One-key on-off circuit based on CAN bus

Abstract

The invention aims to provide a one-key on-off circuit based on a CAN bus. The circuit comprises a power management board, a key switch and a control board, the power management board is connected with the key switch through a CAN bus, and the control board is connected with the key switch through the CAN bus; the power management board comprises a first switching circuit and a first control unit; the control panel comprises a second switching circuit and a second control unit; the first switching circuit is connected with the key switch and the first control unit, the first switching circuit is connected with the second switching circuit through a CAN bus, the second switching circuit is connected with the key switch and the second control unit, and the first control unit is used for transmitting a high level to the second control unit based on a startup signal. And the second control unit is used for controlling the first control unit to output a low-level signal based on the shutdown signal. Therefore, the switch key does not need to lead out a lead independently, and the one-key on-off circuit with zero standby power consumption is realized.

Description

Technical Field

[0001] The present application relates to the field of circuits, and in particular to a one-button power on / off circuit based on a CAN bus. Background Art

[0002] With the development of electronic technology, the integration of electronic products is getting higher and higher, the size of electronic products is getting smaller and smaller, and the physical size of products is also getting smaller and smaller. In the case of unchanged battery capacity, it is hoped that the power consumption in the shutdown state can be reduced as much as possible. The traditional power button requires the control unit to be kept in a low power state. The device will consume battery power in the shutdown state. In addition, the communication lines between traditional boards are used independently, and the switch button needs to be led out separately. The shutdown requires the control unit to be in a normally powered mode. The battery power loss is increased for the battery-powered mode. Therefore, the current problem that needs to be solved urgently is how to achieve a zero power consumption shutdown and reduce the connection problem between boards. Summary of the invention

[0003] One purpose of the present application is to provide a one-button power on / off circuit based on the CAN bus, so as to solve the problem in the prior art that the communication between boards is used independently, the switch button needs to lead out separately and the battery power consumption is increased.

[0004] According to one aspect of the present application, a one-key on / off circuit based on a CAN bus is provided, the circuit comprising: a power management board, a key switch and a control board;

[0005] The power management board is connected to the key switch via the CAN bus and is used to receive a power-on signal from the key switch. The control board is connected to the key switch via the CAN bus and is used to receive a power-off signal from the key switch.

[0006] The power management board includes a first switching circuit and a first control unit;

[0007] The control board includes a second switching circuit and a second control unit;

[0008] The first switching circuit is connected to the push switch and the first control unit, the first switching circuit is connected to the second switching circuit via a CAN bus, the second switching circuit is connected to the push switch and the second control unit, the first control unit is used to transmit a high level to the second control unit based on a power-on signal, and the second control unit is used to control the first control unit to output a low level signal based on a power-off signal.

[0009] Optionally, the power management board includes a DC / DC circuit, a voltage stabilizing circuit, a driving circuit and a voltage divider circuit, the voltage divider circuit is connected to the driving circuit, the driving circuit is connected to the voltage stabilizing circuit, the voltage stabilizing circuit is connected to the DC / DC circuit, and the DC / DC circuit is connected to the first control unit.

[0010] Optionally, the first switching circuit includes a second pin, a third pin, a sixth pin and a seventh pin, and the second pin, the third pin, the sixth pin and the seventh pin are in a normally closed state by default.

[0011] Optionally, the push switch is used to transmit a power-on signal to the first switching circuit, the second pin, the third pin, the sixth pin and the seventh pin in the first switching circuit are short-circuited, the voltage divider circuit forms a loop, the drive circuit outputs a high-level signal to the DC / DC circuit, the DC / DC circuit supplies power to the first control unit, the first control unit communicates with the second control unit through CAN, and the second control unit outputs a high-level signal.

[0012] Optionally, the second switching circuit includes a second relay and a resistor R14, the second relay includes a fourth pin and a fifth pin, and when the second control unit is running, the second control unit outputs a high-level signal to the resistor R14, the second relay switches to the fourth pin and the fifth pin, and the second control unit outputs a high-level signal.

[0013] Optionally, the push switch is used to transmit a shutdown signal to the second switching circuit, the fourth and fifth pins of the second relay are short-circuited, the fifth pin is connected to GND, the second control unit sends a low level to the first control unit through the CAN bus, and the first control unit sends a low level signal to the DC / DC circuit.

[0014] Optionally, the circuit includes: a magnetic connector, and the power management board and the control board are connected to each other through the magnetic connector.

[0015] Optionally, the magnetic connector includes a first connector and a second connector, one end of the first connector is connected to the first switching circuit, and the other end is connected to the second connector, and the other end of the second connector is connected to the second switching circuit.

[0016] Optionally, the control board sends a shutdown signal to the first control unit through the CAN bus, and when the first control unit receives the shutdown signal three times, the first control unit turns off the enable pin of the DC / DC circuit.

[0017] Optionally, when the key switch is used, when the user presses the key switch for a specified time, the first switching circuit receives a power-on signal, and when the specified time is exceeded, the second switching circuit receives a power-off signal.

[0018] Compared with the prior art, the present application provides a one-key on / off circuit based on CAN bus, the circuit comprising: a power management board, a key switch and a control board; the power management board is connected to the key switch through the CAN bus, and is used to receive the power-on signal of the key switch; the control board is connected to the key switch through the CAN bus, and is used to receive the power-off signal of the key switch; the power management board comprises a first switching circuit and a first control unit; the control board comprises a second switching circuit and a second control unit; the first switching circuit is connected to the key switch and the first control unit, the first switching circuit is connected to the second switching circuit through the CAN bus, the second switching circuit is connected to the key switch and the second control unit, the first control unit is used to transmit a high level to the second control unit based on the power-on signal, and the second control unit is used to control the first control unit to output a low level signal based on the power-off signal. Therefore, the switch button does not need to lead out a lead wire separately, and a one-key on / off circuit with zero standby power consumption is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0020] Figure 1 A schematic structural diagram of a one-button power on / off circuit based on a CAN bus is shown according to one aspect of the present application;

[0021] Figure 2 A schematic diagram of a framework of a one-button power on / off circuit using a CAN bus with zero standby power consumption in one embodiment of the present application is shown;

[0022] Figure 3 A schematic diagram showing the principle of a one-button power on / off circuit in an embodiment of the present application is shown;

[0023] Figure 4 A schematic diagram showing a power-on mode and a power-off mode in an embodiment of the present application is shown.

[0024] The same or similar reference numerals in the drawings represent the same or similar components. DETAILED DESCRIPTION

[0025] The present application is described in further detail below in conjunction with the accompanying drawings.

[0026] Figure 1A structural schematic diagram of a one-button power on / off circuit based on a CAN bus provided according to one aspect of the present application is shown, the circuit comprising: a power management board 100, a key switch 200 and a control board 300; the power management board 100 is connected to the key switch 200 through the CAN bus, and is used to receive a power-on signal of the key switch 200, and the control board 300 is connected to the key switch 200 through the CAN bus, and is used to receive a power-off signal of the key switch; the power management board 100 comprises a first switching circuit 101 and a first control unit 102; the control board 300 comprises a second switching circuit 301 and a second control unit 302; the first switching circuit 101 is connected to the key switch 200 and the first control unit 102, the first switching circuit 101 is connected to the second switching circuit 301 through the CAN bus, the second switching circuit 301 is connected to the key switch 200 and the second control unit 302, the first control unit 102 is used to transmit a high level to the second control unit 302 based on the power-on signal, and the second control unit 302 is used to control the first control unit 102 to output a low level signal based on the power-off signal.

[0027] Here, two boards are used to reduce lead constraints, and switching circuits and control units are respectively set on the power management board and the control board. The two boards communicate using the CAN bus, so that the CAN bus is used to form a one-button switch circuit with zero standby power consumption. According to the user's use of the key switch, the output level of the first control unit in the power management board and the output level of the second control unit in the control board are controlled. The power-on process is to output a high-level signal to the second control unit of the control board through the first control unit in the power management board. The output process is carried out through CAN communication between the switching circuits, so that the second control unit can operate and the system starts working. When shutting down, the second control unit in the control board outputs a low level to the first control unit in the power management board, thereby lowering the level of the power management board and shutting down the system. The one-button switch circuit described in this application is applied to detachable devices, such as foldable or detachable electric smart wheelchairs.

[0028] In one embodiment of the present application, the power management board includes a DC / DC circuit, a voltage stabilizing circuit, a driving circuit and a voltage dividing circuit, the voltage dividing circuit is connected to the driving circuit, the driving circuit is connected to the voltage stabilizing circuit, the voltage stabilizing circuit is connected to the DC / DC circuit, and the DC / DC circuit is connected to the first control unit. Figure 2In the circuit diagram shown, board A is a power management board, and board B is a control board. The circuit of board A includes: a voltage divider circuit, a drive circuit, a voltage stabilizing circuit, a DC / DC voltage conversion circuit, a first control unit (MCU1) and a switching circuit 1; board B includes a switching circuit 2 and a second control unit (MCU2). The DC / DC circuit with an enable function turns off the power output when the voltage is low, and enables the power output when the voltage is high. The voltage divider circuit is used to determine whether the voltage in the circuit is reduced or increased. When the voltage is increased, the loop is closed and the high level is transmitted to the drive circuit, so that the drive circuit outputs a stable high level to the DC / DC circuit through the voltage stabilizing circuit. The DC / DC circuit outputs an enable signal, and MCU1 controls MUC2 to run through the switching circuit to start working. When shutting down, MCU2 sends a low level signal to MCU1 through the switching circuit, and then MCU1 controls the low level signal of the DC / DC to enable shutdown and enter the power-off shutdown state.

[0029] Continuing with the above embodiment, the first switching circuit includes a second pin, a third pin, a sixth pin and a seventh pin, and the second pin, the third pin, the sixth pin and the seventh pin are in a normally closed state by default. The push switch is used to transmit a power-on signal to the first switching circuit, the second pin, the third pin and the sixth pin and the seventh pin in the first switching circuit are short-circuited, the voltage divider circuit forms a loop, the drive circuit outputs a high-level signal to the DC / DC circuit, the DC / DC circuit supplies power to the first control unit, the first control unit performs CAN communication with the second control unit, and the second control unit outputs a high-level signal. Here, if Figure 3 As shown, the voltage divider circuit includes resistors R7, R9 and a light-emitting diode, the driving circuit includes resistors R8, R10, R12 and a transistor, resistor R8 is connected to resistors R7 and R9, and R12 is connected to GND; the switching circuit 1 includes resistors R13, R15, transistor Q3, pins 1 to 8, and relay K1; the switching circuit 2 includes resistors R14, R16, transistor Q4, pins 1 to 8, and relay K2. After pressing the switch button, the second and third pins of the switching circuit 1 are in a normally closed state, and the sixth and seventh pins are in a normally closed state by default. When the switch is pressed, the second and third pins and the sixth and seventh pins of the switching circuit 1 are short-circuited, and the voltage divider circuit forms a loop; at this time, the third pin of the driving circuit U1 outputs a high-level signal, and the high-level signal is given to the DC / DC circuit enable signal. The DC / DC circuit works to power MCU1. After the MCU works, a high level is given to the resistor R11 to maintain the power on. MCU1 drives the relay K1 to switch to CAN communication mode; after the power supply is normal, MCU2 runs, and the MCU detects that the power on is completed as a high-level signal.

[0030] Continuing with the above embodiment, the second switching circuit includes a second relay and a resistor R14, the second relay includes a fourth pin and a fifth pin, and when the second control unit is running, the second control unit outputs a high-level signal to the resistor R14, the second relay switches to the fourth pin and the fifth pin, and the second control unit outputs a high-level signal. Here, after the power supply is normal, MCU2 runs, drives the relay K2 to switch to the switching circuit 2, MCU1 outputs a high-level signal to the resistor R14 through IO, switches to the fourth pin and the fifth pin of K2, the fourth pin of K2 is pulled up through the resistor R17 (not shown), and MCU2 detects that the power-on is completed as a high-level signal.

[0031] In one embodiment of the present application, the button switch is used to transmit the shutdown signal to the second switching circuit, the fourth and fifth pins of the second relay are short-circuited, the fifth pin is connected to GND, the second control unit sends a low level to the first control unit through the CAN bus, and the first control unit sends a low level signal to the DC / DC circuit. Here, after pressing the button switch, the fourth and fifth pins of the second relay K2 are short-circuited, the fifth pin of K2 is connected to GND, MCU2 detects that IO is a low level signal, and sends it to board A through CAN communication. Board A receives the signal and executes shutdown. MCU1 sends a low level signal to the DC / DC circuit through the SHDN_R shutdown signal, the DC / DC circuit enables shutdown, and the system enters the power-off shutdown state.

[0032] In one embodiment of the present application, the circuit includes: a magnetic connector, and the power management board and the control board are connected to each other through the magnetic connector. Here, the one-button power on / off circuit described in the present application is preferably used on a detachable device. When two boards are used, the upper and lower boards are connected to each other through the magnetic connector.

[0033] Specifically, the magnetic connector includes a first connector and a second connector, one end of the first connector is connected to the first switching circuit, the other end of the first connector is connected to the second connector, and the other end of the second connector is connected to the second switching circuit. Figure 3 Two magnetic connectors J1 and J2 are used. Connector J1 is connected to the third and sixth pins of switching circuit 1, and connected to connector 2 through the CAN bus. Connector 2 is connected to the third and sixth pins of the second switching circuit, so that the interfaces of the two switching circuits can be connected to each other and communicate through the CAN bus.

[0034] In one embodiment of the present application, the control board sends a shutdown signal to the first control unit via the CAN bus. When the first control unit receives the shutdown signal three times, the first control unit turns off the enable pin of the DC / DC circuit. After the first control unit MCU1 receives the shutdown command three times, MCU1 turns off the enable pin of the DC / DC voltage conversion circuit and pulls down the system shutdown to complete. The logical judgment of the three commands is used to prevent misoperation.

[0035] In one embodiment of the present application, when the key switch is used, when the user presses the key switch for a specified time, the first switching circuit receives a power-on signal, and when the specified time is exceeded, the second switching circuit receives a power-off signal. Figure 4 As shown, the power-on mode is: when the key switch is long pressed for a specified time (for example, 3s), the default pins 2 and 3 of the switching circuit 1 are normally closed, and the pins 6 and 7 are normally closed. When the switch button is pressed, the pins 2 and 3 of the switching circuit 1 are short-circuited with the pins 6 and 7, and the voltage divider circuit forms a loop. At this time, the third pin of the driving circuit U1 outputs a high-level signal, and the high-level signal gives the DC / DC circuit an enable signal. The DC / DC circuit works to power MUC1. After MCU1 works, it gives R11 a high level to maintain the power-on, and MCU1 drives K1 to switch to CAN communication mode. After the power supply is normal, MCU2 runs and drives K2 to switch circuit 2. MCU gives R14 a high-level signal through IO, switches to K2 pins 4 and 5, and K2 pin 4 is pulled up through R17. MCU2 detects that the power-on is completed as a high-level signal. The shutdown method is: after long pressing the key switch, the 4th and 5th pins of K2 are short-circuited, and the 5th pin of K2 is connected to GND. MCU2 detects that IO is a low-level signal, and first shuts down the peripherals of board B. After the peripherals of board B are shut down, a shutdown signal is sent through the CAN serial bus. After MCU1 receives three shutdown commands, MUC shuts down the DC / DC voltage conversion circuit and pulls down the enable pin to complete the system shutdown. In this way, the serial bus is used to realize one-button power on and off, and zero power loss is achieved at the same time.

[0036] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

Claims

1. A one-button power on / off circuit based on CAN bus, characterized in that: The circuit includes: a power management board, a key switch and a control board; The power management board is connected to the key switch via the CAN bus and is used to receive a power-on signal from the key switch. The control board is connected to the key switch via the CAN bus and is used to receive a power-off signal from the key switch. The power management board includes a first switching circuit and a first control unit; The control board includes a second switching circuit and a second control unit; The first switching circuit is connected to the push switch and the first control unit, the first switching circuit is connected to the second switching circuit via a CAN bus, the second switching circuit is connected to the push switch and the second control unit, the first control unit is used to transmit a high level to the second control unit based on a power-on signal, and the second control unit is used to control the first control unit to output a low level signal based on a power-off signal.

2. The circuit according to claim 1, characterized in that The power management board includes a DC / DC circuit, a voltage stabilizing circuit, a driving circuit and a voltage dividing circuit, the voltage dividing circuit is connected to the driving circuit, the driving circuit is connected to the voltage stabilizing circuit, the voltage stabilizing circuit is connected to the DC / DC circuit, and the DC / DC circuit is connected to the first control unit.

3. The circuit according to claim 2, characterized in that The first switching circuit includes a second pin, a third pin, a sixth pin and a seventh pin, and the second pin, the third pin, the sixth pin and the seventh pin are in a normally closed state by default.

4. The circuit according to claim 3, characterized in that The push switch is used to transmit the power-on signal to the first switching circuit, the second pin, the third pin, the sixth pin and the seventh pin in the first switching circuit are short-circuited, the voltage divider circuit forms a loop, the drive circuit outputs a high-level signal to the DC / DC circuit, the DC / DC circuit supplies power to the first control unit, the first control unit communicates with the second control unit through CAN, and the second control unit outputs a high-level signal.

5. The circuit according to claim 4, characterized in that The second switching circuit includes a second relay and a resistor R14, the second relay includes a fourth pin and a fifth pin, when the second control unit is running, the second control unit outputs a high level signal to the resistor R14, the second relay switches to the fourth pin and the fifth pin, and the second control unit outputs a high level signal.

6. The circuit according to claim 5, characterized in that The push switch is used to transmit the shutdown signal to the second switching circuit, the fourth and fifth pins of the second relay are short-circuited, the fifth pin is connected to GND, the second control unit sends a low level to the first control unit through the CAN bus, and the first control unit sends a low level signal to the DC / DC circuit.

7. The circuit according to claim 1, characterized in that The circuit comprises: a magnetic attraction connector, and the power management board and the control board are connected to each other via the magnetic attraction connector.

8. The circuit according to claim 7, characterized in that The magnetic connector includes a first connector and a second connector, one end of the first connector is connected to the first switching circuit, and the other end of the first connector is connected to the second connector, and the other end of the second connector is connected to the second switching circuit.

9. The circuit according to claim 2, characterized in that The control board sends a shutdown signal to the first control unit through the CAN bus. When the first control unit receives the shutdown signal three times, the first control unit turns off the enable pin of the DC / DC circuit.

10. The circuit according to claim 1, characterized in that When the key switch is used When the user presses the switch button for a specified time, the first switching circuit receives a power-on signal. When the specified time is exceeded, the second switching circuit receives a shutdown signal.

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