWD1 is low, and the level of the fifth control signal Delay1 is low. At this time, the motor M1 is off.

[0060] In the next starting phase of the motor M1 (phase t4), the working process is the same as that of the above-mentioned phase t1, and will not be described again here.

[0061] It can be understood that the above embodiments are all described with the first MOS tube, the fourth MOS tube, the fifth MOS tube, the sixth MOS tube and the seventh MOS tube being N-type tubes, the second MOS tube and the third MOS tube being P-type tubes, and the first switch tube and the second switch tube being NPN-type tubes. In other embodiments, the first MOS tube, the fourth MOS tube, the fifth MOS tube, the sixth MOS tube and the seventh MOS tube may also be P-type tubes, the second MOS tube and the third MOS tube may be N-type tubes, and the first switch tube and the second switch tube may be PNP-type tubes. This embodiment does not specifically limit this.

[0062] The embodiment of the present invention further provides a motor driving method, which can be applied to the motor driving circuit provided by any of the above embodiments, so the motor driving method has the beneficial effects of any of the above embodiments. The motor driving method is described in detail below.

[0063] Figure 6is a flow chart of a motor driving method provided according to an embodiment of the present invention, with reference to Figure 6 , the motor driving method includes:

[0064] S101, during the startup phase, the driving module is controlled to turn on the driving motor, the current limiting module is controlled to delay turning on, and the body diode of the current limiting module is turned on during the shutdown period.

[0065] The technical solution of the embodiment of the present invention is to set a current limiting module, and the current limiting module is connected in series in the driving circuit connecting the driving module and the motor. During the motor starting stage, the current limiting module is in a cut-off state, but the body diode of the current limiting module itself is in a conducting state, and a forward voltage drop is generated through the body diode, thereby reducing the voltage when the motor starts, and then the starting current of the motor can be reduced. It can avoid the problem of insufficient power supply capacity of the power supply due to the large starting current during the motor starting stage, and can improve the endurance of the motor power supply and the stability of the power supply. At the same time, it can avoid the problem of the motor not being able to work normally due to the low energy of the power supply, thereby improving the reliability of the motor-based equipment and improving the user experience.

[0066] In an optional implementation manner provided in this embodiment, the driving module includes an H-bridge driving circuit, the current limiting module includes a first MOS transistor, and the first MOS transistor is reversely connected between the H-bridge driving circuit and the ground.

[0067] During the startup phase, the control drive module is turned on to drive the motor, the control current limiting module is delayed to turn on, and the body diode of the current limiting module is turned on during the shutdown period, including:

[0068] The H-bridge driving circuit is controlled to conduct to drive the motor to work, and the first MOS tube is controlled to conduct with delay. During the period when the first MOS tube is not conducted, the body diode of the first MOS tube itself is conducted.

[0069] For example, reference Figure 2 The H-bridge driving circuit 11 includes a second MOS tube Q2, a third MOS tube Q3, a fourth MOS tube Q4, a fifth MOS tube Q5, a first switch tube Q6 and a second switch tube Q7.

[0070] Specifically, in the startup phase of the motor M1, the first switch tube Q6 is turned off when the level of the first control signal REV is low, so that the fourth MOS tube Q4 is turned on; the second switch tube Q7 is turned on when the level of the second control signal FED0 is high, so that the third MOS tube Q3 is turned on; the first MOS tube Q1 is turned off when the level of the third control signal Delay0 is low, but the body diode of the first MOS tube Q1 is in a conducting state, thereby generating a forward voltage drop on the body diode, thereby reducing the startup current of the motor M1.

[0071] In the next startup phase of the motor M1, the first switch tube Q6 is turned on when the level of the first control signal REV is high, so that the second MOS tube Q2 is turned on; the second switch tube Q7 is turned off when the level of the second control signal FED0 is low, so that the fifth MOS tube Q5 is turned on; the first MOS tube Q1 is turned off when the level of the third control signal Delay0 is low, but the body diode of the first MOS tube Q1 is in a conducting state, thereby generating a forward voltage drop on the body diode, reducing the starting current of the motor M1.

[0072] In another optional implementation manner provided by this embodiment, the current limiting module includes a sixth MOS tube, and the sixth MOS tube is reversely connected between the driving module and the ground; the driving module includes: a seventh MOS tube;

[0073] During the startup phase, the control drive module is turned on to drive the motor, the control current limiting module is delayed to turn on, and the body diode of the current limiting module is turned on during the shutdown period, including:

[0074] The seventh MOS tube is controlled to be turned on to drive the motor to work, and the sixth MOS tube is controlled to be turned on with a delay. When the sixth MOS tube is not turned on, the body diode of the sixth MOS tube is turned on.

[0075] For example, reference Figure 4 In the starting stage of the motor M1, the seventh MOS tube Q9 is turned on when the level of the fourth control signal FWD1 is high, and the sixth MOS tube Q8 is turned off when the level of the fifth control signal Delay1 is low, but the body diode of the sixth MOS tube Q8 is in a conducting state, thereby generating a forward voltage drop on the body diode, reducing the starting current of the motor M1.

[0076] Figure 7 FIG. 1 is a flow chart of another motor driving method provided according to an embodiment of the present invention. Figure 7 , based on the above embodiment, the motor driving method includes:

[0077] S201, during the startup phase, the driving module is controlled to turn on the driving motor, the current limiting module is controlled to delay turning on, and the body diode of the current limiting module is turned on during the shutdown period.

[0078] Specifically, during the motor startup phase, the current limiting module is in the cut-off state, but the body diode of the current limiting module itself is in the on state. At this time, the voltage in the drive circuit is reduced by the forward voltage drop of the body diode itself, thereby reducing the voltage when the motor is started, and further reducing the starting current of the motor.

[0079] S202, check whether the motor starts normally.

[0080] Specifically, when the drive module is turned on and the current limiting module is turned on with a delay, it is detected whether the motor starts normally. Exemplarily, the delay time of the current limiting module can be 10ms. The motor start detection can determine whether the motor has started by detecting the motor's current, speed, or start command.

[0081] For example, reference Figure 2 or Figure 4 , when the level of the second control signal FWD0 is high, the level of the first control signal REV is low, the level of the third control signal Delay0 is low and the duration of the low level is 10ms, the H-bridge drive circuit 11 is turned on, that is, the third MOS tube Q3 and the fourth MOS tube Q4 are turned on, and the first MOS tube Q1 is in the off state. At this time, it is detected whether the motor M1 starts normally within 10ms. Or, when the level of the fourth control signal FWD1 is high, the level of the fifth control signal Delay1 is low and the duration of the low level is 10ms, the seventh MOS tube Q9 is turned on, and the sixth MOS tube Q8 is in the off state. At this time, it is detected whether the motor M1 starts normally within 10ms.

[0082] S203: If yes, control the current limiting module to be turned on.

[0083] Specifically, when the motor starts normally within 10ms, the current limiting module is controlled to be turned on, thereby short-circuiting its own body diode. At this time, the conduction voltage drop is about 0V, so that the voltage across the motor is increased to the power supply voltage, the current limiting module remains on, and the motor enters the rated working state.

[0084] S204: If not, increase the delay conduction time.

[0085] Specifically, when the motor does not start normally within 10ms, the delay on time of the current limiting module is increased until the number of times the delay on time is increased reaches a preset number. For example, each increase in the delay on time can be set to 10ms, and the preset number of times can be 3 times, that is, the maximum delay on time of the current limiting module can be 30ms.

[0086] S205: When the delayed on time reaches a preset time, an alarm mode is triggered.

[0087] Specifically, when the motor does not start normally within 30ms, the alarm mode is triggered. Exemplarily, the alarm mode can be a sound alarm mode or a light alarm mode.

[0088] Figure 8 FIG. 1 is a flow chart of another motor driving method provided according to an embodiment of the present invention. Figure 8 Based on the above embodiments, the motor driving method includes:

[0089] S301: System initialization.

[0090] S302, check whether the power supply and the motor are faulty; if so, execute S312, if not, execute S303.

[0091] Specifically, the fault detection of the power supply may include checking whether the voltage, current, frequency and other parameters of the power supply are faulty. The fault detection of the motor may include checking whether the winding, rotor, bearing, temperature and other aspects are faulty. The specific detection method can be detected in an existing manner, which will not be described in detail here.

[0092] S303 , control the first control signal REV to be at a low level and the second control signal FWD0 to be at a high level; or control the fourth control signal FWD1 to be at a high level.

[0093] Specifically, refer to Figure 2 or Figure 4 , this step can be specifically understood as: controlling the H-bridge drive circuit to conduct and drive the motor to work;

[0094] or,

[0095] The seventh MOS tube is controlled to be turned on to drive the motor to work.

[0096] S304, delay 10ms.

[0097] Specifically, this step can be understood as: controlling the current limiting module to delay conduction. Figure 2 or Figure 4 , controlling the current limiting module to delay conduction, including: controlling the first MOS tube to delay conduction, during which the first MOS tube is not turned on, the body diode of the first MOS tube itself is turned on.

[0098] or,

[0099] Controlling the current limiting module to delay conduction includes: controlling the sixth MOS tube to delay conduction, and when the sixth MOS tube is not turned on, the body diode of the sixth MOS tube itself is turned on.

[0100] S305, check whether the motor starts normally; if so, execute S306, if not, execute S307.

[0101] S306 , controlling the current limiting module to be turned on.

[0102] Specifically, refer to Figure 2 or Figure 4 , this step can be specifically understood as: controlling the third control signal Delay0 to be a high level; or controlling the fifth control signal Delay1 to be a high level.

[0103] S307, increase the delay conduction time.

[0104] S308: Whether the delayed on time reaches the preset time; if so, execute S312; if not, execute S305.

[0105] S309: Check whether the motor operates normally; if yes, execute S310; if no, execute S312.

[0106] S310, the motor runs with full functions.

[0107] Specifically, this step can be understood as: the motor is running at rated value.

[0108] S311. The motor stops running according to a timeout signal or a stop signal.

[0109] Specifically, during the operation of the motor, if the predetermined operation target or state (such as overtemperature, overload, failure to start normally, etc.) is not reached within the set time, the control system will detect such abnormality and trigger a shutdown through a timeout signal. This setting can prevent the motor from being damaged due to long-term abnormal operation. The shutdown signal usually comes from an external control system (such as a PLC, sensor, or operator input) to control the motor to stop running.

[0110] S312, alarm mode.

[0111] Optionally, an embodiment of the present invention further provides an electric device, comprising the motor drive circuit provided by any of the above embodiments. Therefore, the electric device also has the beneficial effects of any of the above embodiments.

[0112] Among them, electric equipment may include electric stationery and electric toys.

[0113] For example, Fig. 9 FIG. 1 is a schematic diagram of a structure of an electric device provided according to an embodiment of the present invention, with reference to FIG. Fig. 9 The electric device further includes a battery 300 and a main control board 200. The motor drive circuit is integrated on the main control board 200, and the battery 300 can be integrated on the main control board 200 or can be independently provided from the main control board 200. The battery 300 and the motor M1 are both connected to the main control board 200.

[0114] The battery 300 may be a lithium battery or a dry cell battery.

[0115] The electric device provided by the embodiment of the present invention can reduce the current when the motor starts through the motor driving circuit, and can avoid the problem of voltage drop caused by insufficient battery power supply when the electric stationery or electric toy uses a battery as a power source, and can avoid the problem of power waste and reduced user experience caused by the main control board chip being reset or the motor being blocked and stopped when the battery power is low. The battery power in the electric device provided by this embodiment can be fully utilized, thereby improving the battery life and working stability.

[0116] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0117] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor drive circuit, characterized in that: include: Driver module and current limiting module; The driving module is connected to the motor, and the driving module is used to drive the motor to work; The current limiting module is connected in series in a driving circuit connecting the driving module and the motor. The current limiting module is used to delay conduction during the motor startup phase and conduct its own body diode during the shutdown period to reduce the current in the driving circuit.

2. The motor drive circuit according to claim 1, characterized in that: The driving module includes an H-bridge driving circuit, and the current limiting module includes a first MOS transistor, which is reversely connected between the H-bridge driving circuit and ground.

3. The motor drive circuit according to claim 2, characterized in that: The H-bridge driving circuit comprises: a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a first resistor, a second resistor, a first switch unit and a second switch unit; The first end of the first resistor is respectively connected to the control electrode of the third MOS tube, the control electrode of the fifth MOS tube, and the second end of the second switch unit; the first end of the second resistor is respectively connected to the control electrode of the second MOS tube, the control electrode of the fourth MOS tube, and the second end of the first switch unit; the first electrode of the second MOS tube, the first electrode of the third MOS tube, the second end of the first resistor, and the second end of the second resistor are all connected to a power supply; the second electrode of the second MOS tube is respectively connected to the second electrode of the fourth MOS tube and the first end of the motor; the second electrode of the third MOS tube is respectively connected to the second electrode of the fifth MOS tube and the second end of the motor; the first electrode of the fourth MOS tube and the first electrode of the fifth MOS tube are both connected to the first electrode of the first MOS tube; the first end of the first switch unit is grounded; the control end of the first switch unit is connected to a first control signal; the first end of the second switch unit is grounded; the control end of the second switch unit is connected to a second control signal; and the control electrode of the first MOS tube is connected to a third control signal.

4. The motor drive circuit according to claim 3, characterized in that: The first switch unit includes: a first switch tube and a third resistor; the second switch unit includes: a second switch tube and a fourth resistor; The second electrode of the first switch tube is respectively connected to the control electrode of the second MOS tube, the control electrode of the fourth MOS tube, and the first end of the second resistor, the first electrode of the first switch tube is grounded, the control electrode of the first switch tube is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first control signal; the second electrode of the second switch tube is respectively connected to the control electrode of the third MOS tube, the control electrode of the fifth MOS tube, and the first end of the first resistor, the first electrode of the second switch tube is grounded, the control electrode of the second switch tube is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second control signal.

5. The motor drive circuit according to claim 1, characterized in that: The current limiting module includes a sixth MOS tube, and the sixth MOS tube is reversely connected between the driving module and the ground; the driving module includes: a seventh MOS tube; The control electrode of the seventh MOS tube is connected to the fourth control signal, the first electrode of the seventh MOS tube is connected to the first electrode of the sixth MOS tube, the second electrode of the seventh MOS tube is connected to the first end of the motor, the second end of the motor is connected to the power supply, the second electrode of the sixth MOS tube is grounded, and the control electrode of the sixth MOS tube is connected to the fifth control signal.

6. A motor driving method, characterized in that: include: In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on, and the body diode of the current limiting module is turned on during the shutdown period.

7. The motor driving method according to claim 6, characterized in that: The driving module includes an H-bridge driving circuit, and the current limiting module includes a first MOS transistor, and the first MOS transistor is reversely connected between the H-bridge driving circuit and the ground; In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on. The body diode of the current limiting module is turned on during the shutdown period, including: The H-bridge driving circuit is controlled to be turned on to drive the motor to work, and the first MOS tube is controlled to be turned on with a delay. When the first MOS tube is not turned on, the body diode of the first MOS tube itself is turned on.

8. The motor driving method according to claim 6, characterized in that: The current limiting module includes a sixth MOS tube, and the sixth MOS tube is reversely connected between the driving module and the ground; the driving module includes: a seventh MOS tube; In the startup phase, the driving module is controlled to turn on the driving motor to work, and the current limiting module is controlled to delay turning on. The body diode of the current limiting module is turned on during the shutdown period, including: The seventh MOS tube is controlled to be turned on to drive the motor to work, and the sixth MOS tube is controlled to be turned on with a delay. During the period when the sixth MOS tube is not turned on, the body diode of the sixth MOS tube itself is turned on.

9. The motor driving method according to claim 6, characterized in that: Also includes: Detecting whether the motor starts normally; If yes, control the current limiting module to be turned on; If not, increase the delay time; When the delayed on time reaches the preset time, the alarm mode is triggered.

10. An electric device, characterized in that: The motor drive circuit comprises the motor drive circuit according to any one of claims 1 to 5.

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