Reverse dynamic potential detection integrated device for direct current brushless motor

Abstract

The utility model provides a reverse dynamic potential detection integrated device for a direct current brushless motor. The reverse dynamic potential detection integrated device comprises a circuit board, a single-chip microcomputer MCU and an external circuit. Wherein an anti-dynamic-potential integrated resistor is arranged in the single-chip microcomputer MCU, and the outside of the single-chip microcomputer MCU is connected outwards through a pin; and an external circuit is provided with a filter capacitor which is connected with the anti-dynamic-potential integrated resistor through a pin. According to the anti-dynamic potential detection integrated device for the direct current brushless motor provided by the utility model, the anti-dynamic potential resistors are integrated and arranged in the single chip microcomputer, so that the layout of an external circuit is reduced, the layout space of a circuit board is reduced, the circuit design is simplified, and the risk of SMT (Surface Mount Technology) is also reduced.

Description

Technical Field

[0001] The utility model relates to a back electromotive force detection integrated device for a DC brushless motor. Background Art

[0002] During the operation of the motor, due to the structure of the motor coil, three-phase circuit signals will be formed inside the circuit. In order to detect the electrical network signals in the three-phase circuit under the working condition of the motor, the voltage signals of the three-phase circuit need to be input into the single-chip microcomputer to detect the electromotive force generated by its voltage. Since the input voltage of the motor in the motor is different, the peak voltage of each phase circuit is from more than ten volts to dozens of volts. Therefore, the phase voltage needs to be divided to a voltage below 5V or 3V for the analog voltage that can be safely recognized by the MCU. Therefore, a back electromotive force detection circuit needs to be arranged.

[0003] In a traditional DC brushless motor (BLDC), the motor drives the stator coil through a three-phase H-bridge circuit ( Figure 1 as shown), the midpoint lead-out wire (electrical network number U) of the upper tube Q1-MOS and the lower tube Q4-MOS controls the U phase; the midpoint lead-out wire (electrical network number V) of the upper tube Q2-MOS and the lower tube Q5-MOS controls the V phase; the midpoint lead-out wire (electrical network number W) of the upper tube Q3-MOS and the lower tube Q6-MOS controls the W phase; and then through the back electromotive force detection circuit ( Figure 2 as shown), each phase circuit needs at least two resistors (pull-up and pull-down) to divide the voltage of the phase voltage, and one capacitor for filtering. A total of at least 6 resistors and 3 capacitors are required for the three-phase circuit. The electrical network number U is sent to the MCU for detection after being divided by R35 and R43 and filtered by C29 to obtain the electrical network number BEMFU; the electrical network number V is sent to the MCU for detection after being divided by R36 and R44 and filtered by C28 to obtain the electrical network number BEMFV; the electrical network number W is sent to the MCU for detection after being divided by R37 and R45 and filtered by C30 to obtain the electrical network number BEMFW.

[0004] In this way, three input circuits with different phases need to be arranged around the single-chip microcomputer MCU on the integrated circuit, and the back electromotive force resistors are arranged on the pin side of the single-chip microcomputer MCU. Since the structure of the single-chip microcomputer itself is highly integrated, the distance between its pins is very small. Once complex circuits are arranged, the space on the circuit board needs to be borrowed, which affects the circuit layout. At the same time, because the space is occupied, there will be a risk of SMT soldering, affecting the yield of the entire circuit board. Summary of the Utility Model

[0005] The utility model aims to provide a back electromotive force detection integrated device for a DC brushless motor. By integrating the back electromotive force resistors into the single-chip microcomputer MCU, the external circuit layout space on the circuit board is reduced, the external circuit is simplified, the utilization rate of the circuit board space is improved, and the risk of SMT soldering is further reduced.

[0006] To solve the above problems, a back electromotive force detection integrated device for a DC brushless motor provided by the present utility model adopts the following technical solutions:

[0007] A back electromotive force detection integrated device for a DC brushless motor includes a circuit board, a single-chip microcomputer MCU, and an external circuit; wherein a back electromotive force integrated resistor is provided inside the single-chip microcomputer MCU and is connected outward through pins; a filter capacitor is provided in the external circuit and is connected to the back electromotive force integrated resistor through pins.

[0008] The back electromotive force integrated resistors are set to three, which are respectively connected to the three-phase H-bridge circuits inside the brushless motor, and are set as the U-phase circuit, the V-phase circuit, and the W-phase circuit. The back electromotive force integrated resistors are also correspondingly set as the U-phase integrated resistor, the V-phase integrated resistor, and the W-phase integrated resistor. Each phase of the resistor is provided with three pins and is connected outward to the three-phase H-bridge circuit of the motor.

[0009] Further, a U-phase input pin, a U-phase voltage-dividing pin, and a U-phase grounding pin are provided on the U-phase integrated resistor; the U-phase input pin is connected outward to the U-phase circuit of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase voltage-dividing pin is connected to the inside of the U-phase integrated resistor, and one end is connected outward to the filter capacitor; the U-phase grounding pin extends outward to ground and is also connected to the other end of the filter capacitor.

[0010] Further, a V-phase input pin, a V-phase voltage-dividing pin, and a V-phase grounding pin are provided on the V-phase integrated resistor; the V-phase input pin is connected outward to the V-phase circuit of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase voltage-dividing pin is connected to the inside of the V-phase integrated resistor, and one end is connected outward to the filter capacitor; the V-phase grounding pin extends outward to ground and is also connected to the other end of the filter capacitor.

[0011] Further, a W-phase input pin, a W-phase voltage-dividing pin, and a W-phase grounding pin are provided on the W-phase integrated resistor; the W-phase input pin is connected outward to the W-phase circuit of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase voltage-dividing pin is connected to the inside of the W-phase integrated resistor, and one end is connected outward to the filter capacitor; the W-phase grounding pin extends outward to ground and is also connected to the other end of the filter capacitor.

[0012] Further, the filter capacitor corresponds to the integrated resistor and is also provided with a U-phase capacitor, a V-phase capacitor, and a W capacitor.

[0013] The beneficial effects of the present utility model are as follows: A back electromotive force detection integrated device for a DC brushless motor provided by the present utility model integrates the back electromotive force resistors and arranges them inside the single-chip microcomputer, reducing the external circuit layout, decreasing the layout space of the circuit board, simplifying the circuit design, and also reducing the risk of SMT patching. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 is a schematic diagram of a three-phase H-bridge circuit of the prior art of the present utility model.

[0015] Attached Figure 2 is a schematic diagram of a back electromotive force detection circuit of the prior art of the present utility model.

[0016] Attached Figure 3 is a schematic diagram of an external circuit of the back electromotive force integrated device of the present utility model.

[0017] Attached Figure 4 is a schematic diagram of a circuit of a single-chip microcomputer integrated resistor of the back electromotive force integrated device of the present utility model.

[0018] Wherein: 1. U-phase circuit, 2. V-phase circuit, 3. W-phase circuit, 4. U-phase integrated resistor, 5. V-phase integrated resistor, 6. W-phase integrated resistor, 7. U-phase input pin, 8. U-phase voltage-dividing pin, 9. U-phase grounding pin, 10. V-phase input pin, 11. V-phase voltage-dividing pin, 12. V-phase grounding pin, 13. W-phase input pin, 14. W-phase voltage-dividing pin, 15. W-phase grounding pin, 16. U-phase capacitor, 17. V-phase capacitor, 18. W capacitor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to understand the technical solution provided by the present utility model more clearly, the following further describes the present utility model in conjunction with the drawings and specific embodiments.

[0020] As shown in the drawings, a back electromotive force detection integrated device for a DC brushless motor provided by the present utility model includes a circuit board, a single-chip microcomputer MCU, and an external circuit; wherein a back electromotive force integrated resistor is arranged inside the single-chip microcomputer MCU and is connected outward by pins; the external circuit is provided with filter capacitors and is connected to the back electromotive force integrated resistor through pins;

[0021] The back electromotive force integrated resistors are set to three, respectively corresponding to connecting the three-phase H-bridge circuits in the brushless motor, set as the U-phase circuit 1, the V-phase circuit 2, and the W-phase circuit 3. The back electromotive force integrated resistors are also correspondingly set as the U-phase integrated resistor 4, the V-phase integrated resistor 5, and the W-phase integrated resistor 6. Each phase of the resistor is provided with three pins and is connected outward to the three-phase H-bridge circuit of the motor.

[0022] Further, a U-phase input pin 7, a U-phase voltage-dividing pin 8, and a U-phase grounding pin 9 are provided on the U-phase integrated resistor 4; the U-phase input pin 7 is externally connected to the U-phase circuit 1 of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase voltage-dividing pin is connected to the inside of the U-phase integrated resistor 4, and one end is externally connected to the filter capacitor; the U-phase grounding pin 9 extends externally to ground and is simultaneously connected to the other end of the filter capacitor.

[0023] Further, a V-phase input pin 10, a V-phase voltage-dividing pin 11, and a V-phase grounding pin 12 are provided on the V-phase integrated resistor 5; the V-phase input pin 10 is externally connected to the V-phase circuit 2 of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase voltage-dividing pin is connected to the inside of the V-phase integrated resistor 5, and one end is externally connected to the filter capacitor; the V-phase grounding pin 12 extends externally to ground and is simultaneously connected to the other end of the filter capacitor.

[0024] Further, a W-phase input pin 13, a W-phase voltage-dividing pin 14, and a W-phase grounding pin 15 are provided on the W-phase integrated resistor 6; the W-phase input pin 13 is externally connected to the W-phase circuit 3 of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase voltage-dividing pin is connected to the inside of the W-phase integrated resistor 6, and one end is externally connected to the filter capacitor; the W-phase grounding pin 15 extends externally to ground and is simultaneously connected to the other end of the filter capacitor.

[0025] Further, the filter capacitor corresponds to the integrated resistor and is also provided with a U-phase capacitor 16, a V-phase capacitor 17, and a W capacitor 18.

Claims

1. A DC brushless motor reaction potential detection integrated device, comprising a circuit board, a single-chip microcomputer MCU and an external circuit; characterized in that: The single-chip microcomputer MCU is provided with a back-potential integrated resistor, which is externally connected to the outside through pins; the external circuit is provided with a filter capacitor, which is connected to the back-potential integrated resistor through pins; The back-motive force integrated resistor is set to three, which are respectively connected to the three-phase H-bridge circuit in the brushless motor, and are set to U-phase circuit, V-phase circuit and W-phase circuit. The back-motive force integrated resistor is also correspondingly set to U-phase integrated resistor, V-phase integrated resistor and W-phase integrated resistor. The resistor of each phase is provided with three pins, which are externally connected to the three-phase H-bridge circuit of the motor.

2. The integrated device for detecting reaction potential of a brushless DC motor according to claim 1, characterized in that: The U-phase integrated resistor is provided with a U-phase input pin, a U-phase voltage dividing pin and a U-phase grounding pin; the U-phase input pin is externally connected to the U-phase circuit of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase voltage dividing pin is cross-connected to the inside of the U-phase integrated resistor, and one end is externally connected to the filter capacitor; the U-phase grounding pin extends outward to be grounded, and is connected to the other end of the filter capacitor at the same time.

3. The integrated device for detecting reaction potential of a brushless DC motor according to claim 1, characterized in that: The V-phase integrated resistor is provided with a V-phase input pin, a V-phase voltage-dividing pin and a V-phase grounding pin; the V-phase input pin is externally connected to the V-phase circuit of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase voltage-dividing pin is cross-connected to the inside of the V-phase integrated resistor, and one end is externally connected to the filter capacitor; the V-phase grounding pin is extended outward to be grounded, and is connected to the other end of the filter capacitor at the same time.

4. The integrated device for detecting reaction potential of a brushless DC motor according to claim 1, characterized in that: The W-phase integrated resistor is provided with a W-phase input pin, a W-phase voltage-dividing pin and a W-phase grounding pin; the W-phase input pin is externally connected to the W-phase circuit of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase voltage-dividing pin is cross-connected to the inside of the W-phase integrated resistor, and one end is externally connected to the filter capacitor; the W-phase grounding pin extends outward to be grounded, and is connected to the other end of the filter capacitor.

5. The integrated device for detecting reaction potential of a brushless DC motor according to claim 1, characterized in that: The filter capacitor corresponds to the integrated resistor, and is also provided with a U-phase capacitor, a V-phase capacitor and a W capacitor.

Images