Half-duplex communication circuit for brushless motor

Abstract

The utility model relates to a half-duplex communication circuit for a brushless motor, which comprises a battery pack and a motor controller, and a signal line DATA is connected between the battery pack and the motor controller. A field effect transistor Q1, a field effect transistor Q2, a signal transmitting end TXD1 and a signal receiving end RXD1 are arranged in the battery pack; and a field effect transistor Q3, a field effect transistor Q4, a signal transmitting end TXD2 and a signal receiving end RXD2 are arranged in the motor controller. According to the utility model, single-bus half-duplex communication between the motor and the battery pack is realized, and the wire harness cost of the whole machine is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electric control, in particular to a half-duplex communication circuit for a brushless motor. Background Art

[0002] Brushless motors used in vacuum cleaners are typically paired with lithium-ion battery packs, and some applications require data exchange. Communication signals are typically TTL-level, with voltages between 3.3V and 5V. However, the signal cables connecting the two modules are often long, making them susceptible to interference and thus affecting communication quality. The signal cables used for both transmission and reception consume a lot of wires, resulting in high costs.

[0003] Therefore, it is very important to design a half-duplex communication circuit for brushless motors. Utility Model Content

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problems of high wire consumption and high cost in the brushless motor and lithium battery pack communication system used in vacuum cleaner products in the prior art.

[0005] In order to solve the above technical problems, the utility model provides a half-duplex communication circuit for a brushless motor, characterized in that: it includes a battery pack and a motor controller, and a signal line DATA is connected between the battery pack and the motor controller;

[0006] The battery pack is provided with a field effect transistor Q1, a field effect transistor Q2, a signal transmitting terminal TXD1, and a signal receiving terminal RXD1; the gate of the field effect transistor Q2 is connected to the signal transmitting terminal TXD1, the drain of the field effect transistor Q2 is connected to the signal line DATA, and the source of the field effect transistor Q2 is connected to the signal power supply VCC inside the battery pack; the gate of the field effect transistor Q1 is connected to the signal line DATA, the drain of the field effect transistor Q1 is connected to the signal receiving terminal RXD1 and the signal power supply VCC inside the battery pack, respectively, and the source of the field effect transistor Q1 is grounded;

[0007] The motor controller is provided with a field effect transistor Q3, a field effect transistor Q4, a signal sending terminal TXD2 and a signal receiving terminal RXD2; the gate of the field effect transistor Q3 is connected to the signal sending terminal TXD2, the drain of the field effect transistor Q3 is connected to the signal line DATA, and the source of the field effect transistor Q3 is connected to the signal power supply VCC inside the motor controller; the gate of the field effect transistor Q4 is connected to the signal line DATA, the drain of the field effect transistor Q4 is connected to the signal receiving terminal RXD2, the drain of the field effect transistor Q4 is respectively connected to the signal receiving terminal RXD2 and the signal power supply VCC inside the motor controller, and the source of the field effect transistor Q4 is grounded.

[0008] In an embodiment of the present utility model, the gate of the field effect transistor Q1 is connected to the signal line DATA through a resistor R4 and a resistor R5 in sequence;

[0009] A resistor R3 is further provided between the connection node of the gate of the field effect transistor Q1 and the resistor R4 and the source of the field effect transistor Q1.

[0010] In an embodiment of the present utility model, the drain output of the field effect transistor Q1 includes a first branch and a second branch. The first branch of the drain of the field effect transistor Q1 is connected to the signal receiving end RXD1 through a resistor R1; the second branch of the drain of the field effect transistor Q1 is connected to the signal power supply VCC inside the battery pack through a resistor R2.

[0011] In an embodiment of the present utility model, the drain of the field effect transistor Q2 is connected to the connection node of the resistor R4 and the resistor R5 through a diode D1.

[0012] In an embodiment of the present utility model, the gate of the field effect transistor Q2 is connected to the signal sending end TXD1 through a resistor R6. A resistor R7 is further provided between the connection node of the gate of the field effect transistor Q2 and the resistor R6 and the source of the field effect transistor Q2.

[0013] In an embodiment of the present utility model, the gate of the field effect transistor Q3 is connected to the signal sending end TXD2 through a resistor R10. A resistor R9 is further provided between the connection node of the gate of the field effect transistor Q3 and the resistor R10 and the source of the field effect transistor Q3.

[0014] In an embodiment of the present utility model, the drain of the field effect transistor Q3 is connected to one end of a resistor R8. The other end of the resistor R8 is respectively connected to the signal line DATA and one end of a resistor R11. The other end of the resistor R11 is connected to the gate of the field effect transistor Q4.

[0015] A resistor R13 is further provided between the connection node of the gate of the field effect transistor Q4 and the other end of the resistor R1 and the source of the field effect transistor Q4.

[0016] In an embodiment of the present utility model, the drain output of the field effect transistor Q4 includes a first branch and a second branch. The first branch of the drain of the field effect transistor Q4 is connected to the signal receiving end RXD2 through a resistor R14; the second branch of the drain of the field effect transistor Q4 is connected to the signal power supply VCC inside the motor controller through a resistor R12.

[0017] In one embodiment of the present utility model, the field effect transistor Q1 and the field effect transistor Q4 are both N-channel enhancement mode field effect transistors, and the field effect transistor Q2 and the field effect transistor Q3 are both P-channel enhancement mode field effect transistors.

[0018] The above technical solution of the present utility model has the following advantages compared with the prior art:

[0019] The signal received by the signal receiving end RXD2 of the present utility model is the same as the signal sent by the signal sending end TXD1, and the signal received by the signal receiving end RXD1 is the same as the signal sent by the signal sending end TXD2, realizing single-bus half-duplex communication between the motor and the battery pack, reducing the wiring harness cost of the whole machine, and using field effect transistors to isolate the signals, avoiding the influence of interference caused by different MCU power supply voltages and transmission distances. Description of the Drawings

[0020] In order to make the content of the present utility model easier to be clearly understood, the present utility model will be further described in detail below according to the specific embodiments of the present utility model and in conjunction with the drawings.

[0021] Figure 1 It is a block diagram of a half-duplex communication circuit for a brushless motor of the present utility model. Detailed Embodiment

[0022] The present utility model will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present utility model and be able to implement it, but the embodiments given are not intended to limit the present utility model.

[0023] Embodiment 1

[0024] Referring to Figure 1 As shown, the present utility model relates to a half-duplex communication circuit for a brushless motor, including a battery pack and a motor controller, and a signal line DATA is connected between the battery pack and the motor controller.

[0025] The battery pack is provided with a field effect transistor Q1, a field effect transistor Q2, a signal sending end TXD1 and a signal receiving end RXD1; the gate of the field effect transistor Q2 is connected to the signal sending end TXD1, the drain of the field effect transistor Q2 is connected to the signal line DATA, and the source of the field effect transistor Q2 is connected to the signal power supply VCC inside the battery pack; the gate of the field effect transistor Q1 is connected to the signal line DATA, the drain of the field effect transistor Q1 is respectively connected to the signal receiving end RXD1 and the signal power supply VCC inside the battery pack, and the source of the field effect transistor Q1 is grounded;

[0026] A field-effect transistor Q3, a field-effect transistor Q4, a signal transmission end TXD2, and a signal reception end RXD2 are provided inside the motor controller; the gate of the field-effect transistor Q3 is connected to the signal transmission end TXD2, the drain of the field-effect transistor Q3 is connected to the signal line DATA, and the source of the field-effect transistor Q3 is connected to the signal power supply VCC inside the motor controller; the gate of the field-effect transistor Q4 is connected to the signal line DATA, the drain of the field-effect transistor Q4 is connected to the signal reception end RXD2, the drain of the field-effect transistor Q4 is respectively connected to the signal reception end RXD2 and the signal power supply VCC inside the motor controller, and the source of the field-effect transistor Q4 is grounded.

[0027] It should be noted that Figure 1 the two signal power supplies VCC in the battery pack communication circuit in [[]] are the same VCC, and the corresponding single-chip microcomputer on the battery pack is used to cut off / energize the battery pack. Similarly, the signal power supply VCC inside the motor controller is connected by the corresponding single-chip microcomputer of the motor controller, and this single-chip microcomputer is used to control the normal operation of the motor connected to the motor controller.

[0028] Figure 1 In addition to being connected by the signal line DATA between the battery pack and the motor controller in [[]], they are also connected by a power line. This power line includes a power positive line and a power negative line (i.e., ground). The power positive line is obtained by connecting the power positive P+ of the respective power lines of the battery pack and the motor controller through Figure 1 The power negative line (i.e., ground) is obtained by connecting the power negative GND of the respective power lines of the battery pack and the motor controller through Figure 1 in [[]].

[0029] Further, the gate of the field-effect transistor Q1 is sequentially connected to the signal line DATA through a resistor R4 and a resistor R5; a resistor R3 is also provided between the connection node of the gate of the field-effect transistor Q1 and the resistor R4 and the source of the field-effect transistor Q1.

[0030] Further, the drain output of the field-effect transistor Q1 includes a first branch and a second branch. The first branch of the drain of the field-effect transistor Q1 is connected to the signal reception end RXD1 through a resistor R1; the second branch of the drain of the field-effect transistor Q1 is connected to the signal power supply VCC through a resistor R2. In an abnormal state, the resistor R2 can adjust the voltage at the resistor R1 (reduce the possibility of the resistor R1 burning out) and reduce the short-circuit risk.

[0031] Further, the drain of the field-effect transistor Q2 is connected to the connection node of the resistor R4 and the resistor R5 through a diode D1.

[0032] Further, the gate of the field effect transistor Q2 is connected to the signal sending end TXD1 through a resistor R6, and a resistor R7 is also provided between the connection node of the gate of the field effect transistor Q2 and the resistor R6 and the source of the field effect transistor Q2.

[0033] Further, the gate of the field effect transistor Q3 is connected to the signal sending end TXD2 through a resistor R10, and a resistor R9 is also provided between the connection node of the gate of the field effect transistor Q3 and the resistor R10 and the source of the field effect transistor Q3.

[0034] Further, the drain of the field effect transistor Q3 is connected to one end of a resistor R8, the other end of the resistor R8 is respectively connected to a signal line DATA and one end of a resistor R11, and the other end of the resistor R11 is connected to the gate of the field effect transistor Q4.

[0035] Further, a resistor R13 is also provided between the connection node of the gate of the field effect transistor Q4 and the other end of the resistor R1 and the source of the field effect transistor Q4.

[0036] Further, the drain output of the field effect transistor Q4 includes a first branch and a second branch. The first branch of the drain of the field effect transistor Q4 is connected to the signal receiving end RXD2 through a resistor R14; the second branch of the drain of the field effect transistor Q4 is connected to a signal power supply VCC through a resistor R12. In an abnormal state, the resistor R12 can adjust the voltage at the resistor R14 (reduce the possibility of the resistor R14 being burned out) and reduce the short - circuit risk.

[0037] The resistors R3, R4, R5, R8, R11 and R13 provided in this embodiment can adjust the voltages at the field effect transistors Q1, Q2, Q3 and Q4.

[0038] The resistor R6 stabilizes the waveform sent by the signal sending end TXD1, the resistor R7 makes the field effect transistor Q2 non - conductive during power - on, the resistor R9 makes the field effect transistor Q3 non - conductive during power - on, and the resistor R10 stabilizes the waveform sent by the signal sending end TXD2.

[0039] Further, both the field effect transistor Q1 and the field effect transistor Q4 are N - channel enhancement - type field effect transistors (with TVS protection), and both the field effect transistor Q2 and the field effect transistor Q3 are P - channel enhancement - type field effect transistors (with TVS protection).

[0040] For the battery pack, the field effect transistor Q1 is used to connect the signal receiving end RXD1 to the signal line DATA when receiving data. The field effect transistor Q2 is used to connect the signal sending end TXD1 to the signal line DATA when sending data. For the motor controller, the field effect transistor Q3 is used to connect the signal sending end TXD2 to the signal line DATA when sending data. The field effect transistor Q4 is used to connect the signal receiving end RXD2 to the signal line DATA when receiving data.

[0041] The working principle of this embodiment will be introduced in detail as follows:

[0042] When the battery pack sends data through the signal line DATA, the motor controller is in the receiving state. The signal sending end TXD1 sends a low-level signal. The gates of the field effect transistors Q2 and Q3 are at low level. The field effect transistors Q2 and Q3 are in the conducting state. The signal line DATA is at high level. The gate of the field effect transistor Q4 is at high level. The field effect transistor Q4 is in the conducting state. The signal receiving end RXD2 is connected to the negative power supply terminal GND, and the signal receiving end RXD2 is at low level. When the signal sending end TXD1 sends a high-level signal, the field effect transistor Q1 is in the cut-off state. The signal line DATA is at low level. The field effect transistor Q4 is in the cut-off state. The signal receiving end RXD2 is at high level driven by the signal power supply VCC.

[0043] Similarly, when the motor controller sends data through the signal line DATA, the battery pack is in the receiving state. At this time, the signal sending end TXD1 is set to low level, and the signal sending end TXD2 sends a low-level signal. The gates of the field effect transistors Q2 and Q3 are at low level. The field effect transistors Q2 and Q3 are in the conducting state. The signal line DATA is at high level. The gate of the field effect transistor Q1 is at high level. The field effect transistor Q1 is in the conducting state. The signal receiving end RXD1 is connected to the negative power supply terminal GND, and the signal receiving end RXD1 is at low level. When the signal sending end TXD2 sends a high-level signal, the field effect transistor Q3 is in the cut-off state. The signal line DATA is at low level. The field effect transistor Q1 is in the cut-off state. The signal receiving end RXD1 is at high level driven by the signal power supply VCC. During this process, the signal received by the signal receiving end RXD2 is the same as the signal sent by the signal sending end TXD1, and the signal received by the signal receiving end RXD1 is the same as the signal sent by the signal sending end TXD2, realizing single-bus half-duplex communication between the battery pack and the motor controller, reducing the wiring harness cost of the whole machine, and using field effect transistors to isolate signals to avoid the influence of signal interference and transmission distance.

[0044] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the creation of the present utility model.

Claims

1. A half-duplex communication circuit for a brushless motor, characterized in that: It includes a battery pack and a motor controller, and a signal line DATA is connected between the battery pack and the motor controller; A field effect transistor Q1, a field effect transistor Q2, a signal transmitting end TXD1 and a signal receiving end RXD1 are arranged in the battery pack; the gate of the field effect transistor Q2 is connected to the signal transmitting end TXD1, the drain of the field effect transistor Q2 is connected to the signal line DATA, and the source of the field effect transistor Q2 is connected to the signal power supply VCC inside the battery pack; the gate of the field effect transistor Q1 is connected to the signal line DATA, the drain of the field effect transistor Q1 is respectively connected to the signal receiving end RXD1 and the signal power supply VCC inside the battery pack, and the source of the field effect transistor Q1 is grounded; A field effect transistor Q3, a field effect transistor Q4, a signal transmitting end TXD2 and a signal receiving end RXD2 are arranged in the motor controller; the gate of the field effect transistor Q3 is connected to the signal transmitting end TXD2, the drain of the field effect transistor Q3 is connected to the signal line DATA, and the source of the field effect transistor Q3 is connected to the signal power supply VCC inside the motor controller; the gate of the field effect transistor Q4 is connected to the signal line DATA, the drain of the field effect transistor Q4 is connected to the signal receiving end RXD2, the drain of the field effect transistor Q4 is respectively connected to the signal receiving end RXD2 and the signal power supply VCC inside the motor controller, and the source of the field effect transistor Q4 is grounded.

2. The half-duplex communication circuit for a brushless motor according to claim 1, wherein: The gate of the field effect transistor Q1 is sequentially connected to the signal line DATA through a resistor R4 and a resistor R5; a resistor R3 is also arranged between the connection node of the gate of the field effect transistor Q1 and the resistor R4 and the source of the field effect transistor Q1.

3. The half-duplex communication circuit for a brushless motor according to claim 1, characterized in that: The drain output of the field effect transistor Q1 includes a first branch and a second branch. The first branch of the drain of the field effect transistor Q1 is connected to the signal receiving end RXD1 through a resistor R1; the second branch of the drain of the field effect transistor Q1 is connected to the signal power supply VCC inside the battery pack through a resistor R2.

4. The half-duplex communication circuit for a brushless motor according to claim 2, characterized in that: The drain of the field effect transistor Q2 is connected to the connection node of the resistor R4 and the resistor R5 through a diode D1.

5. The half-duplex communication circuit for a brushless motor according to claim 1, characterized in that: The gate of the field effect transistor Q2 is connected to the signal transmitting end TXD1 through a resistor R6, and a resistor R7 is also arranged between the connection node of the gate of the field effect transistor Q2 and the resistor R6 and the source of the field effect transistor Q2.

6. The half-duplex communication circuit for a brushless motor according to claim 1, characterized in that: The gate of the field effect transistor Q3 is connected to the signal transmitting end TXD2 through a resistor R10, and a resistor R9 is also arranged between the connection node of the gate of the field effect transistor Q3 and the resistor R10 and the source of the field effect transistor Q3.

7. The half-duplex communication circuit for a brushless motor according to claim 1, characterized in that: The drain of the field effect transistor Q3 is connected to one end of a resistor R8. The other end of the resistor R8 is respectively connected to the signal line DATA and one end of a resistor R11, and the other end of the resistor R11 is connected to the gate of the field effect transistor Q4.

8. The half-duplex communication circuit for a brushless motor according to claim 7, wherein: A resistor R13 is also arranged between the connection node of the gate of the field effect transistor Q4 and the other end of the resistor R1 and the source of the field effect transistor Q4.

9. The half-duplex communication circuit for a brushless motor according to claim 1, wherein: The drain output of the field effect transistor Q4 includes a first branch and a second branch. The first branch of the drain of the field effect transistor Q4 is connected to the signal receiving end RXD2 through a resistor R14; the second branch of the drain of the field effect transistor Q4 is connected to the signal power supply VCC inside the motor controller through a resistor R12.

10. The half-duplex communication circuit for a brushless motor according to claim 1, characterized in that: Both the field effect transistor Q1 and the field effect transistor Q4 are N-channel enhancement mode field effect transistors, and both the field effect transistor Q2 and the field effect transistor Q3 are P-channel enhancement mode field effect transistors.

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