Direct current motor control circuit

Abstract

The utility model discloses a direct current motor control circuit, and belongs to the technical field of motor control. The direct current motor control circuit comprises a key circuit, a control module, a driving module and a power supply module, the key circuit is electrically connected with the control module, the control module is electrically connected with the driving module, and the driving module is electrically connected with the direct current motor; an overcurrent protection circuit is arranged between the power supply module and the control module; voltage conversion circuits are arranged between the power supply module and the key circuit and between the driving module and the direct current motor; the voltage conversion circuit comprises a voltage regulator, the first end of the voltage regulator is grounded, and the third end of the voltage regulator is electrically connected with a second resistor and a first capacitor which are connected in series; the second end of the voltage regulator is electrically connected with a second capacitor and a third capacitor which are connected in parallel. The direct current motor control circuit does not need a relay, and is simple in structure, high in reliability and good in safety. The problem that the service life of an existing direct-current motor control circuit is limited is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of motor control, in particular to a DC motor control circuit. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] A DC motor is a rotating motor that can convert DC electrical energy into mechanical energy. It is widely used in various industries due to its advantages such as simple operation, convenient control, smooth speed regulation and wide range.

[0004] When a DC motor is in operation, its rotation is controlled by a drive circuit, sometimes requiring the motor to accelerate, decelerate, and reverse. Relays are a key component of existing DC motor drive circuits. Switching between these functions causes wear on the relays, shortening their service life and limiting their application and expansion. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a DC motor control circuit that can drive the DC motor without a relay, has a simple circuit structure, high reliability, good safety, easy operation and low cost.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A DC motor control circuit includes a key circuit, a control module, a drive module for driving the DC motor, and a power supply module;

[0008] The key circuit is electrically connected to the control module, the control module is electrically connected to the drive module, and the drive module is electrically connected to the DC motor; the power module is electrically connected to the key circuit, the control module, the drive module, and the DC motor respectively;

[0009] An overcurrent protection circuit is provided between the power module and the control module, and a voltage conversion circuit is provided between the power module and the key circuit, the drive module and the DC motor;

[0010] In which, the voltage conversion circuit includes a voltage regulator, a first end of the voltage regulator is grounded, a third end of the voltage regulator is electrically connected to a second resistor and a first capacitor in series, and the power supply module is electrically connected between the second resistor and the first capacitor; the second end of the voltage regulator is electrically connected to a second capacitor and a third capacitor in parallel, the first end of the third capacitor is electrically connected to the key circuit, the drive module and the DC motor respectively, and the second end of the third capacitor is grounded.

[0011] In some embodiments, the voltage regulator is a LM1117MP voltage regulator.

[0012] In some embodiments, the overcurrent protection circuit includes a dual operational amplifier;

[0013] The first end of the dual operational amplifier is electrically connected to the third resistor and the fourth capacitor, respectively; the second end of the dual operational amplifier is electrically connected to the eighth resistor and the fifth capacitor, respectively; the third end of the dual operational amplifier is electrically connected to the sixth capacitor, the ninth resistor, and the tenth resistor; the fourth end of the dual operational amplifier is grounded; and the fifth end of the dual operational amplifier is electrically connected to the seventh capacitor.

[0014] In some embodiments, the dual operational amplifier is an LM358 dual operational amplifier.

[0015] In some embodiments, the button circuit includes a plurality of pull-up resistors and a control button;

[0016] A first end of the control button is grounded, and a second end of the control button is electrically connected to the pull-up resistor and the control module respectively.

[0017] In some embodiments, a liquid crystal display module is further included, and the liquid crystal display module is electrically connected to the control module.

[0018] In some embodiments, the liquid crystal display module is an LM016L liquid crystal display.

[0019] In some implementations, a simulation oscilloscope is further included, and the simulation oscilloscope is electrically connected to the control module.

[0020] In some implementations, the control module is an STM32F103 single-chip microcomputer.

[0021] In some embodiments, the driving module is an L298 motor driving chip.

[0022] One or more technical solutions provided in this utility model have at least the following technical effects or advantages:

[0023] 1. The technical solution provided by the utility model is to form a DC motor control circuit through a key circuit, a control module, a drive module and a power module. The circuit structure is simple and the DC motor can be controlled without a relay, thereby avoiding the influence of the relay life on the service life of the DC motor control circuit and facilitating the application and expansion of the DC motor.

[0024] 2. The technical solution provided by the present invention designs an overcurrent protection circuit and a voltage conversion circuit to ensure that the DC motor control circuit operates in a relatively safe, stable, low-voltage environment, further improving the reliability and safety of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0026] Figure 1 This is a system framework diagram of a DC motor control circuit provided by an embodiment of the utility model;

[0027] Figure 2 This is a circuit diagram of a key circuit provided by an embodiment of the present utility model;

[0028] Figure 3 This is a circuit diagram of a driving module provided by an embodiment of the present utility model;

[0029] Figure 4 This is a circuit diagram of a liquid crystal display module provided by an embodiment of the present utility model;

[0030] Figure 5 This is a circuit diagram of a voltage conversion circuit provided by an embodiment of the utility model

[0031] Figure 6 This is a circuit diagram of an overcurrent protection circuit provided by an embodiment of the present utility model;

[0032] In the figure: 1. Control module; 2. Overcurrent protection circuit; 3. Power module; 4. Voltage conversion circuit; 5. Drive module; 6. Key circuit.

[0033] In order to show the positions of various parts, the distances or sizes between them are exaggerated. The schematic diagram is for reference only. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] As introduced in the background technology, the DC motor control circuit in the prior art relies on relays to adjust the state of the DC motor, resulting in a reduction in the overall life and reliability. In order to solve the above technical problems, the present invention proposes a DC motor control circuit.

[0036] Combine Figures 1-6 The DC motor control circuit includes a key circuit 6 for selecting the rotation state and speed of the DC motor, a control module 1 for outputting a PWM signal to control the DC motor, a drive module 5 for driving the DC motor, and a power supply module 3 for supplying power to various components. The key circuit 6 is electrically connected to the control module 1, the control module 1 is electrically connected to the drive module 5, and the drive module 5 is electrically connected to the DC motor; the power supply module 3 is electrically connected to the overcurrent protection circuit 2 and the voltage conversion circuit 4, the overcurrent protection circuit 2 is electrically connected to the control module 1, and the voltage conversion circuit 4 is electrically connected to the key circuit 6, the drive module 5, and the DC motor, respectively.

[0037] Combine Figure 2 The key circuit 6 includes five parallel pull-up resistors (R1, R4, R5, R6, and R7). The first end of each pull-up resistor is electrically connected to the output terminal of the voltage conversion circuit 4, and the second end of each pull-up resistor is electrically connected to a control button. The five control buttons control the corresponding motor states of forward rotation, reverse rotation, acceleration, deceleration, and stop, respectively, from top to bottom. The first ends of the five control buttons are all connected to the ground line, and the second ends are respectively electrically connected to pins 14, 15, 16, 17, and 20 of the control module 1, and are also electrically connected to the second ends of the corresponding pull-up resistors.

[0038] Pin 21 of the control module 1 is electrically connected to pin 5 of the driving module 5, pin 22 of the control module 1 is electrically connected to pin 7 of the driving module 5, and pins 2 and 3 of the driving module 5 are electrically connected to ports DC_OUT1 and DC_OUT2 of the DC motor respectively.

[0039] The key circuit 6 serves as the input of the DC motor control circuit and plays a pivotal role in human-computer interaction. The control pin of the control module 1 to which the key circuit 6 is connected is at a high level by default. When the control button is pressed, the control pin of the control module 1 becomes a low level, thereby manually inputting the control command by pressing the control button on the key circuit 6. At the same time, the stable output of the key signal is ensured by the provision of a pull-up resistor.

[0040] In this embodiment, control module 1 is an STM32F103 single-chip microcomputer, and driver module 5 is an L298 motor driver chip. The L298 motor driver chip can control the direction and speed of the DC motor through the input logic level. It also has overcurrent protection and overtemperature protection functions to protect the chip and the connected motor from damage.

[0041] In order to improve the safety and operational stability of the DC motor control circuit, in this embodiment, an overcurrent protection circuit 2 is provided between the power module 3 and the DC motor, and a voltage conversion circuit 4 is provided between the power module 3 and the drive module 5 to ensure that the DC motor control circuit operates in a relatively safe, stable, low-voltage environment, thereby reducing the power supply voltage.

[0042] Combine Figure 5 The voltage conversion circuit 4 includes a voltage regulator U2, a first capacitor C1, a second resistor R2, a second capacitor C2 and a third capacitor C3. Pin 1 of the voltage regulator U2 is grounded, the first end of the first capacitor C1 is grounded, the second end of the first capacitor C1 is electrically connected to the first end of the second resistor R2, and the second end of the second resistor R2 is electrically connected to pin 3 and pin 2 / 4 of the voltage regulator U2 respectively. The power supply module 3 is electrically connected between the second resistor R2 and the first capacitor C1 and inputs a 3.3V voltage; pins 2 / 4 of the voltage regulator U2 are electrically connected to the first ends of the second capacitor C2 and the third capacitor C3 and output a 1.25V power supply, which are respectively electrically connected to the key circuit 6, the drive module 5 and the power input end of the DC motor. The second ends of the second capacitor C2 and the third capacitor C3 are grounded.

[0043] In this embodiment, the voltage regulator U2 is of model LM1117MP, the resistance of the second resistor R2 is 220 ohms, the capacitance of the first capacitor C1 is 10 microfarads, the capacitance of the second capacitor C2 is 10 microfarads, and the capacitance of the third capacitor C3 is 100 nanofarads.

[0044] When in use, the current output by the power module 3 flows through the capacitor, which stores energy. Then, the current passes through the voltage regulator, and the capacitor releases energy, so that the output voltage is lower than the input voltage.

[0045] Combine Figure 6The overcurrent protection circuit 2 includes a dual operational amplifier U3, a third resistor R3, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7. Pin 1 of the dual operational amplifier is electrically connected to the first end of the third resistor R3 and the first end of the fourth capacitor C4, respectively. The second end of the third resistor R3 is electrically connected to the power module 3, and the second end of the fourth capacitor C4 is grounded. Pin 2 of the dual operational amplifier is electrically connected to the first end of the eighth resistor R8 and the sixth capacitor C6, respectively. The second ends of the eighth resistor R8 and the sixth capacitor C6 are grounded. Pin 3 of the dual operational amplifier is electrically connected to the first end of the tenth resistor R10, the first end of the seventh capacitor C7, and the second end of the ninth resistor R9, respectively. The first end of the tenth resistor R10 and the second end of the seventh capacitor C7 are grounded, and the first end of the ninth resistor R9 is electrically connected to the power module 3. Pin 8 of the dual operational amplifier is electrically connected to the first end of the fifth capacitor C5 and the power module 3, respectively, and the second end of the fifth capacitor C5 is grounded. The pin 29 of the control module 1 is electrically connected to the first end of the fourth capacitor C4.

[0046] In this embodiment, the model of the dual operational amplifier U3 is LM358, the resistance values ​​of the third resistor R3, the eighth resistor R8, the ninth resistor R9, and the tenth resistor R10 are 10K ohms, 100 ohms, 10K ohms, and 1K ohms, respectively, and the capacitance of the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 are all 0.1 microfarads.

[0047] During use, when the current of the input control module 1 exceeds the set range, the sensing element (capacitor) will detect the abnormal current and send a signal to LM358. LM358 triggers the protection mechanism to cut off or limit the current based on the received signal to protect the safe operation of the circuit and equipment.

[0048] The DC motor control circuit described in this embodiment works as follows:

[0049] When the user presses the corresponding control button according to needs, the control pin of the corresponding STM32F103 microcontroller becomes a low level. The STM32F103 microcontroller receives the control signal and transmits the control signal to the L298 motor driver chip. The L298 motor driver chip controls the direction and speed of the DC motor according to the input logic level.

[0050] Furthermore, in some embodiments, in order to monitor the working status of the motor, a liquid crystal display module and a simulation oscilloscope are also included. The control module 1 is electrically connected to the liquid crystal display module and the simulation oscilloscope, respectively. The liquid crystal display module is used to display the operating status of the DC motor, and the simulation oscilloscope is used to display the output waveform.

[0051] Specifically, the VSS pin of the LCD module is grounded, the VSS pin of the LCD module is grounded, the VDD pin of the LCD module is electrically connected to pin 7 of the control module 1, the D0 to D7 pins of the LCD module are electrically connected to pins 8 to 11, pin 24, pin 25, pin 37, and pin 38 of the control module 1, respectively, and pin 23 of the control module 1 is electrically connected to pin A of the simulation oscilloscope.

[0052] In this embodiment, the liquid crystal display module is an LM016L liquid crystal display. The LM016L liquid crystal display is a 16x2 character liquid crystal display module that is driven in parallel, that is, the transmission of data and commands is controlled simultaneously through multiple pins. At the same time, the LM016L has a simple interface and is easy to use, so this liquid crystal display is used.

[0053] Although the above description of the specific implementation methods of the present invention is combined with the accompanying drawings, it does not limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present invention.

Claims

1. A DC motor control circuit, characterized in that: It includes a key circuit, a control module, a drive module for driving a DC motor, and a power supply module; The key circuit is electrically connected to the control module, the control module is electrically connected to the drive module, and the drive module is electrically connected to the DC motor; the power module is electrically connected to the key circuit, the control module, the drive module, and the DC motor respectively; An overcurrent protection circuit is provided between the power module and the control module, and a voltage conversion circuit is provided between the power module and the key circuit, the drive module and the DC motor; In which, the voltage conversion circuit includes a voltage regulator, a first end of the voltage regulator is grounded, a third end of the voltage regulator is electrically connected to a second resistor and a first capacitor in series, and the power supply module is electrically connected between the second resistor and the first capacitor; the second end of the voltage regulator is electrically connected to a second capacitor and a third capacitor in parallel, the first end of the third capacitor is electrically connected to the key circuit, the drive module and the DC motor respectively, and the second end of the third capacitor is grounded.

2. The DC motor control circuit according to claim 1, wherein: The voltage regulator is an LM1117MP voltage regulator.

3. The DC motor control circuit according to claim 1, wherein: The overcurrent protection circuit includes a dual operational amplifier; The first end of the dual operational amplifier is electrically connected to the third resistor and the fourth capacitor, respectively; the second end of the dual operational amplifier is electrically connected to the eighth resistor and the fifth capacitor, respectively; the third end of the dual operational amplifier is electrically connected to the sixth capacitor, the ninth resistor, and the tenth resistor; the fourth end of the dual operational amplifier is grounded; and the fifth end of the dual operational amplifier is electrically connected to the seventh capacitor.

4. The DC motor control circuit according to claim 3, wherein: The dual operational amplifier is an LM358 dual operational amplifier.

5. The DC motor control circuit according to claim 1, wherein: The key circuit includes a plurality of pull-up resistors and a control key; A first end of the control button is grounded, and a second end of the control button is electrically connected to the pull-up resistor and the control module respectively.

6. The DC motor control circuit according to claim 1, wherein: It also includes a liquid crystal display module, which is electrically connected to the control module.

7. The DC motor control circuit according to claim 6, wherein: The liquid crystal display module is an LM016L liquid crystal display.

8. The DC motor control circuit according to claim 1, wherein: It also includes a simulation oscilloscope, which is electrically connected to the control module.

9. The DC motor control circuit according to claim 1, wherein: The control module is an STM32F103 single chip microcomputer.

10. The DC motor control circuit according to claim 1, wherein: The driving module is an L298 motor driving chip.

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