Ethernet power supply and power saving control method thereof

Abstract

An Ethernet power supply and its power-saving control method are disclosed. The Ethernet power supply receives a DC voltage via a positive bus and a negative bus, and is coupled to a load device. The Ethernet power supply includes a first control module and a second control module. The first control module provides a first control signal via the negative bus to confirm whether the load device is a valid load, and the second control module switches the electrical coupling between the positive bus and the first control module on or off based on whether the load device is connected.

Description

Technical Field

[0001] The present invention relates to an Ethernet power supply and a control method thereof, and more particularly to an Ethernet power supply with a power saving function and a power saving control method thereof. Background Art

[0002] Most products currently on the market use a full-time first control signal communication between the power source equipment (PSE) and the load power device (PD) to determine whether the PSE should power the correct load PD. Therefore, even if the load PD is not connected, the PSE will continue to send the first control signal for detection, resulting in power loss. This makes the current Ethernet power supply unable to meet the requirements of current efficiency and energy regulations (Ex: DoE, EC CoC, etc.). The circuit structure diagram is shown below. Figure 1 shown.

[0003] When this circuit design implements full-time first control signal communication, the power supply controller (PSE) will continue to send the first control signal to consume power even when the load (PD) system is disconnected. Therefore, it cannot meet the no-load power consumption (NoLoad Power) requirements of current energy efficiency regulations (Ex: DoE, EC CoC, etc.).

[0004] Therefore, the authors of this invention have been interested in designing an Ethernet power supply and a power-saving control method thereof so that the PSE controller inside the power supply is powered off and stopped when the load device is not connected to the Ethernet power supply. Summary of the Invention

[0005] To address the aforementioned issues, the present invention provides a Power over Ethernet (PoE) power supply that overcomes the drawbacks of the prior art. The PoE power supply of the present invention couples the positive and negative terminals of a load device via a positive bus and a negative bus, and receives a DC voltage. The PoE power supply includes a first control module and a second control module, wherein the second control module includes a path control circuit, a first control loop, and a second control loop. The first control module includes a power supply terminal, with another terminal coupled to the negative bus terminal and used to control the power supplied by the PoE power supply to the load device. The second control module is coupled to the first control module, the positive bus terminal, and the negative bus terminal. The path control circuit is used to connect or disconnect the power supply terminal from the positive bus terminal. The first control loop couples the negative bus terminal to the path control circuit and provides a first control signal to connect the path control circuit during a transient phase when the negative terminal is connected to the negative bus terminal. The second control loop couples the first control module to the path control circuit and provides a second control signal to connect the path control circuit to the first control module. The negative pole of the bus provides a first control signal according to whether the negative pole is connected to or removed from the negative pole of the bus; the first control module provides a second control signal; the second control module is used to shut down the path control circuit according to whether the negative pole is removed from the negative pole of the bus; and the first control module is used to be in a powered-on working state according to whether the path control circuit is turned on, and to be in a powered-off and stopped working state according to whether the path control circuit is turned off.

[0006] To address the aforementioned issues, the present invention provides an Ethernet power supply that overcomes the drawbacks of the prior art. The Ethernet power supply of the present invention couples the positive and negative terminals of a load device via a positive bus and a negative bus, and receives a DC voltage. The Ethernet power supply includes a first control module and a second control module, wherein the second control module includes a path control circuit, a first control loop, and a second control loop. The first control module includes a power supply terminal, and its other terminal is coupled to the negative bus terminal and is used to control the power supplied by the Ethernet power supply to the load device. The second control module is coupled to the first control module, the positive bus terminal, and the negative bus terminal, and the path control circuit is used to connect or disconnect the power supply terminal from the positive bus terminal. The first control loop couples the negative bus terminal to the path control circuit and, upon connection of the negative bus terminal to the negative bus terminal, provides a first control loop valid signal, triggering the path control circuit from an off state to an on state, and the first control module is accordingly powered on. The second control loop is coupled to the first control module and the path control circuit and is configured to provide a second control loop disable signal in response to the negative terminal being removed from the negative pole of the bus, triggering the path control circuit to switch from an on state to an off state, and correspondingly placing the first control module in a powered-off state. When the first control module is in a powered-on state, the first control module causes the second control loop to provide the second control loop disable signal in response to the negative terminal being removed from the negative pole of the bus.

[0007] To address the aforementioned issues, the present invention provides a power-saving control method for an Ethernet power supply, overcoming the problems of the prior art. The Ethernet power supply of the present invention receives a DC voltage and couples the positive and negative terminals of a load device. The Ethernet power supply includes a first control module, which receives the DC voltage via the positive and negative terminals of a bus and couples the negative terminal via the negative terminal of the bus to provide a first control signal via the negative terminal of the bus to confirm whether the load device is a valid load. The power-saving control method includes the following steps: (a) detecting whether the load device is connected and turning on or off a path control circuit between the power terminal of the first control module and the positive terminal of the bus. (b) turning on the path control circuit via a first control loop when the negative terminal is connected to the negative terminal of the bus. (c) turning on the path control circuit via a second control loop when the negative terminal of the bus is grounded. (d) turning off the path control circuit when the negative terminal is disconnected from the negative terminal of the bus.

[0008] The primary purpose and purpose of the present invention is to enable a Power over Ethernet (PoE) power supply to detect whether a load device is connected to determine whether to activate the first control module. When the load device is not connected to the PoE power supply, the second control module powers down the first control module, causing it to cease operation. This reduces PoE power consumption and complies with energy efficiency regulations.

[0009] In order to further understand the techniques, means and effects adopted by the present invention to achieve the intended objectives, please refer to the following detailed description of the present invention and the accompanying drawings. It is believed that the objectives, features and characteristics of the present invention can be further understood in detail. However, the accompanying drawings are provided for reference and illustration only and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A circuit block diagram of an Ethernet power supply with a power saving function according to the present invention;

[0011] Figure 2 is a detailed block diagram of the Ethernet power supply with power saving function of the present invention;

[0012] Figure 3A is a circuit block diagram of a first embodiment of the second control module of the present invention;

[0013] Figure 3B is a circuit block diagram of a second embodiment of the second control module of the present invention;

[0014] Figure 4 is a circuit block diagram of a third embodiment of the second control module of the present invention; and

[0015] Figure 5This is a flow chart of the power saving control method of the Ethernet power supply of the present invention.

[0016]

Explanation of symbols

[0017] L…Power cord

[0018] 100…Ethernet Power Supply

[0019] 100-1…first end

[0020] 100-2…Second end

[0021] 100-3…the third end

[0022] Bp…bus positive

[0023] Bn…bus negative

[0024] 1…First control module

[0025] 1-1…Power supply terminal

[0026] 12…voltage stabilizing energy storage module

[0027] 14…Power supply controller

[0028] VDD...power supply pin

[0029] Ec…communication terminal

[0030] Ec1…pin 1

[0031] Ec2…pin 2

[0032] 16…Communication module

[0033] SWc…switch

[0034] 2…Second control module

[0035] 22…Path control circuit

[0036] 222…Path switch

[0037] 224…Drive switch

[0038] 24…First control loop

[0039] SW1…first switch element

[0040] 26…Second control loop

[0041] SW2…Second switch element

[0042] 3…Data conversion module

[0043] 200…Load equipment

[0044] 200-1…Device interface

[0045] Ep…positive extreme

[0046] En…Negative terminal

[0047] 300…External device

[0048] Po…output power

[0049] Vdc…DC voltage

[0050] Vcc…power supply voltage

[0051] Vc…Terminal voltage

[0052] Vref1…first reference voltage

[0053] Vref2…second reference voltage

[0054] Sc1…first control signal

[0055] Sc2…Second control signal

[0056] Sc3…the third control signal

[0057] Sc4…the fourth control signal

[0058] So…external signal

[0059] Se1…The first control loop effective signal

[0060] Sn1…Invalid signal of the first control loop

[0061] Se2…Second control loop valid signal

[0062] Sn2…Second control loop invalid signal DETAILED DESCRIPTION

[0063] The technical content and detailed description of the present invention are described as follows with reference to the accompanying drawings:

[0064] See also Figure 1This is a circuit block diagram of a Power over Ethernet (PoE) power supply with a power-saving function according to the present invention. The PoE power supply 100 is configured to provide a DC voltage Vdc to a load device 200 to power the load device 200. The PoE power supply 100 includes a first control module 1, a second control module 2, and a data conversion module 3. The first control module 1 is coupled to the second control module 2 and the data conversion module 3. The first control module 1 is coupled to a power line L (the DC voltage Vdc may be, for example, but not limited to, 20V to 55V, depending on the specifications of the PoE power supply 100) via a first terminal 100-1. The first control module 1 operates by receiving the DC voltage Vdc provided by the power line L via a positive bus terminal Bp and a negative bus terminal Bn. The data conversion module 3 is coupled to an external device 300 (for example, but not limited to, a network camera or a central server) via a second terminal 100-2 to receive an external signal So provided by the external device 300.

[0065] Specifically, the primary purpose and function of the present invention is that the Power over Ethernet (PoE) supply 100 detects whether a load device 200 is connected to determine whether to supply power to the first control module 1 and activate it. When the load device 200 is not connected to the PoE supply 100, the second control module 2 controls the first control module 1 to power down and enter a non-operating state, thereby conserving power consumption within the PoE supply 100 and complying with energy efficiency regulations (such as, but not limited to, Department of Energy (DoE), EC CoC, MEPS, Tier 1, etc.). When the load device 200 is connected to the PoE supply 100, the second control module 2 controls the first control module 1 to power up and enter an operating state, thereby controlling the PoE supply 100 to supply power to the load device.

[0066] See also Figure 2 This is a detailed block diagram of the Ethernet power supply with power saving function of the present invention, and is also referred to in conjunction with Figure 1The first control module 1 includes a power supply terminal 1-1, and the other end is coupled to the bus cathode Bn and is used to control the Ethernet network power supply 100 to supply power to the load device 200. The second control module 2 includes a path control circuit 22, a first control loop 24, and a second control loop 26. The bus cathode Bn outputs a first control signal Sc1 according to whether the negative terminal En of the load device 200 is connected to or removed from the bus cathode Bn. The first control signal Sc1 can be, but is not limited to, a DC voltage Vdc of the bus cathode Bn. The path control circuit 22 couples the power supply terminal 1-1 of the first control module 1 and the bus positive terminal Bp to turn on or off the coupling relationship between the power supply terminal 1-1 and the bus positive terminal Bp. The first control loop 24 couples the bus cathode Bn and the path control circuit 22 and is used to turn on the path control circuit 22 according to the first control signal Sc1 provided by the bus cathode Bn. The second control loop 26 is coupled to the first control module 1 and the path control circuit 22 , and is configured to turn on the path control circuit 22 according to a second control signal Sc2 provided by the first control module 1 .

[0067] Specifically, when the load device 200 is not yet connected to the Power over Ethernet (PoE) supply 100 and the negative terminal En is not connected to the bus negative terminal Bn, the DC voltage Vdc corresponding to the first control signal Sc1 provided by the bus negative terminal Bn is the same as the negative terminal En not connected to the bus negative terminal Bn and not grounded. Furthermore, the first control module 1 is powered off and stopped operating, and does not provide the second control signal Sc2. Therefore, the first control loop 24 and the second control loop 26 cause the path control circuit 22 to disconnect the power terminal 1-1 from the bus positive terminal Bp based on the states of the first control signal Sc1 and the second control signal Sc2, respectively.

[0068] Furthermore, when the load device 200 is connected to the Power over Ethernet (PoE) supply 100 and the negative terminal En is connected to the negative bus terminal Bn, a transient connection phase occurs in the PoE supply 100 and the load device 200, generating a loop from the first terminal 100-1, the positive bus terminal Bp, and the load device 200 to the negative bus terminal Bn. This increases the voltage Vc at the negative bus terminal Bn and provides it as a first control signal Sc1 to the first control loop 24. Based on the first control signal Sc1 during the transient connection phase, the first control loop 24 provides a first control loop valid signal Se1 to the path control circuit 22. Furthermore, during the transient connection phase, the second control loop 26 provides a second control loop invalid signal Sn2 to the path control circuit 22, based on the fact that the first control module 1 is still powered off and inoperative. Therefore, the path control circuit 22 is turned on according to the first control loop valid signal Se1 to electrically couple the power terminal 1-1 with the bus positive electrode Bp, and the first control module 1 receives the power supply voltage Vcc (or DC voltage Vdc) through the path control circuit 22 and is in a powered-on working state.

[0069] Based on the aforementioned embodiment, during the connection transient phase and with the first control module 1 in the powered-on state, the first control module 1 begins providing the third control signal Sc3 via the bus negative terminal Bn and the negative terminal En to perform handshaking communication with the load device 200. Based on the handshaking communication results, the first control module 1 controls the state of the Power over Ethernet (PoE) supplying power to the load device 200 by the PoE 100. The handshaking communication between the first control module 1 and the load device 200 includes determining whether the load device 200 is a valid load or an inactive load. If the first control module 1 determines that the load device 200 is a valid load, the PoE 100 is controlled to supply power to the load device 200, exiting the connection transient phase and entering the power supply phase. If the first control module 1 determines that the load device 200 is an inactive load, the PoE 100 is controlled to stop supplying power to the load device 200, exiting the power supply phase and entering the no-power phase.

[0070] See also Figure 1 and Figure 2 Based on the above embodiment, another specific embodiment is that the first control module 1 includes a voltage-stabilizing energy storage module 12, a power supply controller 14, and a communication module 16, and the voltage-stabilizing energy storage module 12 is coupled to the second control module 2 via the power supply terminal 1-1. The voltage-stabilizing energy storage module 12 can be, for example but not limited to, a voltage-stabilizing circuit, an energy storage element, a converter, or other element or circuit with voltage stabilization, energy storage, or power conversion functions. The power supply controller 14 has a power pin VDD and a communication terminal Ec. The power pin VDD is coupled to the power supply terminal 1-1 via the voltage-stabilizing energy storage module 12, and the communication terminal Ec is coupled to the second control module 2 and the communication module 16. The communication terminal Ec can include a first pin Ec1 and a second pin Ec2. The first pin Ec1 is coupled to the second control loop 26, and the second pin Ec2 is coupled to the negative pole of the bus Bn via the communication module 16. Furthermore, the power supply controller 14 is used to provide a second control signal Sc2 and a third control signal Sc3 via the first pin Ec1 and the second pin Ec2 respectively when in the working state, so as to perform corresponding control.

[0071] Furthermore, the aforementioned voltage-stabilizing energy storage module 12 is used to store the DC voltage Vdc as the supply voltage Vcc and stabilize the voltage value of the supply voltage Vcc to provide power to the power controller 14 to power on and maintain operation. It is worth noting that if the power controller 14 can directly utilize the DC voltage Vdc for operation, the voltage-stabilizing energy storage module 12 can be omitted.

[0072] In the aforementioned second control module 2, the first control loop 24 couples the bus cathode Bn and the control terminal of the path control circuit 22, and the second control loop 26 couples the first pin Ec2 of the power controller 14 and the control terminal of the path control circuit 22. In response to the first control signal Sc1 during the transient phase when the cathode terminal En is connected to the bus cathode Bn, the first control loop 24 provides a first control loop active signal Se1 to the path control circuit 22, causing the path control circuit 22 to electrically couple the power terminal 1-1 to the bus cathode Bp, and further placing the power controller 14 in a powered-on state. In the powered-on state, the power controller 14 provides a third control signal Sc3 via the second pin Ec2, coupled to the bus cathode Bn via the communication module 16, to perform handshaking communication with the load device 200. Based on the handshaking communication result, the power controller 14 outputs a second control signal Sc2 from the first pin Ec1. The second control loop 26 provides a second control loop valid signal Se2 to the path control circuit 22 based on the second control signal Sc2 output from the first pin Ec1. Based on the second control loop valid signal Se2, the path control circuit 22 electrically couples the power terminal 1-1 to the positive bus terminal Bp, allowing the power controller 14 to remain in the powered-on state. The power controller 14 controls the Power over Ethernet (PoE) 100 to provide the DC voltage Vdc to the load device 200, thereby entering the power supply phase. Furthermore, based on the first pin Ec1 not outputting the second control signal Sc2, the second control loop 26 provides a second control loop invalid signal Sn2 to the path control circuit 22. Based on the second control loop invalid signal Sn2, the path control circuit 22 electrically disconnects the power terminal 1-1 from the positive bus terminal Bp, causing the power controller 14 to enter a power-off, inactive state. The power controller 14 controls the Power over Ethernet (PoE) 100 to stop providing the DC voltage Vdc to the load device 200, thereby entering the no-power phase.

[0073] The power controller 14 provides a third control signal Sc3 at the second pin Ec2, coupled to the negative bus terminal Bn via the communication module 16, to perform handshake communication with the load device 200 to determine whether the load device 200 is a valid load or an inactive load. The power controller 14 outputs a second control signal Sc2 via the first pin Ec1 if the load device 200 is a valid load, and outputs a fourth control signal Sc4 via the first pin Ec1 if the load device 200 is an inactive load. The second control loop 26 provides a second control loop valid signal Se2 to the path control circuit 22 based on the second control loop valid signal Se2 output from the first pin Ec1. The path control circuit 22 electrically couples the power terminal 1-1 to the positive bus terminal Bp based on the second control loop valid signal Se2, maintaining the power controller 14 in a powered-on state. The power controller 14 then controls the Power over Ethernet (PoE) supply 100 to provide a DC voltage Vdc to the load device 200, thereby entering the power supply phase. Furthermore, the second control loop 26 provides a second control loop invalidation signal Sn2 to the path control circuit 22 in response to the fourth control signal Sc4 outputted from the first pin Ec1. The path control circuit 22 disconnects the power terminal 1-1 from the positive bus terminal Bp in response to the second control loop invalidation signal Sn2, causing the power controller 14 to enter a power-off and shutdown state. Furthermore, the power controller 14 controls the Power over Ethernet (PoE) supply 100 to stop providing the DC voltage Vdc to the load device 200, thereby entering a no-power supply state.

[0074] Furthermore, the power supply controller 14 couples the bus cathode Bn to the ground when the load device 200 is a valid load, and the power supply controller 14 disconnects the bus cathode Bn and grounds when the load device 200 is a reactive load.

[0075] In the aforementioned embodiment, the communication module 16 may further include a switch SWc, with the first pin Ec1 coupled to the control terminal of the switch SWc. One terminal of the switch SWc is grounded, and the other terminal is coupled to the negative terminal of the bus Bn. Furthermore, the second pin Ec2 is coupled to the negative terminal of the bus Bn through the communication module 16. Therefore, the power controller 14 provides a second control signal Sc2 to turn on the switch SWc and connect the negative terminal of the bus Bn to ground when the load device 200 is an active load. Furthermore, the power controller 14 provides a fourth control signal Sc4 to turn off the switch SWc and connect the negative terminal of the bus Bn to ground when the load device 200 is an inactive load.

[0076] The power controller 14 determines whether the load device 200 is an active load or an inactive load according to the Power over Ethernet (PoE) specification (such as, but not limited to, the IEEE 802.3 PoE specification). The power controller 14 begins providing a third control signal Sc3 via the bus negative terminal Bn and the negative terminal En to perform handshaking communication with the load device 200. Based on the handshaking communication results, the power controller 14 controls the power supplied to the load device 200 by the PoE power supply 100. Therefore, when the power controller 14 determines that the load device 200 is an active load and is in the power supply phase, the power supplied to the load device 200 by the power controller 14 is controlled in accordance with the PoE specification.

[0077] In addition, the aforementioned Power over Ethernet specification can also be defined by users to define effective loads and ineffective loads, and can also be defined by users to define the power range to be supplied when the effective load is defined.

[0078] The first control loop 24 provides a first control loop valid signal Se1 or a first control loop invalid signal Sn1 based on the voltage Vc at the bus cathode Bn corresponding to the first control signal Sc1. When the first control signal Sc1 corresponds to a transient connection phase (when the bus cathode En is connected to the bus cathode Bn and the bus cathode Bn is not yet grounded), the first control loop 24 provides the first control loop valid signal Se1 to the path control circuit 22 based on the first control signal Sc1. The path control circuit 22 is turned on based on the first control loop valid signal Se1, putting the power supply controller 14 into a powered-on state. When the first control signal Sc1 corresponds to a state where the bus cathode En is connected to the bus cathode Bn and the bus cathode Bn is grounded, thus exiting the transient connection phase, the first control loop 24 provides the first control loop invalid signal Sn1 to the path control circuit 22 based on the first control signal Sc1. Furthermore, when the first control signal Sc1 corresponds to a state where the bus cathode En is disconnected from the bus cathode Bn, the first control loop 24 provides the first control loop invalid signal Sn1 to the path control circuit 22 based on the first control signal Sc1. Therefore, when the first control loop 24 provides the first control loop valid signal Se1 and the second control loop 26 provides the second control loop invalid signal Sn2, the path control circuit 22 electrically couples the power supply terminal 1-1 to the bus positive electrode Bp, and the power supply controller 14 enters the powered-on state, but remains in the power-off phase. When the first control loop 24 provides the first control loop invalid signal Sn1 and the second control loop 26 provides the second control loop valid signal Se2, the path control circuit 22 electrically couples the power supply terminal 1-1 to the bus positive electrode Bp, and the power supply controller 14 enters the powered-on state, while also entering the power supply phase. Furthermore, when the first control loop 24 provides the first control loop invalid signal Sn1 and the second control loop 26 provides the second control loop invalid signal Sn2, the path control circuit 26 disconnects the power supply terminal 1-1 from the bus positive electrode Bp, and the power supply controller 14 enters the powered-off state.

[0079] Specifically, when the load device 200 is connected to the negative bus terminal Bn of the Power over Ethernet (PoE) supply 100, a transient connection phase occurs between the first terminal 100-1, the positive bus terminal Bp, and the load device 200 and the negative bus terminal Bn. This causes the voltage Vc at the negative bus terminal Bn to increase. Therefore, the first control loop 24 provides a first control loop valid signal Se1 to the path control circuit 22 in response to the increase in the voltage Vc at the negative bus terminal Bn during the transient connection phase of the load device 200. Simultaneously, because the power supply controller 14 is currently powered off and inoperative, the second control loop 26 provides a second control loop invalid signal Sn2 to the path control circuit 22. Subsequently, the path control circuit 22 is turned on in response to the first control loop valid signal Se1, electrically coupling the power terminal 1-1 to the positive bus terminal Bp. At the same time, the power controller 14 receives the power voltage Vcc (or DC voltage Vdc) through the path control circuit 22 and is in a powered-on state, and the second pin Ec2 of the power controller 14 starts to provide a third control signal Sc3 to attempt to communicate with the load device 200 to determine whether the load device 200 is a valid load or an invalid load.

[0080] When the power supply controller 14 communicates with the load device 200 via the third control signal Sc3 and determines that the load device 200 is a valid load, the power supply controller 14 provides a second control signal Sc2 (for example, but not limited to, a high-voltage signal) to the communication module 16 to control the communication module 16 to ground the bus negative electrode Bn, thereby entering the power supply phase. During the power supply phase, the power supply controller 14 also provides the second control signal Sc2 to the second control circuit 26. After the bus negative electrode Bn is grounded, the DC voltage Vdc is provided to the load device 200 via the bus positive electrode Bp and the bus negative electrode Bn, thereby supplying the power required by the load device 200. At this time, since the bus negative electrode Bn is grounded, the transient phase is exited and the power supply phase begins. Therefore, the first control circuit 24 provides the first control circuit invalidation signal Sn1 to the path control circuit 22 in accordance with the power supply phase. The second control loop 26 provides a second control loop valid signal Se2 to the path control circuit 22 according to the second control signal Sc2 provided by the second pin Ec2, so that the path control circuit 22 is continuously turned on according to the second control loop valid signal Se2.

[0081] Furthermore, the aforementioned communication module 16 can be implemented, for example but not limited to, using a switch SWc. When the second pin Ec2 of the communication terminal Ec provides the third control signal Sc3, the power controller 14 transmits the third control signal Sc3 to the negative bus terminal Bn. After communication is complete, the first pin Ec1 of the communication terminal Ec of the power controller 14 provides the second control signal Sc2 to turn on the switch SWc, grounding the negative bus terminal Bn through the switch SWc. In other words, the second control signal Sc2 can be a high-voltage signal, and this signal voltage is sufficient to turn on the switch SWc. Furthermore, when the load device 200 is disconnected from the Power over Ethernet (PoE) supply 100, the first pin Ec1 of the communication terminal Ec provides the fourth control signal Sc4 to turn off the switch SWc, returning the negative bus terminal Bn to a state where the load device 200 is not connected.

[0082] See also Figure 3A This is a circuit block diagram of the first embodiment of the second control module of the present invention, Figure 3B This is a circuit block diagram of the second embodiment of the second control module of the present invention, and is also referred to in conjunction with Figures 1-2 .exist Figure 3A In the embodiment, the first control loop 24 and the second control loop 26 can be circuits with potential comparison functions. Taking a comparator circuit as an example, the first control loop 24 can be coupled to a first reference voltage Vref1, and the second control loop 26 can be coupled to a second reference voltage Vref2. The first control loop 24 compares the signal provided by the negative terminal of the bus Bn with the first reference voltage Vref1 and, based on the comparison result, provides a first control loop enable signal Se1. The first control loop 24 provides the first control loop enable signal Se1 to turn on the path control circuit 22. Furthermore, the second control loop 26 compares the signal provided by the first pin Ec1 with the second reference voltage Vref2 and, based on the comparison result, provides the second control loop enable signal Se2. The second control loop 26 provides the second control loop enable signal Se2 to turn on the path control circuit 22. When the signal potential provided by the bus cathode Bn is higher than the first reference voltage Vref1, the first control loop 24 provides a first control loop valid signal Se1 to turn on the path control circuit 22, and when the signal potential provided by the first pin Ec1 is higher than the second reference voltage Vref2, the second control loop 26 provides a second control loop valid signal Se2 to turn on the path control circuit 22.

[0083] In addition, the first control loop 24 can further compare the first control signal Sc1 corresponding to the voltage Vc at the bus negative terminal Bn with the first reference voltage Vref1 to provide a first control loop valid signal Se1. Furthermore, the second control loop 26 can further compare the second control signal Sc2 provided by the first pin Ec1 with the second reference voltage Vref2 to provide a second control loop valid signal Se2.

[0084] Furthermore, the first control loop 24 can further compare the voltage Vc of the bus negative terminal Bn with the first control signal Sc1, corresponding to the voltage Vc, and provide a first control loop valid signal Se1 when the first control signal Sc1 is higher than the first reference voltage Vref1, and provide a first control loop invalid signal Sn1 when the first control signal Sc1 is lower than the first reference voltage Vref1. Furthermore, the second control loop 26 can further compare the second control signal Sc2 provided by the first pin Ec1 with the voltage Vc, corresponding to the voltage Vc, and provide a second control loop valid signal Se2 when the second control signal Sc2 is lower than the second reference voltage Vref2. Furthermore, the second control loop 26 can further compare the voltage Vc of the second control signal Sc2 provided by the first pin Ec1 with the voltage Vc, corresponding to the voltage Vc, and provide a second control loop invalid signal Sn2 when the second control signal Sc2 is lower than the second reference voltage Vref2.

[0085] In the first embodiment, when the voltage level of the first pin Ec1 providing the second control signal Sc2 or not providing the second control signal Sc2 is lower than the second reference voltage Vref2 , the second control loop provides the second control loop invalid signal Sn1 .

[0086] In the aforementioned first embodiment, when the voltage level of the third control signal Sc3 provided by the first pin Ec1 is lower than the second reference voltage Vref2 , the second control loop provides the second control loop invalid signal Sn1 .

[0087] In the first embodiment described above, the path control circuit 22 includes a path switch 222. The path switch 222 can be composed of, for example, but not limited to, components with switching functions such as MOSFET transistors and electronic components (such as resistors, capacitors, etc.). Taking a transistor as an example, one end of the path switch 222 is coupled to the positive electrode of the bus Bp, and the other end is coupled to the power supply terminal 1-1. The control end of the path switch 222 is coupled to the first control loop 24 and the second control loop 26 to control the path switch 222 to be turned on or off by the signals provided by the first control loop 24 and the second control loop 26. When one of the first control loop 24 and the second control loop 26 provides a valid signal, the path switch 222 is turned on, and when both the first control loop 24 and the second control loop 26 provide an invalid signal, the path switch 222 is turned off.

[0088] Figure 3BIn the embodiment, the first control loop 24 and the second control loop 26 can be switching circuits composed of, for example, but not limited to, switching elements such as MOSFET transistors and electronic components (e.g., resistors, capacitors, etc.). The first control loop 24 can be a switching circuit composed of a first switching element SW1, and the second control loop 26 can be a switching circuit composed of a second switching element SW2. The first switching element SW1 and the second switching element SW2 can be, for example, but not limited to, switching elements such as MOSFET transistors. When the first control loop 24 receives a first control signal Sc1 from the negative line Bn, the first switching element SW1 provides a first control loop enable signal Se1 to turn on the path control circuit 22, thereby establishing an electrical coupling relationship between the power supply terminal 1-1 and the positive bus terminal Bp. When the second control loop 26 receives a second control signal Sc2, the second switching element SW2 provides a second control loop enable signal Se2 to turn on the path control circuit 22, thereby establishing an electrical coupling relationship between the power supply terminal 1-1 and the positive bus terminal Bp.

[0089] In the aforementioned embodiment, in which the first switch element SW1 and the second switch element SW2 are implemented as transistors, the first switch element SW1 can be turned on or off by driving the control terminal of the first switch element SW1 according to the first control signal Sc1 corresponding to the corresponding terminal voltage Vc. The first control loop 24 provides a first control loop valid signal Se1 or a first control loop invalid signal Sn1 in response to the first switch element SW1 being turned on or off. Furthermore, the second switch element SW2 can be turned on or off by driving the control terminal of the second switch element SW2 according to the second control signal Sc2 provided by the first pin Ec1. The second control loop 26 provides a second control loop valid signal Se2 or a second control loop invalid signal Sn2 in response to the second switch element SW2 being turned on or off.

[0090] In addition, the control end of the second switch element SW2 can be further driven according to the second control signal Sc2 and the fourth control signal Sc4 provided by the first pin Ec1, and the second switch element SW2 can be turned on and off respectively. Therefore, the second control loop 26 provides the second control loop valid signal Se2 according to the second control signal Sc2, and the second control loop 26 provides the second control loop invalid signal Sn2 according to the fourth control signal Sc4.

[0091] In the aforementioned embodiment, when the first control loop 24 provides the first control loop valid signal Se1 or the second control loop 26 provides the second control loop valid signal Se2, the path switch 222 is turned on to establish an electrical coupling relationship between the power terminal 1-1 and the bus positive electrode Bp. When the first control loop 24 provides the first control loop invalid signal Sn1 and the second control loop 26 provides the second control loop invalid signal Sn2, the path switch 222 is turned off.

[0092] In the aforementioned embodiment, the first control loop 24 may be turned on according to the first control signal Sc1 corresponding to the increase in the voltage Vc at the negative terminal of the bus Bn.

[0093] It is worth noting that, in one embodiment of the present invention, the path control circuit 22 further includes a drive switch 224. One end of the drive switch 224 is coupled to the control end of the path switch 222, and the control end of the drive switch 224 is coupled to the first control loop 24 and the second control loop 26. The drive switch 224 is used to drive the path switch 222 on or off. Specifically, because the DC voltage Vdc received by the first terminal 100-1 can be a high voltage of 48V to 55V, the transistor of the path switch 222 must use a p-MOSFET to withstand the DC voltage Vdc to avoid insufficient transistor voltage resistance (using a qualified n-MOSFET would be too expensive). Therefore, the drive switch 224 is required to drive the path switch 222 so that the path switch 222 can smoothly conduct electricity between the first terminal 100-1 and the power supply terminal 1-1 of the voltage-stabilizing energy storage module 12. However, if the DC voltage Vdc is not high or a qualified n-MOSFET transistor is available, the drive switch 224 can be omitted. Furthermore, if the DC voltage Vdc is above a certain voltage (such as but not limited to 30V), it is better to use Figure 3B The two switches 222 and 224 are used as the switch unit 22 to better withstand the DC voltage Vdc. On the contrary, below a certain voltage, the Figure 3A A single switch 222 is used as the switch unit 22.

[0094] See also Figure 4 This is a circuit block diagram of the third embodiment of the second control module of the present invention, and is also referred to in conjunction with Figure 3BIn a third embodiment of the present invention, the path control circuit 22 further comprises a self-locking circuit. When the first control loop 24 provides the first control loop valid signal Se1, the path control circuit 22 establishes the electrical coupling between the power terminal 1-1 and the positive bus electrode Bp. While the path control circuit 22 remains in the conductive state, if the first control loop 24 stops providing the first control loop valid signal Se1, the path control circuit 22 remains in the conductive state. Furthermore, while the path control circuit 22 remains in the conductive state and the first control loop 24 stops providing the first control loop valid signal Se1, if the second control loop 26 provides the second control loop invalid signal Sn2, the path control circuit 22 disconnects the electrical coupling between the power terminal 1-1 and the positive bus electrode Bp.

[0095] To further illustrate, the first control loop 24 provides a first control loop valid signal Se1 to cause the trigger path control circuit 22 to switch from an off state to an on state. When the path control circuit 22 is in the on state, stopping or intermittently providing the first control loop valid signal Se1 by the first control loop 24 does not change the on state of the path control circuit 22. Furthermore, the second control loop 26 provides a second control loop invalid signal Sn2 to cause the trigger path control circuit 22 to switch from an on state to an off state.

[0096] In the path switch 222 and the driving switch 224 of the aforementioned path control circuit 22, the driving switch 224 may further have one end coupled to the control end of the path switch 222, and the control end of the driving switch 224 may be coupled to the first control loop 24, the second control loop 26, and the path switch 222, so that the first control loop 24 and the path switch 222 are used to drive the driving switch 224 to be turned on, and the second control loop 26 is used to drive the driving switch 224 to be turned off, and the driving switch 224 is further used to drive the path switch 222 to be turned on or off. Therefore, when the first control loop 24 provides the first control loop valid signal Se1 to drive the driving switch 224 to be turned on, the driving switch 224 is further used to drive the path switch 222 to be turned on, so that the path control circuit 22 is electrically coupled between the power supply terminal 1-1 and the bus positive electrode Bp. When the first control loop 24 stops providing the first control loop valid signal Se1 while the path control circuit 22 remains in the on state, the already turned-on path switch 222 is further used to drive the driving switch 224 to be turned on, so that the path switch 222 and the driving switch 224 continue to drive each other to be turned on, thereby locking the path control circuit 22 to remain in the on state, so that the path control circuit 22 also maintains the electrical coupling relationship between the power supply terminal 1-1 and the bus positive electrode Bp. Furthermore, when the path control circuit 22 remains in the on state and the first control loop 24 stops providing the first control loop valid signal Se1, when the second control loop 26 provides the second control loop invalid signal Sn2 to turn off the drive switch 224, the turned-off drive switch 224 further turns off the path control circuit 22, and finally causes the path control circuit 22 to cut off the electrical coupling relationship between the power terminal 1-1 and the bus positive electrode Bp.

[0097] See also Figure 5 This is a flow chart of the power saving control method of the Ethernet power supply of the present invention, and is also referred to in conjunction with Figures 1 to 4The power-saving control method of the present invention is mainly used to control the first control module 1 to be powered off and in a stopped state when the load device 200 is not connected to the Ethernet power supply 100, so as to save power consumption of the Ethernet power supply 100. Therefore, the power-saving control method includes detecting whether the load device is connected or not and turning on or off the path control circuit between the power end of the first control module and the positive pole of the bus (S100). The Ethernet power supply 100 detects whether the load device 200 is connected to determine whether to operate the first control module 1. When the load device 200 is not connected to the Ethernet power supply 100, the second control module 2 controls the first control module 1 to be powered off and in a stopped state, and when the load device 200 is connected to the Ethernet power supply 100, the second control module 2 controls the first control module 1 to be powered on and in an operating state. Then, according to whether the negative end is connected to the negative pole of the bus, the path control circuit is turned on through the first control loop (S200). In a preferred embodiment, the first control loop 24 provides a first control loop valid signal Se1 to the path control circuit 22 in response to an increase in the voltage Vc at the negative bus terminal Bn during a transient phase when the load device 200 is connected. The path control circuit 22 is turned on in response to the first control loop valid signal Se1, electrically coupling the power supply terminal 1-1 to the positive bus terminal Bp at the first end.

[0098] Then, in response to the bus negative pole being grounded, the path control circuit is switched on through the second control loop (S300). In a preferred embodiment, when the bus negative pole Bn is grounded and disconnected from the negative pole En and connected to the bus negative pole Bn in a transient phase, the DC voltage Vdc can be provided to the load device 200 via the bus positive pole Bp and the bus negative pole Bn to power the load device 200. At this time, since the bus negative pole Bn is grounded, the second control loop 26 provides a second control loop valid signal Se2 to the path control circuit 22 in response to the second control signal Sc2 provided by the first pin Ec1 of the communication terminal Ec. The path control circuit 22 remains on in response to the second control loop valid signal Se2. Finally, in response to the negative pole being disconnected from the bus negative pole, the path control circuit is turned off (S400). In a preferred embodiment, when the load device 200 is disconnected from the Ethernet power supply 100, the terminal voltage Vc of the bus negative pole Bn changes. The power controller 14 provides a fourth control signal Sc4 to the communication module 16 based on changes in the voltage Vc at the negative terminal of the bus Bn. The first control loop 24 provides a first control loop disable signal Sn1 to the path control circuit 22 based on changes in the voltage Vc at the negative terminal of the bus Bn. The second control loop 26 provides a second control loop disable signal Sn2 to the path control circuit 22 based on the fourth control signal Sc4. The path control circuit 22 shuts down based on the first control loop disable signal Sn1 and the second control loop disable signal Sn2.

[0099] It is worth mentioning that the above embodiments do not limit the specific circuit elements and their coupling relationships contained in each circuit. Any circuit, controller (with internal software control) and other implementation methods that can achieve the above functions should be included in the scope of this embodiment. In addition, in one embodiment of the present invention, the detailed process of the above steps can be referred to Figure 2 The content described will not be repeated here.

[0100] However, the above description is only a detailed description and drawings of the preferred specific embodiments of the present invention. The features of the present invention are not limited thereto and are not intended to limit the present invention. The full scope of the present invention shall be based on the appended claims. All embodiments that are consistent with the spirit of the claims of the present invention and similar variations thereof shall be included in the scope of the present invention. Any changes or modifications that can be easily conceived by a person familiar with the art within the field of the present invention shall be covered by the appended claims of this case.

Claims

1. An Ethernet power supply, characterized in that: The Ethernet power supply is coupled to a positive terminal and a negative terminal of a load device via a bus positive electrode and a bus negative electrode and receives a DC voltage. The Ethernet power supply includes: a first control module comprising a power supply terminal, the other terminal of which is coupled to the negative terminal of the bus and is used to control the Ethernet power supply to supply power to the load device; and a second control module coupled to the first control module, the positive pole of the bus, and the negative pole of the bus, and comprising: a path control circuit for switching on or off the coupling relationship between the power supply terminal and the positive electrode of the bus; a first control loop coupled to the bus cathode and the path control circuit, and configured to provide a first control signal to turn on the path control circuit according to a transient phase when the cathode terminal is connected to the bus cathode; and a second control loop coupled to the first control module and the path control circuit, and configured to conduct the path control circuit according to a second control signal provided by the first control module; The first control module further includes a voltage-stabilizing energy storage module, which is coupled to the second control module via the power supply terminal and stores the DC voltage as a supply voltage. The negative pole of the bus provides the first control signal according to whether the negative pole is connected to or removed from the negative pole of the bus; the first control module provides the second control signal; the second control module is used to shut down the path control circuit according to whether the negative pole is removed from the negative pole of the bus; and the first control module is used to be in a powered-on working state according to the conduction of the path control circuit, and is used to be in a powered-off and stopped working state according to the shutdown of the path control circuit.

2. The Ethernet power supply according to claim 1, wherein: The first control module is in a power-on working state and the negative electrode of the bus is grounded, and is out of a connection transient phase, so as to provide the DC voltage to the load device through the positive electrode of the bus and the negative electrode of the bus.

3. The Ethernet power supply according to claim 2, wherein: The first control module provides the second control signal and grounds the negative pole of the bus when confirming that the load device is a valid load, and disconnects and grounds the negative pole of the bus when confirming that the load device is an invalid load.

4. The Ethernet power supply according to claim 3, wherein: The first control signal is a voltage at a terminal of the negative electrode of the bus. The first control loop compares the first control signal with a first reference voltage and, based on the comparison result between the first control signal and the first reference voltage, turns on the path control circuit in response to the negative terminal being plugged into the negative electrode of the bus. The second control loop compares the second control signal with a second reference voltage and, based on the comparison result between the second control signal and the second reference voltage, turns on the path control circuit in response to the load device being in an effective load state.

5. The Ethernet power supply according to claim 4, wherein: The first control module provides a fourth control signal upon confirming that the load device is ineffectively loaded and disconnects the negative pole of the bus from grounding. The second control loop compares the fourth control signal with the second reference voltage. Furthermore, based on a comparison result between the first control signal and the first reference voltage indicating that the negative pole is disconnected from the negative pole of the bus and a comparison result between the fourth control signal and the second reference voltage indicating that the load device is ineffectively loaded, the second control module shuts down the path control circuit.

6. The Ethernet power supply according to claim 3, wherein: The second control loop compares the second control signal with a second reference voltage, and turns on the path control circuit according to a comparison result between the second control signal and the second reference voltage corresponding to the load device being in an effective load state.

7. The Ethernet power supply according to claim 6, wherein: The first control module provides a fourth control signal and connects the negative pole of the bus to ground when confirming that the load device is ineffective. The second control loop compares the fourth control signal with a second reference voltage, and the comparison result of the fourth control signal and the second reference voltage corresponds to the ineffective load state of the load device, thereby shutting down the path control circuit.

8. The Ethernet power supply according to claim 3, wherein: The first control loop is a switching circuit comprising a first switching element; the first control signal is a terminal voltage of the negative pole of the bus; the first switching element is turned on according to the first control signal during a transient phase of connection of the load device, and the second control module turns on the path control circuit according to the conduction of the first switching element.

9. The Ethernet power supply according to claim 3, wherein: The second control loop is a switch circuit composed of a second switch element. The second switch element is turned on upon receiving the second control signal, and the second control module turns on the path control circuit according to the turning on of the second switch element.

10. The Ethernet power supply according to claim 9, wherein: The first control module provides a fourth control signal upon confirming that the load device has an invalid load, and the first control module disconnects the negative pole of the bus from the ground; the second switch element is turned off upon receiving the fourth control signal; and the second control module turns off the path control circuit according to the first control signal corresponding to the negative pole being removed from the negative pole of the bus and the second switch element being turned off.

11. The Ethernet power supply according to claim 3, wherein: The first control module includes: a power supply controller coupled to the path control circuit and the second control module, and configured to receive the DC voltage according to the conduction of the path control circuit, so as to be in a power-on working state and provide the second control signal; and A communication module is coupled to the power supply controller and the negative pole of the bus, and transmits a third control signal to the negative pole of the bus to implement a handshake mechanism.

12. The Ethernet power supply according to claim 11, wherein: The power supply controller transmits the third control signal to the negative pole of the bus through the communication module to perform a handshake mechanism and provides the second control signal to control the communication module to ground the negative pole of the bus to confirm that it is the effective load, and provides the fourth control signal to confirm that the load device is in an invalid load state or the negative end is disconnected from the negative pole of the bus.

13. The Ethernet power supply according to claim 12, wherein: The first control signal is a terminal voltage of the negative electrode of the bus, and the path control circuit is turned on in response to the negative terminal being inserted into the negative electrode of the bus according to the first control signal; The first control loop is configured to respond to a transient connection phase in which the negative terminal is connected to the negative pole of the bus according to the first control signal, and the second control loop is configured to respond to a valid load state of the load device according to the second control signal, and the second control module turns on the path control circuit; and the first control loop is configured to respond to a disconnection transient phase or a state in which the negative terminal is disconnected from the negative pole of the bus according to the first control signal, and the second control loop is configured to respond to an invalid load state of the load device according to the fourth control signal, and the second control module turns off the path control circuit.

14. The Ethernet power supply according to claim 3, wherein: The path control circuit includes: a path switch, one end of which is coupled to the positive terminal of the bus and the other end of which is coupled to the power terminal; and a driving switch, one end of which is coupled to the path switch control end, and the driving switch control end is coupled to the first control loop and the second control loop; The first control loop and the second control loop are used to drive the path switch on or off, and the drive switch is used to drive the path switch on or off; the first control loop turns on the drive switch according to the first control signal corresponding to a transient phase in which the negative terminal is connected to the negative terminal of the bus, or the second control loop turns on the drive switch according to the second control signal, and the drive switch in the on state drives the path switch on and further connects the power terminal to the positive terminal of the bus; and the first control loop and the second control loop in the second control module are used to turn off the drive switch according to the withdrawal of the negative terminal from the negative terminal of the bus, and the drive switch in the off state drives the path switch off and further disconnects the power terminal from the positive terminal of the bus.

15. An Ethernet power supply, characterized in that: The Ethernet power supply is coupled to a positive terminal and a negative terminal of a load device via a bus positive electrode and a bus negative electrode and receives a DC voltage. The Ethernet power supply includes: a first control module comprising a power supply terminal, the other terminal of which is coupled to the negative terminal of the bus and is used to control the Ethernet power supply to supply power to the load device; and a second control module coupled to the first control module, the positive pole of the bus, and the negative pole of the bus, and comprising: a path control circuit for switching on or off the coupling relationship between the power supply terminal and the positive electrode of the bus; a first control loop coupled to the negative electrode of the bus and the path control circuit, and configured to provide a first control loop valid signal to trigger the path control circuit from an off state to an on state in response to the negative terminal of the first control loop being connected to the negative electrode of the bus, and the first control module to be in a power-on working state accordingly; and a second control loop coupled to the first control module and the path control circuit, and configured to provide a second control loop invalidation signal to trigger the path control circuit from an on state to an off state in response to the negative terminal being disconnected from the negative terminal of the bus, and the first control module to be in a power-off state accordingly; The first control module further includes a voltage-stabilizing energy storage module, which is coupled to the second control module via the power supply terminal and stores the DC voltage as a supply voltage. When the first control module is in a power-on working state, the first control module causes the second control loop to provide a second control loop invalidation signal according to the negative terminal being pulled away from the negative pole of the bus.

16. The Ethernet power supply according to claim 15, wherein: The path control circuit includes: a path switch, one end of which is coupled to the positive terminal of the bus and the other end of which is coupled to the power terminal; and a driving switch having one end coupled to the path switch control end, and the driving switch control end coupled to the first control loop, the second control loop, and the path switch; The first control loop valid signal triggers the driving switch to the on state, causing the driving switch to drive the path switch to the on state, and the driving switch is maintained in the on state according to the on state of the path switch, and the path control circuit correspondingly maintains the coupling relationship between the power supply terminal and the positive electrode of the bus; and the second control loop invalid signal triggers the driving switch to the off state, causing the driving switch to drive the path switch to the off state, and the driving switch is maintained in the off state according to the off state of the path switch, and the path control circuit correspondingly maintains the disconnection relationship between the power supply terminal and the positive electrode of the bus.

17. A method for controlling an Ethernet power supply, characterized in that: The Ethernet power supply receives a DC voltage and is coupled to a positive terminal and a negative terminal of a load device. The Ethernet power supply includes a first control module, which receives the DC voltage via a positive bus and a negative bus, and is coupled to the negative terminal via the negative bus, so as to provide a first control signal via the negative bus to confirm whether the load device is a valid load. The control method includes the following steps: Detecting whether the load device is connected and turning on or off a path control circuit between a power terminal of the first control module and the positive electrode of the bus; The path control circuit is turned on through a first control loop according to the negative terminal being connected to the negative terminal of the bus, wherein the first control loop couples the negative terminal of the bus and the path control circuit; The path control circuit is turned on via a second control loop in response to the negative electrode of the bus being grounded, wherein the second control loop couples the first control module and the path control circuit; and The path control circuit is turned off according to the negative terminal being pulled away from the negative terminal of the bus. The first control module further includes a voltage-stabilizing energy storage module, which is coupled to the path control circuit via the power supply terminal and stores the DC voltage as a supply voltage.

18. The control method according to claim 17, characterized in that: The following steps are also included: The first control loop provides a first control loop effective signal according to the voltage increase of a terminal of the negative electrode of the bus; The second control loop provides a second control loop invalid signal according to the first control module being in a power-off and stopped working state; and The path control circuit is turned on according to the first control loop valid signal and the second control loop invalid signal.

19. The control method according to claim 18, characterized in that: The first control module is powered on and in a working state according to the conduction of the path control circuit, and confirms whether the load device is the effective load by providing the first control signal.

20. The control method according to claim 18, characterized in that: The first control module provides a second control signal to ground the negative electrode of the bus after the communication is completed, and the control method further includes the following steps: The first control loop provides a first control loop invalid signal according to the grounding of the negative electrode of the bus; The second control loop provides a second control loop valid signal according to the second control signal; and The path control circuit is turned on according to the first control loop invalid signal and the second control loop valid signal.

21. The control method according to claim 18, characterized in that: The first control module provides a fourth control signal according to the negative terminal being pulled away from the negative terminal of the bus, and the control method further includes the following steps: The first control loop provides a first control loop invalid signal according to a voltage at a terminal of the negative electrode of the bus being at a first potential; The second control loop provides a second control loop invalid signal according to the fourth control signal; and The path control circuit is turned off according to the first control loop invalid signal and the second control loop invalid signal.

22. The control method according to claim 18, characterized in that: The first control module confirms that the load device is the effective load and provides a second control signal to control the communication module to ground the negative pole of the bus, and controls the Ethernet power supply to provide a default power to the load device.

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