Power receiving device and power over ethernet system

Abstract

A power receiving device comprises: at least two interfaces, one of which accesses a power supply device through a twisted pair; an interface expansion unit comprising at least two conduction units, each of which is connected to one of the at least two interfaces in one-to-one correspondence, and the corresponding conduction unit is turned on when the one interface accesses the power supply device; and a PoE unit electrically connected to the at least two conduction units, used to extract power signals from the one interface to supply power to a power receiving functional unit when the one interface accesses the power supply device, thereby realizing multi-interface power receiving at the PD end, prolonging the service life of the product, and saving use cost. The application also provides an Ethernet power supply system comprising the power receiving device.

Description

Technical Field

[0001] This invention relates to the field of Power over Ethernet (PoE) technology, and more particularly to a power receiving device and a PoE system. Background Technology

[0002] With the rise of PoE (Power on Ethernet), more and more network communication products have integrated this technology, eliminating the need for a separate power adapter at the PD (Powered Device) end. Power can be supplied directly to the product via the network port. Currently, PDs are powered through designated network ports; other network ports do not have the function of being used as power connectors. If a single network port is used for power supply for an extended period and is damaged due to various reasons, such as lightning strikes or frequent plugging and unplugging of twisted-pair cables, the entire PD product will become unusable. Summary of the Invention

[0003] In view of this, the present invention provides a power receiving device and an Ethernet power supply system, which extends the service life of the product and saves on usage costs.

[0004] This invention provides a power receiving device, comprising: at least two interfaces, one of which is connected to a power supply device via a twisted pair cable; an interface expansion unit, including at least two conduction units, each of which is connected to one of the at least two interfaces respectively, wherein when one of the interfaces is connected to the power supply device, the corresponding conduction unit is activated; and a PoE unit, electrically connected to the at least two conduction units, for extracting a power signal from one of the interfaces to supply power to the power receiving functional unit when one of the interfaces is connected to the power supply device.

[0005] Preferably, each conduction unit includes: a rectifier circuit electrically connected to the corresponding interface, used to convert the power signal provided by the power supply device into a positive phase voltage when the corresponding interface is connected to the power supply device; a clamping circuit electrically connected to the rectifier circuit, used to clamp the positive phase voltage at a preset clamping voltage; a protection circuit electrically connected to the clamping circuit, the protection circuit being a delay circuit; a voltage follower circuit electrically connected to the protection circuit, used to output a stable control signal when the corresponding interface is connected to the power supply device; and a switching circuit electrically connected to the voltage follower circuit, the PoE unit, and the rectifier circuit, used to connect the PoE unit to the corresponding interface when the control signal is received.

[0006] Preferably, the rectifier unit includes: a first diode, the anode of the first diode being grounded; a second diode, the anode of the second diode being electrically connected to the cathode of the first diode, and the common terminal of the first diode and the second diode being electrically connected to the corresponding interface; a third diode, the anode of the third diode being grounded; and a fourth diode, the anode of the fourth diode being electrically connected to the cathode of the third diode, the common terminal of the third diode and the fourth diode being electrically connected to the corresponding interface, and the cathode of the fourth diode being electrically connected to the cathode of the second diode and the clamping circuit.

[0007] Preferably, the clamping circuit includes: a first resistor, one end of which is electrically connected to the common terminal of the second diode and the fourth diode; and a plurality of fifth diodes, which are connected in series, with the anode of the first fifth diode electrically connected to the other end of the first resistor and the cathode of the last fifth diode grounded.

[0008] Preferably, the protection circuit includes: a second resistor, one end of which is electrically connected to the other end of the first resistor; and a first capacitor, one end of which is electrically connected to the other end of the second resistor, and the other end of which is grounded.

[0009] Preferably, the voltage follower circuit includes: an operational amplifier, the non-inverting input terminal of which is electrically connected to the common terminal of the second resistor and the first capacitor, the inverting input terminal of which is electrically connected to the output terminal of which is electrically connected to the switching circuit for outputting the control signal; and a third resistor, one end of which is grounded and the other end of which is electrically connected to the output terminal of the operational amplifier.

[0010] Preferably, the switching circuit includes: a first transistor, the base of which is electrically connected to the output of the operational amplifier via a fourth resistor to receive the control signal, and the emitter of the first transistor being grounded; a fifth resistor, one end of which is electrically connected to the collector of the first transistor, and the other end of which is electrically connected to one end of the first resistor; and a first MOSFET, the gate of which is electrically connected to the collector of the first transistor, the source of which is electrically connected to the other end of the fifth resistor, and the drain of which is electrically connected to the PoE cell.

[0011] Preferably, when the base of the first transistor receives the control signal, the first transistor is turned on, and then the first MOS transistor is turned on, and the power signal provided by the power supply device is supplied to the power receiving functional unit after passing through the rectifier circuit.

[0012] Preferably, the interface expansion unit further includes an isolation circuit, which includes at least two Zener diodes, the anodes of the at least two Zener diodes being electrically connected to the drains of the corresponding first MOS transistors, and the cathodes of the at least two Zener diodes being electrically connected to the power receiving functional unit.

[0013] The present invention also provides a Power over Ethernet (PoE) system, including the power receiving device described in any of the preceding claims.

[0014] Compared with the prior art, the power receiving device of the present invention includes at least two interfaces, and is connected to the power supply device through one of the at least two interfaces. The at least two interfaces are electrically connected to the PoE unit through at least two conduction units. When one of the interfaces is connected to the power supply device, the corresponding conduction unit conducts the connection between the PoE unit and the corresponding interface, thereby realizing multi-interface power receiving at the PD end, extending the service life of the product and saving usage costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a Power over Ethernet (PoE) system according to an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of a power receiving device according to an embodiment of the present invention.

[0017] Figure 3 This is a circuit diagram of a power receiving device according to an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the voltage curves of the input, output, and control signals of the interface expansion unit of the powered device according to an embodiment of the present invention.

[0019] Explanation of main component symbols Power over Ethernet 1 Power supply equipment 10 20 power receiving devices Twisted pair 30 Interfaces 200a and 200b Interface Expansion Unit 201 Conducting units 201a, 201b PoE Unit 202 Power receiving functional unit 203 Rectifier circuit 2011 Clamping Circuit 2012 Protection Circuit 2013 Voltage Follower Circuit 2014 Switching Circuits 2015 First diode - Fourth diode D1-D4 First resistor - Fifth resistor R1-R5 Fifth diode D5a-D5e First capacitor C1 Operational amplifier AP Public terminals V+ and V- First transistor Q1 First MOSFET M1 Curve S1-S3 Isolation Circuits 2016 Zener diodes Z1-Z2 The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0020] To facilitate understanding and implementation of this invention by those skilled in the art, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that this invention provides many applicable inventive concepts, which can be implemented in various specific forms. Those skilled in the art can utilize the details described in these or other embodiments, as well as other available structural, logical, and electrical variations, to implement the invention without departing from its spirit and scope.

[0021] This specification provides different embodiments to illustrate the technical features of different implementations of the invention. The configuration of elements in the embodiments is for illustrative purposes only and is not intended to limit the invention. Furthermore, the repetition of some reference numerals in the embodiments is for simplification and does not imply any correlation between different embodiments. The same element numbers used in the illustrations and specification represent the same or similar components. The illustrations in this specification are simplified and not drawn to scale.

[0022] Furthermore, in describing some embodiments of the present invention, the specification describes the method and / or procedure of the present invention in a specific order of steps. However, since the method and procedure are not necessarily performed according to the specific order of steps described, they are not limited to the specific order of steps. Those skilled in the art will understand that other orders are also possible implementations. Therefore, the specific order of steps described in the specification is not intended to limit the scope of the patent application. Moreover, the scope of the present invention for the method and / or procedure is not limited to the order of execution steps written therein, and those skilled in the art will understand that adjusting the order of execution steps does not depart from the spirit and scope of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Some embodiments of the invention are described in detail below with reference to the accompanying drawings.

[0024] Please see Figure 1 , Figure 1 This is a schematic diagram of a Power over Ethernet (PoE) system according to an embodiment of the present invention. In this embodiment, as... Figure 1 As shown, the Power over Ethernet (PoE) system 1 includes a Power Sourcing Equipment (PSE) 10 and a Powered Device (PD) 20. The PSE 10 can be a PoE Ethernet switch, router, or hub, etc. The PD 20 can be selected according to actual needs, such as an IP phone, wireless access point (AP), network camera (IPC), or other IP-based terminal devices. The PD 20 includes at least two interfaces, one of which is connected to the PSE 10 via a twisted-pair cable 30. This embodiment uses two interfaces 200a and 200b as examples. Either interface 200a or 200b of the PD 20 can be connected to the PSE 10 via the twisted-pair cable 30, allowing the PSE 10 to supply power to the PD 20. When interface 200a fails, the PD 20 can connect to the PSE 10 via the other interface 200b, thus achieving multi-interface power reception at the PD end and extending the product's lifespan.

[0025] Specifically, the power receiving device 20 further includes an interface expansion unit 201, a PoE unit 202, and a power receiving function unit 203. The interface expansion unit 201 includes at least two conduction units, each connected to one of the at least two interfaces. When one of the interfaces is connected to the power supply device 10, the corresponding conduction unit is activated. Specifically, taking two conduction units 201a and 201b as an example, conduction unit 201a is electrically connected to interface 200a, and conduction unit 201b is electrically connected to interface 200b. The PoE unit 202 is electrically connected to conduction units 201a and 201b, and is used to extract a power signal from one of the interfaces to supply power to the power receiving function unit 203 when one of the interfaces is connected to the power supply device 10.

[0026] Please refer to the following: Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a power receiving device according to an embodiment of the present invention. Figure 3 This is a circuit diagram of a power receiving device according to an embodiment of the present invention. Figure 2 As shown, in this embodiment, each conduction unit includes a rectifier circuit 2011, a clamping circuit 2012, a protection circuit 2013, a voltage follower circuit 2014, and a switching circuit 2015. The rectifier circuit 2011 is electrically connected to the corresponding interface and is used to convert the power signal provided by the power supply device 10 into a positive voltage when the corresponding interface is connected to the power supply device 10. Specifically, as shown... Figure 3 As shown, the rectifier circuit 2011 is a diode full-wave rectifier circuit, including a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is grounded; the anode of the second diode D2 is electrically connected to the cathode of the first diode D1, and the common terminal V+ of the first diode D1 and the second diode D2 is electrically connected to the corresponding interface; the anode of the third diode D3 is grounded; the anode of the fourth diode D4 is electrically connected to the cathode of the third diode D3, and the common terminal V- of the third diode D3 and the fourth diode D4 is electrically connected to the corresponding interface; the cathode of the fourth diode D4 is electrically connected to the cathode of the second diode D2 and the clamping circuit 2012. Regardless of whether the power signal output from the corresponding interface is positive or negative, it forms a positive voltage after passing through the rectifier circuit 2011.

[0027] like Figure 2 As shown, the clamping circuit 2012 is electrically connected to the rectifier circuit 2011 and is used to clamp the positive phase voltage at a preset clamping voltage. Figure 3 As shown, the clamping circuit 2012 includes a first resistor R1 and a plurality of fifth diodes. The preset clamping voltage is set by setting the number of fifth diodes. In this embodiment, by setting five fifth diodes D5a-D5e, the positive voltage is clamped at 3.3V. One end of the first resistor R1 is electrically connected to the common terminal of the second diode D2 and the fourth diode D4; the plurality of fifth diodes D5a-D5e are connected in series, with the anode of the first diode D5a electrically connected to the other end of the first resistor R1, and the cathode of the last fifth diode D5e grounded.

[0028] like Figure 2 As shown, the protection circuit 2013 is electrically connected to the clamping circuit 2012. The protection circuit 2013 is a delay circuit, used to provide the clamping circuit 2012 with reaction time to prevent instantaneous overvoltage from damaging the voltage follower circuit 2014. Figure 3 As shown, the protection circuit 2013 includes a second resistor R2 and a first capacitor C1. One end of the second resistor R2 is electrically connected to the other end of the first resistor R1; one end of the first capacitor C1 is electrically connected to the other end of the second resistor R2, and the other end of the first capacitor C1 is grounded.

[0029] like Figure 2As shown, the voltage follower circuit 2014 is electrically connected to the protection circuit 2013, and is used to output a stable control signal to the switching circuit 2015 when the corresponding interface is connected to the power supply device 10. Figure 3 As shown, the voltage follower circuit 2014 includes an operational amplifier AP and a third resistor R3. The non-inverting input of the operational amplifier AP is electrically connected to the common terminal of the second resistor R1 and the first capacitor C1, and the inverting input of the operational amplifier AP is electrically connected to the output of the operational amplifier AP. The output of the operational amplifier AP is electrically connected to the switching circuit 2015 for outputting the control signal. One end of the third resistor R3 is grounded, and the other end of the third resistor is electrically connected to the output of the operational amplifier AP. When the corresponding interface is connected to the power supply device 10, the clamping circuit 2012 outputs a 3.3V voltage to the non-inverting input of the operational amplifier AP, and the operational amplifier AP outputs a control signal with the same voltage value and polarity as the preset clamping voltage, that is, the operational amplifier AP outputs a 3.3V level signal.

[0030] like Figure 2 As shown, the switching circuit 2015 is electrically connected to the voltage follower circuit 2014, the PoE unit 202, and the rectifier unit 2011, and is used to connect the PoE unit 202 to the corresponding interface when the control signal is received. Figure 3 As shown, the switching circuit 2015 includes a fourth resistor R4, a first transistor Q1, a fifth resistor R5, and a first MOSFET M1. One end of the fourth resistor R4 is electrically connected to the other end of the third resistor R3; the base of the first transistor Q1 is electrically connected to the output of the operational amplifier AP through the fourth resistor R4 to receive the control signal, and the emitter of the first transistor Q1 is grounded; one end of the fifth resistor R5 is electrically connected to the collector of the first transistor Q1, and the other end of the fifth resistor R5 is electrically connected to one end of the first resistor R1; the gate of the first MOSFET M1 is electrically connected to the collector of the first transistor Q1, the source of the first MOSFET M1 is electrically connected to the other end of the fifth resistor R5, and the drain of the first MOSFET M1 is electrically connected to the PoE unit 202. When the base of the first transistor Q1 receives the control signal, the first transistor Q1 is grounded, and the gate of the first MOS transistor M1 is at a low level. The first MOS transistor M1 is turned on, and the power signal provided by the power supply device 10 is rectified by the rectifier circuit 2011 and then supplied to the power receiving unit 203.

[0031] In this embodiment, the interface expansion circuit further includes an isolation circuit 2016, which is electrically connected between the interface expansion unit 201 and the PoE unit 202. The isolation circuit 2016 includes at least two Zener diodes Z1. Taking two Zener diodes Z1 and Z2 as an example, the anodes of Zener diodes Z1 and Z2 are electrically connected to the drains of the corresponding first MOSFETs, and the cathodes of Zener diodes Z1 and Z2 are electrically connected to the powered functional unit 203. When the power supply device 10 supplies power to the powered functional unit 203 through the interface 200a, the isolation circuit 2016 ensures that the voltage through the conduction unit 201a will not be reverse-biased into the interface 200b. Similarly, when the power supply device 10 supplies power to the powered functional unit 203 through the interface 200b, the isolation circuit 2016 ensures that the voltage through the conduction unit 201b will not be reverse-biased into the interface 200a.

[0032] Please see Figure 4 , Figure 4 This is a schematic diagram showing the voltage curves of the input, output, and control signals of the interface expansion unit of a powered device according to an embodiment of the present invention. Figure 4 As shown, curve S1 is the input voltage curve of interface expansion unit 201 (i.e., the output voltage of the corresponding interface), and curve S3 is the output voltage curve of interface expansion unit 201. The output voltage is consistent with the input voltage, and no distortion occurs. Curve S2 is the control signal output by the operational amplifier AP of interface expansion unit 201. The control signal is stably controlled at around 3.3V, and the circuit performance is stable.

[0033] Compared with the prior art, the power receiving device of the present invention includes at least two interfaces, and is connected to the power supply device through one of the at least two interfaces. The at least two interfaces are electrically connected to the PoE unit through at least two conduction units. When one of the interfaces is connected to the power supply device, the corresponding conduction unit conducts the connection between the PoE unit and the corresponding interface, thereby realizing multi-interface power receiving at the PD end, extending the service life of the product and saving usage costs.

[0034] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any appropriate changes and modifications made to the above embodiments within the essential spirit and scope of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A power receiving device, characterized in that, include: At least two interfaces, one of which is connected to the power supply equipment via a twisted pair cable; An interface expansion unit includes at least two conduction units, each of which is connected to one of the at least two interfaces. When one of the interfaces is connected to the power supply equipment, the corresponding conduction unit is turned on. The PoE unit is electrically connected to the at least two conduction units and is used to extract a power signal from one of the interfaces to supply power to the powered functional unit when one of the interfaces is connected to the power supply equipment.

2. The power receiving equipment as described in claim 1, characterized in that, Each of the at least two conduction units includes: A rectifier circuit, electrically connected to the corresponding interface, is used to convert the power signal provided by the power supply device into a positive voltage when the corresponding interface is connected to the power supply device. A clamping circuit, electrically connected to the rectifier circuit, is used to clamp the positive phase voltage at a preset clamping voltage. A protection circuit is electrically connected to the clamping circuit, and the protection circuit is a time delay circuit. A voltage follower circuit, electrically connected to the protection circuit, is used to output a stable control signal when the corresponding interface is connected to the power supply equipment; A switching circuit, electrically connected to the voltage follower circuit, the PoE unit, and the rectifier circuit, is used to connect the PoE unit to the corresponding interface when the control signal is received.

3. The power receiving equipment as described in claim 2, characterized in that, The rectifier circuit includes: The first diode, with its anode grounded; The second diode has its anode electrically connected to the cathode of the first diode, and the common terminal of the first diode and the second diode is electrically connected to the corresponding interface; The third diode, wherein the anode of the third diode is grounded; The fourth diode has its anode electrically connected to the cathode of the third diode, the common terminal of the third diode and the fourth diode electrically connected to the corresponding interface, and the cathode of the fourth diode electrically connected to the cathode of the second diode and the clamping circuit.

4. The power receiving equipment as described in claim 3, characterized in that, The clamping circuit includes: A first resistor, one end of which is electrically connected to the common terminal of the second diode and the fourth diode; A plurality of fifth diodes are connected in series, with the anode of the first fifth diode connected to the other end of the first resistor and the cathode of the last fifth diode grounded.

5. The power receiving device as described in claim 4, characterized in that, The protection circuit includes: A second resistor, one end of which is electrically connected to the other end of the first resistor; A first capacitor, one end of which is electrically connected to the other end of the second resistor, and the other end of which is grounded.

6. The power receiving equipment as described in claim 5, characterized in that, The voltage follower circuit includes: An operational amplifier, wherein the non-inverting input terminal of the operational amplifier is electrically connected to the common terminal of the second resistor and the first capacitor, the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is electrically connected to the switching circuit for outputting the control signal; The third resistor has one end grounded and the other end electrically connected to the output terminal of the operational amplifier.

7. The power receiving equipment as described in claim 6, characterized in that, The switching circuit includes: The base of the first transistor is electrically connected to the output of the operational amplifier through a fourth resistor to receive the control signal, and the emitter of the first transistor is grounded. A fifth resistor, one end of which is electrically connected to the collector of the first transistor, and the other end of which is electrically connected to one end of the first resistor; The first MOS transistor has its gate electrically connected to the collector of the first transistor, its source electrically connected to the other end of the fifth resistor, and its drain electrically connected to the PoE cell.

8. The power receiving equipment as described in claim 7, characterized in that: When the base of the first transistor receives the control signal, the first transistor turns on, and then the first MOS transistor turns on. The power signal provided by the power supply device is then rectified and supplied to the power receiving unit.

9. The power receiving equipment as described in claim 7, characterized in that, The interface expansion unit further includes an isolation circuit, which includes: At least two Zener diodes, wherein the anodes of the at least two Zener diodes are electrically connected to the drains of the corresponding first MOSFETs, and the cathodes of the at least two Zener diodes are electrically connected to the power receiving functional unit.

10. A Power over Ethernet (PoE) system, characterized in that, Includes the power receiving equipment as described in any one of claims 1-9.

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