CN105978113A - Charging circuit, control method thereof and mobile terminal - Google Patents

Abstract

The invention provides a charging circuit, its control method and a mobile terminal. The charging circuit includes: a charging output terminal; a battery to be charged connected to the first terminal of the charging output terminal; a temperature detection element for detecting the temperature of the battery to be charged; a magnetic field generating element connected to the second terminal of the charging output terminal , when the temperature of the battery to be charged is less than or equal to the preset temperature value, the current output from the second terminal of the charging output terminal is used to generate a magnetic field, and the battery to be charged is heated in the magnetic field; the control switch connected to the temperature detection element, and the control switch One end is connected to the magnetic field generating element, and the other end is connected to the second end of the charging output end, which is used to control the connection and disconnection of the magnetic field generating element and the second end of the charging output end according to the temperature of the battery to be charged detected by the temperature detection element. This solution ensures that the battery can be charged at the optimal charging temperature, shortens the charging time, and improves the user experience.

Description

A charging circuit, its control method and mobile terminal

technical field

The invention relates to the technical field of mobile terminals, in particular to a charging circuit, its control method and a mobile terminal.

Background technique

With the wide application of lithium-ion batteries in various electronic devices, the charging requirements for lithium-ion batteries are also getting higher and higher. Generally, the operating temperature of lithium-ion batteries is -20°C-60°C, and the lowest temperature can reach -40°C under special conditions, but this is only the discharge temperature; for the charging temperature, the range given by each cell factory can only be within 0-45°C, and the best charging temperature for lithium-ion batteries is 20-35°C, as the temperature decreases, the fluidity and ionic conductivity of the electrolyte will decrease, and if you still use high current charging at low temperatures, It will cause lithium ions to deposit on the surface of the negative electrode graphite to form lithium metal with irreversible capacity, resulting in attenuation of battery capacity. In severe cases, lithium dendrites will be formed, which may pierce the separator and cause a short circuit risk. Therefore, many mobile terminal devices have made corresponding settings - setting a lower charging current in a low-temperature environment to ensure the reliability and safety of lithium batteries, but this will slow down the charging speed of the device and prolong the charging time. Poor question.

In a low temperature environment, the activity of lithium ions is very low. If the charging current is the same as that at normal temperature, it is easy to produce lithium, which will reduce the battery life. For example, if the fast charging core is also charged with fast charging current at 0°C, the cycle diving phenomenon will occur. As the number of cycles increases, the capacity retention of the battery (Capacity Retention) is gradually declining. Therefore, in order to ensure the cycle life of the battery, it is necessary to reduce the charging current at low temperature, but reducing the charging current will increase the charging completion time and affect the user experience.

Contents of the invention

The present invention provides a charging circuit, its control method and a mobile terminal, which are used to solve the problem that the existing mobile terminal reduces the charging current when charging at low temperature, resulting in slower charging speed, longer charging time, and affecting user experience.

In order to solve the above technical problems, an embodiment of the present invention provides a charging circuit, including:

The charging output terminal is used to connect with external charging equipment to provide charging current for the battery to be charged;

A battery to be charged connected to the first end of the charging output end;

A temperature detection element connected to the battery to be charged, used to detect the temperature of the battery to be charged;

A magnetic field generating element, the magnetic field generating element is connected to the second end of the charging output end, and is used to use the second end of the charging output end to output when the temperature of the battery to be charged is less than or equal to a preset temperature value. the current generates a magnetic field, wherein the battery to be charged is heated in the magnetic field;

A control switch connected to the temperature detection element, and one end of the control switch is connected to the magnetic field generating element, and the other end is connected to the second end of the charging output end, for The temperature of the battery to be charged controls the state of connection and disconnection between the magnetic field generating element and the second end of the charging output end.

An embodiment of the present invention provides a mobile terminal, including the charging circuit described above.

An embodiment of the present invention provides a method for controlling a charging circuit, including:

Obtain the temperature of the battery to be charged;

According to the comparison result between the temperature and the preset temperature value, the state of connection and disconnection between the magnetic field generating element and the second terminal of the charging output terminal is controlled.

The beneficial effects of the present invention are:

In the above scheme, when the battery of the mobile terminal is being charged, when the battery temperature of the mobile terminal is lower than the preset temperature value, the battery is heated by the principle of current generation of a magnetic field, which avoids the decrease of the charging current and the increase of the charging current due to the low temperature of the battery. The problem of long charging time ensures that the battery can be charged at the optimal charging temperature, shortens the charging time, and improves the user experience.

Description of drawings

Fig. 1 shows the structural representation of the charging circuit of the first embodiment of the present invention;

Fig. 2 shows the structural representation of the charging circuit of the second embodiment of the present invention;

FIG. 3 shows a schematic flowchart of a method for controlling a charging circuit according to a third embodiment of the present invention;

FIG. 4 shows a schematic structural diagram of a mobile terminal according to a fourth embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The present invention aims at the problem that the existing mobile terminal reduces the charging current when charging at low temperature, resulting in slower charging speed and longer charging time, which affects user experience, and provides a charging circuit, its control method and a mobile terminal.

first embodiment

As shown in Figure 1, the charging circuit of the embodiment of the present invention includes:

The charging output terminal 110 is used to connect with an external charging device to provide charging current for the battery 120 to be charged;

A battery to be charged 120 connected to the first end of the charging output end 110;

A temperature detection element 130 connected to the battery to be charged 120, for detecting the temperature of the battery to be charged 120;

A magnetic field generating element 140, the magnetic field generating element 140 is connected to the second end of the charging output end 110, and is used to use the charging output end when the temperature of the battery to be charged 120 is less than or equal to a preset temperature value. The current output by the second end of 110 generates a magnetic field, wherein the battery to be charged 120 is heated in the magnetic field;

A control switch 150 connected to the temperature detection element 130, and one end of the control switch 150 is connected to the magnetic field generating element 140, and the other end is connected to the second end of the charging output terminal 110, for detecting The temperature of the battery to be charged 120 detected by the element 130 controls the state of connection and disconnection between the magnetic field generating element 140 and the second end of the charging output end 110 .

It should be noted that the charging output terminal 110 usually refers to the charging port of the mobile terminal. At the charging port, the current obtained from the charging source is divided into two parts, one part is directly used for battery charging, and the other part is used when the battery temperature is low. , used to heat up the battery. At the same time, the on-off control is performed between the magnetic field generating element 140 and the charging output terminal 110 through the control switch 150. Only when the temperature of the battery 120 to be charged detected by the temperature detecting element 130 is lower than a preset value, the magnetic field generating element 140 and the charging output terminal 110 are connected to each other. The charging output terminal 110 is connected to heat up the battery 120 to be charged, thereby ensuring that the battery can be charged at an optimal charging temperature, shortening the charging time, and improving user experience.

second embodiment

As shown in Figure 2, the charging circuit of the embodiment of the present invention includes:

The charging output terminal 110 is used to connect with an external charging device to provide charging current for the battery 120 to be charged;

A battery to be charged 120 connected to the first end of the charging output end 110;

A temperature detection element 130 connected to the battery to be charged 120, for detecting the temperature of the battery to be charged 120;

A magnetic field generating element 140, the magnetic field generating element 140 is connected to the second end of the charging output end 110, and is used to use the charging output end when the temperature of the battery to be charged 120 is less than or equal to a preset temperature value. The current output by the second end of 110 generates a magnetic field, wherein the battery to be charged 120 is heated in the magnetic field;

Wherein, the magnetic field generating element 140 includes:

A current converter 141, connected to the second end of the charging output end 110, for collecting the current output by the second end of the charging output end 110, and converting the current into a first current;

A coil 142 connected to the current converter 141, configured to generate a magnetic field for heating the battery 120 to be charged according to the first current output by the current converter 141;

The charging circuit also includes:

A control switch 150 connected to the temperature detection element 130, and one end of the control switch 150 is connected to the magnetic field generating element 140, and the other end is connected to the second end of the charging output terminal 110, for detecting The temperature of the battery to be charged 120 detected by the element 130 controls the state of connection and disconnection between the magnetic field generating element 140 and the second end of the charging output end 110 .

Preferably, the temperature detection element 130 may be a positive temperature coefficient (PTC) thermistor or a negative temperature coefficient (NTC) thermistor.

It should be noted that since the output of the charging output terminal 110 is direct current, when using this current for heating, the direct current needs to be converted into alternating current, and the current converter 141 converts direct current into high-frequency alternating current (ie The device for the above-mentioned first current), usually, the current converter 141 is an inverter or an insulated gate bipolar transistor (IGBT) power tube.

It should be noted that, in order to better heat the battery, it is necessary to set ferromagnetic material elements in the mobile terminal. Usually, the ferromagnetic material elements are attached to the surface of the battery to be charged 120 or arranged on the surface of the battery to be charged. In the battery compartment of the battery 120.

In the embodiment of the present invention, a current converter 141 is connected to the charging output terminal of the mobile terminal, and a coil is added to the mobile terminal. Usually, a ring coil can be used. Converter 141 into high-frequency alternating current; high-frequency alternating current generates a magnetic field through the toroidal coil, mainly based on the LC oscillating circuit of the toroidal coil to generate a magnetic field; and the toroidal coil with high-frequency alternating current will generate eddy current when passing through ferromagnetic material components, so that the iron The magnetic material element oscillates to generate high temperature, and the temperature of the battery 120 to be charged will also rise accordingly.

In the embodiment of the present invention, by setting a current converter and a coil to assist in heating the battery to be charged, the temperature of the battery to be charged can be raised when the temperature of the battery to be charged is low, ensuring that the battery can be charged at an optimal charging temperature. The charging time is shortened, and the user experience effect is improved.

third embodiment

As shown in FIG. 3 , an embodiment of the present invention provides a method for controlling the above-mentioned charging circuit, including:

Step 31, acquiring the temperature of the battery to be charged.

This step 31 is usually implemented by a temperature detection element in the charging circuit.

Step 32, according to the comparison result between the temperature and the preset temperature value, control the state of connection and disconnection between the magnetic field generating element and the second terminal of the charging output terminal.

It should be noted that because the suitable charging temperature of the battery is within a range of values, when it is lower than the lowest value of the range, the charging current will be too small and the charging speed will be slowed down, and when it exceeds the maximum value of the range, it will Bring certain potential safety hazards, so the specific implementation of step 32 in the embodiment of the present invention is:

If the temperature is less than or equal to the first preset value, control the magnetic field generating element to be connected to the second end of the charging output end to heat the battery to be charged;

If the temperature is greater than or equal to a second preset value, control the magnetic field generating element to disconnect from the second end of the charging output end, and stop heating the battery to be charged;

Wherein, the second preset value is greater than the first preset value.

It should be noted that when the temperature of the battery to be charged is less than or equal to the lowest optimal charging temperature, the path between the magnetic field generating element and the charging output terminal needs to be turned on by the control switch to heat the battery to be charged; in order to avoid continuous charging When the battery is heated, when the temperature of the battery to be charged is greater than or equal to the highest optimal charging temperature, the control switch needs to disconnect the path between the magnetic field generating element and the charging output terminal to stop the heating of the battery to be charged. In practical applications, this process can be described as: when charging the battery of the mobile terminal, due to environmental reasons, the temperature of the battery is suddenly lower than the minimum value of the most suitable charging temperature. At this time, in order to ensure the charging of the mobile terminal In order to ensure the safety of charging, the temperature of the battery should not be increased any more when the temperature of the battery rises to the maximum value of the most suitable charging temperature. At this time, it is necessary to stop heating the battery; when the heating is stopped, the temperature of the battery may slowly drop until the temperature of the battery drops below the minimum value of the most suitable charging temperature, then heat the battery again , repeat the above process until the charging of the battery is completed.

When charging the battery to be recharged, after heating the battery to be recharged, the internal components of the mobile terminal sense the battery temperature, and then adjust the charging current to a size suitable for the battery temperature, thereby shortening the charging time. At the same time, the high-frequency current can be adjusted according to the change of temperature to realize intermittent heating of the battery and ensure that the temperature of the battery is kept at the optimal charging temperature during charging.

Fourth embodiment

The fourth embodiment of the present invention also provides a mobile terminal, including the charging circuit described above.

The mobile terminal of this embodiment can effectively heat up the battery in a low-temperature environment, so that it can reach a temperature that can withstand high-current charging, thereby shortening the charging time at low temperature and improving user experience.

Fig. 4 is a schematic structural diagram of a mobile terminal according to an embodiment of the present invention. Specifically, the mobile terminal in FIG. 4 may be a mobile phone, a tablet computer, a personal digital assistant (Personal Digital Assistant, PDA), or a vehicle-mounted computer.

The mobile terminal in FIG. 4 includes a radio frequency (Radio Frequency, RF) circuit 410 , a memory 420 , an input unit 430 , a display unit 440 , a processor 450 , an audio circuit 460 , a WiFi (Wireless Fidelity) module 470 and a power supply 480 .

Wherein, the input unit 430 can be used to receive number or character information input by the user, and generate signal input related to user setting and function control of the mobile terminal. Specifically, in the embodiment of the present invention, the input unit 430 may include a touch panel 431 . The touch panel 431, also referred to as a touch screen, can collect user's touch operations on or near it (such as the user's operation on the touch panel 431 using any suitable object or accessory such as a finger, a stylus), and The specified program drives the corresponding connected device. Optionally, the touch panel 431 may include two parts, a touch detection device and a touch controller. Among them, the touch detection device detects the user's touch orientation, and detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts it into contact coordinates, and sends it to the to the processor 450, and can receive and execute commands sent by the processor 450. In addition, the touch panel 431 can be implemented in various types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel 431, the input unit 430 may also include other input devices 432, which may include but not limited to physical keyboards, function keys (such as volume control buttons, switch buttons, etc.), trackballs, mice, joysticks, etc. one or more of.

Wherein, the display unit 440 can be used to display information input by the user or information provided to the user and various menu interfaces of the mobile terminal. The display unit 440 may include a display panel 441, and optionally, the display panel 441 may be configured in the form of an LCD or an organic light-emitting diode (Organic Light-Emitting Diode, OLED).

It should be noted that the touch panel 431 can cover the display panel 441 to form a touch display screen. When the touch display screen detects a touch operation on or near it, it is sent to the processor 450 to determine the type of the touch event, and then the processor 450 provides corresponding visual output on the touch display screen according to the type of touch event.

The touch display screen includes an application program interface display area and a common control display area. The arrangement of the display area of the application program interface and the display area of the commonly used controls is not limited, and may be an arrangement in which the two display areas can be distinguished, such as vertical arrangement, left-right arrangement, and the like. The application program interface display area can be used to display the interface of the application program. Each interface may include at least one interface element such as an icon of an application program and/or a widget desktop control. The application program interface display area can also be an empty interface without any content. The commonly used control display area is used to display controls with a high usage rate, for example, application icons such as setting buttons, interface numbers, scroll bars, and phonebook icons.

Wherein the processor 450 is the control center of the mobile terminal, utilizes various interfaces and lines to connect the various parts of the whole mobile phone, by running or executing the software programs and/or modules stored in the first memory 421, and calling the software programs and/or modules stored in the second memory The data in 422 executes various functions of the mobile terminal and processes data, so as to monitor the mobile terminal as a whole. Optionally, the processor 450 may include one or more processing units.

What has been described above is a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications can also be made without departing from the principles described in the present invention. within the scope of protection of the invention.

Claims (9)

1. A charging circuit, characterized in that, comprising: The charging output terminal is used to connect with external charging equipment to provide charging current for the battery to be charged; A battery to be charged connected to the first end of the charging output end; A temperature detection element connected to the battery to be charged, used to detect the temperature of the battery to be charged; A magnetic field generating element, the magnetic field generating element is connected to the second end of the charging output end, and is used to use the second end of the charging output end to output when the temperature of the battery to be charged is less than or equal to a preset temperature value. the current generates a magnetic field, wherein the battery to be charged is heated in the magnetic field; A control switch connected to the temperature detection element, and one end of the control switch is connected to the magnetic field generating element, and the other end is connected to the second end of the charging output end, for The temperature of the battery to be charged controls the state of connection and disconnection between the magnetic field generating element and the second end of the charging output end. 2. The charging circuit according to claim 1, wherein the temperature detection element is a positive temperature coefficient thermistor or a negative temperature coefficient thermistor. 3. The charging circuit according to claim 1, wherein the battery to be charged is provided with a ferromagnetic material element that uses the magnetic field to heat the battery to be charged, wherein the ferromagnetic material The component is pasted on the surface of the battery to be charged or arranged in the battery compartment of the battery to be charged. 4. The charging circuit according to claim 1, wherein the magnetic field generating element comprises: A current converter, connected to the second end of the charging output end, for collecting the current output by the second end of the charging output end, and converting the current into a first current; The coil connected to the current converter is used to generate a magnetic field for heating the battery to be charged according to the first current output by the current converter. 5. The charging circuit according to claim 4, wherein the current converter is an inverter or an IGBT power transistor. 6. A mobile terminal, characterized by comprising the charging circuit according to any one of claims 1 to 5. 7. The mobile terminal according to claim 6, wherein the mobile terminal is a mobile phone, an e-book reader, a tablet computer, a notebook computer, a personal digital assistant, a music player or a navigator. 8. A control method for the charging circuit according to any one of claims 1 to 5, characterized in that it comprises: Obtain the temperature of the battery to be charged; According to the comparison result between the temperature and the preset temperature value, the state of connection and disconnection between the magnetic field generating element and the second terminal of the charging output terminal is controlled. 9. The control method according to claim 8, characterized in that, according to the comparison result between the temperature and the preset temperature value, the step of controlling the state of connection and disconnection between the magnetic field generating element and the second end of the charging output end include: If the temperature is less than or equal to the first preset value, control the magnetic field generating element to be connected to the second end of the charging output end to heat the battery to be charged; If the temperature is greater than or equal to a second preset value, control the magnetic field generating element to disconnect from the second end of the charging output end, and stop heating the battery to be charged; Wherein, the second preset value is greater than the first preset value.