CN112234704B

CN112234704B - Flash lamp power supply switching circuit, flash lamp control method and electronic equipment

Info

Publication number: CN112234704B
Application number: CN202011083253.1A
Authority: CN
Inventors: 冯帅
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2020-10-12
Filing date: 2020-10-12
Publication date: 2022-08-02
Anticipated expiration: 2040-10-12
Also published as: CN112234704A

Abstract

The embodiment of the application discloses a flash lamp power supply switching circuit, a flash lamp control method and electronic equipment, and belongs to the technical field of communication. Wherein flash lamp power supply switching circuit is applied to the electronic equipment including USB interface, battery and flash lamp, and flash lamp power supply switching circuit includes: a first input terminal, a second input terminal and a power supply terminal; the first input end is connected with a VBUS pin in the USB interface, the second input end is connected with the output end of the battery, and the power supply end is connected with the flash lamp; the flash lamp power supply switching circuit comprises a first working state and a second working state which can be switched, a first input end is conducted with the power supply end under the condition that the flash lamp power supply switching circuit is in the first working state, and a second input end is conducted with the power supply end under the condition that the flash lamp power supply switching circuit is in the second working state. The embodiment of the application can avoid the flash lamp from being damaged by high voltage on the VBUS pin.

Description

Flash lamp power supply switching circuit, flash lamp control method and electronic equipment

Technical Field

The application belongs to the technical field of communication equipment, and particularly relates to a flash lamp power supply switching circuit, a flash lamp control method and electronic equipment.

Background

In the prior art, a flash lamp is provided on an electronic device for illumination or light supplement during photographing. When the flash lamp is used for light supplement in photography, the voltage required by the flash lamp is greater than the voltage required by the flash lamp when the flash lamp is used for illumination, so that a booster circuit needs to be arranged in the electronic equipment, and the input voltage of the flash lamp meets the requirement of light supplement.

In The related art, in order to save costs, a flash lamp is connected to a power bus VBUS in a USB interface supporting a portable (On The Go, OTG) function. The USB interface supporting the OTG function is internally provided with a booster circuit, so that when the electronic equipment is not charged, the voltage transmitted by VBUS in the USB interface meets the light supplement requirement of the flash lamp, and when the electronic equipment is charged to close the OTG function, the voltage meeting the light supplement requirement of the flash lamp can be acquired from the charger through the VBUS.

However, with the development of the fast charging technology, the USB interface often supports the fast charging technology, so that when the electronic device is charged, the voltage transmitted through the VBUS rises, which often reaches 10V or even higher, and at this time, the flash lamp is damaged due to overvoltage.

Disclosure of Invention

The embodiment of the application aims to provide a flash lamp power supply switching circuit, a flash lamp control method and electronic equipment, and the problem that a flash lamp is damaged due to overvoltage can be solved.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides a flash lamp power switching circuit, which is applied to an electronic device, where the electronic device includes a USB interface, a battery, and a flash lamp, and the flash lamp power switching circuit includes: a first input terminal, a second input terminal and a power supply terminal;

the first input end is connected with a VBUS pin in the USB interface, the second input end is connected with the output end of the battery, and the power supply end is connected with the flash lamp;

the flash lamp power supply switching circuit comprises a first working state and a second working state which can be switched, the first input end is conducted with the power supply end under the condition that the flash lamp power supply switching circuit is in the first working state, and the second input end is conducted with the power supply end under the condition that the flash lamp power supply switching circuit is in the second working state;

in the first working state, the voltage value of the first input end is less than or equal to the maximum working voltage of the flash lamp; and in the second working state, the voltage value of the first input end is greater than the maximum working voltage of the flash lamp.

In a second aspect, an embodiment of the present application provides an electronic device, which includes a flash lamp, a battery, a USB interface, and a flash lamp power switching circuit in the first aspect, a first input end of the flash lamp power switching circuit is connected to a VBUS pin in the USB interface, a second input end is connected to an output end of the battery, and a power supply end provides electric energy for the flash lamp.

In a third aspect, an embodiment of the present application provides a flash control method applied to the electronic device described in the second aspect, where the method includes:

when a light supplement mode of a flash lamp is started and a VBUS pin of the USB interface has electric signal transmission, acquiring a first voltage transmitted on the VBUS pin;

under the condition that the voltage value of the first voltage is determined to be larger than the maximum working voltage of the flash lamp, controlling the flash lamp power supply switching circuit to be in a first working state;

and under the condition that the voltage value of the first voltage is determined to be less than or equal to the maximum working voltage of the flash lamp, controlling the flash lamp power supply switching circuit to be in a second working state.

In a fourth aspect, embodiments of the present application provide various flash lamp control devices applied to the electronic device according to the second aspect, the flash lamp control devices include:

the device comprises a first acquisition module, a second acquisition module and a control module, wherein the first acquisition module is used for acquiring a first voltage transmitted on a VBUS pin when a light supplement mode of a flash lamp is started and the VBUS pin of the USB interface has electric signal transmission;

the first control module is used for controlling the flash lamp power supply switching circuit to be in a first working state under the condition that the voltage value of the first voltage is determined to be larger than the maximum working voltage of the flash lamp;

and the second control module is used for controlling the flash lamp power supply switching circuit to be in the second work under the condition that the voltage value of the first voltage is determined to be less than or equal to the maximum working voltage of the flash lamp.

In a fifth aspect, the present application provides a readable storage medium, on which a program or instructions are stored, which when executed by a processor implement the steps of the method according to the third aspect.

In a sixth aspect, embodiments of the present application provide a chip, where the chip includes a processor and a communication interface, where the communication interface is coupled to the processor, and the processor is configured to execute a program or instructions to implement the method according to the third aspect.

In the embodiment of the application, under the condition that the voltage value of the first input end is greater than the maximum working voltage of the flash lamp, the power supply end is communicated with the second input end so as to supply power to the flash lamp through a battery, otherwise, the power supply end is communicated with the first input end so as to supply power to the flash lamp through the VBUS pin, and the battery loss is reduced. Therefore, the electronic equipment can be charged quickly, and when the voltage on the VBUS pin is too high, the flashlight is powered by the battery, so that the flashlight is prevented from being damaged by the too high voltage on the VBUS pin.

Drawings

Fig. 1 is a circuit diagram of a flash lamp power switching circuit according to an embodiment of the present disclosure;

FIG. 2 is a circuit diagram of another flash power switching circuit provided by an embodiment of the present application;

FIG. 3 is a circuit diagram of another flash power switching circuit provided by an embodiment of the present application;

fig. 4 is a flowchart of a flash control method provided in an embodiment of the present application;

fig. 5 is a block diagram of an electronic device according to an embodiment of the present disclosure;

fig. 6 is a block diagram of another electronic device provided in the embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

The flash power switching circuit, the flash control method, and the electronic device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Referring to fig. 1, a circuit diagram of a flash power switching circuit according to an embodiment of the present disclosure is shown in fig. 1, where the flash power switching circuit 100 is applied to an electronic device, the electronic device includes a USB interface (not shown), a battery (not shown), and a flash (not shown), and the flash power switching circuit 100 includes: a first input terminal (i.e., the VBUS terminal as shown in FIG. 1), a second input terminal (i.e., the VBAT terminal as shown in FIG. 1), and a supply terminal (i.e., the VOUT terminal as shown in FIG. 1);

the VBUS end is connected with a VBUS pin in the USB interface, the VBAT end is connected with the output end of the battery, and the VOUT end is connected with the flash lamp;

the flash lamp power supply switching circuit 100 includes a first working state and a second working state which are switchable, when the flash lamp power supply switching circuit 100 is in the first working state, the VBUS terminal is conducted with the VOUT terminal, and when the flash lamp power supply switching circuit 100 is in the second working state, the VBAT terminal is conducted with the VOUT terminal;

in the first working state, the voltage value of the VBUS end is less than or equal to the maximum working voltage of the flash lamp; and in the second working state, the voltage value of the VBUS end is greater than the maximum working voltage of the flash lamp.

In a specific implementation, when the electronic device is charged, a charger or other main devices capable of providing power supply the electronic device through a VBUS pin, and in a common charging mode, a first voltage on the VBUS pin is often 5V, which conforms to an operating voltage of a flash lamp; in addition, in the fast charging mode, the first voltage on the VBUS pin is often 10V or more, which exceeds the rated maximum voltage value of the flash lamp, and at this time, if the flash lamp is connected to the VBUS pin, the flash lamp will be damaged by overvoltage.

Of course, in The case that The electronic device further has a portable (On The Go, OTG) function, The electronic device can also be used as a master device to provide power to other slave devices, and in this case, The voltage value On The VBUS pin may also be 5V, which is in accordance with The operating voltage of The flash lamp.

Therefore, when the electronic equipment is charged in a common mode, the flash lamp can be connected with the VBUS pin (namely, the VOUT end is communicated with the VBUS end) so as to obtain the working voltage for the charger or other main equipment capable of providing electric energy through the VBUS pin; in addition, when the electronic device starts the OTG function, the flash lamp is connected to the VBUS pin (i.e., the VOUT terminal is communicated with the VBUS terminal) to obtain the operating voltage from the battery of the electronic device through the VBUS pin and the boost circuit in the OTG circuit; in addition, when the electronic device is charged quickly, the flash lamp is disconnected from the VBUS pin and connected to a battery in the electronic device (i.e., the VOUT terminal is connected to the VBAT terminal) to obtain a voltage from the battery, wherein the voltage may be slightly lower than a rated operating voltage of the flash lamp, and the brightness of the flash lamp is slightly lower than the rated operating voltage, but the flash lamp can still be started to operate without damaging the flash lamp.

It should be noted that, the switching circuit shown in fig. 1 is a schematic diagram, and the above-mentioned flash power switching circuit 100 may further include a switching module such as a switch and a transistor switch, so as to switch the VOUT terminal to be communicated with the VBUS terminal or to be switched to an electronic component communicated with the VBAT terminal through the switching module. Of course, the flash power supply switching circuit 100 also includes a module operable to compare the magnitude relationship of the first voltage on the VBUS terminal to the second voltage on the VBAT terminal, such as: the comparator, the transistor switch group, the digital detection circuit, the digital control circuit, and the like are not particularly limited herein.

In a specific implementation, it may be determined whether the flash lamp power switching circuit 100 needs to operate in the first operating state or the second operating state according to a comparison result between the first voltage obtained through the VBUS terminal and the second voltage obtained through the VBAT terminal.

Specifically, when the switching circuit 1 determines that the voltage value transmitted on the VBUS pin is greater than the maximum operating voltage of the flash lamp based on the comparison result between the first voltage acquired through the VBUS terminal and the second voltage acquired through the VBAT terminal, the VOUT terminal is connected to the VBAT terminal, and the VOUT terminal is disconnected from the VBUS terminal;

under the condition that the switching circuit 1 determines that the voltage value transmitted on the VBUS pin is less than or equal to the maximum working voltage of the flash lamp based on the comparison result of the first voltage and the second voltage, connecting the VOUT end and the VBUS end, and disconnecting the VOUT end and the VBAT end;

the maximum working voltage of the flash lamp can be also called as a rated maximum voltage value (the working voltage of the flash lamp can be in a range of 3.5-5.5V (volt), for example, the maximum working voltage of the flash lamp is 5.5V), and the second voltage is smaller than or equal to the rated maximum voltage value of the flash lamp.

In practical applications, the above determining that the voltage value transmitted on the VBUS pin is greater than the maximum operating voltage of the flash lamp by the flash lamp power switching circuit 100 based on the comparison result between the first voltage acquired through the VBUS terminal and the second voltage acquired through the VBAT terminal can be understood as follows: in view of that the second voltage acquired by the VBAT terminal is a fixed voltage value or voltage range, the value of the first voltage can be determined according to the quantitative relationship between the first voltage and the second voltage, so that the magnitude relationship between the first voltage and the maximum operating voltage of the flash lamp can be determined.

Optionally, as shown in fig. 2, the flash lamp power switching circuit 100 further includes a first resistor R1, a second resistor R2, a comparator 12, and a switch circuit 13, wherein the first resistor R1 and the second resistor R2 together form a voltage dividing module 11;

the first resistor R1 and the second resistor R2 are connected in series between the VBUS terminal and the ground terminal, and the first power input terminal of the comparator 12 is connected between the first resistor R1 and the second resistor R2;

a second power input end of the comparator 12 is connected to the VBAT end, and an output end of the comparator 12 is connected to a control end of the switch circuit 13;

the switch circuit 13 is connected to the VBUS terminal, the VBAT terminal, and the VOUT terminal, respectively.

The comparator 12 drives the switch circuit 13 to switch the flash power switching circuit 100 to the first operating state or the second operating state based on the comparison result between the voltage value of the first power input terminal and the voltage value of the second power input terminal.

In a specific implementation, the comparator 12 may compare the voltage of the first power input terminal and the voltage of the second power input terminal, and after the voltage of the VBUS terminal is divided by the first resistor R1 and the second resistor R2, if the voltage of the VBUS terminal is less than or equal to a preset voltage, the voltage of the first power input terminal is less than or equal to the voltage of the second power input terminal, at this time, the comparator 12 sends a first electrical signal to the control terminal of the switch circuit 13, so that the switch circuit 13 connects the VBUS terminal and the VOUT terminal in response to the first electrical signal; if the VBUS terminal voltage is greater than the predetermined voltage, the voltage value of the first power input terminal is greater than the voltage value of the second power input terminal, and at this time, the comparator 12 sends a second electrical signal to the control terminal of the switching circuit 13, so that the switching circuit 13 connects the VBAT terminal and the VOUT terminal in response to the second electrical signal.

Specifically, as shown in fig. 2, the ratio of the first resistor R1 to the second resistor R2 is greater than the first maximum voltage VBAT _max And a second maximum voltage VBUS _max Is less than the first minimum voltage VBAT _min VBUS with a second minimum voltage _min Ratio, the first maximum voltage VBAT _max The first minimum voltage VBAT is the maximum output voltage of the battery _min The second maximum voltage VBUS is the minimum output voltage of the battery _max The second minimum voltage VBUS is the maximum output voltage transmitted on the VBUS pin _min The minimum output voltage transmitted on the VBUS pin;

the comparator 12 controls the switch circuit 13 to connect the terminal VOUT to the terminal VBUS or the terminal VBAT based on a magnitude relationship between the third voltage across the second resistor R2 and the second voltage transmitted through the terminal VBAT.

In operation, the voltage dividing module 11 is configured to divide the first voltage transmitted on the VBUS pin, so that a third voltage obtained at the first power input terminal of the comparator 12 is equal to a voltage of the second resistor R2, where V3 is V1 × R2/(R1+ R2), V3 represents the third voltage, V1 represents the first voltage, R1 represents a resistance value of the first resistor R1, and R2 represents a resistance value of the second resistor R2. Therefore, in the ordinary charging, the second voltage acquired by the VBAT terminal is greater than the third voltage, and at this time, the comparator 12 outputs the first electric signal, so that the switching circuit 13 communicates the VOUT terminal with the VBUS terminal under the action of the first electric signal; during the fast charging, the second voltage acquired by the VBAT terminal is less than or equal to the third voltage, and at this time, the comparator 12 outputs a second electrical signal, so that the switching circuit 13 communicates the VOUT terminal with the VBAT terminal under the action of the second electrical signal.

It should be noted that the switch circuit 13 may be an analog signal control switch or an analog signal control switch group, and when receiving the first electrical signal output by the comparator 12, the switch circuit 13 is capable of connecting the VOUT terminal and the VBUS terminal and disconnecting the VOUT terminal and the VBAT terminal; the switch circuit 13 is capable of connecting the terminal VOUT to the terminal VBAT and disconnecting the terminal VOUT from the terminal VOUT upon receiving the second electrical signal output from the comparator 12.

In a specific implementation, the voltage dividing module 11 may be implemented by adjusting resistance values of the first resistor R1 and the second resistor R2: in normal charging, the second voltage acquired by the VBAT terminal is greater than the divided first voltage, and in rapid charging, the second voltage acquired by the VBAT terminal is less than or equal to the divided first voltage. Specifically, VBAT _max /VBUS _max <R1：R2<VBAT _min /VBUS _min 。

Wherein, VBAT _max Represents the maximum value of the battery output voltage; VBAT _min Represents the minimum value of the battery output voltage; VBUS _max Represents the maximum value of the voltage transmitted on the VBUS pin; VBUS _min Representing the minimum value of the voltage transmitted on the VBUS pin.

For example: the voltage transmitted on the VBUS pin may be 5V or 10V, and the battery voltage is 3.4V to 4.5V, so that the voltage ratio of R1: r2 is 0.5, and if the voltage transmitted through the VBUS pin is 5V, the voltage transmitted to the comparator 12 after dividing the voltage of 5V by R1 and R2 is ((2/3) × 5) ≈ 3.33V, which is smaller than VBAT _min (i.e., 3.4V); at this time, if the voltage transmitted on the VBUS pin is 10V, the voltage of 10V divided by R1 and R2 and transmitted to the comparator 12 is ((2/3) × 10) ≈ 6.67V, which is smaller than VBAT _max (i.e., 4.5V).

In this embodiment, the voltage on the VBUS pin is divided by the voltage dividing module 11, so that the comparator 12 can obtain the magnitude relation between the voltage on the VBUS pin and the preset voltage by comparing the divided voltage with the VBAT voltage, and the switching circuit 13 is controlled to operate in a corresponding switching state, thereby realizing switching of the power supply of the flash lamp, and avoiding damage to the flash lamp due to the overhigh voltage on the VBUS pin.

In addition, the preset voltage value may be matched with a maximum operating voltage of the flash lamp, and specifically may be: when the voltage on the VBUS pin can be adjusted in multiple gears, the preset voltage value may be any voltage value between a first gear and a second gear, where the first gear is one of gears greater than or equal to the maximum operating voltage of the flash lamp and having the smallest difference with the maximum operating voltage of the flash lamp, and the second gear is the maximum gear. For example: if the maximum operating voltage of the flash lamp is 5V, the preset voltage value may be any value greater than 5V and less than or equal to 10V when the voltage on the VBUS pin may be 5V or 10V.

It should be noted that, in a specific implementation, in the fixed charging mode, the voltage on the VBUS pin may fluctuate within a certain range, and the maximum operating voltage value of the flash lamp may be slightly larger than the rated operating voltage of the flash lamp, for example: if the rated operating voltage of the flash lamp is 5V, the rated maximum voltage value of the flash lamp may be 5.6V. In this way, frequent switching by the switching circuit 13 can be avoided when the voltage on the VBUS pin fluctuates within a certain range.

Optionally, as shown in fig. 2, the comparator 12 is a Rail-to-Rail (Rail-to-Rail) operational amplifier, the first power input terminal is a positive power input terminal, and the second power input terminal is a negative power input terminal;

when the voltage value (i.e., the third voltage) of the first power input terminal is greater than the voltage value (i.e., the second voltage) of the second power input terminal, the output terminal of the comparator 12 outputs a high level signal, and the switching circuit 13 connects the VOUT terminal with the VBAT terminal and disconnects the VOUT terminal from the VBUS terminal based on the high level signal;

when the voltage value of the first power input terminal is less than or equal to the voltage value of the second power input terminal, the output terminal of the comparator 12 outputs a low level signal, and the switching circuit 13 connects the VOUT terminal with the VBUS terminal and disconnects the VOUT terminal from the VBAT terminal based on the low level signal.

In a specific implementation, the high level signal may be an analog signal for enabling the switch circuit 13 to conduct the VOUT terminal and the VBAT terminal, and the second level signal may be an analog signal for enabling the switch circuit 13 to conduct the VOUT terminal and the VBUS terminal.

For example: the switching circuit 13 includes a first switching transistor and a second switching transistor, a gate of the first switching transistor and a gate of the second switching transistor are both connected to the output terminal of the comparator 12, a drain of the first switching transistor and a drain of the second switching transistor are both connected to the VOUT terminal, a source of the first switching transistor is connected to the VBUS terminal, and a source of the second switching transistor is connected to the VBAT terminal. Thus, the gate of the first switching transistor and the gate of the second switching transistor are control terminals of the switching circuit 13, the gate of the first switching transistor disconnects the drain and the source thereof when receiving a high level signal, and the gate of the second switching transistor conducts the drain and the source thereof when receiving a high level signal; the gate of the first switching transistor turns on its drain and source when receiving a low level signal, and the gate of the second switching transistor turns off its drain and source when receiving a low level signal.

In this embodiment, specific values of the high level signal and the low level signal may be determined according to on-voltage and off-voltage of the first switching transistor and the second switching transistor, for example: the high level signal may be a voltage greater than 0V, and the low level signal may be a voltage equal to 0V, and the like, and is not particularly limited herein.

In the embodiment of the application, the switching of the flash lamp power supply is realized through the analog circuit, so that the problem that the flash lamp is damaged due to overvoltage because the flash lamp is communicated with a VBUS pin in the quick charging process due to the fact that the flash lamp is damaged due to the fact that the flash lamp is blocked by software and the reliability of a system is low in the process that the flash lamp acquires the power supply which accords with the working voltage of the flash lamp from the VBUS is avoided being solved by switching the charging mode of the electronic equipment to the common charging mode through the software.

In the embodiment of the application, whether the voltage value transmitted on the VBUS pin is greater than the maximum operating voltage of the flash lamp is determined by comparing the first voltage and the second voltage through the switching circuit, wherein in the case that the voltage value transmitted on the VBUS pin is greater than the maximum operating voltage of the flash lamp, the power supply end is communicated with the second input end to supply power to the flash lamp through the battery, otherwise, the power supply end is communicated with the first input end to supply power to the flash lamp through the VBUS pin. Therefore, when the voltage on the VBUS pin is too high, the flashlight is powered by the battery in the process of quickly charging the electronic equipment, so that the flashlight is prevented from being damaged by the too high voltage on the VBUS pin.

Referring to fig. 3, which is a circuit diagram of another flash power switching circuit provided in the present embodiment, as shown in fig. 3, the flash power switching circuit 200 is different from the flash power switching circuit 100 provided in the previous embodiment in that:

as shown in fig. 3, the switching circuit 13 includes: a switch transistor Q1, a first diode D1 and a second diode D2, the first diode D1 is connected between the VBUS terminal and the first pole of the switch transistor Q1, the second diode D2 is connected between the VBAT terminal and the second pole of the switch transistor Q1, the second pole of the switch transistor Q1 is also connected with the VOUT terminal, and the third pole of the switch transistor Q1 is the control terminal of the switch circuit 13.

In operation, when the voltage value delivered by the first power supply input terminal of the comparator 12 is greater than the voltage value delivered by the second power supply input terminal, the switching transistor Q1 is turned off by the comparator 12, and the second diode is turned on;

when the voltage value delivered by the first power input terminal of the comparator 12 is less than or equal to the voltage value delivered by the second power input terminal, the switching transistor Q1 is turned on by the comparator 12, the first diode is turned on, and the second diode is turned off.

The above-mentioned turning on of the switching transistor Q1 can be understood as: the first pole and the second pole of the switching transistor Q1 are turned on, and the turning off of the switching transistor Q1 can be understood as: the first and second poles of the switching transistor Q1 are off.

In addition, the comparator 12 may be a Rail-to-Rail (Rail-to-Rail) operational amplifier, so that when the voltage value transmitted by the first power input terminal is greater than the voltage value transmitted by the second power input terminal, the comparator 12 outputs a high level signal; and when the voltage value delivered by the first power input terminal is less than or equal to the voltage value delivered by said second power input terminal, the comparator 12 outputs a low level signal.

At this time, the switching transistor Q1 may be a P-channel power metal oxide (semiconductor) field effect transistor (e.g., a P-CH MOSFET or a PMOS transistor, and the following embodiments exemplify the switching transistor Q1 as a PMOS transistor), and the first pole of the switching transistor Q1 may be a source, the second pole of the switching transistor Q1 may be a drain, and the third pole of the switching transistor Q1 may be a gate.

Specifically, when the gate of the PMOS transistor receives the high-level signal, the source and the drain of the PMOS transistor are disconnected, and at this time, the voltage value of the VBAT terminal is greater than the voltage value of the second pole of the switching transistor Q1, so that the second diode D2 is turned on, and therefore the VOUT terminal and the VBAT terminal are turned on, and the VOUT terminal and the VBUS terminal are disconnected.

In addition, when the gate of the PMOS transistor receives the low level signal, the source and the drain of the PMOS transistor are turned on, and at this time, the voltage value of the VBAT terminal is smaller than the voltage value of the second pole of the switching transistor Q1, so that the second diode D2 is turned off, thereby implementing the turning on of the VOUT terminal and the VBUS terminal, and the turning off of the VOUT terminal and the VBAT terminal.

In a specific implementation, when there is no voltage on the VBUS pin (e.g., the electronic device is charging and the OTG function is enabled), the switching transistor Q1 is turned on, but the voltage on the first pole of the switching transistor Q1 is greater than the voltage on VBUS, so that the first diode D1 is turned off, thereby preventing the voltage on the VBAT terminal from flowing to the VBUS pin.

It should be noted that, in a specific implementation, the comparator 12 may also output a low level signal when the voltage value transmitted by the first power input terminal is greater than the voltage value transmitted by the second power input terminal; and when the voltage value delivered by the first power input terminal is less than or equal to the voltage value delivered by the second power input terminal, the comparator 12 outputs a high level signal. And the switching transistor Q1 is an NMOS transistor or other switching structure, so as to realize: when the voltage value transmitted by the first power supply input end is larger than the voltage value transmitted by the second power supply input end, the switch transistor Q1 conducts VBAT and VOUT; the switching transistor Q1 turns on VBUS and VOUT when the voltage value transmitted by the first power input terminal is less than or equal to the voltage value transmitted by the second power input terminal, which is not limited in this respect.

Optionally, the first diode D1 and the second diode D2 are low forward voltage diodes.

In a specific implementation, the forward voltages of the first diode D1 and the second diode D2 may be less than or equal to 0.3V, and of course, the forward voltages of the first diode D1 and the second diode D2 may be lower as the semiconductor technology advances, and are not limited in this respect.

In this embodiment, the forward voltage of the first diode D1 and the second diode D2 is low, so that when the VBAT terminal is communicated with the VOUT terminal, the conduction voltage of the second diode D2 is reduced, the voltage difference between the VBAT terminal and the VOUT terminal is low, the voltage value obtained by the flash lamp is further increased, and unnecessary loss is avoided. For example: if the forward voltage of the second diode D2 is 0.3V and the output voltage of the battery is 4.5V, the voltage at VOUT terminal may be equal to (4.5-0.3-VQ1) V, where VQ1 represents the turn-on voltage difference of the switching transistor Q1.

In addition, when the VBUS terminal is communicated with the VOUT terminal, the turn-on voltage of the first diode D1 is reduced, so that the voltage difference between the VBUS terminal and the VOUT terminal is low, the voltage value acquired by the flash lamp is further increased, and unnecessary loss is avoided.

In this embodiment, the function of the switching circuit 13 can be realized by one switching transistor and two diodes, and when there is no voltage on the VBUS pin, the problem of abnormality caused by the voltage of the battery flowing backward to the VBUS pin can be avoided.

The embodiment of the invention also provides electronic equipment which comprises a flash lamp, a battery, a USB interface and any one of the flash lamp power supply switching circuits provided by the previous embodiment, wherein a VBUS end of the flash lamp power supply switching circuit is connected with a VBUS pin in the USB interface, a VBAT end is connected with an output end of the battery, and a VOUT end provides electric energy for the flash lamp.

The electronic device in the embodiment of the present application may be a mobile electronic device, and may also be a non-mobile electronic device. By way of example, the mobile electronic device may be a mobile phone, a tablet computer, a notebook computer, a palm top computer, a vehicle-mounted electronic device, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a Personal Digital Assistant (PDA), and the like, and the non-mobile electronic device may be a Personal Computer (PC), a Television (TV), a teller machine, a self-service machine, and the like, and the embodiments of the present application are not particularly limited.

In addition, the electronic equipment can perform quick charging and ordinary charging, wherein in a quick charging mode, the voltage on the VBUS pin exceeds the rated maximum working voltage of the flash lamp; in the normal charging mode, the voltage on the VBUS pin does not exceed the rated maximum operating voltage of the flash lamp. Therefore, when the electronic equipment is normally charged, the VBUS pin provides electric energy for the flash lamp, when the electronic equipment is rapidly charged, if the photographing light supplement function of the flash lamp is started, the charging mode can be controlled to be switched to the normal charging mode through software, whether the switching is successful or not is judged through the flash lamp power supply switching circuit provided by the embodiment of the application, the VBUS pin provides the electric energy for the flash lamp under the condition of successful switching, and the battery provides the electric energy for the flash lamp under the condition of unsuccessful switching.

Of course, the electronic device may also support the OTG function, so that the OTG function may be activated to charge the VBUS pin during the non-charging process of the electronic device, so that the VBUS pin provides power to the flash lamp.

In the embodiment of the application, can reduce the boost circuit of flash light, simultaneously, ensure that the flash light is not damaged by the high voltage on the VBUS pin, and through hardware circuit: the flash lamp power supply switching circuit realizes that the battery is communicated with the flash lamp when the voltage on the VBUS pin is ultrahigh, and has high reliability.

Referring to fig. 4, which is a flowchart illustrating a flash control method according to an embodiment of the present disclosure, where the flash control method can be applied to an electronic device according to an embodiment of the present disclosure, as shown in fig. 4, the flash control method may include the following steps:

step 401, when a fill-in mode of the flash lamp is started and the VBUS pin of the USB interface has an electrical signal transmission, acquiring a first voltage transmitted on the VBUS pin.

Step 402, under the condition that the voltage value of the first voltage is determined to be larger than the maximum working voltage of the flash lamp, controlling the flash lamp power supply switching circuit to be in a first working state.

And step 403, controlling the flash lamp power supply switching circuit to be in a second working state under the condition that the voltage value of the first voltage is determined to be less than or equal to the maximum working voltage of the flash lamp.

The first operating state and the second operating state have the same meanings as the first operating state and the second operating state in the circuit embodiment shown in fig. 1-3, respectively, and are not described herein again.

In the same application scenario, only one of the

above steps

402 and 403 is executed, specifically, the step 402 is executed when the voltage value of the first voltage is greater than the maximum operating voltage of the flash lamp, and the step 403 is executed when the voltage value of the first voltage is less than or equal to the maximum operating voltage of the flash lamp.

In specific implementation, when the electronic device takes a picture in a dark environment, or the light supplement mode for taking a picture is started, the electronic device starts the light supplement mode of the flash lamp.

In a specific implementation, a voltage measuring instrument such as a voltmeter may be used to detect the voltage value of the first voltage, so as to determine a magnitude relationship between the voltage value of the first voltage and the maximum operating voltage of the flash lamp, which is not described herein again.

Of course, in the case that the embodiment of the present application is applied to the flash control circuit shown in fig. 2 or fig. 3, the above step 401 may be: when a light supplement mode of a flash lamp is started and a VBUS pin of the USB interface has electric signal transmission, acquiring a first voltage transmitted on the VBUS pin and acquiring a second voltage transmitted by the battery.

The

steps

402 and 403 may specifically be: and determining the magnitude relation between the voltage value of the first voltage and the maximum working voltage of the flash lamp based on the numerical relation between the first voltage and the second voltage, and controlling the flash lamp power supply switching circuit to be in a working state corresponding to the magnitude relation.

Specifically, the numerical relationship between the first voltage and the second voltage may be understood as follows: magnitude relation, proportional relation, etc. of the first voltage and the second voltage, for example: as shown in fig. 2, the comparator 12 compares the voltage at the first power supply input terminal with the voltage at the second power supply input terminal.

The flash lamp control method provided by the embodiment of the application can realize the switching process of the flash lamp control circuit provided by the embodiment of the application, can obtain the same beneficial effects, and is not repeated herein for avoiding repetition.

As an optional implementation, after the controlling the flash lamp power supply switching circuit to be in the first operating state, the method further includes:

when a light supplement mode of a flash lamp is started and the electronic equipment is in a charging state, acquiring a charging mode of the electronic equipment;

when the charging mode of the electronic equipment is quick charging, switching the charging mode to a preset charging mode, wherein under the quick charging, a first voltage transmitted on the VBUS pin is greater than the maximum working voltage of the flash lamp, and under the preset charging mode, the first voltage transmitted on the VBUS pin is less than or equal to the maximum working voltage of the flash lamp;

and controlling the flash lamp power supply switching circuit to be in the second working state.

In specific implementation, the method can be controlled by software, for example: the charging negotiation with the charging equipment is realized in the following mode: and switching the charging mode to a preset charging mode. Wherein, the preset charging mode can also be called as: a normal charging mode.

According to the embodiment, the quick charging mode can be switched to the common charging mode in advance in the quick charging mode, so that the flash lamp can acquire working voltage from the VBUS pin on the premise of successful switching, and the working performance of the flash lamp is high; certainly, on the premise of switching failure, the flash lamp can obtain voltage from the battery, at this time, the voltage of the battery is lower than the rated working voltage of the flash lamp, so that the brightness of the flash lamp is slightly lower than that under the rated working voltage when the flash lamp performs photographing and light supplementing, and here, on the basis of reducing the brightness of the flash lamp, the flash lamp cannot be damaged by high voltage on VBUS, and the function of light supplementing can be executed.

As an optional implementation, the USB interface is configured with an OTG circuit, the OTG circuit is connected to the VBUS pin, and the method further includes:

when a light supplement mode of a flash lamp is started and the electronic equipment is not in a charging state, starting the OTG circuit;

and controlling the flash lamp power supply switching circuit to communicate the VBUS end with the VOUT end and disconnect the VOUT end from the VBAT end.

The OTG circuit is provided with the boosting module, so that when the electronic equipment is not charged, the boosting module in the OTG circuit can be multiplexed, the voltage of the battery is boosted and then transmitted to the VBUS pin, and the voltage value on the VBUS pin is enabled to be in accordance with the rated working voltage of the flash lamp.

Specifically, when the OTG function is started, the voltage value on the VBUS pin is greater than the battery voltage and less than or equal to the rated maximum operating voltage of the flash lamp.

In this embodiment, can multiplex the boost module in the OTG circuit, provide operating voltage for the flash lamp, avoid electronic equipment when not charging, the flash lamp only can be from the voltage that acquires being less than rated operating voltage on the battery, the relatively poor problem of the light filling effect of flash lamp that causes.

Optionally, as shown in fig. 5, an embodiment of the present application further provides a flash control device 500, including:

a first obtaining module 501, configured to obtain a first voltage transmitted on a VBUS pin of the USB interface when a light supplement mode of a flash lamp is started and the VBUS pin of the USB interface has an electrical signal transmission;

a first control module 502, configured to control the flash lamp power switching circuit to be in a first operating state when it is determined that the voltage value of the first voltage is greater than the maximum operating voltage of the flash lamp;

a second control module 503, configured to control the flash lamp power switching circuit to perform a second operation when it is determined that the voltage value of the first voltage is less than or equal to the maximum operating voltage of the flash lamp.

Optionally, the flash control device 500 further includes:

the second acquisition module is used for acquiring the charging mode of the electronic equipment when the light supplement mode of the flash lamp is started and the electronic equipment is in the charging state;

the electronic device comprises a switching module, a charging module and a control module, wherein the switching module is used for switching a charging mode of the electronic device to a preset charging mode when the charging mode is quick charging, under the quick charging, a first voltage transmitted on a VBUS pin is greater than the maximum working voltage of the flash lamp, and under the preset charging mode, the first voltage transmitted on the VBUS pin is less than or equal to the maximum working voltage of the flash lamp;

and the third control module is used for controlling the flash lamp power supply switching circuit to be in the second working state.

Optionally, the USB interface is configured with an OTG circuit, the OTG circuit is connected to the VBUS pin, and the flash control device 500 further includes:

the starting module is used for starting the OTG circuit when a light supplementing mode of a flash lamp is started and the electronic equipment is not in a charging state;

and the fourth control module is used for controlling the flash lamp power supply switching circuit to communicate the VBUS end with the VOUT end and disconnect the VOUT end from the VBAT end.

The flashlight control device 500 provided in the embodiment of the present application can perform each process of the flashlight control method embodiment described above, and can achieve the same technical effect, and for avoiding repetition, the details are not repeated here.

It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and the non-mobile electronic devices described above.

Fig. 6 is a schematic diagram of a hardware structure of an electronic device implementing an embodiment of the present application.

The electronic device 600 includes, but is not limited to: a radio frequency unit 601, a network module 602, an audio output unit 603, an input unit 604, a sensor 605, a display unit 606, a user input unit 607, an interface unit 608, a memory 609, a processor 610, and the like.

Those skilled in the art will appreciate that the electronic device 600 may further comprise a power source (e.g., a battery) for supplying power to the various components, and the power source may be logically connected to the processor 610 through a power management system, so as to implement functions of managing charging, discharging, and power consumption through the power management system. The electronic device structure shown in fig. 6 does not constitute a limitation of the electronic device, and the electronic device may include more or less components than those shown, or combine some components, or arrange different components, and thus, the description is omitted here.

The electronic device 600 includes, among other things, a flash power switching circuit as provided in the embodiments of fig. 1, 2 or 3.

In addition, the processor 610 is configured to obtain a first voltage transmitted on a VBUS pin of the USB interface when a light supplement mode of the flash lamp is started and the VBUS pin of the USB interface has an electrical signal transmission;

the processor 610 is further configured to control the flash lamp power supply switching circuit to be in a first working state under the condition that the voltage value of the first voltage is determined to be greater than the maximum working voltage of the flash lamp;

the processor 610 is further configured to control the flash lamp power switching circuit to be in a second operating state when it is determined that the voltage value of the first voltage is less than or equal to the maximum operating voltage of the flash lamp.

Optionally, after performing the control to set the flash lamp power supply switching circuit in the first operating state, the processor 610 is further configured to:

Optionally, the USB interface is configured with an OTG circuit, the OTG circuit is connected to the VBUS pin, and the processor 610 is further configured to:

The electronic device provided in the embodiment of the present application can perform each process of the method embodiment shown in fig. 4, and can obtain the same beneficial effects, and for avoiding repetition, details are not repeated here.

It should be understood that, in the embodiment of the present application, the input Unit 604 may include a Graphics Processing Unit (GPU) and a microphone, and the Graphics Processing Unit processes image data of still pictures or videos obtained by an image capturing device (such as a camera) in a video capturing mode or an image capturing mode. The display unit 606 may include a display panel, which may be configured in the form of a liquid crystal display, an organic light emitting diode, or the like. The user input unit 607 includes a touch panel and other input devices. Touch panels, also known as touch screens. The touch panel may include two parts of a touch detection device and a touch controller. Other input devices may include, but are not limited to, a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which are not described in detail herein. The memory 609 may be used to store software programs as well as various data including, but not limited to, application programs and an operating system. The processor 610 may integrate an application processor, which primarily handles operating systems, user interfaces, applications, etc., and a modem processor, which primarily handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 610.

The embodiment of the present application further provides a readable storage medium, where a program or an instruction is stored on the readable storage medium, and when the program or the instruction is executed by a processor, the program or the instruction implements each process of the above flash lamp control method embodiment, and can achieve the same technical effect, and in order to avoid repetition, details are not repeated here.

The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and so on.

The embodiment of the present application further provides a chip, where the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is configured to run a program or an instruction to implement each process of the above flash lamp control method embodiment, and can achieve the same technical effect, and is not described herein again to avoid repetition.

It should be understood that the chips mentioned in the embodiments of the present application may also be referred to as system-on-chip, system-on-chip or system-on-chip, etc.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Further, it should be noted that the scope of the methods and apparatus of the embodiments of the present application is not limited to performing the functions in the order illustrated or discussed, but may include performing the functions in a substantially simultaneous manner or in a reverse order based on the functions involved, e.g., the methods described may be performed in an order different than that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present application.

While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a flash lamp power supply switching circuit, is applied to electronic equipment, electronic equipment includes USB interface, battery and flash lamp, its characterized in that, flash lamp power supply switching circuit includes: a first input terminal, a second input terminal and a power supply terminal;

2. The flash power switching circuit of claim 1, further comprising a first resistor, a second resistor, a comparator, and a switching circuit;

the first resistor and the second resistor are connected between the first input end and a ground end in series, and a first power supply input end of the comparator is connected between the first resistor and the second resistor;

a second power supply input end of the comparator is connected to the second input end, and an output end of the comparator is connected with a control end of the switch circuit;

the switch circuit is respectively connected with the first input end, the second input end and the power supply end;

the comparator drives the switch circuit to switch the flash lamp power supply switching circuit to the first working state or the second working state based on a comparison result of the voltage value of the first power supply input end and the voltage value of the second power supply input end.

3. The flash lamp power switching circuit of claim 2, wherein the comparator is a rail-to-rail operational amplifier, the first power input is a positive power input, and the second power input is a negative power input;

when the voltage value of the first power supply input end is larger than that of the second power supply input end, the output end of the comparator outputs a high level signal, and the switching circuit connects the power supply end with the second input end and disconnects the power supply end from the first input end based on the high level signal;

when the voltage value of the first power supply input end is smaller than or equal to the voltage value of the second power supply input end, the output end of the comparator outputs a low level signal, and the switching circuit connects the power supply end with the first input end and disconnects the power supply end from the second input end based on the low level signal.

4. The flash power switching circuit of claim 2, wherein the switching circuit comprises: the power supply circuit comprises a switch transistor, a first diode and a second diode, wherein the first diode is connected between the first input end and the first pole of the switch transistor, the second diode is connected between the second input end and the second pole of the switch transistor, the second pole of the switch transistor is also connected with the power supply end, and the third pole of the switch transistor is the control end of the switch circuit.

5. The flash lamp power switching circuit of claim 4, wherein the first diode and the second diode are low forward voltage diodes.

6. The flash lamp power switching circuit of claim 4, wherein the switching transistor is a PMOS transistor if the comparator is a rail-to-rail operational amplifier.

7. An electronic device comprising a flash lamp, a battery and a USB interface, further comprising the flash lamp power switching circuit of any of claims 1-6, wherein a first input terminal of the flash lamp power switching circuit is connected to a VBUS pin in the USB interface, a second input terminal of the flash lamp power switching circuit is connected to an output terminal of the battery, and the power supply terminal provides power for the flash lamp.

8. A flash control method applied to the electronic device of claim 7, the method comprising:

9. A flash control apparatus applied to the electronic device according to claim 7, the apparatus comprising:

10. A readable storage medium, characterized in that it stores thereon a program or instructions which, when executed by a processor, implement the steps of the flash control method according to claim 8.