Switching circuit board for solving power supply and TYPE-C cable

Abstract

The present invention discloses a switching circuit board for solving power supply, which includes a reverse cut-off unit and a switch control unit. One end of the reverse cut-off unit is connected to the host power input interface, and the other end is connected to the output interface. One end of the switch control unit is connected to the reverse cut-off unit, and the other end is connected to the independent power input interface. The switch control unit is used to control the cut-off of the reverse cut-off unit to prevent the current of the external independent power supply from flowing into the computer host. The present invention can achieve the technical effect of powering a handwriting device with a screen size of more than 11.6 inches through a single wire and preventing the independent power supply from backflowing into the computer host.

Description

Technical Field

[0001] The present invention relates to an external power supply circuit for an electromagnetic handwriting device, and particularly to a switching circuit board and a TYPE-C cable for solving power supply switching.

Background Art

[0002] For an electromagnetic handwriting device, in a normal application scenario, the transmission of its handwriting signal and the computer host is through USB communication in the TYPE-C cable of the handwriting screen driver board interface. Its power supply transmission uses four fixed power lines of TYPE-C, and its video signal is transmitted through four groups of differential lines and their auxiliary control lines in the TYPE-C cable.

[0003] In the actual transmission process, for a small-screen electromagnetic handwriting device with a display screen size of less than 11.6 inches, due to its low power consumption, it is powered by TYPE-C at both ends. At this time, the power supply of the computer host can meet the power supply requirements of the electromagnetic handwriting device. However, for a mobile phone or an electromagnetic handwriting device with a display screen size of more than 11.6 inches, due to its high power consumption, the existing TYPE-C cable cannot simultaneously implement the functions of its USB communication, power supply, and video signal transmission. For a mobile phone or an electromagnetic handwriting device with a display screen size of more than 11.6 inches, the existing solution is to use an external power supply to charge it. However, the existing technical solution will bring new technical problems, that is, the external power supply is directly connected to the USB communication power supply, resulting in the external power supply flowing back to the computer host and causing damage to the computer host. If a separate cable is set to supply power to the handwriting device alone, it will increase the number of wires and bring inconvenience to the user.

[0004] Therefore, it is necessary to provide a switching circuit board and a TYPE-C cable for solving power supply switching to solve the above problems.

Summary of the Invention

[0005] Based on the above technical problems, the present invention discloses a switching circuit board for solving power supply switching, including an independent power input interface, a host power input interface, an output interface, a reverse cut-off unit, and a switch control unit. The independent power input interface is used to connect an external independent power supply. The host power input interface is used to connect an external computer host, and the host power input interface is connected in parallel with the power input interface. The output interface is used to connect an external handwriting device. One end of the reverse cut-off unit is connected to the host power input interface, and the other end is connected to the output interface. The reverse cut-off unit is used to conduct the connection between the host power input interface and the output interface. One end of the switch control unit is connected to the reverse cut-off unit, and the other end is connected to the independent power input interface. The switch control unit is used to control the cut-off of the reverse cut-off unit to prevent the external independent power supply from flowing into the computer host.

[0006] Preferably, the reverse cut-off unit includes a diode and a first field-effect transistor. The input end of the diode is connected to the host power input interface, and the output end is connected to the output interface. The drain of the first field-effect transistor is connected to the input end of the diode, the source is connected to the output interface, and the gate is connected to the switch control unit and the output end of the diode.

[0007] Preferably, the reverse cut-off unit further includes a first resistor. One end of the first resistor is connected to the output end of the diode, and the other end is connected to the gate of the first field-effect transistor.

[0008] Preferably, the switch control unit includes a second field-effect transistor, a second resistor, and a third resistor. The drain of the second field-effect transistor is connected to the gate of the first field-effect transistor, the source is grounded, and the gate is connected to the host power input interface. One end of the second resistor is connected to the output interface, and the other end is connected to the host power input interface. One end of the third resistor is grounded, and the other end is connected to the host power input interface.

[0009] Preferably, the switch control unit further includes a fourth resistor. One end of the fourth resistor is connected to the gate of the second field-effect transistor, and the other end is connected to the host power input interface.

[0010] Preferably, the first field-effect transistor is a P-type field-effect transistor. When the first field-effect transistor is closed, the electrical signal flows from the source of the first field-effect transistor into the drain of the first field-effect transistor.

[0011] Preferably, the second field-effect transistor is an N-type field-effect transistor. When the second field-effect transistor is closed, the electrical signal flows from the drain of the second field-effect transistor into the source of the second field-effect transistor.

[0012] Preferably, the switching circuit board further includes a video input interface. The video input interface is connected in parallel with the host power input interface and is externally connected to a video signal source.

[0013] In addition, the present invention also provides a TYPE-C cable for solving power supply, including the above-mentioned switching circuit board, an independent power input line, a host power input line, and an output line. One end of the independent power input line is connected to the independent power input interface of the switching circuit board, and the other end is externally connected to an independent power supply. The host power input line is connected in parallel with the independent power input line. One end of it is connected to the host power input interface of the switching circuit board, and the other end is connected to a computer host. One end of the output line is connected to the output interface of the switching circuit board, and the other end is connected to a handwriting device.

[0014] Preferably, the TYPE-C cable further includes a video input cable, which is connected in parallel with the host power input cable, with one end connected to the video input interface of the switching circuit board and the other end connected to the video signal source.

[0015] The switching circuit board and the TYPE-C cable for solving power supply provided by the present invention, when the user is using an electromagnetic handwriting device or a mobile phone with a display screen size of more than 11.6 inches, through the reverse cut-off unit and the switch control unit, the independent power input interface and the host power input interface supply power to the handwriting device simultaneously, and through the switch control unit, the reverse cut-off unit is caused to perform reverse cut-off to prevent the independent power source externally connected to the independent power input interface from flowing back into the computer host. The switching circuit board and the TYPE-C cable for solving power supply provided by the present invention improve the convenience during the user's use process and at the same time improve the security of the computer host.

Description of the Drawings

[0016] Figure 1 is a circuit schematic diagram of the switching circuit board for solving power supply provided by the present invention;

[0017] Figure 2 is a circuit diagram of the switching circuit board for solving power supply provided by the present invention;

[0018] Figure 3 is a schematic diagram of the TYPE-C cable for solving power supply provided by the present invention.

Detailed Embodiments

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by terms such as "one end", "the other end", "both ends", "between", "one end", "input end" or "output end" are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. At the same time, the "first", "second", "third" before each electrical component in the present invention or the "R1", "R2", "R3", "R4", "V1", "V301", "G", "TP1", "TP2", "TP3", "TP4", "TP5", "TP6", "TP7" and "TP8" etc. after each electrical component do not have specific meanings, and are only used to distinguish each electrical component or as electrical symbols of the corresponding electrical components, without generating other meanings for each electrical component.

[0021] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be a non-structural connection such as an electrical connection or a signal connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Please refer to Figure 1 , Figure 1 FIG. is a circuit schematic diagram of a switching circuit board for solving power supply switching in the present invention. The switching circuit board 1 includes an independent power input interface 18, a host power input interface 17, an output interface 15, a video input interface 16, a reverse cut-off unit 13, and a switch control unit 10. The independent power input interface 18 is used to externally connect an independent power supply. The host power input interface 17 is used to externally connect a computer host, and the host power input interface 17 is connected in parallel with the power input interface 17. The output interface 15 is used to externally connect a handwriting device. One end of the reverse cut-off unit 13 is connected to the host power input interface 17, and the other end is connected to the output interface 15. The reverse cut-off unit 13 is used to conduct the connection between the host power input interface 17 and the output interface 15. One end of the switch control unit 10 is connected to the reverse cut-off unit 13, and the other end is connected to the independent power input interface 18. The switch control unit 10 is used to control the cut-off of the reverse cut-off unit 13 to prevent the independent power supply from flowing into the computer host. The video input interface 18 is connected in parallel with the host power input interface 17 and externally connects a video signal source.

[0023] Please also refer to Figure 1 and Figure 2, Figure 2 This is the circuit diagram of the switching circuit board provided by the present invention for solving power supply switching, where the reverse cut-off unit 13 includes a diode D1 and a first field effect transistor V1. The input end of the diode D1 is connected to the host power input interface 17, and the output end is connected to the output interface 15. The drain of the first field effect transistor V1 is connected to the input end of the diode D1, the source is connected to the output interface 15, and the gate is connected to the switch control unit 10 and the output end of the diode D1. The reverse cut-off unit 13 further includes a first resistor R1. One end of the first resistor R1 is connected to the output end of the diode D1, and the other end is connected to the gate of the first field effect transistor.

[0024] The switch control unit 10 includes a second field effect transistor V301, a second resistor R2, a third resistor R3, and a fourth resistor R4. The drain of the second field effect transistor V301 is connected to the gate of the first field effect transistor V1, the source is grounded, and the gate is connected to the host power input interface 17. One end of the second resistor R2 is connected to the output interface 15, and the other end is connected to the host power input interface 17. One end of the third resistor R3 is grounded, and the other end is connected to the host power input interface 17. One end of the fourth resistor R4 is connected to the gate of the second field effect transistor V301, and the other end is connected to the host power input interface 17.

[0025] Among them, the first field effect transistor V1 is a P-type field effect transistor. When there is voltage at the gate of the first field effect transistor V1, the electrical signal flows from the source of the first field effect transistor V1 into the drain of the first field effect transistor V1. The second field effect transistor V301 is an N-type field effect transistor. When there is voltage at the gate of the second field effect transistor V301, the electrical signal flows from the drain of the second field effect transistor V301 into the source of the second field effect transistor V301.

[0026] Please also refer to Figure 1 and Figure 3 , Figure 3It is a schematic diagram of a TYPE-C line provided by the present invention for solving power supply. The present invention also discloses a TYPE-C line for solving power supply, including the switching circuit board 1, an independent power input line 8, a host power input line 7, a video input line 6, and an output line 5. One end of the independent power input line 8 is connected to the independent power input interface 18 of the switching circuit board 1, and the other end is externally connected to an independent power supply. The host power input line 7 is connected in parallel with the independent power input line 8. One end of it is connected to the host power input interface 17 of the switching circuit board 1, and the other end is connected to the computer host. One end of the output line 5 is connected to the output interface 15 of the switching circuit board 1, and the other end is connected to the handwriting device driving board. The video input line 6 is connected in parallel with the host power input line 17. One end of it is connected to the video input interface 16 of the switching circuit board 1, and the other end is connected to the video signal source.

[0027] Please refer to Figure 1 , Figure 2 and Figure 3 simultaneously. The independent power input interface 18 of the switching circuit board 1 includes a TP7 interface, a TP3 interface, and a TP4 interface, which are connected to the independent power supply. The connection between the independent power input line 8 and the independent power supply is a USB interface connection. Among them, the TP7 interface transmits current, and the TP3 interface and the TP4 interface are used for signal transmission. The host power input interface 17 corresponds to the TP2 interface, and the connection between the host power input line 7 and the computer host is also a USB interface connection. The output interface 15 corresponds to TP1, and the connection between the output interface 15 and the external device is a TYPE-C interface connection. The TP5 interface, the TP6 interface, and the TP8 interface are left unconnected.

[0028] When the display screen size of the handwriting device is less than 11.6 inches, using only the power supply of the computer host can meet the power supply of the handwriting device. The TP7 interface, the TP3 interface, and the TP4 interface do not work. The TP2 interface is connected to the computer host through the host power input interface 17. The current output by the computer host passes through the high level provided by the second resistor R2 and the second resistor R4, making the gate of the second field-effect transistor V301 in a high-level state, resulting in the conduction of the second field-effect transistor V301. The current output by the computer host also flows through the diode D1 and the first resistor R1 to the connection between the gate of the first field-effect transistor V1 and the drain of the second field-effect transistor V301. At this time, due to the conduction of the second field-effect transistor V301, the current flows through the second field-effect transistor V301 to the ground electrode. At the same time, due to the conduction of the second field-effect transistor V301, there is a voltage value at the gate of the first field-effect transistor V1, resulting in the conduction of the first field-effect transistor V1.

[0029] At this time, the current output by the computer main unit can be transmitted to TP1 corresponding to the output interface 15 through both the diode D1 and the first field-effect transistor V1, and finally transmitted to the handwriting device through the output line 5. However, since the resistance value of the diode D1 is much larger than that of the first field-effect transistor V1, during the current transmission process, the current mainly flows into the handwriting device through the first field-effect transistor V1.

[0030] When the display screen size of the handwriting device is larger than 11.6 inches or the handwriting device is a mobile phone, using only the computer main unit power supply cannot meet the power supply requirements of the handwriting device. The TP7 interface, the TP3 interface, and the TP4 interface correspond to the independent power input interface 18, and the TP2 interface is connected to the computer main unit through the host power input interface 17. When the TP3 interface and the TP4 interface are externally connected to the independent power supply, the TP3 interface and the TP4 interface are short-circuited and connected, and the resistance values of the second resistor R2 and the third resistor R3 are set, resulting in the gate voltage value of the second field-effect transistor V301 being insufficient to turn on the second field-effect transistor V301, thereby causing the first field-effect transistor V1 to also be in the cut-off state. At this time, the TP2 interface is externally connected to the computer main unit, and the current of the computer main unit flows through the diode D1 and then through the output interface 15 corresponding to the TP1 interface, and finally flows into the handwriting device. At the same time, the TP7 interface is externally connected to the independent power supply, and the current of the independent power supply directly supplies power to the external device corresponding to TP1. Since the first field-effect transistor V1 is in the cut-off state and the diode D1 is also in the reverse cut-off state, the current of the independent power supply will not flow back into the computer main unit corresponding to the TP2 interface.

[0031] The switching circuit board and TYPE-C cable for solving power supply disclosed in the present invention, when the user uses an electromagnetic handwriting device with a display screen size of more than 11.6 inches or a mobile phone, through the reverse cut-off unit and the switch control unit, the independent power input interface and the host power input interface supply power to the handwriting device at the same time, and through the switch control unit, the reverse cut-off unit is caused to perform reverse cut-off to prevent the independent power supply externally connected to the independent power input interface from flowing back into the computer main unit. The switching circuit board and TYPE-C cable for solving power supply provided by the present invention improve the convenience during the user's use process and at the same time improve the security of the computer main unit.

[0032] It should be noted that in this embodiment, an electromagnetic handwriting device with a display screen is taken as an example to specifically describe the switching circuit board and TYPE-C cable for solving power supply. However, the application scenario of the present invention is not limited to the electromagnetic screen signal power integrated power supply line, and the protection scope of this patent includes all such protection applications for signal power integrated power supply lines such as handwriting tablets.

[0033] The above is the embodiment of the present invention. The foregoing are the various preferred embodiments of the present invention. If the preferred implementation manners in the various preferred embodiments are not obviously self-contradictory or premised on a certain preferred implementation manner, the various preferred implementation manners can be arbitrarily superimposed and combined for use. The said embodiments and the specific parameters in the embodiments are only for clearly expressing the inventor's invention verification process, and are not used to limit the patent protection scope of the present invention. The patent protection scope of the present invention still takes its claims as the criterion. All equivalent structural changes made by using the content of the specification and drawings of the present invention should similarly be included in the protection scope of the present invention.

Claims

1. A switching circuit board for solving power supply, comprising: An independent power input interface, which is a USB interface for connecting an external independent power supply; A host power input interface for connecting an external computer host, and the host power input interface is connected in parallel with the independent power input interface; And An output interface for connecting an external handwriting device driver board, characterized in that it further comprises: A reverse cut-off unit, one end of which is connected to the host power input interface and the other end is connected to the output interface; A switch control unit, one end of which is connected to the reverse cut-off unit and the other end is connected to the independent power input interface. The switch control unit is used to control the cut-off of the reverse cut-off unit to prevent the current of the external independent power supply from flowing into the computer host; The independent power input interface includes a TP7 interface, a TP3 interface and a TP4 interface. The TP7 interface transmits current, and the TP3 interface and the TP4 interface are used for signal transmission; the host power input interface corresponds to the TP2 interface; when the TP3 interface and the TP4 interface are connected to the external independent power supply, the TP3 interface and the TP4 interface are short-circuited and connected. The TP3 interface is connected to a second resistor, and the TP4 interface is connected to a third resistor. The resistance values of the second resistor and the third resistor make the voltage value of the switch control unit insufficient to conduct.

2. The switching circuit board according to claim 1, wherein The reverse cut-off unit includes: A diode, the input end of which is connected to the host power input interface and the output end is connected to the output interface; A first field-effect transistor, the drain of which is connected to the input end of the diode, the source of which is connected to the output interface, and the gate of which is connected to the output ends of the switch control unit and the diode.

3. The switching circuit board according to claim 2, wherein The reverse cut-off unit further includes a first resistor, one end of which is connected to the output end of the diode and the other end is connected to the gate of the first field-effect transistor.

4. The switching circuit board according to claim 2, wherein The switch control unit includes: A second field-effect transistor, the drain of which is connected to the gate of the first field-effect transistor, the source of which is grounded, and the gate of which is connected to the host power input interface; A second resistor, one end of which is connected to the output interface, the output interface corresponds to the TP1 interface, and the other end of the second resistor is respectively connected to the TP3 interface and the host power input interface. Among them, the second resistor is sequentially connected to the host power input interface through the second field-effect transistor, the first field-effect transistor and the TP2 interface; A third resistor, when the TP3 interface and the TP4 interface are connected to the external independent power supply, one end of the third resistor is grounded, and the other end is sequentially connected to the host power input interface through the TP4 interface, the TP3 interface, the second field-effect transistor, the first field-effect transistor and the TP2 interface.

5. The switching circuit board according to claim 4, characterized in that, The switch control unit further includes a fourth resistor, one end of which is connected to the gate of the second field-effect transistor, and the other end is sequentially connected to the host power input interface through the second resistor, the first field-effect transistor and the TP2 interface.

6. The switching circuit board according to claim 2, characterized in that, The first field-effect transistor is a P-type field-effect transistor. When the first field-effect transistor is closed, an electrical signal flows from the source electrode of the first field-effect transistor into the drain electrode of the first field-effect transistor.

7. The switching circuit board according to claim 4, characterized in that, The second field-effect transistor is an N-type field-effect transistor. When the second field-effect transistor is closed, an electrical signal flows from the drain electrode of the second field-effect transistor into the source electrode of the second field-effect transistor.

8. The switching circuit board according to claim 1, wherein It further includes: A video input interface, which is connected in parallel with the host power input interface and is used for externally connecting a video signal source.

9. A TYPE-C cable for solving power supply, characterized in that, It includes: The switching circuit board according to any one of claims 1 to 7; An independent power input line, one end of which is connected to the independent power input interface of the switching circuit board, and the other end is externally connected to an independent power supply; A host power input line, which is connected in parallel with the independent power input line of the switching circuit board, one end of which is connected to the host power input interface of the switching circuit board, and the other end is connected to a computer host; An output line, one end of which is connected to the output interface of the switching circuit board, and the other end is connected to a handwriting device driver board.

10. The TYPE-C cable according to claim 9, wherein It further includes: A video input line, which is connected in parallel with the host power input line, one end of which is connected to the video input interface of the switching circuit board, and the other end is connected to a video signal source.

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