Low-voltage protection charging circuit

Abstract

The utility model provides a low-voltage protection charging circuit. The low-voltage protection charging circuit comprises an isolated DC / DC system power supply which is electrically connected with an external charging power supply through an input interface; the MCU is electrically connected to the isolated DC / DC power supply and is powered by the isolated DC / DC power supply; a battery module; two common ends of the charging main switch SW1 and the pre-charging MOS tube one-way switch are electrically connected to the input interface and the battery module respectively after the charging main switch and the pre-charging MOS tube one-way switch are connected in parallel; wherein the battery module, the charging main switch SW1 and the pre-charging MOS tube one-way switch are electrically connected with a first communication module, a second communication module and a third communication module respectively, and a fourth communication module which is in communication connection with the first communication module, the second communication module and the third communication module is arranged in the MCU. Through communication between the MCU and the battery module, whether the input voltage is normal or not is detected, whether normal charging can be carried out or not is further judged, the situation that normal use of the host is affected by starting in an abnormal charging state is prevented, the safety of the host is improved, the service life of the host is prolonged, and the manual maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to a circuit, in particular to a low-voltage protection charging circuit. Background Art

[0002] Most existing robots have the ability to autonomously find charging stations or charge through manual operation. Automatic charging or manual charging has become standard for robots. When the battery is too low, a reminder will be displayed, and the robot will automatically return to the charging point to charge or shut down to cut off the power, which will affect the user experience.

[0003] There are no corresponding protection measures for charging the robot when it is turned on or off, or for low voltage caused by not charging for a long time. The imperfect charging method and the inability to autonomously switch to the appropriate charging path are also the main shortcomings of the robot, which will affect the battery life and safety of the robot, affect the user experience, and increase the cost of maintenance. Summary of the invention

[0004] The embodiment of the present application solves the technical problem of how to protect the autonomous switching charging circuit under low voltage state in the prior art by providing a low voltage protection charging circuit.

[0005] The embodiment of the present application provides a low-voltage protection charging circuit, an isolated DC / DC system power supply electrically connected to an external charging power supply through an input interface; an MCU electrically connected to the isolated DC / DC system power supply and powered by the isolated DC / DC system power supply; a battery module; a charging main switch SW1 and a pre-charging MOS tube unidirectional switch, whose two common ends are electrically connected to the input interface and the battery module after being connected in parallel; wherein the battery module, the charging main switch SW1, and the pre-charging MOS tube unidirectional switch are electrically connected to a first communication module, a second communication module, and a third communication module, respectively, and the MCU has a built-in fourth communication module that communicates with the first communication module, the second communication module, and the third communication module.

[0006] Furthermore, the first, second, third and fourth communication modules adopt RS-485 serial communication protocol or I2C bidirectional serial communication protocol.

[0007] Furthermore, it includes a diode DV1, whose anode and one end of the charging main switch SW1 are commonly connected to the input interface; a control coil CO for controlling the charging main switch SW1, one end of which is connected to the cathode of the diode DV1, and the other end of which is connected to the second communication module.

[0008] Furthermore, the battery module includes a battery and a battery management system BMS electrically connected to the battery, and the low-voltage protection charging circuit also includes a circuit breaker and a fuse connected in series between the charging main switch SW1, the common end of the pre-charging MOS tube unidirectional switch and the battery management system BMS.

[0009] Furthermore, it also includes a diode D1 whose positive electrode is connected to the input interface and whose negative electrode is connected to the isolated DC / DC system power supply.

[0010] Furthermore, it includes a wireless communication module for communicating with an external terminal; the VCC interface of the wireless communication module is electrically connected to the VCC interface of the MCU, and is also communicatively connected to the communication interface of the MCU.

[0011] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: the present application transmits the external charger power supply to the isolated DC / DC system power supply through the input interface, and supplies power to the MCU after voltage reduction. The MCU detects and communicates with the first communication module to turn on the charging main switch SW1 or the pre-charging MOS tube unidirectional switch. The mode of autonomous switching charging is realized to protect the battery from possible failures caused by low voltage. The corresponding charging mode can be realized according to different charging voltage conditions to prevent direct power supply from affecting the performance and life of the battery, and reduce the cost of manual repair and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of low-voltage protection charging according to an embodiment of the utility model;

[0013] Figure 2 This is a schematic diagram of the circuit structure of the utility model embodiment

[0014] Figure 3 This is a flowchart of robot charging in an embodiment of the present application;

[0015] Figure 4 This is a flowchart of turning on and off the robot in an embodiment of the present application. DETAILED DESCRIPTION

[0016] The embodiment of the present application solves the problem of how to protect the autonomous switching charging circuit under low voltage state in the prior art by providing a low voltage protection charging circuit.

[0017] In the embodiments of the present application, D0~D8, DV, DS unidirectional conductive devices or combinations are logically equivalent to diodes, SW relays or high-power MOS tube switches, SB key switches, "A" current detection circuits, "V" voltage detection circuits, MCU microcontrollers, DC / DC voltage conversion circuits, RTC clock circuits, BMS battery management systems, E-STOP emergency stop switches, and WKUP wake-up pins.

[0018] In this embodiment, an isolated DC / DC system power supply is electrically connected to an external charging power supply through an input interface; an MCU is electrically connected to the isolated DC / DC system power supply and powered by the isolated DC / DC system power supply; a battery module; a charging main switch SW1 and a pre-charging MOS tube unidirectional switch, whose two common ends are electrically connected to the input interface and the battery module after being connected in parallel; wherein the battery module, the charging main switch SW1, and the pre-charging MOS tube unidirectional switch are electrically connected to the first communication module, the second communication module, and the third communication module, respectively, and the MCU has a built-in fourth communication module that communicates with the first communication module, the second communication module, and the third communication module.

[0019] In this embodiment, the external charging power supply is connected to the isolated DC / DC system power supply through the input interface to power the MCU. After waking up the MCU, the MCU communicates with the first communication module in the isolated DC / DC system power supply through the fourth communication module, and then detects the current and voltage of the isolated DC / DC system power supply, and then determines to power the battery module through the charging main switch SW1 or the pre-charging MOS tube unidirectional switch. Among them, the external charging power supply is connected to the diode D1 through the input interface, and the diode D1 is a unidirectional conductive diode connected to the isolated DC / DC system power supply. The isolated DC / DC system power supply is powered by the MCU after stepping down. The MCU performs charging detection on the external charger power supply through the diode DS1, and the diode DS1 transmits a signal to the isolated input detection circuit, and the isolated signal is transmitted to the MCU through the isolated input detection circuit. The isolated signal is connected to the wake-up pin WKUP so that the MCU starts to monitor the charging state of the external charging power supply in real time. The fourth communication module of the MCU communicates with the communication module of the external charging power supply input interface and the first communication module of the isolated DC / DC system power supply and performs current and voltage detection, so as to determine to open the charging main switch SW1 or the pre-charging MOS tube unidirectional switch and monitor the external charging power supply in real time.

[0020] In this embodiment, after the external charging power supplies power to the battery module through the charging main switch SW1 or the pre-charging MOS tube unidirectional switch, the external charging power reaches the main line through the battery module, the circuit breaker and the fuse, so that the diodes D1 to D4 can ensure the triggering of the MCU, and the MCU starts to detect the charging status. The diode D0 turns on the key switch SB and the diode D2 supplies power to the MCU through the DC / DC system power supply. The diode D0 does not pass through the key switch and the diode D3 supplies power to the MCU through the DC / DC system power supply. The diode DO passes through the key switch and the diode D4 reaches the MCU through the isolated input detection circuit, and the MCU is awakened by the key switch. Therefore, each branch can supply power to the MCU. When the device is in the low-voltage protection state, D1 forces the MCU to be powered, ensuring that D1 to D4 can trigger the MCU, and the MCU and the external charging power supply communicate by handshake, and the charging is monitored in real time. It should be noted that when a charger is connected to the charging input interface, the charger starting voltage satisfies the charger electrode and has a certain starting output voltage without reverse rotation. At this time, regardless of whether the key is turned on or not, and whether the battery is under low-power protection, the initial voltage can only flow from the positive electrode of diode D1 to the negative electrode to supply power to the DC / DC system power supply, and then to the MCU. The MCU detects the charging input through diode DS1 to detect whether the charger is connected, and at the same time checks whether the input voltage is normal. Then, it communicates with the BMS and the external charging power supply through the communication module to confirm whether pre-charging is enabled or normal charging. If the battery voltage is low and pre-charging needs to be activated, the current must be limited to pre-charge first. Normal charging is performed when the normal charging standard is reached, and the main charging switch is turned on.

[0021] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] refer to Figures 1-2As shown, in one embodiment, when the external charging power input provides power to the MCU, if it is charging normally, that is, the battery voltage is within the normal output range and can provide standby power to the MCU, the charging input voltage is normal, and in normal shutdown charging, regardless of whether the MCU has other branches to supply power, the MCU is forced to be powered by the diode D1, and the charging input signal calls the MCU to communicate with the charger and turn on the main charging switch control terminal, start charging and verify the charging current curve in real time until it is full. In normal startup charging, the charging input signal triggers the MCU to communicate with the charger and turn on the main charging switch control terminal, start charging and verify the charging current curve in real time until it is full. Because the charger initially only has a starting voltage, the current is limited. Only when the MCU and the charger shake hands correctly, that is, the normal charger voltage is detected, and the communication handshake is performed, and the charging current is configured normally, can it be charged normally. In this way, it can be ensured that the MCU can be started when the charger is connected. Even if the battery is out of power, the MCU is forced to be powered by D1 to ensure that the MCU can be started normally.

[0023] In one embodiment, when the external charging power input provides power to the MCU, if it is abnormal charging, the charging main switch SB is turned on through the charging input to connect with the battery module, and the battery module is connected through the fuse and the circuit breaker. After the MCU communicates with the charging input and the battery module, the battery module is activated by controlling the pre-charging MOS tube unidirectional switch. The external charging power is connected to the battery module through the pre-charging MOS tube unidirectional switch through the fuse and the circuit breaker and activated. Among them, the charging main switch SW1 and the pre-charging MOS tube unidirectional switch are mutually exclusive. When the MCU controls the charging main switch SW1 to be turned on, the pre-charging switch is turned off through the third communication module built into the pre-charging MOS tube unidirectional switch. On the contrary, when the pre-charging MOS tube unidirectional switch is turned on, the charging main switch SW1 is controlled to be turned off. Therefore, the charging power can only switch the circuit through the turned-on switch, and the autonomous switching charging can be completed through low-voltage protection and wake-up charging. The charging mode is set according to the set program according to different situations, which greatly reduces the cost of manual repair and maintenance.

[0024] When in use, the charging input interface has automatic charging source identification. The external charging power supply is connected to the diode D1 through the input interface. The external charging power supply passes through the input voltage detection circuit and supplies power to the DC / DC signal power supply through the diode D1, and then supplies power to the MCU. At this time, the MCU detects whether the external charger power supply is connected through the diode DS1 and performs real-time charging monitoring of the external charging power supply. Then, the fourth communication module in the MCU communicates with the communication module of the input interface and the first communication module of the isolated DC / DC system power supply and performs current and voltage detection. If the voltage of the charging power supply entering the isolated DC / DC system power supply is normal, the fourth communication module of the MCU controls the second communication module of the charging main switch SW1 to open the switch. The charging main switch SW1 is connected to the control coil CO through the diode DV1. The diode DV1 is connected to the anti-reverse circuit to prevent the positive and negative poles of the power supply from being reversed. The second communication module controls the control coil CO to open the charging main switch SW1, thereby entering the battery module. If the voltage of the charging power supply entering the isolated DC / DC system power supply is too low, the third communication module of the pre-charging MOS tube unidirectional switch is controlled by the fourth communication module of the MCU to open the pre-charging switch, and the pre-charging MOS tube unidirectional switch is used to limit the current, thereby entering the battery module. At the same time, the whole machine is controlled to prohibit starting, and the status light is displayed. Only when the charging meets the set power standard value and the battery meets the normal charging, it automatically switches to the normal shutdown or power-on charging mode. Through the low-voltage protection of the host and the wake-up charging, the failure rate of the host can be effectively reduced, the service life of the host can be increased, and the safety can be greatly improved.

[0025] In one embodiment, after the battery module is activated, the external charging power reaches the main line through the battery module, the circuit breaker and the fuse. The device host has a powered sleep function, which can actively sleep or trigger passive sleep according to the set time. If the host is powered on and sleeps, the DC / DC signal power supply is provided with power through the diode D6, but the power supply will be controlled by the MCU. Otherwise, when the host is not powered on and sleeps, power is supplied through the diode D7. The MCU can be triggered to start the device through the key switch and then through the diode D4 signal. When the host is not used for powered sleep, the isolated DC / DC system power supply or MCU is powered through the diode D2. If the host is used for powered sleep, the isolated power supply or MCU is powered directly through the diode D3 without passing through the key switch; the diode D0 is connected to the diode D8 through the key switch SB, and the diode D8 is connected to the emergency stop switch to provide a starting power supply for the relay or N-way switch, wherein the external charging power supply is connected to the DC / DC signal power supply by the diode D5, the battery module is connected to the DC / DC signal power supply by the diode D6, the battery module is connected to the DC / DC signal power supply by the diode D7 through the key switch SB, and the diode D5, the diode D6, and the diode D7 are connected to the DC / DC signal power supply Power supply, power supply for peripheral loads through DC / DC signal power supply; external charging power supply is connected to isolated DC / DC system power supply through diode D1, battery module is connected to isolated DC / DC system power supply through diode D2 through key switch SB, battery module is connected to isolated DC / DC system power supply through diode D3, diode D1, diode D2, diode D3 are connected to isolated DC / DC system power supply for power supply, power supply for MCU through isolated DC / DC system power supply; battery module transmits battery module signal to isolated input detection circuit through diode D4 through key switch SB; key switch SB with shutdown charging and startup charging status indication is controlled by MCU, and the fourth communication module of MCU controls the communication module of key switch SB to control key switch SB and status light and shutdown charging light.

[0026] In one embodiment, the input interface is built with a communication module connected to an external charging power source, the first communication module of the battery module, the second communication module of the charging main switch SW1, and the third communication module of the pre-charging MOS tube unidirectional switch are controlled by the fourth communication module of the MCU, and the first communication module, the second communication module, the third communication module, and the fourth communication module are RS-485 serial communication protocols or I2C bidirectional serial communication protocols. Among them, because the fourth communication module communicates with the first communication module and the communication module of the input interface for voltage detection, the fourth communication module and the second communication module and the third communication module are directly controlled switches and need to be distinguished. It can also be an SPI synchronous serial communication protocol or an MCU isolation control 485 connected to the RS-485 serial communication protocol interface outside the first communication module and the communication module of the input interface.

[0027] refer to Figure 3 As shown, in one embodiment, the isolated DC / DC system power supply is connected with an MCU and a wireless communication module, and the isolated DC / DC system power supply supplies power to the MCU and the wireless communication module. One end of the MCU and the wireless communication module is connected through a power supply interface VCC, and the other end is connected through a communication interface to realize bidirectional interrupt wake-up and serial port communication. Through the wireless communication module, remote communication with the outside world can be realized. The isolated DC / DC system power supply is also connected with a clock circuit RTC to determine the time reference for the MCU, which is used for the host's sleep and power on and off. When the MCU is selected to sleep with power on, after waking up, it can wake up the wireless module without a server or charging station communication, and the server can also reversely wake up the MCU through the wireless communication module to start the device or execute the task.

[0028] In one embodiment, the battery module includes a battery and a battery management system BMS. The battery module is connected to a relay through a circuit breaker and a fuse through a main line current detection circuit and a main line voltage detection circuit. The relay is a main power switch SW0 and an N-way power switch. The power main switch SW0 is connected to the main line switch voltage detection circuit and is connected to the main load, and the N-way power switch is connected to the current feedback detection circuit and is connected to the load N.

[0029] refer to Figure 4As shown, in another embodiment, the circuit breaker has the highest main power switch authority, followed by the key switch SB, and the emergency stop switch has a hardware on / off load power function, and can notify the MCU, protect the locking device and sound an alarm. When the main power switch of the circuit breaker is in the off state, the host device will not work due to power failure. If the key switch is in the off state, even if other branches supply power to the MCU or other events trigger the MCU, it will only wake up the MCU, but will not start up. When the main power switch of the circuit breaker is turned on, and the device is in the boot state when the key switch SB is turned on, the soft shutdown can be triggered by software timing or other tasks or instructions. After shutdown, the device is not powered except for the MCU and the wireless communication module. The MCU can be controlled to be powered off or dormant, and the MCU also enters a deep sleep mode. At this time, the device can wake up the MCU or start it up in four ways. First: the MCU actively starts up, and the boot time of the MCU is written before the program shuts down, such as a timing task or other conditions, and the clock circuit RTC wakes up the MCU and starts it up; second: the MCU is passively awakened by connecting to an external charging power supply. At this time, the MCU will determine whether to start up according to the user configuration. For example, the user can choose to automatically start up after soft shutdown charging or keep it as it is. If it is kept as it is, it will only wake up the processing event but will not start up; third: the wireless communication module is configured to be awakenable, and the wireless communication module receives a remote boot command or an event that requires booting, and wakes up the MCU or starts up through a signal. Fourth: the user turns off the key switch and turns it on again, and the soft shutdown can be lifted and the device can be turned on directly. When the key is off, the device is in shutdown state. Even if the MCU is powered on or triggered by other events, it will only wake up but not start. When the emergency stop switch is pressed, the power load of the device is powered off and the MCU prohibits the device from working.

[0030] In summary, the circuit of this application supplies power to the MCU through an external charging power supply. After waking up the MCU, the communication module communicates with the battery module, detects the current and voltage of the battery module to determine normal charging or pre-charging, and thus autonomously completes the switching circuit for the corresponding situation. By completing autonomous and diverse charging methods and power on and off methods, the user experience is improved, while protecting the product to reduce failures and providing convenient and rich functions. The circuit of this application is also highly versatile, can match most products, complete autonomous operation, reduce labor costs, and improve safety.

[0031] Although the preferred embodiments of the present invention have been described, the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by a technician familiar with the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A low voltage protection charging circuit, characterized in that: include An isolated DC / DC system power supply electrically connected to an external charging power supply via an input interface; an MCU electrically connected to and powered by the isolated DC / DC system power supply; Battery module; After being connected in parallel, the two common ends are electrically connected to the input interface and the charging main switch SW1 of the battery module and the pre-charging MOS tube unidirectional switch respectively; Among them, the battery module, the charging main switch SW1, and the pre-charging MOS tube unidirectional switch are electrically connected to the first communication module, the second communication module and the third communication module respectively, and the MCU has a built-in fourth communication module that communicates with the first communication module, the second communication module and the third communication module.

2. The low voltage protection charging circuit according to claim 1, characterized in that: The first, second, third and fourth communication modules adopt RS-485 serial communication protocol or I2C bidirectional serial communication protocol.

3. The low voltage protection charging circuit according to claim 1, characterized in that: It includes a diode DV1, the positive electrode of which is connected to the input interface together with one end of the charging main switch SW1; A control coil CO for controlling the charging main switch SW1 has one end connected to the cathode of the diode DV1 and the other end connected to the second communication module.

4. The low voltage protection charging circuit according to claim 1, characterized in that: The battery module includes a battery and a battery management system BMS electrically connected to the battery. The low-voltage protection charging circuit also includes a circuit breaker and a fuse connected in series between the charging main switch SW1, the common end of the pre-charging MOS tube unidirectional switch and the battery management system BMS.

5. The low voltage protection charging circuit according to claim 1, characterized in that: It also includes a diode D1 whose positive electrode is connected to the input interface and whose negative electrode is connected to the isolated DC / DC system power supply.

6. The low voltage protection charging circuit according to claim 1, characterized in that: including a wireless communication module for communicating with an external terminal; The VCC interface of the wireless communication module is electrically connected to the VCC interface of the MCU, and is also communicatively connected to the communication interface of the MCU.

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