Brushless motor driver circuit with duty ratio monitoring function

Abstract

The utility model relates to the technical field of circuit design, in particular to a brushless motor driver circuit with duty ratio monitoring. Comprising an F / V circuit and a logic processing circuit. The input end of the F / V circuit is connected with the MCU end; the output end of the F / V circuit is connected with the input end of the logic processing circuit. According to the utility model, through the combination of the F / V circuit and the logic processing circuit, the PWM signal is converted into the voltage signal by using the F / V circuit so as to reflect the change of the duty ratio, thereby realizing the duty ratio monitoring of the PWM signal sent by the MCU end, effectively preventing the misoperation of the motor when the MCU end is electrified and initialized, and improving the stability and reliability of the brushless motor driver.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit design technical field especially relates to a kind of brushless motor driver circuit with duty cycle monitoring. BACKGROUND

[0002] In brushless motor driver, most of speed, direction control principle is carried out by the PWM signal of MCU duty cycle, frequency control, and MCU in power-on initialization, there is the problem of uncertain port level state, leading to brushless motor driver in MCU power-on initialization It is prone to appear with full speed state jitter and cause unstable situation of misoperation.

[0003] Therefore, there is an urgent need to provide a technical solution to solve the above problems. INVENTION CONTENTS

[0004] To solve the above technical problems, the utility model provides a kind of brushless motor driver circuit with duty cycle monitoring.

[0005] A kind of brushless motor driver circuit with duty cycle monitoring, comprising: F / V circuit and logic processing circuit;

[0006] The input end of the F / V circuit is connected with MCU end;

[0007] The output end of the F / V circuit is connected with the input end of the logic processing circuit.

[0008] The utility model has the beneficial effects of a kind of brushless motor driver circuit with duty cycle monitoring as follows:

[0009] The utility model is combined by F / V circuit and logic processing circuit, using F / V circuit to convert PWM signal into voltage signal to reflect duty cycle change, realizes the duty cycle monitoring of the PWM signal of MCU end, effectively prevents motor misoperation when MCU end power-on initialization, improves the stability and reliability of brushless motor driver.

[0010] In an alternative way, further comprising: isolation circuit;

[0011] The input end of the isolation circuit is connected with the MCU end;

[0012] The output end of the isolation circuit is connected with the input end of the F / V circuit and the input end of the logic processing circuit respectively.

[0013] In the above alternative way, by adding isolation circuit, the electrical isolation between MCU and brushless motor driver circuit is realized, the safety and stability of system are improved, and the misoperation caused by electrical interference is prevented.

[0014] In an optional manner, further comprising: a Hall signal input end;

[0015] The Hall signal input end is connected with the input end of the logic processing circuit.

[0016] In the above optional manner, the introduction of the Hall signal input end enables the brushless motor driver to receive signals from the motor Hall sensor, thereby realizing accurate control of the motor position and speed and improving the operation efficiency and stability of the motor.

[0017] In an optional manner, further comprising: an input circuit;

[0018] The input end of the input circuit is connected with the Hall signal input end;

[0019] The output end of the input circuit is connected with the input end of the logic processing circuit.

[0020] In the above optional manner, the input circuit filters and processes the Hall signal, improving the quality and reliability of the signal and further ensuring the accuracy of motor control.

[0021] In an optional manner, further comprising: a drive circuit;

[0022] The input end of the drive circuit is connected with the output end of the logic processing circuit.

[0023] In the above optional manner, the addition of the drive circuit enables the output of the logic processing circuit to drive the MOS tube switch in the three-phase bridge, thereby realizing accurate modulation of the motor power supply and controlling the operation of the motor.

[0024] In an optional manner, further comprising: a linear voltage stabilizing circuit;

[0025] The input end of the linear voltage stabilizing circuit is connected with the power supply input end;

[0026] The output end of the linear voltage stabilizing circuit is connected with the input end of the F / V circuit, the input end of the logic processing circuit, the input end of the isolation circuit, the input end of the input circuit, and the input end of the drive circuit, respectively.

[0027] In the above optional manner, the linear voltage stabilizing circuit provides a stable power supply voltage for the brushless motor driver circuit, ensuring the normal operation of each circuit module and improving the stability and reliability of the system.

[0028] In an optional manner, further comprising: a three-phase bridge;

[0029] The three-phase bridge comprises a plurality of MOS tubes;

[0030] The input end of the three-phase bridge is connected with the input end of the power supply and the output end of the driving circuit respectively.

[0031] The output end of the three-phase bridge is connected with the input end of the logic processing circuit.

[0032] In the optional mode, the three-phase bridge serves as the power output part of the motor, and the motor speed and direction are controlled by precisely controlling the switch of the MOS tube.

[0033] In an optional mode, the three-phase voltage output end is further included.

[0034] The three-phase voltage output end is connected with the output end of the three-phase bridge.

[0035] In the optional mode, the three-phase voltage output end provides the driving voltage for the motor, and the normal operation of the motor is realized.

[0036] In an optional mode, the resistor is further included.

[0037] The input end of the resistor is connected with the output end of the three-phase bridge.

[0038] In the optional mode, the resistor can be used for current sampling or voltage division, so as to monitor the current or voltage of the motor, and thus the real-time monitoring and protection of the motor operation state are realized.

[0039] In an optional mode, the input end of the resistor is further connected with the input end of the logic processing circuit.

[0040] In the optional mode, the current or voltage signal of the motor is introduced into the logic processing circuit through the resistor, and thus the real-time monitoring and feedback control of the motor operation state are realized, and the control precision and stability of the motor are improved.

[0041] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0042] The drawings are only used to show the embodiments and are not considered as limiting the present application.

[0043] Figure 1The utility model discloses a kind of brushless motor driver circuit with duty cycle monitoring of the schematic diagram of the utility model;

[0044] Reference signs: 1, F / V circuit;2, logic processing circuit;3, MCU end;4, isolation circuit;5, hall signal input end;6, input circuit;7, drive circuit;8, linear voltage regulator circuit;9, three-phase bridge;10, three-phase voltage output end;RS: resistance. DETAILED DESCRIPTION

[0045] Exemplary embodiments of the utility model will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the utility model are shown in the accompanying drawings, it should be understood that the utility model can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0046] Figure 1 A schematic diagram of a brushless motor driver circuit with duty cycle monitoring of the utility model is shown. As shown, it comprises: F / V circuit 1 and logic processing circuit 2; Figure 1

[0047] The input end of F / V circuit 1 is connected with MCU end 3;

[0048] The output end of F / V circuit 1 is connected with the input end of logic processing circuit 2.

[0049] Among them, F / V circuit 1 is used to generate enable signal or disable signal according to the duty cycle of PWM signal input from MCU end 3, control the enable state of logic processing circuit 2. Further, F / V circuit 1 receives PWM signal from MCU end 3, converts PWM signal into voltage signal through F / V circuit 1 to reflect the change of duty cycle, so as to detect the duty cycle of PWM signal. If the duty cycle is 0% or 100%, F / V circuit 1 generates disable signal; if the duty cycle is between 1% and 99%, F / V circuit 1 generates enable signal. Then, F / V circuit 1 outputs the generated enable signal or disable signal to the input end (enable control end EN) of logic processing circuit 2 to control the working state of logic processing circuit 2.

[0050] It should be noted that, by using the characteristics of F / V circuit 1, the digital frequency signal of PWM is converted into voltage signal to control the output of logic processing circuit 2. When the input signal of F / V circuit 1 is 0V (duty cycle is 0%) or high level (duty cycle is 100%) (no edge jump), F / V circuit 1 outputs disable signal to prevent motor misoperation. When the input signal of F / V circuit 1 is the square wave signal of duty cycle (with edge jump), F / V circuit 1 outputs enable signal to control logic processing circuit 2 to receive PWM signal.

[0051] ​The logic processing circuit 2 is used for determining whether to process the PWM signal from the MCU end 3 according to the enable signal or the disable signal provided by the F / V circuit 1, and generating a corresponding control timing. Further, the logic processing circuit 2 receives the enable control signal or the disable signal from the F / V circuit 1. If the enable signal is received (indicating that the PWM duty cycle is between 1% and 99%), the logic processing circuit 2 will continue to process other input signals (such as Hall signals). If the disable signal is received (indicating that the PWM duty cycle is 0% or 100%), the logic processing circuit 2 will disable the output control timing to prevent misoperation. The logic processing circuit 2 can generate a corresponding control signal according to the state of the enable signal, and output the generated control signal.

[0052] The MCU end 3 is used for generating and outputting a PWM signal (pulse width modulation signal) and an F / M signal (frequency signal) to control the operation of the F / V circuit 1. Further, the MCU end 3 generates and outputs the PWM signal and the F / M signal according to control requirements, and outputs the generated PWM signal and the F / M signal to the input end of the F / V circuit 1.

[0053] It should be noted that when the MCU end 3 is initialized, the state of the PWM port of the MCU end 3 is not determined, and the misoperation caused by the fault of the MCU end 3 can be shielded through the detection protection of the F / V circuit 1.

[0054] The brushless motor driver circuit with duty cycle monitoring of the utility model through the combination of F / V circuit 1 and logic processing circuit 2, utilizes F / V circuit 1 to convert PWM signal into voltage signal to reflect the change of duty cycle, realizes the duty cycle monitoring of PWM signal sent by MCU end 3, effectively prevents the misoperation of motor during the power-on initialization of MCU end 3, and improves the stability and reliability of brushless motor driver.

[0055] In an alternative way, further comprising: an isolation circuit 4;

[0056] The input end of the isolation circuit 4 is connected with the MCU end 3;

[0057] The output end of the isolation circuit 4 is connected with the input end of the F / V circuit 1 and the input end of the logic processing circuit 2 respectively.

[0058] The isolation circuit 4 is used for providing electrical isolation between different circuits to prevent high voltage or noise interference from affecting sensitive circuits (such as the MCU end 3 and the logic processing circuit 2). The isolation circuit 4 ensures that the signal can be safely transmitted from the MCU end 3 to the F / V circuit 1 and the logic processing circuit 2 without introducing interference or damaging sensitive components. The isolated PWM signal is transmitted to the logic processing circuit 2 for control and regulation. The isolated F / M signal is transmitted to the F / V circuit 1 for frequency-to-voltage conversion.

[0059] It should be noted that the MCU end 3 is a customer control end, and the MCU end 3 sends out a PWM signal, which is provided to the logic processing circuit 2 and the F / V circuit 1 after passing through the isolation circuit 4.

[0060] In an alternative way, it further comprises a Hall signal input end 5.

[0061] The Hall signal input end 5 is connected with the input end of the logic processing circuit 2.

[0062] Among them, the Hall signal input end 5 is used to receive signals from the Hall sensor in the motor, and to deliver the Hall signal to the logic processing circuit 2 to assist in generating correct timing control signals.

[0063] In an alternative way, it further comprises an input circuit 6.

[0064] The input end of the input circuit 6 is connected with the Hall signal input end 5.

[0065] The output end of the input circuit 6 is connected with the input end of the logic processing circuit 2.

[0066] Among them, the input circuit 6 is used to receive the Hall signal (three-way motor Hall signal) delivered by the Hall signal input end 5, and to process and adjust the Hall signal to ensure that the Hall signal can be correctly recognized and used by the logic processing circuit 2. Further, the input circuit 6 receives the Hall signal from the Hall signal input end 5. The Hall signal is generated by the Hall sensor and reflects the position information of the motor rotor. If the Hall signal is disturbed or distorted during transmission, the input circuit 6 will shape the signal to ensure the integrity of the signal. If the voltage level of the Hall signal does not match the level required by the logic processing circuit 2, the input circuit 6 will perform level conversion to make the level meet the requirements of the logic processing circuit 2. The input circuit 6 can also filter the Hall signal to remove high-frequency noise and interference, ensuring the stability of the signal. After processing, the input circuit 6 outputs a stable and reliable Hall signal, and outputs the processed Hall signal to the input end of the logic processing circuit 2.

[0067] In an alternative way, it further comprises a drive circuit 7.

[0068] The input end of the drive circuit 7 is connected with the output end of the logic processing circuit 2.

[0069] The driving circuit 7 is configured to receive the control signal from the logic processing circuit 2 and amplify and convert the control signal to drive the load (e.g. motor) to work in the expected manner. Further, the driving circuit 7 receives the control signal from the output end of the logic processing circuit 2. The control signal is a timing control signal generated by the logic processing circuit 2 according to the Hall signal, which determines the driving timing and phase of the load. The control signal output by the logic processing circuit 2 is a low-current logic level signal, which cannot directly drive the load. The driving circuit 7 amplifies the low-current logic level signal to provide sufficient current and voltage to drive the load. If the voltage level of the control signal does not match the voltage level of the load, the driving circuit 7 converts the signal to ensure that the signal can correctly drive the load. The driving circuit 7 can also prevent overcurrent, overvoltage and overheating from damaging the circuit and the load. After processing, the driving circuit 7 outputs a high-power driving signal.

[0070] It should be noted that the three motor Hall signals output by the Hall signal input end 5 are filtered by the input circuit 6, transmitted to the logic processing circuit 2 for logic conversion, six timing control signals are generated, and the six signals are transmitted to the driving circuit 7 (half-bridge driving chip) for driving amplification, thereby controlling the three-phase bridge 9 (six MOS tubes) to open and close in time sequence, realizing power supply modulation, and outputting three-way (U, V, W) voltage signals (driving signals) capable of driving the motor to rotate.

[0071] In an alternative way, the linear voltage stabilizing circuit 8 is further included.

[0072] The input end of the linear voltage stabilizing circuit 8 is connected with the power supply input end.

[0073] The output end of the linear voltage stabilizing circuit 8 is connected with the input end of the F / V circuit 1, the input end of the logic processing circuit 2, the input end of the isolation circuit 4, the input end of the input circuit 6 and the input end of the driving circuit 7, respectively.

[0074] The linear voltage stabilizing circuit 8 is used to convert the high input voltage received from the power supply input into a stable voltage suitable for the normal operation of the F / V circuit 1, the logic processing circuit 2, the isolation circuit 4, the input circuit 6 and the driving circuit 7, so as to ensure that the above-mentioned circuits can obtain the required operating voltage and operate stably. After the power supply input passes through the linear voltage stabilizing circuit 8, it is converted into a VCC power supply for powering each functional circuit. At the same time, the linear voltage stabilizing circuit 8 outputs the VCC power supply to power the Hall device. Further, the linear voltage stabilizing circuit 8 receives the high input voltage from the power supply input, reduces and stabilizes the high input voltage to a fixed output voltage value through an internal regulating mechanism, so as to ensure that the output voltage is stable and has no fluctuation. The linear voltage stabilizing circuit 8 can also effectively remove the high-frequency noise and interference in the input power supply, provide a pure DC voltage, and prevent the load current from being too large to damage the circuit. The linear voltage stabilizing circuit 8 finally outputs the stabilized voltage to the F / V circuit 1, the logic processing circuit 2, the isolation circuit 4, the input circuit 6 and the driving circuit 7.

[0075] In an alternative manner, the application further comprises a three-phase bridge 9.

[0076] The three-phase bridge 9 comprises a plurality of MOS tubes.

[0077] The input end of the three-phase bridge 9 is connected with the power supply input and the output end of the driving circuit 7 respectively.

[0078] The output end of the three-phase bridge 9 is connected with the input end of the logic processing circuit 2.

[0079] The three-phase bridge 9 is used to convert the power from the power supply input into three-phase AC power suitable for the load by switching control of a plurality of MOSFETs. The three-phase bridge 9 performs precise power switching operation under the control of the drive circuit 7 to ensure that the output meets the control requirements set by the logic processing circuit 2. Further, the three-phase bridge 9 receives high-current, high-voltage DC power from the power supply input to supply the load. The three-phase bridge 9 receives control signals from the drive circuit 7 at its output to control the switching state of the MOSFETs in the three-phase bridge 9 to achieve precise control of the power. Based on the control signals provided by the drive circuit 7, the MOSFETs can perform high-speed switching operation to convert the DC power into three-phase AC power. The switching timing and state of each MOSFET are precisely controlled by the drive circuit 7. Through the switching operation of the MOSFETs, the DC power from the power supply input is converted into three-phase AC power to meet the requirements of the load. The three-phase bridge 9 can also adjust the size and waveform of the output current based on the control signals from the drive circuit 7 to ensure that the output meets the control requirements of the logic processing circuit 2. Through switching control and power conversion of the MOSFETs, the three-phase bridge 9 can output a three-phase AC power that meets the requirements of the load, with the phase, frequency, and current size of the three-phase AC power being precisely controlled by the drive circuit 7. The three-phase bridge 9 finally outputs the processed three-phase AC power to the input of the logic processing circuit 2 for further signal processing and control adjustment by the logic processing circuit 2.

[0080] In an alternative way, further comprising: a three-phase voltage output 10;

[0081] The three-phase voltage output 10 is connected to the output of the three-phase bridge 9.

[0082] The three-phase voltage output 10 is used to deliver the three-phase AC power output by the three-phase bridge 9 to the load. The three-phase voltage output 10 serves as an output interface in the circuit to output the processed power from the three-phase bridge 9 to the load, ensuring that the load can receive the required three-phase AC power.

[0083] In an alternative way, further comprising: a resistor RS;

[0084] The input of the resistor RS is connected to the output of the three-phase bridge 9.

[0085] The input of the resistor RS is also connected to the input of the logic processing circuit 2.

[0086] The resistor RS is used for load simulation or current detection, protects circuit elements by limiting current or converting power, or performs signal sampling. The resistor RS can also be used to stabilize the output of the three-phase bridge 9 and prevent overcurrent in the circuit. Further, the input end of the resistor RS is connected to the output end of the three-phase bridge 9, so the resistor RS receives three-phase alternating current from the three-phase bridge 9. The three-phase bridge 9 has converted the power from the power supply into three-phase alternating current and outputs the three-phase alternating current to the resistor RS through the output end of the three-phase bridge 9. By limiting the current through the resistor RS by the resistance value, excessive current is prevented from damaging other circuit elements. The resistor RS can divide the voltage output by the three-phase bridge 9 to adapt to the input requirements of the logic processing circuit 2. At the same time, the resistor RS can act as a load to consume the power output by the three-phase bridge 9, especially during testing or debugging to simulate the actual load operation. The resistor RS can also be used for current sampling, by measuring the voltage difference across the resistor RS, the current flowing through can be calculated and the information can be fed back to the logic processing circuit 2 for analysis and control adjustment.

[0087] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A brushless motor driver circuit with duty cycle monitoring, characterized by, Comprise: F / V circuit and logic processing circuit; The input end of the F / V circuit is connected with the MCU end; The output end of the F / V circuit is connected with the input end of the logic processing circuit.

2. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 1, characterized in that, Also include: Isolation circuit; The input end of the isolation circuit is connected with the MCU end; The output end of the isolation circuit is connected with the input end of the F / V circuit and the input end of the logic processing circuit respectively.

3. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 2, characterized in that, Also include: Hall signal input end; The Hall signal input end is connected with the input end of the logic processing circuit.

4. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 3, characterized in that, Also include: Input circuit; The input end of the input circuit is connected with the Hall signal input end; The output end of the input circuit is connected with the input end of the logic processing circuit.

5. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 4, characterized in that, Also include: Drive circuit; The input end of the drive circuit is connected with the output end of the logic processing circuit.

6. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 5, characterized in that, Also include: Linear voltage stabilizing circuit; The input end of the linear voltage stabilizing circuit is connected with the power supply input end; The output end of the linear voltage stabilizing circuit is connected with the input end of the F / V circuit, the input end of the logic processing circuit, the input end of the isolation circuit, the input end of the input circuit and the input end of the drive circuit respectively.

7. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 6, characterized in that, Also include: Three-phase bridge; The three-phase bridge includes a plurality of MOS tubes; The input end of the three-phase bridge is connected with the power supply input end and the output end of the drive circuit respectively; The output end of the three-phase bridge is connected with the input end of the logic processing circuit.

8. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 7, characterized in that, Also include: Three-phase voltage output end; The three-phase voltage output end is connected with the output end of the three-phase bridge.

9. A brushless motor driver circuit with duty cycle monitoring as claimed in claim 8, characterized in that, Also include: Resistance; The input end of the resistance is connected with the output end of the three-phase bridge.

10. The brushless motor driver circuit with duty cycle monitoring of claim 9, wherein, The input end of the resistance is also connected with the input end of the logic processing circuit.

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