A can bus wake-up circuit and a brushless motor controller

Abstract

The utility model relates to CAN bus awakening technical field discloses a CAN bus awakening circuit and brushless motor controller, CAN bus awakening circuit includes photoelectric coupler unit, first voltage dividing unit, second voltage dividing unit, shutdown unit, triode Q1, triode Q2 and output resistance R7, when the CAN bus has signal to arrive temporarily in actual use time, photoelectric coupler unit makes the output end of first voltage dividing unit ground connection, and first voltage dividing unit provides the base of triode Q1 with bias voltage, makes triode Q1 conduct, output resistance R7 enables signal to output to wake up subsequent circuit module at this time, after triode Q1 conducts, and the intermediate node of second voltage dividing unit provides the base of triode Q2 with bias voltage, makes triode Q2 conduct, thereby can make triode Q1 continue to conduct, makes subsequent circuit module continuous work, when needing to make subsequent circuit module dormancy, through to shutdown unit input shutdown control signal, thereby makes triode Q1 shutdown, no longer output enables signal.

Description

Technical Field

[0001] This utility model relates to the field of CAN bus wake-up technology, specifically to a CAN bus wake-up circuit and a brushless motor controller. Background Technology

[0002] Brushless electric fans are widely used in automobiles, data centers, and smart homes due to their advantages such as high efficiency and energy saving, intelligent control, long lifespan and low maintenance costs, low noise and quiet operation, wide environmental adaptability, reliability and electromagnetic compatibility.

[0003] In automobiles, to facilitate the control of brushless motors by the vehicle's central control system, the brushless motor controller is equipped with a CAN bus, through which the vehicle's central control system communicates with the brushless motor controller. In actual use, the brushless motor controller does not need to control the brushless motor at all times. However, in order to receive control signals sent by the vehicle's central control system in real time, the existing brushless motor controller is always running, resulting in high power consumption. Utility Model Content In view of the shortcomings of the prior art, the present invention provides a CAN bus wake-up circuit and a brushless motor controller, which are used to wake up the brushless motor controller when the central control of the car needs to communicate with the brushless motor controller via CAN, thereby reducing power consumption.

[0004] To solve the above technical problems, this utility model provides the following technical solution: a CAN bus wake-up circuit, including an optocoupler unit, a first voltage divider unit, a second voltage divider unit, a turn-off unit, transistor Q1, transistor Q2 and output resistor R7; The input terminal of the first voltage divider unit is used to connect to the power supply voltage and is electrically connected to the emitter of transistor Q1. The intermediate node of the first voltage divider unit is electrically connected to the base of transistor Q1. The output terminal of the first voltage divider unit is electrically connected to the collector of transistor Q2 and the optocoupler unit, respectively. The optocoupler unit provides a grounding path for the output of the first voltage divider unit based on the CAN bus signal; The collector of transistor Q1 is electrically connected to the input terminal of the second voltage divider unit, and an enable signal EN is output through the output resistor R7; the intermediate node of the second voltage divider unit is electrically connected to the base of transistor Q2, and the output terminal of the second voltage divider unit and the emitter of transistor Q2 are both grounded. The shutdown unit is electrically connected to the base of the transistor Q2 and controls the transistor Q2 to turn off based on the input shutdown control signal.

[0005] In one embodiment, the input terminal of the first voltage divider unit is electrically connected to the cathode of diode D2, and the anode of diode D2 is used to input the power supply voltage.

[0006] In one embodiment, the power supply voltage is a 24V DC voltage.

[0007] In one embodiment, the first voltage divider unit includes resistor R3 and resistor R4. One end of resistor R3 is the input terminal of the first voltage divider unit, the other end of resistor R3 is the intermediate node of the first voltage divider unit and is electrically connected to one end of resistor R4, and the other end of resistor R4 is the output terminal of the first voltage divider unit.

[0008] In one embodiment, the second voltage divider unit includes resistors R5 and R6. One end of resistor R5 is the input terminal of the second voltage divider unit, and the other end of resistor R5 is the intermediate node of the second voltage divider unit, which is electrically connected to one end of resistor R6. The other end of resistor R6 is the output terminal of the second voltage divider unit.

[0009] In one embodiment, the optocoupler unit includes resistors R1 and R2 and an optocoupler U1. One end of resistor R1 is electrically connected to the CANH terminal of the CAN bus, one end of resistor R2 is electrically connected to the CANL terminal of the CAN bus, the other end of resistor R1 is electrically connected to pin 1 of optocoupler U1, the other end of resistor R2 is electrically connected to pin 2 of optocoupler U1, pin 4 of optocoupler U1 is electrically connected to the output terminal of the first voltage divider unit, and pin 3 of optocoupler U1 is grounded.

[0010] In one embodiment, the base of the transistor Q2 is grounded through capacitor C1.

[0011] In one embodiment, the shutdown unit includes a resistor R8 and a transistor Q3. One end of the resistor R8 is used to receive a shutdown control signal, and the other end of the resistor R8 is electrically connected to the base of the transistor Q3. The collector of the transistor Q3 is electrically connected to the base of the transistor Q2, and the emitter of the transistor Q3 is grounded.

[0012] In one embodiment, one end of the resistor R8 is also grounded through the capacitor C2.

[0013] Secondly, this utility model also provides a brushless motor controller, including an MCU main control unit, a power management unit, and a functional module, and also includes the aforementioned CAN bus wake-up circuit. The enable signal EN is input to the enable terminal of the power management unit to control the power management unit to output a working voltage. The power supply terminal of the power management unit receives the power supply voltage, and the working voltage output terminal of the power management unit provides working voltage for the MCU main control unit and the functional module. The MCU main control unit is electrically connected to one end of resistor R8 and the functional module respectively, and sends a shutdown control signal to the shutdown unit and drives the functional module to work.

[0014] The advantages of this invention compared to existing technologies are as follows: In practical use, when a signal arrives on the CAN bus, the optocoupler unit grounds the output of the first voltage divider unit, which provides a bias voltage to the base of transistor Q1, turning on transistor Q1. At this time, the output resistor R7 outputs an enable signal to wake up the subsequent circuit modules. After transistor Q1 is turned on, the intermediate node of the second voltage divider unit provides a bias voltage to the base of transistor Q2, turning on transistor Q2, thus allowing transistor Q1 to continue to conduct and enabling the subsequent circuit modules to continue working. When it is necessary to put the subsequent circuit modules into sleep mode, a shutdown control signal is input to the shutdown unit, thereby turning off transistor Q1 and stopping the output of the enable signal. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the CAN bus wake-up circuit in Example 1; Figure 2 This is a schematic diagram of the brushless motor controller in Embodiment 2. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0017] Example 1 like Figure 1 As shown, this embodiment provides a CAN bus wake-up circuit, including an optocoupler unit 1, a first voltage divider unit 2, a second voltage divider unit 3, a turn-off unit 4, transistors Q1 and Q2, and an output resistor R7. The input terminal of the first voltage divider unit 2 is used to connect to the power supply voltage and is electrically connected to the emitter of transistor Q1. The intermediate node of the first voltage divider unit 2 is electrically connected to the base of transistor Q1. The output terminal of the first voltage divider unit 2 is electrically connected to the collector of transistor Q2 and optocoupler unit 1 respectively. Optocoupler unit 1 provides a grounding path for the output of the first voltage divider unit 2 based on the CAN bus signal; The collector of transistor Q1 is electrically connected to the input terminal of the second voltage divider unit 3, and the enable signal EN is output through the output resistor R7; the intermediate node of the second voltage divider unit 3 is electrically connected to the base of transistor Q2, and the output terminal of the second voltage divider unit 3 and the emitter of transistor Q2 are both grounded. The shutdown unit 4 is electrically connected to the base of transistor Q2, and controls transistor Q2 to turn off based on the input shutdown control signal.

[0018] In practical use, when a signal arrives on the CAN bus, optocoupler unit 1 grounds the output of the first voltage divider unit 2, which in turn provides a bias voltage to the base of transistor Q1, turning on transistor Q1. At this time, output resistor R7 outputs an enable signal EN to wake up the subsequent circuit module. After transistor Q1 is turned on, the intermediate node of the second voltage divider unit 3 provides a bias voltage to the base of transistor Q2, turning on transistor Q2, thus allowing transistor Q1 to continue conducting and enabling the subsequent circuit module to continue working. When it is necessary to put the subsequent circuit module into sleep mode, a shutdown control signal is input to the shutdown unit 4, which turns off transistor Q1 and stops outputting the enable signal EN, putting the subsequent circuit module into sleep mode.

[0019] Specifically, in this embodiment, the input terminal of the first voltage divider unit 2 is electrically connected to the cathode of diode D2, and the anode of diode D2 is used to input the power supply voltage. During actual operation, when the enable signal EN is output, diode D2 illuminates as a notification, thus providing a convenient indication of the circuit's operating status.

[0020] In one implementation, the light emission color of diode D2 can be set according to actual needs; for example, it can be red or green.

[0021] In addition, in this embodiment, the power supply voltage is 24V DC voltage.

[0022] Specifically, in this embodiment, the first voltage divider unit 2 includes resistor R3 and resistor R4. One end of resistor R3 is the input terminal of the first voltage divider unit 2, and the other end of resistor R3 is the intermediate node of the first voltage divider unit 2, which is electrically connected to one end of resistor R4. The other end of resistor R4 is the output terminal of the first voltage divider unit 2.

[0023] In one implementation, the number of resistors in the first voltage divider unit 2 can be increased to provide different voltage division ratios, or different voltage division ratios can be achieved by adjusting the resistance ratio of resistor R3 to resistor R4.

[0024] Specifically, in this embodiment, the second voltage divider unit 3 includes resistor R5 and resistor R6. One end of resistor R5 is the input terminal of the second voltage divider unit 3, and the other end of resistor R5 is the intermediate node of the second voltage divider unit 3, which is electrically connected to one end of resistor R6. The other end of resistor R6 is the output terminal of the second voltage divider unit 3.

[0025] Similarly, in one implementation, the number of resistors in the second voltage divider unit 3 can be increased to provide different voltage division ratios, or different voltage division ratios can be achieved by adjusting the resistance ratio of resistor R5 to resistor R6.

[0026] Specifically, in this embodiment, the optocoupler unit 1 includes resistor R1, resistor R2 and optocoupler U1. One end of resistor R1 is electrically connected to the CANH terminal of the CAN bus, one end of resistor R2 is electrically connected to the CANL terminal of the CAN bus, the other end of resistor R1 is electrically connected to pin 1 of optocoupler U1, the other end of resistor R2 is electrically connected to pin 2 of optocoupler U1, pin 4 of optocoupler U1 is electrically connected to the output terminal of the first voltage divider unit, and pin 3 of optocoupler U1 is grounded.

[0027] In addition, in this embodiment, the base of transistor Q2 is grounded through capacitor C1.

[0028] Specifically, in this embodiment, the shutdown unit 4 includes a resistor R8 and a transistor Q3. One end of the resistor R8 is used to receive the shutdown control signal, and the other end of the resistor R8 is electrically connected to the base of the transistor Q3. The collector of the transistor Q3 is electrically connected to the base of the transistor Q2, and the emitter of the transistor Q3 is grounded. Additionally, in... Figure 1 In the middle, one end of resistor R8 is also grounded through capacitor C2.

[0029] In actual use, when the turn-off control signal is high, transistor Q3 is turned on, which pulls the base of transistor Q2 low, thus turning off transistor Q2. When transistor Q2 is turned off, the collector of transistor Q1 lacks a grounding branch, thus turning off, and the output resistor R7 no longer outputs the enable signal EN.

[0030] Example 2 like Figure 2 As shown, this embodiment also provides a brushless motor controller, including an MCU main control unit 5, a power management unit 6, and a functional module 7. It also includes a CAN bus wake-up circuit as described in Embodiment 1. An enable signal EN is input to the enable terminal of the power management unit 6 to control the power management unit 6 to output a working voltage. The power supply terminal of the power management unit 6 receives a power supply voltage, and the working voltage output terminal of the power management unit 6 provides working voltage for the MCU main control unit 5 and the functional module 7. The MCU main control unit is electrically connected to one end of resistor R8 and the functional module, respectively, and sends a shutdown control signal to the shutdown unit 4 and drives the functional module 7 to work.

[0031] In practical use, when the brushless motor controller needs to be woken up, the signal from the CAN bus interface turns on transistors Q1 and Q2 in sequence. The wake-up circuit inputs an enable signal to the power management unit 6, which then starts working and outputs the operating voltage. After receiving the operating voltage, the MCU main control unit 5 starts working, and the entire brushless motor controller enters the working state. When there is no CAN bus signal, the MCU main control unit 5 sends a shutdown control signal to resistor R8, which turns off transistor Q2, thereby stopping the output of the enable signal EN and putting the brushless motor controller into a sleep state, reducing power consumption.

[0032] In addition, in this embodiment, functional module 7 is an existing module, such as a PWM drive module, which will not be described further. In some implementations, functional module 7 may also be other existing circuit modules. Based on the above description and inspired by this utility model, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A CAN bus wake-up circuit, characterized in that, It includes an optocoupler unit, a first voltage divider unit, a second voltage divider unit, a turn-off unit, transistors Q1 and Q2, and an output resistor R7; The input terminal of the first voltage divider unit is used to connect to the power supply voltage and is electrically connected to the emitter of transistor Q1. The intermediate node of the first voltage divider unit is electrically connected to the base of transistor Q1. The output terminal of the first voltage divider unit is electrically connected to the collector of transistor Q2 and the optocoupler unit, respectively. The optocoupler unit provides a grounding path for the output of the first voltage divider unit based on the CAN bus signal; The collector of transistor Q1 is electrically connected to the input terminal of the second voltage divider unit, and an enable signal EN is output through the output resistor R7; the intermediate node of the second voltage divider unit is electrically connected to the base of transistor Q2, and the output terminal of the second voltage divider unit and the emitter of transistor Q2 are both grounded. The shutdown unit is electrically connected to the base of the transistor Q2 and controls the transistor Q2 to turn off based on the input shutdown control signal.

2. The CAN bus wake-up circuit according to claim 1, characterized in that, The input terminal of the first voltage divider unit is electrically connected to the cathode of diode D2, and the anode of diode D2 is used to input the power supply voltage.

3. The CAN bus wake-up circuit according to claim 1, characterized in that, The power supply voltage is 24V DC.

4. A CAN bus wake-up circuit according to claim 1, characterized in that, The first voltage divider unit includes resistors R3 and R4. One end of resistor R3 is the input terminal of the first voltage divider unit, and the other end of resistor R3 is the intermediate node of the first voltage divider unit, which is electrically connected to one end of resistor R4. The other end of resistor R4 is the output terminal of the first voltage divider unit.

5. A CAN bus wake-up circuit according to claim 1, characterized in that, The second voltage divider unit includes resistors R5 and R6. One end of resistor R5 is the input terminal of the second voltage divider unit, and the other end of resistor R5 is the intermediate node of the second voltage divider unit, which is electrically connected to one end of resistor R6. The other end of resistor R6 is the output terminal of the second voltage divider unit.

6. A CAN bus wake-up circuit according to claim 1, characterized in that, The optocoupler unit includes resistors R1 and R2 and optocoupler U1. One end of resistor R1 is electrically connected to the CANH terminal of the CAN bus, one end of resistor R2 is electrically connected to the CANL terminal of the CAN bus, the other end of resistor R1 is electrically connected to pin 1 of optocoupler U1, the other end of resistor R2 is electrically connected to pin 2 of optocoupler U1, pin 4 of optocoupler U1 is electrically connected to the output terminal of the first voltage divider unit, and pin 3 of optocoupler U1 is grounded.

7. A CAN bus wake-up circuit according to claim 1, characterized in that, The base of the transistor Q2 is grounded through capacitor C1.

8. A CAN bus wake-up circuit according to claim 1, characterized in that, The shutdown unit includes a resistor R8 and a transistor Q3. One end of the resistor R8 is used to receive the shutdown control signal, and the other end of the resistor R8 is electrically connected to the base of the transistor Q3. The collector of the transistor Q3 is electrically connected to the base of the transistor Q2, and the emitter of the transistor Q3 is grounded.

9. A CAN bus wake-up circuit according to claim 8, characterized in that, One end of the resistor R8 is also grounded through capacitor C2.

10. A brushless motor controller, comprising an MCU main control unit, a power management unit, and functional modules, characterized in that, It also includes a CAN bus wake-up circuit as described in any one of claims 1-9, wherein the enable signal EN is input to the enable terminal of the power management unit to control the power management unit to output the operating voltage, the power supply terminal of the power management unit is input to the power supply voltage, the operating voltage output terminal of the power management unit provides the operating voltage for the MCU main control unit and the functional module, the MCU main control unit is electrically connected to one end of resistor R8 and the functional module respectively, and sends a shutdown control signal to the shutdown unit and drives the functional module to work.

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