Motor rotating speed monitoring and control circuit

Abstract

The invention discloses a motor rotating speed monitoring and control circuit, and relates to the field of motors, and the circuit comprises a motor working module which is used for enabling a motor to be connected with alternating current, receiving a control signal of a working control module, and controlling the working state of the motor; the working control module is used for receiving a signal of the microcontroller and outputting a control signal to the motor working module through an optocoupler; compared with the prior art, the method has the advantages that the primary side of the current transformer is connected with one end of the motor in series according to the voltage and current coupling principle of the coil, coupling current signals are collected at the secondary side of the current transformer, the larger the current is, the stronger the coupling signals are, namely the larger the ADC collection value is, the faster the motor rotating speed is, the faster the coupling current polarity conversion is, and the higher the coupling current polarity conversion is. The higher the frequency of the signals collected by the microcontroller is, the interference influence of the environment magnetic field on the detection sensor is reduced, and meanwhile the workload of whole machine assembling personnel is reduced.

Description

Technical Field

[0001] The invention relates to the field of motors, and in particular to a motor speed monitoring and control circuit. Background Art

[0002] With the development of electronic technology and the improvement of people's living standards, higher requirements are placed on electronic products and equipment. In traditional motor speed control and speed monitoring strategies, Hall sensors are generally used for magnetic field detection. The motor speed is monitored and controlled by inducing magnetic field changes. However, for environments with complex magnetic fields, the monitoring precision and accuracy are affected to a certain extent and need to be improved. Summary of the invention

[0003] The object of the present invention is to provide a motor speed monitoring and control circuit to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A motor speed monitoring and control circuit, comprising:

[0006] The motor working module is used to connect the motor to AC power and receive the control signal of the working control module to control the working state of the motor;

[0007] The working control module is used to receive the signal of the microcontroller and output the control signal to the motor working module through the optical coupler;

[0008] The signal acquisition module is used to collect the current flowing through the motor, convert it into a voltage signal and output it to the amplification output module;

[0009] An amplifying output module is used to amplify the input voltage signal and then output it to the microcontroller;

[0010] The motor working module is connected to the signal acquisition module, the signal acquisition module is connected to the amplification output module, and the working control module is connected to the motor working module.

[0011] As a further solution of the present invention: the motor working module includes a motor, a current transformer T135, and a bidirectional thyristor TR6. One end of the motor is connected to the live wire, the other end of the motor is connected to the second end of the current transformer T135, the third end of the current transformer T135 is connected to the signal acquisition module, the fourth end of the current transformer T135 is grounded, the first end of the current transformer T135 is connected to one end of the capacitor C38, one end of the capacitor C36, and the first end of the bidirectional thyristor TR6, the other end of the capacitor C38 is connected to one end of the resistor R106 and one end of the resistor R107, the other end of the resistor R106 is connected to the other end of the resistor R107, one end of the resistor R105, the second end of the bidirectional thyristor TR6, and the neutral line, the other end of the resistor R105 is connected to the other end of the capacitor C36, and the third end of the bidirectional thyristor TR6 is connected to the working control module.

[0012] As a further solution of the present invention: the working control module includes an optocoupler U9, one end of the input end of the optocoupler U9 is connected to one end of the resistor R112, the other end of the resistor R112 is connected to a 5V voltage, the other end of the input end of the optocoupler U9 introduces the signal MOTOR DRIVER output by the first GPIO port of the microcontroller, one end of the output end of the optocoupler U9 is connected to one end of the resistor R111, the other end of the resistor R111 is connected to the other end of the resistor R105, and the other end of the output end of the optocoupler U9 is connected to the third end of the bidirectional thyristor TR6.

[0013] As a further solution of the present invention: the signal acquisition module includes a diode D11, a resistor R128, and a capacitor C57. The positive electrode of the diode D11 is connected to the motor working module, the negative electrode of the diode D11 is connected to one end of the resistor R128, one end of the capacitor C57, and the amplification output module, the other end of the resistor R128 is grounded, and the other end of the capacitor C57 is grounded.

[0014] As a further solution of the present invention: the amplification output module includes an amplifier U4, the inverting end of the amplifier U4 is connected to one end of a resistor R133 and one end of a resistor R134, the other end of the resistor R133 is grounded, the other end of the resistor R134 is connected to the output end of the amplifier U4 and one end of a resistor R127, the other end of the resistor R127 outputs the signal MOTOR CURRENT to the second GPIO port of the microcontroller, the inverting end of the amplifier U4 is connected to one end of a resistor R131 and one end of a resistor R12, the other end of the resistor R131 is connected to the signal acquisition module, and the other end of the resistor R12 is grounded.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention utilizes the coupling principle of the coil to the voltage and current, connects the primary of the current transformer in series to one end of the motor, and collects the coupled current signal at the secondary of the current transformer. The larger the current, the stronger the coupled signal, that is, the larger the ADC acquisition value, the faster the motor speed, the faster the coupling current polarity changes, and the higher the signal frequency collected by the microcontroller, thereby reducing the interference effect of the environmental magnetic field on the detection sensor and reducing the workload of the whole machine assembler. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model is a circuit diagram of a motor speed monitoring and control circuit.

[0017] Figure 2 This is the waveform diagram of the signal MOTOR CURRENT.

[0018] Figure 3 It is the waveform diagram of the signal MOTOR DRIVER. DETAILED DESCRIPTION

[0019] The technical solutions 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, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 , a motor speed monitoring and control circuit, comprising:

[0021] The motor working module is used to connect the motor to AC power and receive the control signal of the working control module to control the working state of the motor;

[0022] The working control module is used to receive the signal of the microcontroller and output the control signal to the motor working module through the optical coupler;

[0023] The signal acquisition module is used to collect the current flowing through the motor, convert it into a voltage signal and output it to the amplification output module;

[0024] An amplifying output module is used to amplify the input voltage signal and then output it to the microcontroller;

[0025] The motor working module is connected to the signal acquisition module, the signal acquisition module is connected to the amplification output module, and the working control module is connected to the motor working module.

[0026] In this example: See Figure 1The motor working module includes a motor, a current transformer T135, and a bidirectional thyristor TR6. One end of the motor is connected to the live wire, the other end of the motor is connected to the second end of the current transformer T135, the third end of the current transformer T135 is connected to the signal acquisition module, the fourth end of the current transformer T135 is grounded, the first end of the current transformer T135 is connected to one end of the capacitor C38, one end of the capacitor C36, and the first end of the bidirectional thyristor TR6, the other end of the capacitor C38 is connected to one end of the resistor R106 and one end of the resistor R107, the other end of the resistor R106 is connected to the other end of the resistor R107, one end of the resistor R105, the second end of the bidirectional thyristor TR6, and the neutral line, the other end of the resistor R105 is connected to the other end of the capacitor C36, and the third end of the bidirectional thyristor TR6 is connected to the working control module.

[0027] When the bidirectional thyristor TR6 is turned on, the live wire, motor, current transformer T135, bidirectional thyristor TR6, and neutral wire form a loop, and the current flowing through the motor is the current flowing through the current transformer T135, which is fed back to the signal acquisition module through the current transformer T135. The faster the bidirectional thyristor TR6 conduction frequency, the faster the motor speed, and the faster the current transformer T135 coupling current polarity changes.

[0028] In this example: See Figure 1 and Figure 3 The working control module includes an optocoupler U9, one end of the input end of the optocoupler U9 is connected to one end of the resistor R112, the other end of the resistor R112 is connected to a 5V voltage, the other end of the input end of the optocoupler U9 introduces a signal MOTOR DRIVER output by the first GPIO port of the microcontroller, one end of the output end of the optocoupler U9 is connected to one end of the resistor R111, the other end of the resistor R111 is connected to the other end of the resistor R105, and the other end of the output end of the optocoupler U9 is connected to the third end of the bidirectional thyristor TR6.

[0029] The GPIO port of the microcontroller outputs the signal MOTOR DRIVER (for example Figure 3 As shown, it can be seen from the curve that the motor speed can be set humanely according to actual needs. The larger the duty cycle, the higher the motor speed, and the larger the duty cycle of the collected waveform). By controlling whether the light-emitting diode inside the optocoupler U9 is turned on or not, the output of the output end of the optocoupler U9 is controlled to control the conduction frequency of the bidirectional thyristor TR6.

[0030] In this example: See Figure 1 The signal acquisition module includes a diode D11, a resistor R128, and a capacitor C57. The positive electrode of the diode D11 is connected to the motor working module, the negative electrode of the diode D11 is connected to one end of the resistor R128, one end of the capacitor C57, and the amplification output module, the other end of the resistor R128 is grounded, and the other end of the capacitor C57 is grounded.

[0031] The third terminal of the current transformer T135 outputs a current signal, which is rectified by the diode D11 and filtered by the capacitor C57. The normal voltage signal is output to the amplification output module on the resistor R128.

[0032] In this example: See Figure 1 and Figure 2 The amplification output module includes an amplifier U4, an inverting end of the amplifier U4 is connected to one end of a resistor R133 and one end of a resistor R134, the other end of the resistor R133 is grounded, the other end of the resistor R134 is connected to the output end of the amplifier U4 and one end of a resistor R127, the other end of the resistor R127 outputs a signal MOTOR CURRENT to the second GPIO port of the microcontroller, the inverting end of the amplifier U4 is connected to one end of a resistor R131 and one end of a resistor R12, the other end of the resistor R131 is connected to the signal acquisition module, and the other end of the resistor R12 is grounded.

[0033] The input voltage signal is amplified by amplifier U4 and then outputs the signal MOTOR CURRENT (for example Figure 2 As shown, the preset drive signal is output through the MOTOR DRIVER terminal to drive the motor to rotate, the MOTOR CURRENT terminal monitors the waveform of the motor current feedback, and the microcontroller collects the MOTOR CURRENT terminal signal for a total of 6 times, and then calculates the average value to complete a stable sampling value) to the microcontroller. The microcontroller is a common device, and the input and output signals are common technologies. There is no innovation in the method. Positions T160, T162, T164, T170, T172, T180 in the figure can be connected to the ADC function port of the microcontroller to determine the circuit operation status.

[0034] The working principle of the present invention is: the motor working module is used to connect the motor to alternating current and receive the control signal of the working control module to control the working state of the motor; the working control module is used to receive the signal of the microcontroller and output the control signal to the motor working module through the optical coupler; the signal acquisition module is used to collect the current flowing through the motor, convert it into a voltage signal and output it to the amplification output module; the amplification output module is used to amplify the input voltage signal and output it to the microcontroller.

[0035] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered as exemplary and non-restrictive in all respects.

[0036] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A motor speed monitoring and control circuit, characterized in that: The motor speed monitoring and control circuit includes: The motor working module is used to connect the motor to AC power and receive the control signal of the working control module to control the working state of the motor; The working control module is used to receive the signal of the microcontroller and output the control signal to the motor working module through the optical coupler; The signal acquisition module is used to collect the current flowing through the motor, convert it into a voltage signal and output it to the amplification output module; An amplifying output module is used to amplify the input voltage signal and then output it to the microcontroller; The motor working module is connected to the signal acquisition module, the signal acquisition module is connected to the amplification output module, and the working control module is connected to the motor working module.

2. The motor speed monitoring and control circuit according to claim 1, characterized in that: The motor working module includes a motor, a current transformer T135, and a bidirectional thyristor TR6. One end of the motor is connected to the live wire, the other end of the motor is connected to the second end of the current transformer T135, the third end of the current transformer T135 is connected to the signal acquisition module, the fourth end of the current transformer T135 is grounded, the first end of the current transformer T135 is connected to one end of the capacitor C38, one end of the capacitor C36, and the first end of the bidirectional thyristor TR6, the other end of the capacitor C38 is connected to one end of the resistor R106 and one end of the resistor R107, the other end of the resistor R106 is connected to the other end of the resistor R107, one end of the resistor R105, the second end of the bidirectional thyristor TR6, and the neutral line, the other end of the resistor R105 is connected to the other end of the capacitor C36, and the third end of the bidirectional thyristor TR6 is connected to the working control module.

3. The motor speed monitoring and control circuit according to claim 2, characterized in that: The working control module includes an optocoupler U9, one end of the input end of the optocoupler U9 is connected to one end of a resistor R112, the other end of the resistor R112 is connected to a 5V voltage, the other end of the input end of the optocoupler U9 introduces the signal MOTOR DRIVER output by the first GPIO port of the microcontroller, one end of the output end of the optocoupler U9 is connected to one end of a resistor R111, the other end of the resistor R111 is connected to the other end of the resistor R105, and the other end of the output end of the optocoupler U9 is connected to the third end of the bidirectional thyristor TR6.

4. The motor speed monitoring and control circuit according to claim 1, characterized in that: The signal acquisition module includes a diode D11, a resistor R128, and a capacitor C57. The positive electrode of the diode D11 is connected to the motor working module, the negative electrode of the diode D11 is connected to one end of the resistor R128, one end of the capacitor C57, and the amplification output module, the other end of the resistor R128 is grounded, and the other end of the capacitor C57 is grounded.

5. The motor speed monitoring and control circuit according to claim 1, characterized in that: The amplification output module includes an amplifier U4, an inverting end of the amplifier U4 is connected to one end of a resistor R133 and one end of a resistor R134, the other end of the resistor R133 is grounded, the other end of the resistor R134 is connected to the output end of the amplifier U4 and one end of a resistor R127, the other end of the resistor R127 outputs a signal MOTOR CURRENT to the second GPIO port of the microcontroller, the same phase end of the amplifier U4 is connected to one end of a resistor R131 and one end of a resistor R12, the other end of the resistor R131 is connected to the signal acquisition module, and the other end of the resistor R12 is grounded.

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