Control device for current switching and electronic device

1. A control device for current switching, comprising:

a universal serial bus on-the-go (USB OTG) interface comprising a low level at an identifier (ID) pin, wherein the USB OTG interface is configured to connect to a first device;

a universal serial bus (USB) interface comprising a high level at an ID pin, wherein the USB interface is configured to connect to a second device;

a booster current-limiting circuit comprising:

a step-up circuit;

a resistor R 1 ; and

a resistor R 2 ,

wherein the step-up circuit is connected separately to a first end of the resistor R 1 and a first end of the resistor R 2 ,

wherein a second end of the resistor R 2 is grounded, and wherein a second end of the resistor R 1 is connected to a pinout A of a bus extender,

wherein the booster limiting circuit is disposed between the USB OTG interface and the USB interface, and

wherein the booster current-limiting circuit, the USB OTG interface, and the USB interface form a line for the first device to supply power to the second device; and

a measuring and controlling unit connected to the booster current-limiting circuit, wherein the measuring and controlling unit is configured to change a resistance value of a current-limiting circuit in the booster current-limiting circuit such that the first device supplies a corresponding current to the second device.

2. The device according to claim 1 , wherein the measuring and controlling unit is further configured to:

control the pinout A of the bus extender to be a high level when receiving a request for the first device to supply a first current to the second device; and

control the pinout A of the bus extender to be a low level when receiving a request for the first device to supply a second current to the second device.

3. The device according to claim 2 , further comprising a physical key connected to the measuring and controlling unit, configured to generate, after receiving a signal indicating that the physical key is pressed, a request for the first device to supply a corresponding current to the second device.

4. The device according to claim 2 , wherein an initial current is the first current, and the initial current is a current supplied by the first device to the second device after the first device is connected to the second device by using the control device for current switching and before the measuring and controlling unit receives the current switching request.

5. The device according to claim 1 , further comprising an organ ic light-emitting diode display screen connected to the measuring and controlling unit, configured to display a power supply mode of the control device for current switching.

6. An electronic device, comprising:

a charge circuit;

a booster current-limiting circuit comprising:

a step-up circuit;

a resistor R 5 ;

a resistor R 6 ; and

a resistor R 7 ,

wherein the step-up circuit is connected separately to a first end of the resistor R 5 , a first end of the resistor R 6 , and a first end of the resistor R 7 ,

wherein a second end of the resistor R 5 is grounded,

wherein a second end of the resistor R 6 is connected to a pinout A of a bus extender, and

wherein a second end of the resistor R 7 is connected to a pinout B of the bus extender,

an energy storage module connected separately to the charge circuit and the booster current-limiting circuit;

a universal serial bus on-the-go (USB OTG) interface configured to connect to a second device;

a first control switch disposed between the charge circuit and the USB OTG interface, wherein the energy storage module, the charge circuit, the first control switch, and the USB OTG interface form a line for an external power source to supply power to the electronic device;

a second control switch disposed between the USB OTG interface and the booster current-limiting circuit, wherein the energy storage module, the booster current-limiting circuit, the second control switch, and the USB OTG interface form a line for the electronic device to supply power to the second device; and

a measuring and controlling unit connected separately to a control end of the first control switch and a control end of the second control switch, wherein the measuring and controlling unit is connected to the booster current-limiting circuit, and the measuring and controlling unit is configured to:

detect whether an identifier (ID) pin of the USB OTG interface is at a low level;

control the first control switch to be off, the second control switch to be on, and change, after receiving a current switching request, a resistance value of a current-limiting circuit in the booster current-limiting circuit such that the electronic device supplies a corresponding current to the second device when the ID pin of the USB OTG interface is at the low level; and

control the first control switch to be on and the second control switch to be off when the ID pin of the USB OTG interface is not at the low level.

7. The device according to claim 6 , wherein the measuring and controlling unit is configured to:

control the pinout A and the pinout B of the bus extender both to be a high level when receiving a request for the electronic device to supply a first current to the second device;

control the pinout A of the bus extender to be a low level and the pinout B to be a high level; and

control the pinout A and the pinout B of the bus extender both to be a low level when detecting a request for the electronic device to supply a second current to the second device.

8. The device according to claim 6 , further comprising a physical key connected to the measuring and controlling unit, configured to generate, after receiving a signal indicating that the physical key is pressed, a request for the electronic device to supply a corresponding current to the second device.

9. The device according to claim 6 , wherein the measuring and controlling unit is configured to:

control the pinout A and the pinout B of the bus extender both to be a high level when receiving a request for the electronic device to supply a first current to the second device;

control the pinout A to be a high level and the pinout B to be a low level when detecting that the electronic device needs to communicate with the second device; and

control the pinout A and the pinout B of the bus extender both to be a low level when detecting a request for the electronic device to supply a second current to the second device.