CN104135374A - Powered device - Google Patents

Abstract

The invention discloses a powered device, which is used for electrical connection with power sourcing equipment. The powered device comprises a receiving circuit, a receiving unit and at least one rectifying unit, wherein the receiving unit is used for receiving a voltage signal output by the power sourcing equipment, and the rectifying unit is used for carrying out rectification processing on the voltage signal output by the power sourcing equipment and supplying power to the receiving circuit. The rectifying unit comprises a rectifying circuit, an auxiliary power supply unit, a polarity judging unit, a control unit and a selection unit. The rectifying circuit is used for providing a current path between the receiving unit and the receiving circuit. The auxiliary power supply unit is used for providing an auxiliary power supply signal; the polarity judging unit is used for judging polarity of the input voltage signal and generating a judging signal. The control unit is used for outputting a control signal according to the judging signal and the auxiliary power supply signal. The selection unit is used for selecting a receiving end with positive output voltage in the receiving unit to be connected to the positive input end of the receiving circuit so as to achieve the purpose of rectification at low power consumption.

Description

Receiver equipment

technical field

The invention relates to a power receiving end device, in particular to a power receiving end device applied to an Ethernet power supply system.

Background technique

Power Over Ethernet (POE) refers to the power supply for some Internet Protocol (Internet Protocol, IP)-based terminals (such as IP telephones, Wireless LAN access points, network cameras, etc.) while transmitting data signals, it can also provide DC power supply for such devices.

A complete POE system includes two parts: Power Sourcing Equipment (PSE) and Powered Device (PD). PSE is a device that supplies power to Ethernet client devices, and is also the manager of the entire POE process. The PD is the PSE load that receives power, that is, the client device of the POE system, such as IP phones, network security cameras, wireless LAN access points, and many other Ethernet devices such as notebook or mobile phone chargers (actually, any power does not Devices exceeding 13W can obtain corresponding power from the RJ45 socket). Based on the IEEE802.3af standard, the two establish information links about the connection status, device type, and power consumption level of the power receiving end device PD, and use this as a basis to supply power to the PD through Ethernet through the PSE. In today's era of advocating energy conservation and environmental protection, there is an urgent need for a low-power rectification circuit to provide rectification for POE.

Contents of the invention

In view of this, it is necessary to provide a power receiving end device that can provide rectification for a Power Over Ethernet (POE) system, and has low power consumption, thereby reducing power consumption during the POE process to achieve the purpose of energy saving.

The power receiving end device provided by the embodiment of the present invention is connected to the power supply end device in the Ethernet power supply system. The power receiving end device includes a power receiving circuit, a receiving unit and at least one rectification unit, and the power receiving circuit includes a positive input terminal. , Negative input terminal and output terminal, the power supply terminal equipment outputs voltage signal to the power receiving terminal equipment. The receiving unit includes a first receiving end and a second receiving end for respectively receiving output voltage signals from the first output end and the second output end of the power supply device. At least one rectification unit is used to rectify and process the voltage signal to supply power to the power receiving circuit. Each rectification unit includes a rectification circuit, an auxiliary power supply unit, a polarity judgment unit, a control unit and a selection unit. The rectification circuit includes two input terminals and two output terminals. The two input terminals of the rectification circuit are respectively connected to the first receiving terminal and the second receiving terminal, and the two output terminals are respectively connected to the positive input terminal and the negative direction input terminal of the receiving circuit. The input terminals are connected to provide a current path between the receiving unit and the powered circuit. The auxiliary power supply unit is connected to the output end of the power receiving circuit, and is used for providing an auxiliary power signal after the power supply end device supplies power to the power receiving end. The polarity judging unit is connected to a receiving end of the receiving unit, and is used for judging the polarity of the input voltage signal, and generating a judging signal according to the polarity of the input voltage signal. The control unit is connected with both the auxiliary power supply unit and the polarity judgment unit, and is used for outputting a control signal according to the polarity of the judgment signal and the auxiliary power signal. The selection unit is connected in parallel with the rectifier circuit and connected with the control unit, and is used to select the receiving end whose output voltage is positive among the first receiving end and the second receiving end to be connected to the positive input end of the powered circuit and the first receiving end according to the control signal. The receiving end whose output voltage is negative among the receiving end and the second receiving end is connected to the negative input end of the power receiving circuit.

Preferably, the rectifier circuit includes first, second, third and fourth diodes, the cathode of the first diode and the anode of the second diode are electrically connected to the first receiving end, and the second diode Both the anode of the tube and the anode of the fourth diode are electrically connected to the negative input end of the powered circuit, and the anode of the third diode and the cathode of the fourth diode are both electrically connected to the second receiving end, Both the cathode of the second diode and the cathode of the third diode are electrically connected to the positive input end of the powered circuit.

Preferably, the control unit includes a first control circuit, a second control circuit, a third control circuit and a fourth control circuit, wherein the first control circuit includes a first field effect transistor, a first inverter and a fifth diode , the gate of the first field effect transistor is electrically connected to one end of the first inverter, the source is electrically connected to the auxiliary power supply unit, and the other end of the first inverter is electrically connected to the polarity judging unit. The fifth diode is electrically connected between the source and the drain of the first field effect transistor, and the anode of the fifth diode is electrically connected with the drain of the first field effect transistor.

Preferably, the control unit further includes a second control circuit, wherein the second control circuit includes a second field effect transistor and a sixth diode, and the gate of the second field effect transistor is electrically connected to the other end of the first inverter On the node with the polarity judgment unit, the source is electrically connected to the source of the first field effect transistor and the node of the auxiliary power supply unit, and the sixth diode is electrically connected to the source and drain of the second field effect transistor between the electrodes, and the anode of the sixth diode is electrically connected with the drain of the second field effect transistor.

Preferably, the control unit further includes a third control circuit, wherein the third control circuit includes a third field effect transistor, a second inverter and a seventh diode, and the gate of the third field effect transistor is inverting with the second inverter. One end of the inverter is electrically connected, the source is grounded, the drain is electrically connected to the drain of the first field effect transistor, and the other end of the second inverter is electrically connected to the other end of the first inverter and the polarity judgment unit On the node of , the seventh diode is electrically connected between the source and the drain of the third field effect transistor, and the anode of the seventh diode is electrically connected with the source of the third field effect transistor.

Preferably, the control unit further includes a fourth control circuit, wherein the fourth control circuit includes a fourth field effect transistor and an eighth diode, and the gate of the fourth field effect transistor is electrically connected to the other end of the first inverter On the node with the polarity judgment unit, the source is grounded, the drain is electrically connected to the drain of the second field effect transistor, and the eighth diode is electrically connected between the source and drain of the fourth field effect transistor , and the anode of the eighth diode is electrically connected to the source of the fourth field effect transistor.

Preferably, the selection unit includes a relay, and the relay includes a first contact group type switch, a second contact group type switch and a coil, wherein the coil includes a first access terminal and a second access terminal, and the first access terminal of the coil end and the second access end are electrically connected with the control unit respectively, and are used to receive the control signal generated by the control unit to determine the flow direction of the current in the coil. The first contact group switch includes a first contact, a second contact and the third contact, the second contact group switch includes a fourth contact, a fifth contact and a sixth contact, the second and fifth contacts are respectively connected to the first receiving end and the second receiving end, the first Both the contact and the sixth contact are electrically connected to the positive input end of the power receiving circuit, and the third contact and the fourth contact are both electrically connected to the negative input end of the power receiving circuit.

Preferably, the first, third, fourth and sixth contacts are static contacts, the second and fifth contacts are movable contacts, and the coil is used to control the contact of the six contacts by using its current flow direction. When the coil When controlling the electrical connection between the second contact and the first contact, and the electrical connection between the fifth contact and the fourth contact, the receiving end with a positive output voltage among the first receiving end and the second receiving end is connected to the receiving circuit The positive input end of the first receiving end and the second receiving end whose output voltage is negative are connected to the negative input end of the power receiving circuit.

Preferably, when the coil controls the second contact to be electrically connected to the third contact, and the fifth contact to be electrically connected to the sixth contact, the output voltage of the first receiving end and the second receiving end is a positive receiving end It is connected to the positive input end of the power receiving circuit, and the receiving end whose output voltage is negative among the first receiving end and the second receiving end is connected to the negative input end of the power receiving circuit.

Preferably, the polarity judging unit includes a first resistor, a second resistor and a comparator, one end of the first resistor is electrically connected to the first receiving end, the other end is electrically connected to one end of the second resistor, and the other end of the second resistor One terminal is grounded, the positive input terminal of the comparator is electrically connected to the node of the first resistor and the second resistor, the negative input terminal is electrically connected between the second resistor and the ground, the output terminal of the comparator is electrically connected to the control unit Sexual connection, wherein the comparator is used to compare the magnitude of the voltage between the first receiving end and the ground to generate a judgment signal.

Compared with the prior art, the power receiving end device provided by the embodiment of the present invention can achieve the purpose of rectification with low power consumption through the rectification unit.

Description of drawings

FIG. 1 is a functional block diagram of an embodiment of a power receiving end device according to the present invention.

FIG. 2 is a circuit diagram of an embodiment of the power receiving end device of the present invention.

Description of main component symbols

Receiver equipment 10

Rectifier unit 20

Power receiving circuit 30

Power supply equipment 40

Rectifier circuit 200

Receiving unit 201

Select Unit 202

Polarity judging unit 204

Control unit 206

Auxiliary power supply unit 208

The first to fourth control circuits 212, 214,

216, 218

The first to eighth diodes D1-D8

The first and second resistors R1, R2

First and second inverters N1, N2

The first to the fourth FET M1-M4

Comparator U1

Coil L1

DC/DC Converter T1

The first and second contact group switches S1, S2

The first to sixth contacts S1a, S1b,

S1c, S2a,

S2b, S2c

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

Detailed ways

Please refer to FIG. 1 , which is a functional block diagram of an embodiment of a power receiving device 10 of the present invention. In this embodiment, a power receiving device (Powered Device, PD) 10 is applied to a Power Over Ethernet (POE) system Among them, the POE system includes two parts: power sourcing equipment (Power Sourcing Equipment, PSE) 40 and power receiving equipment 10. The power supply end device 40 is a device that supplies power to the Ethernet client device, and is also the manager of the entire POE process. The power receiving device 10 is a load that accepts the power supply from the power supply device 40, that is, the client device of the POE system, such as an Internet Protocol (Internet Protocol, IP) phone, a network security camera, a wireless local area network access point, and a notebook or mobile phone charger. and other Ethernet devices. Different power receiving end devices 10 have different resistance values after being powered on, and correspondingly generate different characteristic impedances. The power supply end device 40 establishes information contact about the connection status, device type, power consumption level, etc. of the power receiving end device 10, and uses this as a basis to supply power to the power receiving end device 10 through Ethernet.

In this embodiment, the power supply device 40 includes a first output terminal and a second output terminal with opposite polarities. The power supply device 40 is used to detect the characteristic impedance of the power receiving device 10 , and then supply power to the power receiving device 10 according to the detected characteristic impedance. According to different characteristic impedances, the voltage signal output by the power supply terminal device 40 is different. The voltage of the output voltage signal can range from a few volts to tens of volts. In the future, it may support higher voltages to support power receiving terminals of different types of equipment. device10. Each characteristic impedance corresponds to a normal working voltage value, which is stored in the power supply device 40 . In this way, the power supply end device 40 can select the voltage supplied to the power supply end device 40 according to the characteristic impedance of the power receiving end device 10 .

In a specific embodiment, the power supply end device 40 first outputs a very small voltage, and then, after detecting the power receiving end device 10, the power supply end device 40 detects the characteristic impedance of the power receiving end device 10, and the power receiving end device 10 to classify, and increase the voltage supplied to the power receiving end device 10 from a low voltage until reaching the normal operating voltage of the power receiving end device 10; when the power receiving end device 10 is disconnected from the power supply end device 40, the power supply end device 40 The power supply to the receiving end device 10 will be stopped quickly (generally within 300-400 ms), and the detection process will be repeated to detect whether the receiving end device 10 is connected.

In one embodiment of the present invention, the power receiving end device 10 includes a rectifying unit 20, a power receiving circuit 30, and a receiving unit 201, wherein the receiving unit 201 includes a first receiving end and a second receiving end, and the first receiving end and the power supply end The first output end of the device 40 is connected, and the second receiving end is connected to the second output end of the power supply device 40 for receiving output voltage signals from the first output end and the second output end of the power supply device 40 respectively. The power receiving circuit 30 includes a positive input terminal, a negative input terminal and an output terminal. The rectifying unit 20 is connected between the receiving unit 201 and the power receiving circuit 30 , and is used for receiving an input voltage signal from the power supply end device 40 through the receiving unit 201 and supplying power to the power receiving circuit 30 after rectification. Regardless of the polarity of the two output terminals of the power supply device 40, after being processed by the rectifying unit 20, the polarity entering the power receiving circuit 30 is fixed, that is, the first receiving terminal and the second receiving terminal of the receiving unit 201 are rectified. Among the two receiving terminals, the receiving terminal whose output voltage is positive is connected to the positive input terminal of the receiving circuit 30, and the receiving terminal whose output voltage is negative among the first receiving terminal and the second receiving terminal of the receiving unit 201 is connected to the receiving circuit 30 the negative input terminal.

In this embodiment, the rectification unit 20 includes a rectification circuit 200 , a selection unit 202 , a polarity determination unit 204 , a control unit 206 and an auxiliary power supply unit 208 .

The rectifier circuit 200 includes two input terminals and two output terminals, the two input terminals are respectively connected to the first receiving terminal and the second receiving terminal of the receiving unit 201, and the two output terminals are respectively connected to the positive input terminal of the receiving circuit 30 Connect to the negative input. The rectifier circuit 200 is used to provide a current path for the receiving unit 201 and the power receiving circuit 30 when the power supply end device 40 detects the characteristic impedance, and ensure that the polarity entering the power receiving circuit 30 is fixed. In a specific embodiment, the rectification circuit 200 may be a full-bridge rectification circuit composed of four diodes.

The auxiliary power supply unit 208 is connected to the output terminal of the power receiving circuit 30 , and is used for receiving an auxiliary power signal from the power receiving circuit 30 after the power supply device 40 supplies power to the power receiving device 10 . In this embodiment, the polarity of the auxiliary power signal can be positive or negative, and the current is very small, so that there is basically no waste of electric energy.

The polarity judging unit 204 is connected to a receiving end of the receiving unit 201 for judging the polarity of the input voltage signal of the power supply device 40 and generating a judging signal. In this embodiment, the polarity determination unit 204 may be a comparator. In this embodiment, the judgment signal can be high or low level. When the polarity of the input voltage signal at the receiving end of the receiving unit 201 connected to the polarity judging unit 204 is positive, the polarity judging unit 204 will generate a high level signal , then when the polarity of the input voltage signal is negative, the polarity judging unit 204 generates a low-level signal; of course, it is not limited to this, and it can also be when the receiving end of the receiving unit 201 connected to the polarity judging unit 204 inputs When the polarity of the voltage signal is positive, the polarity judging unit 204 will generate a low-level signal, and when the polarity of the input voltage signal is negative, the polarity judging unit 204 will generate a high-level signal.

The control unit 206 is connected to the auxiliary power supply unit 208 and the polarity determination unit 204 , and is used to output a control signal according to the determination signal generated by the polarity determination unit 204 and the polarity of the auxiliary power signal of the auxiliary power supply unit 208 . For example, when the polarity of the auxiliary power supply signal of the auxiliary power supply unit 208 is positive and the judgment signal generated by the polarity judgment unit 204 is at a high level, the control unit 206 will output a corresponding control signal, which can be a control switch Close or conduction signal.

The selection unit 202 is connected in parallel with the rectifier circuit 200, and is connected with the control unit 206, and is used to connect the receiving end with a positive output voltage of the first receiving end and the second receiving end of the receiving unit 201 to the receiving end of the receiving circuit 30 according to the control signal. The positive input terminal connects the receiving terminal with a negative output voltage among the first receiving terminal and the second receiving terminal of the receiving unit 201 to the negative input terminal of the power receiving circuit 30 .

In this embodiment, when the power supply end device 40 is initially connected to the receiving unit 201 of the power receiving end device 10, the power supply end device 40 outputs a very small current to the rectifier circuit 200 through the receiving unit 201, and then flows into the receiving unit 201. In the circuit 30 , the power supply device 40 detects the characteristic impedance of the power receiving device 10 , and then outputs a corresponding voltage according to the detected characteristic impedance to supply power to the power receiving device 10 .

When the power supply device 40 normally supplies power to the power receiving device 10, the auxiliary power supply unit 208 obtains the auxiliary power signal from the power receiving circuit 30; the polarity judgment circuit 204 judges the polarity of the input voltage signal of the power supply device 40, and generates a judgment signal; the control unit 206 outputs the control signal according to the polarity of the auxiliary power supply signal obtained by the auxiliary power supply unit 208 and the judgment signal generated by the polarity judgment circuit 204; the selection unit 202 outputs the first receiving end and the The receiving end whose output voltage is positive in the second receiving end is connected to the positive input end of the power receiving circuit 30, and the receiving end whose output voltage is negative among the first receiving end and the second receiving end of the receiving unit 201 is connected to the receiving end The negative input terminal of the circuit 30 is used to achieve the purpose of rectification. And during the rectification process, almost no current flows into the receiving circuit through the rectifying circuit 200 , and all the current flows into the receiving circuit 30 through the selection unit 202 , thereby reducing power loss during the POE process.

Please refer to FIG. 2 at the same time, which is a circuit diagram of an embodiment of the power receiving end device 10 of the present invention. In this embodiment, the power receiving end device 10 includes a rectifying unit 20, a power receiving circuit 30 and a receiving unit 201, wherein the rectifying unit 20 includes A rectification circuit 200 , a selection unit 202 , a polarity determination unit 204 , a control unit 206 and an auxiliary power supply unit 208 . Wherein, the power receiving circuit 30 includes a positive input terminal and a negative input terminal. The receiving unit 201 includes a first receiving end and a second receiving end, the first receiving end is connected to the first output end of the power supply end device 40, and the second receiving end is connected to the second output end of the power supply end device 40 for respectively receiving The first output terminal and the second output terminal of the power supply device receive the output voltage signal.

In the embodiment shown in FIG. 2, the rectifier circuit 200 is a full-bridge diode rectifier bridge, which may specifically include a first diode D1, a second diode D2, a third diode D3, and a fourth and second diode. Pole tube D4. Wherein, both the cathode of the first diode D1 and the anode of the second diode D2 are electrically connected to the first output terminal of the power supply device 40, and the anode of the first diode D1 and the anode of the fourth diode D4 The anodes are both electrically connected to the negative input end of the power receiving circuit 30, the anode of the third diode D3 and the cathode of the fourth diode D4 are both electrically connected to the second input end of the power supply device 40, and the second Both the cathode of the diode D2 and the cathode of the third diode D3 are electrically connected to the positive input terminal of the power receiving circuit 30 . In other embodiments, the rectification circuit 200 is not limited to the full-bridge diode rectification bridge shown in FIG. 2 , and can also be other rectification circuits.

The auxiliary power supply unit 208 includes a DC/DC converter, wherein the DC/DC converter includes a positive input terminal, a negative input terminal, a positive output terminal and a negative output terminal. The positive input end of the DC/DC converter is electrically connected to the positive output end of the power receiving circuit 30, the negative input end of the DC/DC converter and the negative output end of the power receiving circuit 30 are both grounded, and the DC/DC The negative output end of the converter is grounded, and the positive output end of the DC/DC converter is electrically connected to the control unit 206 to provide an auxiliary power signal. In this embodiment, the polarity of the auxiliary power signal can be positive or negative, and the following will be described in detail by taking the positive polarity of the auxiliary power signal as an example.

In this embodiment, the polarity determination unit 204 includes a first resistor R1 , a second resistor R2 and a comparator U1 . Wherein, one end of the first resistor R1 is connected to the first receiving end of the receiving unit 201 , the other end is electrically connected to one end of the second resistor R2 , and the other end of the second resistor R2 is grounded. The comparator U1 includes a positive input terminal, a negative input terminal and an output terminal, wherein the positive input terminal is electrically connected to the node of the first resistor R1 and the second resistor R2, and the negative input terminal is electrically connected to the second resistor Between R2 and the ground, the output terminal is electrically connected to the control unit 206 . The comparator U1 is used to compare the voltage between the first receiving end of the receiving unit 201 and the ground, so as to output a high level or a low level to the control unit 206 .

The control unit 206 includes a first control circuit 212 , a second control circuit 214 , a third control circuit 216 and a fourth control circuit 218 . Wherein, the first control circuit 212 includes a first field effect transistor M1, a first inverter N1 and a fifth diode D5, wherein the first field effect transistor M1 may be a P-channel field effect transistor, and the first field effect transistor The gate of M1 is electrically connected to one end of the first inverter N1, the source is electrically connected to the auxiliary power supply unit 208 (that is, electrically connected to the positive output end of the DC/DC converter T1), and the first inverter The other end of the phaser N1 is electrically connected to the output end of the polarity determination unit 204 (ie, electrically connected to the output end of the comparator U1 ). The fifth diode D5 is electrically connected between the source and the drain of the first field effect transistor M1, and the anode of the fifth diode D5 is electrically connected to the drain of the first field effect transistor M1, and the cathode is electrically connected to the drain of the first field effect transistor M1. The source of the first field effect transistor M1 is electrically connected.

The second control circuit 214 includes a second field effect transistor M2 and a sixth diode D6, wherein the second field effect transistor M2 can be a P-channel field effect transistor, and the gate of the second field effect transistor M2 is electrically connected to the sixth diode D6. On the node between the other end of an inverter N1 and the output end of the polarity judging unit 204, the source is electrically connected to the source of the first field effect transistor M1 and the node of the auxiliary power supply unit 208, and the sixth diode D6 is electrically connected Connected between the source and drain of the second field effect transistor M2, and the anode of the sixth diode D6 is electrically connected to the drain of the second field effect transistor M2, and the negative electrode is connected to the source of the second field effect transistor M2 electrical connection.

The third control circuit 216 includes a third field effect transistor M3, a second inverter N2 and a seventh diode D7, wherein the third field effect transistor M3 can be an N-channel field effect transistor, and the third field effect transistor M3 The gate is electrically connected to one end of the second inverter N2, the source is grounded, the drain is electrically connected to the drain of the first field effect transistor M1, and the other end of the second inverter N2 is electrically connected to the first On the node between the other end of the inverter N1 and the output end of the polarity determination unit 204, the seventh diode D7 is electrically connected between the source and the drain of the third field effect transistor M3, and the seventh diode D7 The positive electrode is electrically connected to the source of the third field effect transistor M3, and the negative electrode is electrically connected to the source of the third field effect transistor M3.

The fourth control circuit 218 includes a fourth field effect transistor M4 and an eighth diode D8, wherein the fourth field effect transistor M4 can be an N-channel field effect transistor, and the gate of the fourth field effect transistor M4 is electrically connected to the first On the node between the other end of an inverter N1 and the output end of the polarity judging unit 204, the source is grounded, the drain is electrically connected to the drain of the second field effect transistor M2, and the eighth diode D8 is electrically connected to the fourth between the source and drain of the field effect transistor M4, and the anode of the eighth diode D8 is electrically connected to the source of the fourth field effect transistor M4, and the negative electrode is electrically connected to the source of the fourth field effect transistor M4 .

It should be noted that the field effect transistors M1-M4 can also be transistors, and the field effect transistors M1-M4 are not fixed as P-channel or N-channel, and can be adjusted according to different conduction requirements.

The selection unit 202 includes a first contact group switch S1, a second contact group switch S2 and a coil L1, and the first contact group switch S1 includes a first contact S1a, a second contact S1b and a third contact S1c, the second contact group switch S2 includes a fourth contact S2a, a fifth contact S2b and a sixth contact S2c, wherein the first, third, fourth and sixth contacts S1a, S1c, S2a, S2c is a static contact, and the second and fifth contacts S1b, S2b are movable contacts. In this embodiment, the second contact S1b and the fifth contact S2b are electrically connected to the first receiving end and the second receiving end of the receiving unit 201 respectively, and both the first contact S1a and the sixth contact S2c are connected to the power receiving end. The positive input end of the circuit 30 is electrically connected, and both the third contact S1c and the fourth contact S2a are electrically connected to the negative input end of the power receiving circuit 30 . The coil L1 includes a first connection end and a second connection end, wherein the first connection end is electrically connected to the node between the drain of the first field effect transistor M1 and the drain of the third field effect transistor M3, and the second connection end is electrically connected to On the node between the drain of the second field effect transistor M2 and the drain of the fourth field effect transistor M4. In this embodiment, when the current flows into the coil L1 from the first connection end and then flows out from the second connection end, it is defined that the current flows in the coil L1 as clockwise, of course, it can also be defined that the current flows in the coil L1 as counterclockwise, Subsequent description will be made in detail by taking an example in which the current flows clockwise in the coil L1 when the current flows into the coil L1 from the first connection end and then flows out from the second connection end.

The first contact group switch S1 is used to control the second contact S1b to be electrically connected to the first contact S1a or the third contact S1c according to the current flow in the coil L1. When there is no current in the coil L1, the second contact The point S1b is connected to neither the first contact S1a nor the third contact S1c. The second contact group switch S2 is used to control the fifth contact S2b to be electrically connected to the fourth contact S2a or the sixth contact S2c according to the current flow in the coil L1. When there is no current in the coil L1, the fifth contact The point S2b is connected to neither the fourth contact S2a nor the sixth contact S2c. Moreover, the control connection of the first contact group switch S1 and the second contact group switch S2 according to the current flow in the coil L1 is the same. For example, when the current in the coil L1 flows clockwise, the second contact S1b of the first contact group switch S1 may be electrically connected to the first contact S1a, then the second contact S1b of the second contact group switch S2 The five contacts S2b are electrically connected to the fourth contact S2a; or the second contact S1b of the first contact group switch S1 is electrically connected to the third contact S1c, then the second contact S2 of the second contact group switch S2 The fifth contact S2b is electrically connected to the sixth contact S2c, and when the current flow in the coil L1 is clockwise, the second contact S1b of the first contact group switch S1 is connected to the first contact S1a, and the second contact The fifth contact S2b of the point group switch S2 is electrically connected to the fourth contact S2a as an example for detailed description. The first contact group switch S1 and the second contact group switch S2 are controlled by the small current flowing in the coil L1, so that the channel between the receiving unit 201 and the power receiving circuit 30 is connected to achieve the purpose of low power consumption rectification .

In a specific embodiment, when the power supply end device 40 is initially connected to the receiving unit 201 of the power receiving end device 10, the power supply end device 40 outputs a very small current through the first, second, third and fourth second After being rectified by the rectifier bridge formed by the pole tubes D1-D4, it flows into the power receiving circuit 30. The power supply device 40 detects the characteristic impedance of the power receiving device 10, and then outputs a corresponding voltage according to the detected characteristic impedance to provide the power receiving circuit. End device 10 supplies power. When the power supply device 40 supplies power to the power receiving device 10 normally, the DC/DC converter obtains the auxiliary power signal from the power receiving circuit 30 and outputs a small positive current; the comparator U1 compares the receiving unit 201 The voltage between the first receiving terminal input voltage signal and the ground to generate a judgment signal, such as a high level; the first control circuit 212 receives the high level output from the comparator U1 and the positive output from the DC/DC converter Direct current, then the source and drain of the first field effect transistor M1 in the first control circuit 212 will be conducted, and the forward current output by the DC/DC converter will be from the first coil L1 The access end flows into the coil L1, and then flows out from the second access end of the coil L1; the fourth control circuit 218 receives the high level output by the comparator U1 and the positive current flowing out from the second access end of the coil L1, Then the source and drain of the fourth field effect transistor M4 of the fourth control circuit 218 will be turned on, and the positive current flowing from the second access end of the coil L1 will flow into the ground, and the coil L1 will be Form a small current flowing clockwise, the second contact S1b of the first contact group switch S1 is electrically connected to the first contact S1a, the fifth contact S2b of the second contact group switch S2 is connected to the fourth The contact S2a is electrically connected, the channel between the power supply device 40 and the power receiving circuit 30 will be connected, and the receiving end with a positive output voltage of the first receiving end and the second receiving end of the receiving unit 201 will be connected to the receiving end. The positive input end of the circuit 30, the first receiving end of the receiving unit 201 and the receiving end with a negative output voltage in the second receiving end will be connected to the negative input end of the power receiving circuit 30 to achieve the purpose of rectification, and in During the rectification process, almost no current will flow into the power receiving circuit 30 through the rectification bridge composed of four diodes, the current flowing in the coil L1 is very small, and the power consumption of the rectification unit will also be very small, so the purpose of low power consumption rectification is achieved .

Compared with the prior art, the power receiving end device 10 provided by the embodiment of the present invention includes a power receiving circuit 30, a receiving unit 201 and at least one rectifying unit 20, the receiving unit 201 is used to receive the voltage signal output by the power supply end device 40, and rectify The unit 20 is used for supplying power to the receiving circuit 30 after being rectified. Each rectification unit 20 includes a rectification circuit 200 , an auxiliary power supply unit 208 , a polarity determination unit 204 , a control unit 206 and a selection unit 202 . The rectification circuit 200 provides a current path between the receiving unit 201 and the power receiving end device 10 . The auxiliary power supply unit 208 provides an auxiliary power supply signal; the polarity determination unit 204 determines the polarity of the input voltage signal and generates a determination signal. The control unit 206 outputs a control signal according to the judgment signal and the auxiliary power signal. The selection unit 202 selects the positive output terminal of the power supply device 40 to connect to the positive input terminal of the power receiving circuit 30 according to the control signal, so as to achieve the purpose of low power consumption rectification.

It can be understood that those skilled in the art can make various other corresponding changes and modifications according to the technical concept of the present invention, and all these changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (10)

1. A power receiving device connected to a power supply device, the power receiving device includes a power receiving circuit, the power receiving circuit includes a positive input terminal, a negative input terminal and an output terminal, and the power supply terminal device Outputting voltage signals to the power receiving end device, characterized in that the power receiving end device further includes: The receiving unit includes a first receiving end and a second receiving end, configured to receive voltage signals of different polarities from the power supply device; At least one rectification unit is used to rectify and process the voltage signals of different polarities to supply power to the power receiving circuit, and each rectification unit includes: A rectification circuit, including two input terminals and two output terminals, the two input terminals of the rectification circuit are respectively electrically connected to the first receiving terminal and the second receiving terminal, and the two output terminals are respectively connected to the The positive input terminal and the negative input terminal of the power receiving circuit are connected to provide a current path between the receiving unit and the power receiving circuit; An auxiliary power supply unit, connected to the output end of the power receiving circuit, for providing an auxiliary power supply signal after the power supply device supplies power to the power receiving end; A polarity judging unit, connected to one of the first receiving end and the second receiving end of the receiving unit, for judging the polarity of the voltage signal, and generating a judging signal according to the polarity of the voltage signal; a control unit, connected to the auxiliary power supply unit and the polarity judging unit, for outputting a control signal according to the judging signal and the polarity of the auxiliary voltage signal; and A selection unit, connected in parallel with the rectifier circuit and connected with the control unit, is used to select the receiving terminal with a positive output voltage among the first receiving terminal and the second receiving terminal to be connected to the receiving terminal according to the control signal The positive input terminal of the electrical circuit, and select the receiving terminal with a negative output voltage among the first receiving terminal and the second receiving terminal to connect to the negative input terminal of the power receiving circuit. 2. The power receiving end device according to claim 1, wherein the rectifier circuit includes first, second, third and fourth diodes, the cathode of the first diode and the second The anodes of the diodes are both electrically connected to the first receiving end, and the anodes of the first diode and the fourth diode are both electrically connected to the negative input end of the powered circuit, Both the anode of the third diode and the cathode of the fourth diode are electrically connected to the second receiving end, and the cathode of the second diode is connected to the cathode of the third diode Both are electrically connected to the positive input end of the power receiving circuit. 3. The receiving end device according to claim 1, wherein the control unit comprises a first control circuit, wherein the first control circuit comprises a first field effect transistor, a first inverter and a second Five diodes, the gate of the first field effect transistor is electrically connected to one end of the first inverter, the source is electrically connected to the auxiliary power supply unit, and the other end of the first inverter One end is electrically connected to the polarity judging unit, the fifth diode is electrically connected between the source and the drain of the first field effect transistor, and the anode of the fifth diode is connected to the The drain of the first field effect transistor is electrically connected. 4. The power receiving end device according to claim 3, wherein the control unit further comprises a second control circuit, wherein the second control circuit comprises a second field effect transistor and a sixth diode, The gate of the second field effect transistor is electrically connected to the node between the other end of the first inverter and the polarity judging unit, and the source is electrically connected to the source of the first field effect transistor On the node of the auxiliary power supply unit, the sixth diode is electrically connected between the source and the drain of the second field effect transistor, and the anode of the sixth diode is connected to the The drain of the second field effect transistor is electrically connected. 5. The receiving end device according to claim 4, wherein the control unit further comprises a third control circuit, wherein the third control circuit comprises a third field effect transistor, a second inverter and A seventh diode, the gate of the third FET is electrically connected to one end of the second inverter, the source is grounded, and the drain is electrically connected to the drain of the first FET , the other end of the second inverter is electrically connected to the node between the other end of the first inverter and the polarity judging unit, and the seventh diode is electrically connected to the third between the source and the drain of the field effect transistor, and the anode of the seventh diode is electrically connected to the source of the third field effect transistor. 6. The power receiving end device according to claim 5, wherein the control unit further comprises a fourth control circuit, wherein the fourth control circuit comprises a fourth field effect transistor and an eighth diode, The gate of the fourth field effect transistor is electrically connected to the node of the other end of the first inverter and the polarity judging unit, the source is grounded, and the drain is connected to the drain of the second field effect transistor. pole is electrically connected, the eighth diode is electrically connected between the source and the drain of the fourth field effect transistor, and the anode of the eighth diode is connected to the fourth field effect transistor source electrical connection. 7. The power receiving end device according to claim 1, wherein the selection unit includes a relay, and the relay includes a first contact group type switch, a second contact group type switch and a coil, wherein the The coil includes a first access end and a second access end, and the first access end and the second access end of the coil are respectively electrically connected to the control unit, and are used to receive the output generated by the control unit. The control signal is used to determine the flow direction of the current in the coil, the first contact group switch includes a first contact, a second contact and a third contact, and the second contact group switch includes a first contact Four contacts, a fifth contact and a sixth contact, the second and fifth contacts are respectively connected to the first receiving end and the second receiving end, the first contact and the sixth contact Both are electrically connected to the positive input end of the power receiving circuit, and both the third contact and the fourth contact are electrically connected to the negative input end of the power receiving circuit. 8. The receiving end device according to claim 7, wherein the first, third, fourth and sixth contacts are static contacts, and the second and fifth contacts are moving contacts point, the six contacts are in contact with each other according to the current flow in the coil, when the coil controls the electrical connection between the second contact and the first contact, the fifth contact and the first contact When the four contacts are electrically connected, the receiving end whose output voltage is positive among the first receiving end and the second receiving end is connected to the positive input end of the power receiving circuit, and the first receiving end and the second receiving end Among the terminals, the receiving terminal whose output voltage is negative is connected to the negative input terminal of the power receiving circuit. 9. The power receiving end device according to claim 8, wherein when the coil controls the electrical connection between the second contact and the third contact, the fifth contact and the first contact When the six contacts are electrically connected, the receiving end whose output voltage is positive among the first receiving end and the second receiving end is connected to the positive input end of the power receiving circuit, and the first receiving end and the second receiving end Among the terminals, the receiving terminal whose output voltage is negative is connected to the negative input terminal of the power receiving circuit. 10. The power receiving terminal device according to claim 1, wherein the polarity determination unit comprises a first resistor, a second resistor and a comparator, and one end of the first resistor is electrically connected to the first resistor a receiving end, the other end of which is electrically connected to one end of the second resistor, the other end of the second resistor is grounded, and the positive input end of the comparator is electrically connected to the common node of the first resistor and the second resistor, The inverting input terminal is grounded, and the output terminal of the comparator is electrically connected to the control unit, wherein the comparator is used to compare the voltage between the first receiving terminal and ground to generate the judgment signal.