CN110718961A

CN110718961A - Power supply circuit, control method thereof and display device

Info

Publication number: CN110718961A
Application number: CN201911185681.2A
Authority: CN
Inventors: 叶金安; 徐丽华
Original assignee: Tianma Microelectronics Co Ltd
Current assignee: Tianma Microelectronics Co Ltd; Chengdu Tianma Micro Electronics Co Ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-01-21
Anticipated expiration: 2039-11-27
Also published as: CN110718961B

Abstract

The invention discloses a power supply circuit, a control method thereof and a display device.A data processing circuit and a power supply switching circuit are arranged, when the condition that the power supply from a first power supply to a load is switched to the condition that the power supply from a second power supply to the load is determined, a first control signal can be input to the power supply switching circuit through the data processing circuit, the power supply switching circuit is controlled to firstly conduct the second power supply and the load, and after a first time threshold value is passed, a second control signal is input to the power supply switching circuit, and the power supply switching circuit is controlled to disconnect the first power supply and the load. When the fact that the second power supply supplies power to the load is switched to the fact that the first power supply supplies power to the load is determined, the data processing circuit inputs a third control signal to the power supply switching circuit, the power supply switching circuit is controlled to conduct the first power supply and the load firstly, after a second time threshold value passes, a fourth control signal is input to the power supply switching circuit, and the power supply switching circuit is controlled to disconnect the second power supply and the load, so that the problem of load power failure is solved.

Description

Power supply circuit, control method thereof and display device

Technical Field

The present invention relates to the field of electronic technologies, and in particular, to a power supply circuit, a control method thereof, and a display device.

Background

Batteries play a significant role in display devices as a source of energy. For example, a display device driven by a battery generally has a sub-battery in addition to a main battery. Thus, when one of the main battery and the auxiliary battery is dead, the other battery can be switched to supply power for the display device.

Disclosure of Invention

The embodiment of the invention provides a power supply circuit, a control method thereof and a display device, which are used for controlling a switching power supply to supply power.

An embodiment of the present invention provides a power supply circuit, including: the device comprises a plurality of power supplies, a data processing circuit and a power supply switching circuit electrically connected with the power supplies; wherein the plurality of power sources includes a first power source and a second power source;

the data processing circuit is used for inputting a first control signal to the power supply switching circuit when the first power supply is determined to supply power to a load and the second power supply is determined to supply power to the load, and inputting a second control signal to the power supply switching circuit after a first time threshold value is passed; when the second power supply is determined to supply power to the load and the first power supply supplies power to the load, inputting a third control signal to the power supply switching circuit, and inputting a fourth control signal to the power supply switching circuit after a second time threshold value;

the power supply switching circuit is used for conducting the second power supply and the load when receiving the first control signal, and disconnecting the first power supply and the load when receiving the second control signal; and turning on the first power supply and the load when the third control signal is received, and turning off the second power supply and the load when the fourth control signal is received.

The embodiment of the invention also provides a display device which comprises the power supply circuit.

The embodiment of the invention also provides a control method of the power supply circuit, which comprises the following steps:

when the data processing circuit determines that the first power supply supplies power to the load and the second power supply supplies power to the load, the data processing circuit inputs a first control signal to the power supply switching circuit to control the power supply switching circuit to conduct the second power supply and the load; after a first time threshold value, inputting a second control signal to the power supply switching circuit to control the power supply switching circuit to disconnect the first power supply from the load;

when the data processing circuit determines that the second power supply supplies power to the load and the first power supply supplies power to the load, the data processing circuit inputs a third control signal to the power supply switching circuit to control the power supply switching circuit to conduct the first power supply and the load; and after a second time threshold value, inputting a fourth control signal to the power supply switching circuit to control the power supply switching circuit to disconnect the second power supply from the load.

The invention has the following beneficial effects:

according to the power supply circuit, the control method and the display device provided by the embodiment of the invention, the data processing circuit and the power supply switching circuit are arranged, when the condition that the power supply from the first power supply to the load is switched to the condition that the power supply from the second power supply to the load is determined, the data processing circuit can input the first control signal to the power supply switching circuit so as to control the power supply switching circuit to firstly switch on the second power supply and the load, and after the first time threshold value is passed, the second control signal is input to the power supply switching circuit so as to control the power supply switching circuit to switch off the first power supply and the load. Therefore, when the first power supply is determined to supply power to the load and the second power supply is determined to supply power to the load, the first power supply and the load can be disconnected after the second power supply and the load are connected, and the problem of load power failure can be solved. And when the second power supply is determined to supply power to the load and the first power supply is determined to supply power to the load, the data processing circuit firstly inputs a third control signal to the power supply switching circuit to control the power supply switching circuit to firstly switch the first power supply and the load on, and after a second time threshold value is passed, inputs a fourth control signal to the power supply switching circuit to control the power supply switching circuit to switch the second power supply and the load off. Therefore, when the second power supply is determined to supply power to the load and is switched to supply power to the load by the first power supply, the first power supply is firstly conducted with the load, and then the second power supply is disconnected with the load, so that the problem of load power failure can be solved.

Drawings

Fig. 1 is a schematic structural diagram of a power supply circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another power supply circuit according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another power supply circuit according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another power supply circuit according to an embodiment of the present invention;

fig. 5 is a flowchart of a control method of a power supply circuit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. And the embodiments and features of the embodiments may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

It should be noted that the sizes and shapes of the figures in the drawings are not to be considered true scale, but are merely intended to schematically illustrate the present invention. And the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

With the rapid advance of technology, various electronic devices such as display devices have been developed. Batteries generally serve as an energy source and play a significant role in electronic devices. For example, a load (e.g., a display device) driven by a battery usually has a sub-battery in addition to a main battery. Thus, when one of the main battery and the auxiliary battery is dead, the other battery can be switched to supply power to the load.

In practical applications, when the control battery is switched, for example, the control battery is switched from the main battery to the auxiliary battery, the following problems generally occur:

(1) generally, the main battery is electrically connected with the main control transistor, and the auxiliary battery is electrically connected with the auxiliary control transistor. When the main battery is switched to the auxiliary battery, a control signal is generated by comparing the voltages of the main battery and the auxiliary battery, and the control signal is provided to the main control transistor and the auxiliary control transistor, so that the main control transistor is turned off and the auxiliary control transistor is turned on, and the main battery stops supplying power and the auxiliary battery supplies power. However, due to the delay of the signal and the difference in the characteristics of the transistors, a situation may occur in which the main control transistor is turned off but the sub-control transistor is not turned on in time, thereby causing the load to be powered off.

(2) When the electric quantity of the main battery is low, the auxiliary battery is actively activated so as to supply power to the auxiliary battery. However, although the auxiliary battery is already supplying power, the system is still in the process of detecting the electric quantity of the main battery, so that low-electric-quantity reminding can be generated on a display interface of the display device, and a control action of automatically shutting down the power supply due to too low electric quantity is performed, so that the load is powered off.

(3) The electric quantities of the main battery and the auxiliary battery cannot be monitored in real time, so that the electric quantity of the auxiliary battery cannot be determined. When the main battery is switched to the sub-battery, the load is also disconnected if the electric quantity of the sub-battery is too low.

In view of this, an embodiment of the present invention provides a power supply circuit, as shown in fig. 1, which may include: a plurality of power sources 110-K (K is not less than 1 and not more than K, K and K are integers, K is the total number of power sources, and K is 2 in fig. 1), a data processing circuit 130, and a power switching circuit 120 electrically connected to the plurality of power sources; wherein the plurality of power sources includes a first power source 110-1 and a second power source 110-2;

the data processing circuit 130 is configured to input a first control signal to the power switching circuit 120 when it is determined that the power supply from the first power source 110-1 to the load 140 is switched to the power supply from the second power source 110-2 to the load 140, and input a second control signal to the power switching circuit 120 after a first time threshold elapses; when the power supply from the second power supply 110-2 to the load 140 is determined to be switched to the power supply from the first power supply 110-1 to the load 140, inputting a third control signal to the power supply switching circuit 120, and inputting a fourth control signal to the power supply switching circuit 120 after a second time threshold value;

the power switching circuit 120 is configured to turn on the second power supply 110-2 and the load 140 when receiving the first control signal, and turn off the first power supply 110-1 and the load 140 when receiving the second control signal; and turning on the first power supply 110-1 and the load 140 when the third control signal is received, and turning off the second power supply 110-2 and the load 140 when the fourth control signal is received.

In the power supply circuit provided in the embodiment of the present invention, by providing the data processing circuit and the power supply switching circuit, when it is determined that the power supply from the first power supply to the load is switched to the power supply from the second power supply to the load, the data processing circuit may input the first control signal to the power supply switching circuit to control the power supply switching circuit to first turn on the second power supply and the load, and after the first time threshold passes, the second control signal is input to the power supply switching circuit to control the power supply switching circuit to turn off the first power supply and the load. Therefore, when the first power supply is determined to supply power to the load and the second power supply is determined to supply power to the load, the first power supply and the load can be disconnected after the second power supply and the load are connected, and the problem of load power failure can be solved. And when the second power supply is determined to supply power to the load and the first power supply is determined to supply power to the load, the data processing circuit firstly inputs a third control signal to the power supply switching circuit to control the power supply switching circuit to firstly switch the first power supply and the load on, and after a second time threshold value is passed, inputs a fourth control signal to the power supply switching circuit to control the power supply switching circuit to switch the second power supply and the load off. Therefore, when the second power supply is determined to supply power to the load and is switched to supply power to the load by the first power supply, the first power supply is firstly conducted with the load, and then the second power supply is disconnected with the load, so that the problem of load power failure can be solved.

In the power supply circuit according to the embodiment of the present invention, when the power supply from the first power supply to the load is switched to the power supply from the second power supply to the load, the first control signal for controlling the second power supply and the load to be on and the second control signal for controlling the first power supply and the load to be off may be independent of each other. And when the power supply from the second power supply to the load is switched to the power supply from the first power supply to the load, the third control signal for controlling the conduction of the first power supply and the load and the fourth control signal for controlling the disconnection of the second power supply and the load can be mutually independent. This can avoid the problem of load power-off due to signal delay and transistor characteristic differences.

A general display device may include a display panel, a processor (e.g., a Central Processing Unit (CPU)), and the like. Both the display panel and the processor require voltages to operate. In particular implementations, in embodiments of the invention, the load 140 may include at least one of a display panel and a processor. Of course, in practical applications, the load 140 may also include other devices that need to be powered, and is not limited herein.

In particular embodiments, the first power source 110-1 may be a detachable main battery. That is, after the current main battery is low in electric quantity, the current main battery can be detached and replaced by a new main battery. Of course, in practical applications, the first power supply 110-1 may also be designed according to practical application environments, and is not limited herein.

In particular implementation, in the embodiment of the present invention, the second power source 110-2 may be a built-in secondary battery capable of being charged, which is not detachable. That is, the sub-battery is built in the display device and cannot be directly removed and replaced, but the sub-battery can be charged. Of course, in practical applications, the second power supply 110-2 may also be designed according to practical application environments, and is not limited herein.

In particular implementation, in the embodiment of the present invention, the first time threshold may be set to 3s, 4s, or 5 s. Of course, in practical applications, the specific value of the first time threshold may also be determined empirically or may be designed and determined according to the practical application environment, and is not limited herein.

In practical implementation, in the embodiment of the present invention, the second time threshold may be set to 3s, 4s, or 5 s. Of course, in practical applications, the specific value of the second time threshold may also be determined empirically or may be designed and determined according to practical application environments, and is not limited herein.

In practical implementation, in the embodiment of the present invention, the data processing circuit 130 may be further configured to obtain the electric quantities of the first power source 110-1 and the second power source 110-2 in real time. Therefore, the electric quantity of the first power supply 110-1 and the second power supply 110-2 can be obtained in real time, so that the real-time electric quantity of the first power supply 110-1 and the second power supply 110-2 can be known, and the real-time monitoring of the electric quantity of the first power supply 110-1 and the second power supply 110-2 can be realized.

In practical implementation, in the embodiment of the present invention, as shown in fig. 2, the power switching circuit 120 includes: a first sub power supply switching circuit 121 and a second sub power supply switching circuit 122; the input end of the first sub-power switching circuit 121 is electrically connected to the first power supply 110-1, the control end of the first sub-power switching circuit 121 is electrically connected to the data processing circuit 130, and the output end of the first sub-power switching circuit 121 is electrically connected to the load 140; the first sub power switching circuit 121 is configured to turn on the first power source 110-1 and the load 140 when receiving the third control signal; upon receiving the second control signal, the first power supply 110-1 and the load 140 are disconnected. This may control the connection and disconnection of the first power source 110-1 and the load 140 through the first sub power source switching circuit 121.

Moreover, the input end of the second sub-power switching circuit 122 is electrically connected to the second power source 110-2, the control end of the second sub-power switching circuit 122 is electrically connected to the data processing circuit 130, and the output end of the second sub-power switching circuit 122 is electrically connected to the load 140; the second sub power switching circuit 122 is configured to turn on the second power supply 110-2 and the load 140 when receiving the first control signal; upon receiving the fourth control signal, the second power supply 110-2 and the load 140 are disconnected. This may control the connection and disconnection of the second power source 110-2 and the load 140 through the second sub power source switching circuit 122.

In a specific implementation, in the embodiment of the present invention, the data processing circuit 130 may be specifically configured to determine whether the electric quantity of the first power source 110-1 is less than or equal to a first power-down electric quantity threshold and whether the electric quantity of the second power source 110-2 is greater than or equal to a first power-up electric quantity threshold; when the electric quantity of the first power source 110-1 is judged to be smaller than or equal to the first power-down electric quantity threshold value and the electric quantity of the second power source 110-2 is judged to be larger than or equal to the first power-up electric quantity threshold value, the power supply from the first power source 110-1 to the load 140 is determined to be switched to the power supply from the second power source 110-2 to the load 140. Therefore, when it is determined that the power of the first power source 110-1 is insufficient to supply power to the load 140 and the voltage of the second power source 110-2 is capable of supplying power to the load 140, the power supply from the first power source 110-1 to the load 140 can be switched to the power supply from the second power source 110-2 to the load 140, so that the power failure problem caused by the low power of the second power source 110-2 can be avoided.

In practical implementation, in the embodiment of the present invention, the first power-down capacity threshold may be set to be 3%, 4% or 5% of the rated capacity of the first power source, so that when the capacity of the first power source 110-1 is less than or equal to the first power-down capacity threshold, it may be indicated that the capacity of the first power source 110-1 is low and is not enough to supply power to the load 140 in the next time. Of course, in practical applications, the specific value of the first power-down electric quantity threshold may also be determined empirically, or may be designed and determined according to practical application environments, and is not limited herein.

In particular embodiments, the first power-on charge threshold may be set to 50%, 80%, 90%, 95%, or 98% of the rated charge of the second power source, such that when the charge of the second power source 110-2 is greater than or equal to the first power-on charge threshold, it may be stated that the charge of the second power source 110-2 may supply power to the load 140 in the next time. Of course, in practical applications, the specific value of the first power-on electric quantity threshold may also be determined empirically, or may be designed and determined according to practical application environments, and is not limited herein.

After the first power source 110-1 is disconnected from the load 140, the load 140 is powered using the second power source 110-2. The first power supply 110-1 may then be removed and replaced with a new first power supply 110-1. However, the power of the new first power source 110-1 is not clear, so as to avoid the problem that the power of the load 140 is cut off if the power of the new first power source 110-1 is also low, in order to switch the power supply of the load 140 from the second power source 110-2 to the power supply of the load 140 from the new first power source 110-1. In practical implementation, in the embodiment of the present invention, the data processing circuit 130 may be specifically configured to, when it is determined that the first power source 110-1 disconnected from the load 140 is replaced by a new first power source 110-1, determine whether the electric quantity of the new first power source 110-1 is greater than or equal to the second power-on electric quantity threshold; when the power of the new first power source 110-1 is determined to be greater than or equal to the second power-on power threshold, it is determined that the power supplied to the load 140 by the second power source 110-2 is switched to the power supplied to the load 140 by the new first power source 110-1. Thus, the power of the new first power source 110-1 is detected to determine whether the power of the new first power source 110-1 can supply power to the load 140. If it is determined that the new first power source 110-1 can supply power to the load 140, the new first power source 110-1 may be used to supply power to the load 140.

In practical implementation, in the embodiment of the present invention, the second power-on charge threshold may be set to 50%, 80%, 90%, 95%, or 98% of the rated charge of the first power source, so that when the charge of the new first power source 110-1 is greater than or equal to the second power-on charge threshold, it may be indicated that the charge of the new first power source 110-1 is higher, and the load 140 may be powered in the next time. Of course, in practical applications, the specific value of the second power-on electric quantity threshold may also be determined empirically, or may be designed and determined according to practical application environments, and is not limited herein.

Alternatively, the first power-on power amount threshold and the second power-on power amount threshold may be made the same. This makes it possible to uniformly manage the first power supply and the second power supply.

In a specific implementation, in the embodiment of the present invention, the data processing circuit 130 may be further configured to determine whether the electric quantity of the second power source 110-2 is less than or equal to the charging electric quantity threshold every preset time; and when the electric quantity of the second power supply 110-2 is judged to be less than or equal to the charging electric quantity threshold value, determining that the second power supply 110-2 needs to be charged and reminding charging. Since the second power supply 110-2 is built in the display device, the second power supply 110-2 cannot be detached. When the electric quantity of the second power supply 110-2 is low, the second power supply 110-2 can be charged by charging reminding, so that the second power supply 110-2 can be kept in a power-on state all the time.

In particular implementations, the threshold charge level may be set at 50%, 70%, 80%, or 90% of the rated charge level of the second power source in embodiments of the invention. Of course, in practical applications, the specific value of the threshold of the charging amount may be determined empirically or may be designed according to practical application environments, and is not limited herein.

In particular implementations, the predetermined time may be 1 minute, 5 minutes, or 1 hour in embodiments of the present invention. Of course, in practical applications, the specific value of the preset time may be determined empirically or designed according to practical application environments, and is not limited herein.

It should be noted that, for example, when the preset time is set to 1 hour, it is determined whether the electric quantity of the second power supply 110-2 is less than or equal to the charging electric quantity threshold every preset time, which may be: it is determined whether the amount of power of the second power supply 110-2 is less than or equal to the charging power threshold once every 1 hour elapses. For example, taking 24 hours a day as an example, it is determined once at time 13:00 whether the amount of power of the second power supply 110-2 is less than or equal to the charging power threshold, once at time 14:00 whether the amount of power of the second power supply 110-2 is less than or equal to the charging power threshold, and once at time 15:00 whether the amount of power of the second power supply 110-2 is less than or equal to the charging power threshold. The rest is analogized, and the description is omitted here.

In specific implementation, in the embodiment of the present invention, as shown in fig. 3, the power supply circuit may further include: a first power supply capacity detection circuit 151 and a second power supply capacity detection circuit 152;

the first power supply electric quantity detection circuit 151 is electrically connected with the first power supply 110-1 and the data processing circuit 130 respectively; the first power supply electric quantity detection circuit 151 is configured to collect electric quantity of the first power supply 110-1 in real time, and provide the collected electric quantity of the first power supply 110-1 to the data processing circuit 130;

the second power supply electric quantity detection circuit 152 is electrically connected with the second power supply 110-2 and the data processing circuit 130 respectively; the second power supply power detection circuit 152 is configured to collect the power of the second power supply 110-2 in real time, and provide the collected power of the second power supply 110-2 to the data processing circuit 130.

In practical implementation, in the embodiment of the present invention, as shown in fig. 3, the first power supply electric quantity detection circuit 151 is further electrically connected to the second power supply 110-2 to supply power by using the second power supply 110-2. Thus, when the first power supply 110-1 is removed, the first power supply capacity detection circuit 151 can still be powered to operate. Further, the second power level detection circuit 152 may also be powered by the second power source 110-2. Since the second power supply 110-2 can be kept in a power-on state all the time, the first power supply power detection circuit 151 and the second power supply power detection circuit 152 can be kept in operation also in a power-on state of the second power supply 110-2.

In practical implementation, in the embodiment of the present invention, the first power supply electricity quantity detection circuit 151 may be further configured to send an electricity quantity mutation signal to the data processing circuit 130 when detecting that the electricity quantity of the electrically connected first power supply 110-1 has a mutation. And, the data processing circuit 130 is configured to determine that the first power source 110-1 disconnected from the load 140 is replaced with a new first power source 110-1 by the received power amount sudden change signal.

It should be noted that, in the process of replacing the current first power source 110-1 with the new first power source 110-1, the current power amount of the first power source 110-1 and the new power amount of the first power source 110-1 are not exactly the same, for example, the current power amount of the first power source 110-1 is lower (e.g., 2%), the new power amount of the first power source 110-1 is higher (e.g., 98%), and then when the new first power source 110-1 is connected, the detected power amount of the first power source 110-1 is suddenly changed, i.e., 2% of the detected power amount is suddenly changed to 98%, which may indicate that the current first power source 110-1 is replaced with the new first power source 110-1.

The present invention will be described in detail with reference to specific examples. It should be noted that the following examples are provided to better illustrate the present invention, but not to limit the present invention.

In practical implementation, in the embodiment of the present invention, as shown in fig. 4, the first sub power switching circuit 121 may include: a first switching element 1211 and a first transistor M1;

an input terminal of the first switching element 1211 is electrically connected to the first power source 110-1, a control terminal of the first switching element 1211 is electrically connected to a first terminal of the first transistor M1, and an output terminal of the first switching element 1211 is electrically connected to the load 140;

the control terminal of the first transistor M1 is electrically connected to the data processing circuit 130, and the second terminal of the first transistor M1 is electrically connected to the ground GND.

In practical implementation, in the embodiment of the present invention, the first Transistor M1 may be one of a triode, a Thin Film Transistor (TFT), and a Metal oxide semiconductor field effect Transistor (MOS). Of course, in practical applications, the specific structure of the first transistor M1 may be designed according to practical application environments, and is not limited herein.

In practical implementation, in the embodiment of the present invention, as shown in fig. 4, the first transistor M1 may be configured as an NPN-type transistor.

In specific implementation, in the embodiment of the present invention, as shown in fig. 4, the first switching element 1211 may include a first MOS transistor Q1 and a second MOS transistor Q2; the gate of the first MOS transistor Q1 and the gate of the second MOS transistor Q2 are both electrically connected to the first end of the first transistor M1. A first terminal of the first MOS transistor Q1 is used as an input terminal of the first switching element 1211, a second terminal of the first MOS transistor Q1 is electrically connected to a first terminal of the second MOS transistor Q2, and a second terminal of the second MOS transistor Q2 is used as an output terminal of the first switching element 1211.

Optionally, in practical implementation, in the embodiment of the present invention, as shown in fig. 4, the first MOS transistor Q1 and the second MOS transistor Q2 may be P-type MOS transistors.

It should be noted that, in a special application scenario, the current output by the first power supply 110-1 may be relatively large, and in order to improve the transmission capability of the first MOS transistor Q1 and the second MOS transistor Q2, the first MOS transistor Q1 and the second MOS transistor Q2 may be configured as MOS transistors capable of transmitting a large current. For example, as shown in fig. 4, the first end of the first MOS transistor Q1 has 3 input paths: 1-1, 2-1, 3-1, and the second end of the first MOS transistor Q1 has 4 output paths: 4-1, 5-1, 6-1 and 7-1. The first end of the second MOS transistor Q2 has 4 input paths: 1-2, 2-2, 3-2, 4-2, and the second end of the second MOS transistor Q2 has 3 output paths: 5-2, 6-2 and 7-2. Wherein, 1-1, 2-1, 3-1 are electrically connected with each other as the first end of the first MOS transistor Q1, 5-2, 6-2, 7-2 are electrically connected with each other as the second end of the second MOS transistor Q2. And 4-1 is electrically connected with 1-2, 5-1 is electrically connected with 2-2, 6-1 is electrically connected with 3-2, and 7-1 is electrically connected with 4-2.

Further, in order to perform voltage division, in a specific implementation, as shown in fig. 4, in the embodiment of the present invention, the first sub power switching circuit 121 may further include: a first resistor R1; the first end of the first resistor R1 is electrically connected to the first power source 110-1, and the second end of the first resistor R1 is electrically connected to the control end of the first switch source. Alternatively, the resistance value of the first resistor R1 may be 100K Ω. Of course, in practical applications, the resistance value of the first resistor R1 may be designed according to practical application environments, and is not limited herein.

In practical implementation, in the embodiment of the present invention, as shown in fig. 4, the second sub power switching circuit 122 may include: a second switching element 1221 and a second transistor M2;

an input terminal of the second switching element 1221 is electrically connected to the second power supply 110-2, a control terminal of the second switching element 1221 is electrically connected to a first terminal of the second transistor M2, and an output terminal of the second switching element 1221 is electrically connected to the load 140;

the control terminal of the second transistor M2 is electrically connected to the data processing circuit 130, and the second terminal of the second transistor M2 is electrically connected to the ground GND.

In specific implementation, in the embodiment of the present invention, the second Transistor M2 may be one of a triode, a Thin Film Transistor (TFT), and a Metal oxide semiconductor field effect Transistor (MOS). Of course, in practical applications, the specific structure of the second transistor M2 may be determined by design according to practical application environments, and is not limited herein.

In practical implementation, in the embodiment of the present invention, as shown in fig. 4, the second transistor M2 may be configured as an NPN-type transistor.

In specific implementation, in the embodiment of the present invention, as shown in fig. 4, the second switching element 1221 may include a third MOS transistor Q3 and a fourth MOS transistor Q4; the gate of the third MOS transistor Q3 and the gate of the fourth MOS transistor Q4 are both electrically connected to the first end of the second transistor M2. A first terminal of the third MOS transistor Q3 is used as an input terminal of the second switching element 1221, a second terminal of the third MOS transistor Q3 is electrically connected to a first terminal of the fourth MOS transistor Q4, and a second terminal of the fourth MOS transistor Q4 is used as an output terminal of the second switching element 1221.

Optionally, in specific implementation, in the embodiment of the present invention, as shown in fig. 4, the third MOS transistor Q3 and the fourth MOS transistor Q4 may be P-type MOS transistors.

It should be noted that, in a special application scenario, the current output by the second power supply 110-2 may be relatively large, and in order to improve the transmission capability of the third MOS transistor Q3 and the fourth MOS transistor Q4, the third MOS transistor Q3 and the fourth MOS transistor Q4 may be configured as MOS transistors capable of transmitting a large current. For example, as shown in fig. 4, the first end of the third MOS transistor Q3 has 3 input paths: 1-3, 2-3, 3-3, and the second end of the third MOS transistor Q3 has 4 output paths: 4-3, 5-3, 6-3 and 7-3. The first end of the fourth MOS transistor Q4 has 4 input paths: 1-4, 2-4, 3-4, 4-4, and the second end of the fourth MOS transistor Q4 has 3 output paths: 5-4, 6-4 and 7-4. Wherein, 1-3, 2-3, 3-3 are electrically connected with each other as the first end of the third MOS transistor Q3, 5-4, 6-4, 7-4 are electrically connected with each other as the second end of the fourth MOS transistor Q4. And 4-3 is electrically connected with 1-4, 5-3 is electrically connected with 2-4, 6-3 is electrically connected with 3-4, and 7-3 is electrically connected with 4-4.

Further, in order to perform voltage division, in a specific implementation, as shown in fig. 4, in the embodiment of the present invention, the second sub power switching circuit 122 may further include: a second resistor R2; the first end of the second resistor R2 is electrically connected to the second power source 110-2, and the second end of the second resistor R2 is electrically connected to the control terminal of the second switch source. Alternatively, the resistance value of the second resistor R2 may be 100K Ω. Of course, in practical applications, the resistance value of the second resistor R2 may be designed according to practical application environments, and is not limited herein.

In particular implementations, in embodiments of the present invention, as shown in fig. 4, the first power supply charge detection circuit 151 may include a first coulomb counter 1511. It should be noted that the working process of the first coulometer 1511 may be substantially the same as that in the related art, and is not described herein again.

Alternatively, in an embodiment of the present invention, as shown in fig. 4, the first coulometer 1511 may include: a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first diode D1, a first capacitor C1, a second capacitor C2 and a first detection chip U1; the first end of the third resistor R3 is electrically connected to the first power source 110-1, the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is electrically connected to the ground GND. The first end of the first capacitor C1 is electrically connected to the second end of the third resistor R3, and the second end of the first capacitor C1 is electrically connected to the ground GND. The anode of the first diode D1 is electrically connected to the second power source 110-2, the cathode of the first diode D1 is electrically connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is electrically connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is electrically connected to the ground GND. The first pin CTG, the fourth pin GND, the sixth pin QSTRT, and the ninth pin GNDPAD of the first detection chip U1 are all electrically connected to the ground GND. The second pin CELL of the first detecting chip U1 is electrically connected to the second end of the third resistor R3, the third pin VDD of the first detecting chip U1 is electrically connected to the second end of the fifth resistor R5, the fifth pin ALRT _ N of the first detecting chip U1 is electrically connected to the data processing circuit 130 for outputting an electric quantity sudden change signal, and the seventh pin SCL and the eighth pin SDA of the first detecting chip U1 are electrically connected to the data processing circuit 130 for outputting the electric quantity of the first power supply 110-1. Thus, a first coulometer 1511 can be formed by the third resistor R3, the fourth resistor R4, the fifth resistor R5, the first diode D1, the first capacitor C1, the second capacitor C2 and the first detection chip U1.

In practical implementation, in the embodiment of the present invention, the resistance values of the third resistor R3 and the fourth resistor R4 may be set to 200K Ω. Of course, in practical applications, the resistance values of the third resistor R3 and the fourth resistor R4 may be designed according to practical application environments, and are not limited herein.

In practical implementation, in the embodiment of the present invention, the fifth resistor R5, the first diode D1, the first capacitor C1, and the second capacitor C2 may be designed according to practical application environments, and are not limited herein.

In specific implementation, in the embodiment of the present invention, the structure and the operation principle of the first detection chip U1 may be substantially the same as those in the related art, and are not described herein again.

In particular implementation, in an embodiment of the present invention, as shown in fig. 4, the second power supply charge detection circuit 152 includes a second coulomb counter 1521. It should be noted that the operation process of the second coulomb meter 1521 can be substantially the same as that in the related art, and is not described herein again.

Alternatively, in an embodiment of the present invention, as shown in fig. 4, the second coulomb meter 1521 can comprise: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a second diode D2, a third capacitor C3, a fourth capacitor C4 and a second detection chip U2; the first end of the sixth resistor R6 is electrically connected to the first power source 110-1, the second end of the sixth resistor R6 is electrically connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is electrically connected to the ground GND. A first end of the third capacitor C3 is electrically connected to the second end of the sixth resistor R6, and a second end of the third capacitor C3 is electrically connected to the ground GND. The anode of the second diode D2 is electrically connected to the second power source 110-2, the cathode of the second diode D2 is electrically connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is electrically connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is electrically connected to the ground GND. The first pin CTG, the fourth pin GND, the sixth pin QSTRT, and the ninth pin GNDPAD of the second detection chip U2 are all electrically connected to the ground GND. The second pin CELL of the second detecting chip U2 is electrically connected to the second end of the sixth resistor R6, the third pin VDD of the second detecting chip U2 is electrically connected to the second end of the eighth resistor R8, and the fifth pin ALRT _ N of the second detecting chip U2 is electrically connected to the data processing circuit 130, and is configured to output a warning signal to the data processing circuit 130 every preset interval, so that the data processing circuit 130 judges whether the electric quantity of the second power supply 110-2 is less than or equal to the charging electric quantity threshold every preset interval. The seventh pin SCL and the eighth pin SDA of the second detection chip U2 are electrically connected to the data processing circuit 130, and are configured to output the power of the second power source 110-2. Thus, a second coulometer 1521 can be formed by the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the second diode D2, the third capacitor C3, the fourth capacitor C4 and the second detection chip U2.

In practical implementation, in the embodiment of the present invention, the resistance values of the sixth resistor R6 and the seventh resistor R7 may be set to 200K Ω. Of course, in practical applications, the resistance values of the sixth resistor R6 and the seventh resistor R7 may be designed according to practical application environments, and are not limited herein.

In practical implementation, in the embodiment of the present invention, the eighth resistor R8, the second diode D2, the third capacitor C3, and the fourth capacitor C4 may be designed and determined according to an actual application environment, and are not limited herein.

In specific implementation, in the embodiment of the present invention, the structure and the operation principle of the second detection chip U2 may be substantially the same as those in the related art, and are not described herein again.

In a specific implementation, in the triode, the control terminal can be used as a base, the first terminal can be used as a collector, and the second terminal can be used as an emitter according to actual needs. Alternatively, the first terminal may be an emitter, and the second terminal may be a collector, which is not limited herein.

In a specific implementation, the TFT and the MOS transistor may have a control terminal as a gate, a first pole as a source or a drain, and a second pole as a drain or a source, which is not limited herein.

The above is merely to illustrate the specific structure of the power supply circuit provided in the embodiment of the present invention, and in the implementation, the specific structure of the circuit is not limited to the above structure provided in the embodiment of the present invention, and may be other structures known to those skilled in the art, and is not limited herein.

Based on the same inventive concept, an embodiment of the present invention further provides a method for controlling the power supply circuit, as shown in fig. 5, the method may include the following steps:

s10, when the data processing circuit determines that the first power supply supplies power to the load and the second power supply supplies power to the load, the data processing circuit inputs a first control signal to the power supply switching circuit and controls the power supply switching circuit to conduct the second power supply and the load; after a first time threshold value, inputting a second control signal to the power supply switching circuit to control the power supply switching circuit to disconnect the first power supply and the load;

s20, when the data processing circuit determines that the second power supply supplies power to the load and the first power supply supplies power to the load, the data processing circuit inputs a third control signal to the power supply switching circuit to control the power supply switching circuit to conduct the first power supply and the load; and after the second time threshold value, inputting a fourth control signal to the power supply switching circuit to control the power supply switching circuit to disconnect the second power supply and the load.

In specific implementation, the control method may further include: the power of the first power source 110-1 and the second power source 110-2 is acquired in real time. This allows the power levels of the first power supply 110-1 and the second power supply 110-2 to be monitored in real time.

Further, in practical implementation, in an embodiment of the present invention, determining to switch from the first power source 110-1 to the second power source 110-2 for supplying power to the load 140 may specifically include:

judging whether the electric quantity of the first power supply 110-1 is less than or equal to a first power-down electric quantity threshold value and whether the electric quantity of the second power supply 110-2 is greater than or equal to a first power-up electric quantity threshold value;

when the electric quantity of the first power source 110-1 is judged to be smaller than or equal to the first power-down electric quantity threshold value and the electric quantity of the second power source 110-2 is judged to be larger than or equal to the first power-up electric quantity threshold value, the power supply from the first power source 110-1 to the load 140 is determined to be switched to the power supply from the second power source 110-2 to the load 140.

Further, in practical implementation, in an embodiment of the present invention, determining to switch from the second power source 110-2 to the first power source 110-1 for supplying power to the load 140 may specifically include:

upon determining that the first power source 110-1 disconnected from the load 140 is replaced with a new first power source 110-1, determining whether the power of the new first power source 110-1 is greater than or equal to a second power-on power threshold;

when the power of the new first power source 110-1 is determined to be greater than the second power-on power threshold, it is determined that the power supplied to the load 140 by the second power source 110-2 is switched to the power supplied to the load 140 by the new first power source 110-1.

Further, in implementation, in an embodiment of the present invention, determining that the first power source 110-1 disconnected from the load 140 is replaced with a new first power source 110-1 may specifically include:

the first power supply electric quantity detection circuit 151 sends an electric quantity mutation signal to the data processing circuit 130 when detecting that the electric quantity of the electrically connected first power supply 110-1 is mutated;

it is determined that the first power source 110-1 disconnected from the load 140 is replaced with a new first power source 110-1 through the received power burst signal.

Further, in specific implementation, in the embodiment of the present invention, the control method may further include:

judging whether the electric quantity of the second power supply 110-2 is less than or equal to a charging electric quantity threshold value every preset time;

and when the electric quantity of the second power supply 110-2 is judged to be less than or equal to the charging electric quantity threshold value, determining that the second power supply 110-2 needs to be charged and reminding charging.

The following describes the operation of the power supply circuit according to the embodiment of the present invention with reference to the structure of the power supply circuit shown in fig. 4.

The first coulometer 1511 detects the charge of the first power supply 110-1 in real time and the second coulometer 1521 detects the charge of the second power supply 110-2 in real time. Wherein the first coulometer 1511 provides the real-time detected power of the first power supply 110-1 to the data processing circuit 130. The second coulometer 1521 provides the real-time detected electric quantity of the second power supply 110-2 to the data processing circuit 130, and sends a reminding signal to the data processing circuit 130 at preset intervals (for example, 1 hour), the data processing circuit 130 judges whether the electric quantity of the second power supply 110-2 is less than or equal to the charging electric quantity threshold value at preset intervals, and when the electric quantity of the second power supply 110-2 is judged to be less than or equal to the charging electric quantity threshold value, it is determined that the second power supply 110-2 needs to be charged and carries out charging reminding, so as to charge the second power supply 110-2.

The data processing circuit 130 determines whether the power of the first power source 110-1 is less than or equal to a first power down power threshold (e.g., 5%) and the power of the second power source 110-2 is greater than or equal to a first power up power threshold (e.g., 95%). The data processing circuit 130 determines to switch the power supply from the first power source 110-1 to the load 140 from the second power source 110-2 when determining that the power of the first power source 110-1 is less than or equal to a first power-down power threshold (e.g., 5%) and the power of the second power source 110-2 is greater than or equal to a first power-up power threshold (e.g., 95%).

The data processing circuit 130 inputs the first control signal to the power switching circuit 120 to control the second transistor M2 to be turned on, so that the potentials of the gates of the third MOS transistor Q3 and the fourth MOS transistor Q4 can be pulled low to be turned on. And thus, the second power source 110-2 and the load 140 can be turned on, so that the second power source 110-2 supplies power to the load 140. Also, the first power source 110-1 has not been disconnected from the load 140 for a first time threshold (e.g., 5s), such that the first power source 110-1 and the second power source 110-2 together power the load 140.

After the first time threshold (for example, 5s) has elapsed, the second control signal is input to the power switching circuit 120 to control the first transistor M1 to be turned off, so that the potentials of the gates of the first MOS transistor Q1 and the second MOS transistor Q2 can be pulled high by the first resistor R1 to be turned off. The first power source 110-1 and the load 140 may be disconnected, such that the first power source 110-1 stops supplying power to the load 140.

After the first power source 110-1 is disconnected from the load 140, the second power source 110-2 is used to power the load 140. This allows the first power supply 110-1, which was previously disconnected from the load 140, to be detached and replaced with a new first power supply 110-1, and the new first power supply 110-1 to be placed in the display device. And the first coulometer 1511 provides the real-time detected power of the first power supply 110-1 to the data processing circuit 130. Wherein, the first coulometer 1511 sends the electric quantity abrupt change signal to the data processing circuit 130 when detecting the abrupt change of the electric quantity of the electrically connected first power supply 110-1. The data processing circuit 130 determines that the first power source 110-1 disconnected from the load 140 is replaced with a new first power source 110-1 through the received power burst signal.

It is determined whether the new first power source 110-1 has a charge greater than or equal to a second power-on charge threshold (e.g., 95%). Upon determining that the power of the new first power source 110-1 is greater than or equal to the second power-on power threshold (e.g., 95%), it may be determined that the power supplied to the load 140 by the second power source 110-2 is switched to the power supplied to the load 140 by the new first power source 110-1. Otherwise, the second power source 110-2 continues to be used to supply power to the load 140 to avoid powering down the load 140.

The data processing circuit 130 inputs a third control signal to the power switching circuit 120 to control the first transistor M1 to be turned on, so that the potentials of the gates of the first MOS transistor Q1 and the second MOS transistor Q2 are pulled low to be turned on. The first power source 110-1 and the load 140 may be turned on, such that the first power source 110-1 supplies power to the load 140. And, the second power source 110-2 has not been disconnected from the load 140 for a second time threshold (e.g., 5s), such that the second power source 110-2 and the second power source 110-2 together provide power to the load 140.

After the second time threshold (for example, 5s) has elapsed, the fourth control signal is input to the power switching circuit 120 to control the second transistor M2 to turn off, so that the potentials of the gates of the third MOS transistor Q3 and the fourth MOS transistor Q4 can be pulled high by the second resistor R2 to turn off. The second power source 110-2 and the load 140 may be disconnected, such that the second power source 110-2 stops supplying power to the load 140.

Based on the same inventive concept, the embodiment of the invention further provides a display device, which comprises the display panel provided by the embodiment of the invention. The principle of the display device to solve the problem is similar to the display panel, so the implementation of the display device can be referred to the implementation of the display panel, and repeated details are not repeated herein.

In specific implementation, in the embodiment of the present invention, the display device may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like. Other essential components of the display device are understood by those skilled in the art, and are not described herein or should not be construed as limiting the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A power supply circuit, comprising: the device comprises a plurality of power supplies, a data processing circuit and a power supply switching circuit electrically connected with the power supplies; wherein the plurality of power sources includes a first power source and a second power source;

2. The power supply circuit of claim 1 wherein the data processing circuit is further configured to obtain the power of the first power source and the second power source in real time;

the data processing circuit is specifically configured to determine whether the electric quantity of the first power supply is less than or equal to a first power-down electric quantity threshold and whether the electric quantity of the second power supply is greater than or equal to a first power-up electric quantity threshold; and when the electric quantity of the first power supply is judged to be smaller than or equal to the first power-down electric quantity threshold value and the electric quantity of the second power supply is judged to be larger than or equal to the first power-up electric quantity threshold value, the power supply from the first power supply to the load is determined to be switched to the power supply from the second power supply to the load.

3. The power supply circuit of claim 2, wherein the data processing circuit is specifically configured to, upon determining that the first power source disconnected from the load is replaced with a new first power source, determine whether the power of the new first power source is greater than or equal to the second power-on-power-amount threshold; and when the electric quantity of the new first power supply is judged to be larger than or equal to a second power-on electric quantity threshold value, determining that the second power supply supplies power to the load and switching to supply power to the load by the new first power supply.

4. The power supply circuit of claim 3, wherein the power supply circuit further comprises: the power supply comprises a first power supply electric quantity detection circuit and a second power supply electric quantity detection circuit;

the first power supply electric quantity detection circuit is electrically connected with the first power supply and the data processing circuit respectively; the first power supply electric quantity detection circuit is used for acquiring the electric quantity of the first power supply in real time and providing the acquired electric quantity of the first power supply to the data processing circuit;

the second power supply electric quantity detection circuit is electrically connected with the second power supply and the data processing circuit respectively; the second power supply electric quantity detection circuit is used for acquiring the electric quantity of the second power supply in real time and providing the acquired electric quantity of the second power supply for the data processing circuit.

5. The power supply circuit of claim 4 wherein the first power supply power detection circuit is further configured to send a power abrupt change signal to the data processing circuit upon detecting an abrupt change in power of the electrically connected first power supply;

the data processing circuit is used for determining that the first power supply disconnected with the load is replaced by a new first power supply through the received electric quantity sudden change signal.

6. The power supply circuit of claim 4 wherein said first power supply charge detection circuit comprises a first coulomb counter; and/or the second power supply charge detection circuit comprises a second coulometer.

7. The power supply circuit of any of claims 1-6 wherein the data processing circuit is further configured to determine whether the charge of the second power source is less than or equal to a charge threshold every predetermined time interval; and when the electric quantity of the second power supply is judged to be less than or equal to the charging electric quantity threshold value, determining that the second power supply needs to be charged and carrying out charging reminding.

8. The power supply circuit of any of claims 1-6 wherein the power switching circuit comprises: a first sub power supply switching circuit and a second sub power supply switching circuit;

the input end of the first sub-power supply switching circuit is electrically connected with the first power supply, the control end of the first sub-power supply switching circuit is electrically connected with the data processing circuit, and the output end of the first sub-power supply switching circuit is electrically connected with the load; the first sub power supply switching circuit is used for conducting the first power supply and the load when receiving the third control signal; disconnecting the first power source and the load upon receiving the second control signal;

the input end of the second sub-power supply switching circuit is electrically connected with the second power supply, the control end of the second sub-power supply switching circuit is electrically connected with the data processing circuit, and the output end of the second sub-power supply switching circuit is electrically connected with the load; the second sub-power supply switching circuit is used for conducting the second power supply and the load when receiving the first control signal; disconnecting the second power source from the load upon receiving the fourth control signal.

9. The power supply circuit of claim 8, wherein the first sub power supply switching circuit comprises: a first switching element and a first transistor;

an input end of the first switching element is electrically connected with the first power supply, a control end of the first switching element is electrically connected with a first end of the first transistor, and an output end of the first switching element is electrically connected with the load;

the control end of the first transistor is electrically connected with the data processing circuit, and the second end of the first transistor is electrically connected with the grounding end.

10. The power supply circuit of claim 8, wherein the second sub power supply switching circuit comprises: a second switching element and a second transistor;

an input end of the second switching element is electrically connected with the second power supply, a control end of the second switching element is electrically connected with a first end of the second transistor, and an output end of the second switching element is electrically connected with the load;

the control end of the second transistor is electrically connected with the data processing circuit, and the second end of the second transistor is electrically connected with the grounding end.

11. A display device characterized by comprising a power supply circuit according to any one of claims 1 to 10.

12. A method of controlling a power supply circuit according to any one of claims 1 to 10, comprising:

13. The control method according to claim 12, characterized by further comprising: acquiring the electric quantity of the first power supply and the second power supply in real time;

the determining that the first power supply supplies power to the load is switched to the second power supply supplies power to the load specifically includes:

judging whether the electric quantity of the first power supply is smaller than or equal to a first power-down electric quantity threshold value or not and whether the electric quantity of the second power supply is larger than or equal to a first power-up electric quantity threshold value or not;

and when the electric quantity of the first power supply is judged to be smaller than or equal to the first power-down electric quantity threshold value and the electric quantity of the second power supply is judged to be larger than or equal to the first power-up electric quantity threshold value, the power supply from the first power supply to the load is determined to be switched to the power supply from the second power supply to the load.

14. The control method according to claim 13, wherein the determining to switch from the second power source to the load to the first power source comprises:

when the first power supply disconnected with the load is determined to be replaced by a new first power supply, judging whether the electric quantity of the new first power supply is larger than or equal to the second power-on electric quantity threshold value;

and when the electric quantity of the new first power supply is judged to be larger than or equal to a second power-on electric quantity threshold value, determining that the second power supply supplies power to the load and switching to supply power to the load by the new first power supply.

15. The control method of claim 14, wherein the determining that the first power source disconnected from the load is replaced with a new first power source comprises:

the first power supply electric quantity detection circuit sends an electric quantity mutation signal to the data processing circuit when detecting that the electric quantity of the electrically connected first power supply is mutated;

and determining that the first power supply disconnected with the load is replaced by a new first power supply through the received electric quantity sudden change signal.

16. The control method according to any one of claims 11 to 15, characterized by further comprising:

judging whether the electric quantity of the second power supply is smaller than or equal to a charging electric quantity threshold value every preset time interval;

and when the electric quantity of the second power supply is judged to be less than or equal to the charging electric quantity threshold value, determining that the second power supply needs to be charged and carrying out charging reminding.