A split IP intercom device and system

Abstract

The present invention relates to a split IP intercom device and system, including a main controller for controlling the transmission of signals on the split IP intercom device; a power control module is electrically connected to the serial port interface and the power interface of the main controller, for receiving the control signal issued by the main controller, and converting the control signal into a DC carrier signal; a signal transmission module is electrically connected to the video signal interface of the main controller, for receiving the unbalanced video baseband signal issued by the main controller, and converting the unbalanced video baseband signal into a balanced video signal; an interface module is electrically connected to the power control module and the signal transmission module, respectively, and correspondingly receives the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module. The present invention has low construction cost and difficulty, and can avoid mutual interference between analog signals and digital signals during long-distance transmission, meeting practical application requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of intercom equipment, and in particular to a split IP intercom equipment and system. Background Art

[0002] IP intercom refers to the use of TCP / IP technology to transmit audio signals in the form of data packets on the local area network and wide area network. It is a pure digital transmission hands-free intercom system that solves the problems of limited transmission distance and susceptibility to interference in traditional intercom systems.

[0003] The existing split IP intercom needs to use multiple wires to realize the functions of power supply, two-way audio transmission, broadcast audio transmission, video signal transmission and control signal transmission between the intercom host and the intercom panel. Therefore, its construction cost and difficulty are relatively high, and there is a problem of mutual interference between analog signals and digital signals during long-distance transmission. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a split IP intercom device and system with low construction cost and difficulty, and capable of avoiding mutual interference between analog signals and digital signals during long-distance transmission.

[0005] A split IP intercom device, comprising:

[0006] A main controller, used to control the transmission of signals on the split IP intercom device; wherein the main controller includes a serial port interface, a power supply interface and a video signal interface;

[0007] A power control module, electrically connected to the serial port interface and the power interface of the main controller, the power control module is used to receive the control signal sent by the main controller and convert the control signal into a DC carrier signal;

[0008] A signal transmission module, electrically connected to the video signal interface of the main controller, the signal transmission module is used to receive the unbalanced video baseband signal sent by the main controller, and convert the unbalanced video baseband signal into a balanced video signal;

[0009] The interface module is electrically connected to the power control module and the signal transmission module respectively, and correspondingly receives the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module.

[0010] In addition, the split IP intercom device provided by the present invention may also have the following additional technical features:

[0011] Furthermore, the power control module includes a signal conversion circuit, a differential circuit and a coupling circuit;

[0012] The signal conversion circuit is electrically connected to the differential circuit and the serial port interface of the main controller, and is used to convert the main control signal sent by the main controller into a carrier signal and send it to the differential circuit;

[0013] The differential circuit is used to convert the carrier signal into a differential signal and send it to the coupling circuit;

[0014] The coupling circuit is electrically connected to the differential circuit and the power interface of the main controller, and is used to couple the differential signal and the power signal into a DC carrier signal.

[0015] Further, the coupling circuit includes a first working mode inductor and a second working mode inductor; the first end and the fourth end of the first working mode inductor are electrically connected to the differential circuit respectively, and the second end and the third end of the first working mode inductor are electrically connected to the interface module through a resistor respectively; the first end and the second end of the second working mode inductor are electrically connected to the power interface of the main controller respectively, and the third end and the fourth end of the second working mode inductor are electrically connected to the interface module through the second end and the third end of the first working mode inductor respectively.

[0016] Furthermore, the split-type IP intercom device also includes a filter circuit arranged between the differential circuit and the coupling circuit; wherein the filter circuit is an RC filter circuit.

[0017] Furthermore, the signal transmission module includes:

[0018] a first balancing circuit, electrically connected to the video signal interface of the main controller, the first balancing circuit being used for performing a first balancing process on the unbalanced video baseband signal to obtain a balanced video baseband signal, and sending the balanced video baseband signal to a second balancing circuit;

[0019] The second balanced circuit is electrically connected to the first balanced circuit, and the second balanced circuit is used to perform a second balanced processing on the balanced video baseband signal to obtain a balanced video signal.

[0020] Further, the first balancing circuit includes a first electrolytic capacitor, a third working mode inductor and a fourth working mode inductor; the second end of the first electrolytic capacitor is electrically connected to the third end of the third working mode inductor, and the fourth end and the fifth end of the third working mode inductor are electrically connected to the fourth end and the third end of the fourth working mode inductor respectively; wherein the first end of the third working mode inductor is grounded.

[0021] Further, the second balancing circuit includes a second electrolytic capacitor and a fifth working mode inductor; the first end of the second electrolytic capacitor group is electrically connected to the fifth end of the fourth working mode inductor, the second end of the second electrolytic capacitor is electrically connected to the fifth end of the fifth working mode inductor, the fourth end of the fifth working mode inductor is electrically connected to the first end of the fourth working mode inductor through a resistor, and the first end and the third end of the fifth working mode inductor are electrically connected to the interface module.

[0022] Furthermore, the interface module includes a differential video signal interface, a power and control signal interface, an audio signal interface and a three-way analog audio signal interface; wherein the differential video signal interface is used to receive a balanced video signal, and the power and control signal interface is used to receive a DC carrier signal and a power signal respectively.

[0023] Furthermore, the inductance range of the first working mode inductor and the second working mode inductor is 15mH to 78mH, the inductance range of the third working mode inductor, the fourth working mode inductor and the fifth working mode inductor is 230mH to 350mH, and the capacitance range of the first electrolytic capacitor and the second electrolytic capacitor is 1800mF to 420mF.

[0024] In order to solve the above technical problems, an embodiment of the present invention further provides a split IP intercom system, the system comprising:

[0025] The host end and the intercom panel end are connected through the split IP intercom device; wherein the host end can connect to multiple intercom panel ends in parallel or serially with the split IP intercom device.

[0026] The split-type IP intercom device and system proposed in the present invention include: a main controller, which is used to control the transmission of signals on the split-type IP intercom device; wherein the main controller includes a serial port interface, a power interface and a video signal interface; a power control module, which is electrically connected to the serial port interface and the power interface of the main controller, and the power control module is used to receive the control signal issued by the main controller and convert the control signal into a DC carrier signal; a signal transmission module, which is electrically connected to the video signal interface of the main controller, and the signal transmission module is used to receive the unbalanced video baseband signal issued by the main controller and convert the unbalanced video baseband signal into a balanced video signal; an interface module, which is electrically connected to the power control module and the signal transmission module respectively, and correspondingly receives the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module. The present invention can simultaneously transmit and control digital and analog signals such as power supply, control signaling, two-way audio, broadcast audio, video signals, etc. through a universal shielded network cable, thereby simplifying engineering costs and construction difficulties; it enables an intercom host to connect multiple intercom panels in parallel or serial mode (a hand-in-hand mode can actually have up to 8 intercom panels); at the same time, it has long-distance transmission capability (up to 100 meters without interference) and does not have mutual interference problems, thus meeting practical application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural block diagram of a split IP intercom device;

[0028] Figure 2 for Figure 1 The structural block diagram of the power supply control module;

[0029] Figure 3 for Figure 1 The structural block diagram of the signal transmission module;

[0030] Figure 4 for Figure 1 Schematic diagram of;

[0031] Figure 5 for Figure 4 Circuit diagram of the power control module;

[0032] Figure 6 for Figure 4 Circuit diagram of the signal transmission module;

[0033] Figure 7 for Figure 4 The structural diagram of the serial port module;

[0034] Figure 8 It is a connection diagram of a split IP intercom system.

[0035] Description of main component symbols:

[0036] Main Controller 10 Power Control Module 20 Signal conversion circuit 21 Differential Circuit 22 Coupling circuit 23 Signal transmission module 30 First balance circuit 31 Second balance circuit 32 Interface modules 40

[0037] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0038] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0041] like Figures 1 to 8 As shown, a split IP intercom device is used to connect a host end and an intercom device end, including a power control module 20 and a signal transmission module 30 electrically connected to a main controller 10, and the other ends of the power control module 20 and the signal transmission module 30 are electrically connected to an interface module 40.

[0042] The main controller 10 is used to control the transmission of signals on the split IP intercom device. The main controller 10 includes a serial port interface, a power supply interface and a video signal interface. In this embodiment, the control chip of the main controller 10 adopts an arm series control chip.

[0043] The power control module 20 is electrically connected to the serial port interface and the power interface of the main controller 10. The power control module 20 is used to receive the control signal sent by the main controller 10 and convert the control signal into a DC carrier signal.

[0044] Furthermore, the power control module 20 includes a signal conversion circuit 21 , a differential circuit 22 and a coupling circuit 23 .

[0045] The signal conversion circuit 21 is electrically connected to the differential circuit 22 and the serial port interface of the main controller 10 , and is used to convert the main control signal sent by the main controller 10 into a carrier signal and send it to the differential circuit 22 .

[0046] Specifically, the signal conversion circuit 21 includes a DC online communication chip U7, which can transparently convert the serial port data signal into a carrier signal at a user effective real-time rate of less than 56kbps or 115kbps. The TXD and RXD pins of the DC online communication chip U7 are connected to the serial port interface of the main controller 10 for signal interaction.

[0047] The differential circuit 22 is used to convert the carrier signal into a differential signal and send it to the coupling circuit 23 .

[0048] Specifically, the differential circuit 22 includes a control signal conversion chip U6. The TX_EN pin of the DC line communication chip U7 is connected to the DE and RE pins of the control signal conversion chip U6, the PLC_OUT pin of the DC line communication chip U7 is connected to the DI pin of the control signal conversion chip U6, and the PLC_IN pin of the DC line communication chip U7 is connected to the RO pin of the control signal conversion chip U6.

[0049] The coupling circuit 23 is electrically connected to the differential circuit 22 and the power interface of the main controller 10, and is used to couple the differential signal and the power signal into a DC carrier signal.

[0050] Specifically, the coupling circuit 23 includes a first working mode inductor L2 and a second working mode inductor L4. The first end and the fourth end of the first working mode inductor L2 are electrically connected to the differential circuit 22, respectively, and the second end and the third end of the first working mode inductor L2 are electrically connected to the interface module 40 through resistors R50 and R45, respectively; the first end and the second end of the second working mode inductor L4 are electrically connected to the power interface of the main controller 10, respectively, and the third end and the fourth end of the second working mode inductor L4 are electrically connected to the interface module 40 through the second end and the third end of the first working mode inductor, respectively; wherein the power interface includes a high potential terminal 24V and a ground terminal, and the first end and the second end of the second working mode inductor L4 are connected to the ground terminal and the high potential terminal 24V of the power interface, respectively.

[0051] Furthermore, the split-type IP intercom device further includes a filter circuit disposed between the differential circuit 22 and the coupling circuit 23. The filter circuit is an RC filter circuit.

[0052] Specifically, the filtering circuit includes a first filtering unit and a second filtering unit, the first filtering unit is connected to the fourth end of the first working mode inductor L2, and the second filtering unit is connected to the first end of the first working mode inductor L2.

[0053] It can be understood that the control signal in this embodiment can convert the serial data control signal into a carrier signal after passing through the U7 DC line communication chip, and the carrier signal is converted into a differential signal after passing through the U6 control signal conversion chip to enhance anti-interference. The differential carrier signal is coupled with the power signal passing through the second common-mode inductor to form a DC carrier signal after passing through the first common-mode inductor. At this point, the control signal is integrated in the power transmission line for transmission through a carrier. On the one hand, the control signal is converted into a differential signal to enhance anti-interference, and on the other hand, the control signal line and the power transmission line are integrated to save the number of transmission lines.

[0054] The signal transmission module 30 is electrically connected to the video signal interface of the main controller 10. The signal transmission module 30 is used to receive the unbalanced video baseband signal sent by the main controller 10 and convert the unbalanced video baseband signal into a balanced video signal.

[0055] Furthermore, the signal transmission module 30 includes a first balancing circuit 31 and a second balancing circuit 32 which are connected in sequence.

[0056] The first balancing circuit 31 is electrically connected to the video signal interface of the main controller 10. The first balancing circuit 31 is used to perform a first balancing process on the unbalanced video baseband signal to obtain a balanced video baseband signal, and send the balanced video baseband signal to the second balancing circuit 32.

[0057] Specifically, the first balancing circuit 31 includes a first electrolytic capacitor E22, a third working mode inductor L24, and a fourth working mode inductor L25. The second end of the first electrolytic capacitor E22 is electrically connected to the third end of the third working mode inductor L24, and the fourth end and the fifth end of the third working mode inductor L24 are electrically connected to the fourth end and the third end of the fourth working mode inductor L25, respectively; wherein the first end of the third working mode inductor L24 is grounded.

[0058] The second balancing circuit 32 is electrically connected to the first balancing circuit 31. The second balancing circuit 32 is used to perform a second balancing process on the balanced video baseband signal to obtain a balanced video signal.

[0059] Specifically, the second balancing circuit 32 includes a second electrolytic capacitor E23 and a fifth working mode inductor L26. The first end of the second electrolytic capacitor E23 is electrically connected to the fifth end of the fourth working mode inductor L25, and the second end of the second electrolytic capacitor E23 is electrically connected to the fifth end of the fifth working mode inductor L26; the fourth end of the fifth working mode inductor L26 is electrically connected to the first end of the fourth working mode inductor L25 through a resistor, and the first end and the third end of the fifth working mode inductor L26 are electrically connected to the interface module 40. In addition, the fifth end of the fifth working mode inductor L26 is also electrically connected to the interface module 40 through a capacitor C783 and a resistor R884 in sequence, the fourth end of the fifth working mode inductor L26 is also electrically connected to the interface module 40 through a resistor R885, and the fifth end of the fifth working mode inductor L26 is also reversely connected in series with the fourth end of the fifth working mode inductor L26 through a capacitor C783.

[0060] It can be understood that this embodiment converts the unbalanced video baseband signal into a balanced video signal through an inductor and a resistor-capacitor circuit, which can be directly transmitted on a twisted pair and is not easily affected by various interference signals.

[0061] Furthermore, the interface module 40 is electrically connected to the power control module 20 and the signal transmission module 30 respectively, and receives the DC carrier signal and the balanced video signal transmitted by the power control module 20 and the signal transmission module 30 correspondingly.

[0062] The interface module 40 includes a differential video signal interface (VEDIO_P / VEDIO_N), a power and control signal interface (PWR_TRX_P / PWR_TRX_N), an audio signal ground interface (GND), and three analog audio signal interfaces (TALK_IN / SPK_OUT / BC_OUT). The differential video signal interface is used to receive a balanced video signal, and the power and control signal input interface is used to receive a DC carrier signal and a power signal, respectively.

[0063] It should also be noted that the inductance range of the first working mode inductor and the second working mode inductor is 15mH to 78mH, the inductance range of the third working mode inductor, the fourth working mode inductor and the fifth working mode inductor is 230mH to 350mH, and the capacitance range of the first electrolytic capacitor and the second electrolytic capacitor is 1800mF to 420mF.

[0064] It can be understood that the control signal of the main controller of this embodiment interacts through TXD and RXD of U7, is converted through U6, and then coupled with the power supply 24V through L4 and L2 to output to the interface module (corresponding to PWR_TRX_P / PWR_TRX_N). The video input of the main controller is transmitted by VEDIO_TOCPU, converted by L24, L25, L26, E22, and E23 to a balanced signal connected to the interface module (corresponding to VEDIO_P / VEDIO_N). The uplink analog audio (TALK_IN), downlink analog audio (SPK_OUT), broadcast audio (BC_OUT), and loop ground signal (GND) are also transmitted and connected through the interface module.

[0065] A split IP intercom device proposed in the present invention includes a main controller for controlling the transmission of signals on the split IP intercom device; wherein the main controller includes a serial port interface, a power interface and a video signal interface; a power control module, electrically connected to the serial port interface and the power interface of the main controller, the power control module is used to receive the control signal sent by the main controller, and convert the control signal into a DC carrier signal; a signal transmission module, electrically connected to the video signal interface of the main controller, the signal transmission module is used to receive the unbalanced video baseband signal sent by the main controller, and convert the unbalanced video baseband signal into a balanced video signal; an interface module, electrically connected to the power control module and the signal transmission module, respectively, and correspondingly receives the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module. The present invention can simultaneously transmit and control digital and analog signals such as power supply, control signaling, two-way audio, broadcast audio, video signals, etc. through a universal shielded network cable, thereby simplifying engineering costs and construction difficulties; it enables an intercom host to connect multiple intercom panels in parallel or serial mode (a hand-in-hand mode can actually have up to 8 intercom panels); at the same time, it has long-distance transmission capability (up to 100 meters without interference) and does not have mutual interference problems, thus meeting practical application needs.

[0066] The present invention also provides a split IP intercom system, which includes a host end and an intercom panel end, and the host end and the intercom panel end are connected through the split IP intercom device; wherein the host end can be connected to multiple intercom panel ends in parallel or serially with the split IP intercom device.

[0067] It is understandable that the power control signal group and the differential video signal group are designed on the two twisted pairs of the interface module to enhance the anti-interference ability during signal transmission. At the same time, the analog audio signal uses a separate loop signal design to avoid interference from the transmission signal. The existing split IP intercom has high construction costs and is difficult to construct; when the intercom host is connected to the intercom panel in hand-in-hand series or parallel mode, it cannot truly realize the ability of one intercom host to connect multiple panels in hand-in-hand mode (the video interfaces need to be independently connected to the intercom host); the number of visual intercom panels is limited (the number of intercom panels is limited by the input interface of the intercom host video conversion chip); and there is a problem of mutual interference between analog signals and digital signals in long-distance transmission.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0069] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A split IP intercom device, characterized in that: include: A main controller, used to control the transmission of signals on the split IP intercom device; wherein the main controller includes a serial port interface, a power supply interface and a video signal interface; A power control module, electrically connected to the serial port interface and the power interface of the main controller, the power control module is used to receive the control signal sent by the main controller and convert the control signal into a DC carrier signal; A signal transmission module, electrically connected to the video signal interface of the main controller, the signal transmission module is used to receive the unbalanced video baseband signal sent by the main controller, and convert the unbalanced video baseband signal into a balanced video signal; An interface module, electrically connected to the power control module and the signal transmission module respectively, and correspondingly receiving the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module; The power control module includes a signal conversion circuit, a differential circuit and a coupling circuit; The signal conversion circuit is electrically connected to the differential circuit and the serial port interface of the main controller, and is used to convert the main control signal sent by the main controller into a carrier signal and send it to the differential circuit; The differential circuit is used to convert the carrier signal into a differential signal and send it to the coupling circuit; The coupling circuit is electrically connected to the differential circuit and the power interface of the main controller, and is used to couple the differential signal and the power signal into a DC carrier signal; wherein the coupling circuit includes a first common mode inductor and a second common mode inductor; the differential signal passes through the first common mode inductor and is coupled with the power signal passing through the second common mode inductor to form a DC carrier signal; The signal transmission module comprises: a first balancing circuit, electrically connected to the video signal interface of the main controller, the first balancing circuit being used for performing a first balancing process on the unbalanced video baseband signal to obtain a balanced video baseband signal, and sending the balanced video baseband signal to a second balancing circuit; a second balancing circuit, electrically connected to the first balancing circuit, and configured to perform a second balancing process on the balanced video baseband signal to obtain a balanced video signal; The first balancing circuit includes a first electrolytic capacitor, a third common-mode inductor and a fourth common-mode inductor; the second end of the first electrolytic capacitor is electrically connected to the third end of the third common-mode inductor, and the fourth end and the fifth end of the third common-mode inductor are electrically connected to the fourth end and the third end of the fourth common-mode inductor respectively; wherein the first end of the third common-mode inductor is grounded; The second balancing circuit includes a second electrolytic capacitor and a fifth common-mode inductor; the first end of the second electrolytic capacitor is electrically connected to the fifth end of the fourth common-mode inductor, and the second end of the second electrolytic capacitor is electrically connected to the fifth end of the fifth common-mode inductor; the fourth end of the fifth common-mode inductor is electrically connected to the first end of the fourth common-mode inductor through a resistor, and the first end and the third end of the fifth common-mode inductor are electrically connected to the interface module; The control chip of the main controller adopts the control chip of the ARM series.

2. The split IP intercom device according to claim 1 is characterized in that: The first end and the fourth end of the first common-mode inductor are electrically connected to the differential circuit respectively, and the second end and the third end of the first common-mode inductor are electrically connected to the interface module through resistors respectively; the first end and the second end of the second common-mode inductor are electrically connected to the power interface of the main controller respectively, and the third end and the fourth end of the second common-mode inductor are electrically connected to the interface module through the second end and the third end of the first common-mode inductor respectively.

3. The split IP intercom device according to claim 1 is characterized in that: The split-type IP intercom device also includes a filter circuit arranged between the differential circuit and the coupling circuit; wherein the filter circuit is an RC filter circuit.

4. The split IP intercom device according to claim 1, characterized in that: The interface module includes a differential video signal interface, a power and control signal interface, an audio signal ground interface and a three-way analog audio signal interface; wherein the differential video signal interface is used to receive a balanced video signal, and the power and control signal interface is used to receive a DC carrier signal and a power signal respectively.

5. The split IP intercom device according to claim 1 is characterized in that: The inductance range of the first common mode inductor and the second common mode inductor is 15mH to 78mH, the inductance range of the third common mode inductor, the fourth common mode inductor and the fifth common mode inductor is 230mH to 350mH, and the capacitance range of the first electrolytic capacitor and the second electrolytic capacitor is 1800mF to 420mF.

6. A split IP intercom system, characterized in that: The invention comprises a host end and an intercom panel end, wherein the host end and the intercom panel end are connected through a split IP intercom device; wherein the host end can be connected to multiple intercom panel ends in parallel or serially with the split IP intercom device, and the split IP intercom device comprises: A main controller, used to control the transmission of signals on the split IP intercom device; wherein the main controller includes a serial port interface, a power supply interface and a video signal interface; A power control module, electrically connected to the serial port interface and the power interface of the main controller, the power control module is used to receive the control signal sent by the main controller and convert the control signal into a DC carrier signal; A signal transmission module, electrically connected to the video signal interface of the main controller, the signal transmission module is used to receive the unbalanced video baseband signal sent by the main controller, and convert the unbalanced video baseband signal into a balanced video signal; An interface module, electrically connected to the power control module and the signal transmission module respectively, and correspondingly receiving the DC carrier signal and the balanced video signal transmitted by the power control module and the signal transmission module; The power control module includes a signal conversion circuit, a differential circuit and a coupling circuit; The signal conversion circuit is electrically connected to the differential circuit and the serial port interface of the main controller, and is used to convert the main control signal sent by the main controller into a carrier signal and send it to the differential circuit; The differential circuit is used to convert the carrier signal into a differential signal and send it to the coupling circuit; The coupling circuit is electrically connected to the differential circuit and the power interface of the main controller, and is used to couple the differential signal and the power signal into a DC carrier signal; wherein the coupling circuit includes a first common mode inductor and a second common mode inductor; the differential signal passes through the first common mode inductor and is coupled with the power signal passing through the second common mode inductor to form a DC carrier signal; The signal transmission module comprises: a first balancing circuit, electrically connected to the video signal interface of the main controller, the first balancing circuit being used for performing a first balancing process on the unbalanced video baseband signal to obtain a balanced video baseband signal, and sending the balanced video baseband signal to a second balancing circuit; a second balancing circuit, electrically connected to the first balancing circuit, and configured to perform a second balancing process on the balanced video baseband signal to obtain a balanced video signal; The first balancing circuit includes a first electrolytic capacitor, a third common-mode inductor and a fourth common-mode inductor; the second end of the first electrolytic capacitor is electrically connected to the third end of the third common-mode inductor, and the fourth end and the fifth end of the third common-mode inductor are electrically connected to the fourth end and the third end of the fourth common-mode inductor respectively; wherein the first end of the third common-mode inductor is grounded; The second balancing circuit includes a second electrolytic capacitor and a fifth common-mode inductor; the first end of the second electrolytic capacitor is electrically connected to the fifth end of the fourth common-mode inductor, and the second end of the second electrolytic capacitor is electrically connected to the fifth end of the fifth common-mode inductor; the fourth end of the fifth common-mode inductor is electrically connected to the first end of the fourth common-mode inductor through a resistor, and the first end and the third end of the fifth common-mode inductor are electrically connected to the interface module.

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