CN107333085A

CN107333085A - A kind of power supply unit and electric power system

Info

Publication number: CN107333085A
Application number: CN201710701636.2A
Authority: CN
Inventors: 何宇翔; 朱奇峰; 许兴玉; 邓志吉
Original assignee: Zhejiang Dahua Technology Co Ltd
Current assignee: Zhejiang Dahua Technology Co Ltd
Priority date: 2017-08-16
Filing date: 2017-08-16
Publication date: 2017-11-07
Anticipated expiration: 2037-08-16
Also published as: CN107333085B

Abstract

The invention discloses a kind of power supply unit and electric power system, the power supply unit includes power input, recognition unit, processing unit, switch element and external interface；Recognition unit is used for the partial pressure value for obtaining power receiving equipment in real time, determines the rising duration of power receiving equipment partial pressure value, and the rising duration is sent into processing unit；Processing unit judges to rise duration whether in the time span of setting, if it is, being defined as POC equipment, the power input is powered by the switch element to the power receiving equipment；If not, being defined as non-POC equipment, do not powered for the power receiving equipment.It is larger according to the difference of the rising duration of the magnitude of voltage of POC equipment and non-POC equipment in embodiments of the present invention, when in non-power supply state, power supply unit obtains the partial pressure value of power receiving equipment in real time, it is determined that rising duration, so that it is determined that the type of power receiving equipment, it is to avoid the type of POC equipment confirms the problem of power receiving equipment burns caused by mistake.

Description

Power supply equipment and power supply system

Technical Field

The invention relates to the technical field of coaxial power supply, in particular to power supply equipment and a power supply system.

Background

In the analog video transmission system available on the market at present, there is a Power Over Coax (POC) transmission scheme, which includes a Power supply terminal and a Power receiving terminal, and the specific content of the scheme is to couple a Power supply required by a Power receiving device and an analog video signal in the same coaxial line for transmission, so as to reduce the construction cost caused by primary or secondary wiring, and the Power receiving device can normally operate without an external adapter. In the POC transmission scheme, there is a strict requirement on whether the powered device is a POC device. When the powered device is a POC device, the power sourcing equipment may normally source power to the powered device, but when the powered device is a non-POC device, the powered device may be burned when the power sourcing equipment sources power to the powered device in a POC transmission scheme. Therefore, it is important to determine whether a powered device is a POC device in a POC transmission scheme.

In the prior art, a power supply device includes a switch, and the switch is in an off state before the power supply device is powered on, and the type of the power receiving device is detected. Specifically, the type of the power receiving apparatus is determined by a characteristic resistance method, which determines the type of the power receiving apparatus from a divided voltage value of a characteristic resistance of the power receiving apparatus. And when the voltage division value of the characteristic resistor of the powered device is within a preset range, determining that the powered device is a POC device, further controlling a switch in the power supply device to be closed, and supplying power to the powered device, otherwise, determining that the powered device is a non-POC device, and controlling the switch in the power supply device to be continuously in an off state, and not supplying power to the powered device. However, some non-POC devices are similar to the characteristic resistance of the POC device, and at this time, the non-POC devices are mistaken as POC devices, and if the switch in the power supply device is controlled to be closed at this time, power is supplied to the powered device, which may cause the powered device to be burnt.

Disclosure of Invention

The embodiment of the invention provides a power supply device and a power supply system, which are used for solving the problem that the type of a powered device is inaccurate so that the powered device is burnt in the prior art.

The embodiment of the invention provides power supply equipment, which comprises a power supply input end, an identification unit, a processing unit, a switch unit and an external interface, wherein the power supply input end is connected with the identification unit; wherein,

the identification unit is respectively connected with the external interface and the processing unit, and the external interface is used for connecting powered equipment; the identification unit is used for acquiring a voltage division value of the powered device in real time when the powered device is in a non-power-supply state, determining that the powered device is connected with the external interface when the voltage division value is a preset first voltage division value, and taking the current moment as a first moment; determining the moment when the partial pressure value is a preset second partial pressure value as a second moment; determining the rising time of the voltage division value of the powered device according to the first time and the second time, and sending the rising time to a processing unit;

the processing unit is respectively connected with the identification unit and the switch unit, the power supply input end is connected with the switch unit, and the switch unit is connected with an external interface; the processing unit is configured to receive the rise time sent by the identification unit, determine whether the rise time is within a set time length, determine that the powered device is a POC device if the rise time is within the set time length, control the switch unit to be turned on, and supply power to the powered device through the switch unit at the power input end; if not, determining that the powered device is a non-POC device, and controlling the switch unit to be switched off without supplying power to the powered device.

Further, the power supply apparatus further includes: the system comprises a power supply processing unit, a video processing unit and a video receiving end;

the power supply processing unit is respectively connected with the power supply input end and the switch unit and is used for blocking the transmission of the video signal sent by the powered device to the power supply input end when the switch unit is closed;

the video processing unit is respectively connected with the video receiving terminal and the external interface, and is used for receiving the video signal sent by the powered device, compensating the video signal, and sending the video signal after compensation to the video receiving terminal.

Further, the power supply processing unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a first triode, a second triode, an inductor and a magnetic bead;

one end of the first resistor is connected with the power input end, one end of the second resistor is connected with the series connection point of the first resistor and the power input end, and the other end of the second resistor is connected with the emitting electrode of the first triode; one end of the first resistor, which is not connected with the power supply input end, is respectively connected with an emitting electrode of the second triode and one end of the fourth resistor; one end of the first capacitor is connected with the first resistor and the serial connection point of the power input end, and the other end of the first capacitor is respectively connected with the third resistor, the base electrode of the first triode and the base electrode of the second triode;

one end of the third resistor, which is not connected with the first capacitor, the collector of the first triode, the collector of the second triode and one end of the fourth resistor, which is not connected with the first resistor, are respectively connected with one end of the magnetic bead; the other end of the magnetic bead is respectively connected with the inductor and the fifth resistor; and one end of the inductor and the fifth resistor, which is not connected with the magnetic beads, is connected with the switch unit.

Further, the power supply apparatus further includes: a fluctuation detection unit;

the fluctuation detection unit is respectively connected with the video processing unit and the external interface, and is used for performing low-pass filtering processing on the video signal sent by the powered device, detecting the voltage value of the video signal after the low-pass filtering processing, judging whether the voltage value is within a preset voltage value range, and if not, sending a control signal to the video processing unit;

the video processing unit is further configured to filter a video signal of which the voltage value is not within a preset voltage value range in the video signal when receiving the control signal sent by the fluctuation detection unit, perform compensation processing on the filtered video signal, and send the video signal after the compensation processing to a video receiving end.

Further, the video processing unit is further configured to extract a coaxial anti-control signal sent by the video receiving end, superimpose the coaxial anti-control signal, and send the superimposed coaxial anti-control signal to a powered device through the external interface.

Further, the power supply apparatus further includes: a protection unit;

the protection unit is respectively connected with the switch unit, the processing unit and the external interface and is used for judging whether the current value of the protection unit is within a preset current range or not, and if not, sending a disconnection signal to the processing unit;

and the processing unit is also used for controlling the switch unit to be switched off after receiving the switching-off signal.

In another aspect, an embodiment of the present invention provides a power supply system, where the system includes a powered device and the power supply device; wherein,

the power supply equipment is connected with the powered equipment and used for acquiring a voltage division value of the powered equipment in real time when the powered equipment is in a non-power supply state, determining that the powered equipment is connected with the external interface when the voltage division value is a preset first voltage division value, and taking the current moment as a first moment; determining the moment when the partial pressure value is a preset second partial pressure value as a second moment; determining the rising time of the voltage division value of the powered device according to the first time and the second time, judging whether the rising time is within a set time length, if so, determining that the powered device is a POC device, and supplying power to the powered device; if not, determining that the powered device is a non-POC device and not supplying power to the powered device.

Further, the power receiving device is configured to perform isolation processing on the video signal, and send the video signal after the isolation processing to the power supply device.

Furthermore, the power supply device is further configured to extract a coaxial anti-control signal, perform superposition processing on the coaxial anti-control signal, and send the superposed coaxial anti-control signal to a powered device;

the power receiving equipment is also used for adjusting the bias voltage of the power receiving equipment, determining a target coaxial inverse control signal according to the adjusted bias voltage and the received coaxial inverse control signal, and executing a corresponding function according to the target coaxial inverse control signal.

Further, the power receiving device is further configured to rapidly discharge itself when recognizing that itself is disconnected from the power supply device.

Further, the powered device includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third transistor, a fourth transistor, and a second capacitor;

one end of the sixth resistor is connected with the power supply equipment, one end of the eighth resistor is connected with the serial connection point of the sixth resistor and the power supply equipment, and the other end of the eighth resistor is respectively connected with the collector electrode of the third triode and the base electrode of the fourth triode; one end of the ninth resistor is connected with the series connection point of the sixth resistor and the power supply equipment, and the other end of the ninth resistor is connected with the collector of the fourth triode; one end of the second capacitor is connected with the serial connection point of the sixth resistor and the power supply equipment, and the other end of the second capacitor is grounded; one end of the sixth resistor, which is not connected with the power supply equipment, is respectively connected with the seventh resistor and the base electrode of the third triode; one end of the seventh resistor, which is not connected with the sixth resistor, is grounded; and the emitter of the third triode and the emitter of the fourth triode are grounded.

The embodiment of the invention provides a power supply device and a power supply system, wherein the power supply device comprises a power supply input end, an identification unit, a processing unit, a switch unit and an external interface; the identification unit is respectively connected with the external interface and the processing unit, and the external interface is used for connecting powered equipment; the identification unit is used for acquiring a voltage division value of the powered device in real time when the powered device is in a non-power-supply state, determining that the powered device is connected with the external interface when the voltage division value is a preset first voltage division value, and taking the current moment as a first moment; determining the moment when the partial pressure value is a preset second partial pressure value as a second moment; determining the rising time of the voltage division value of the powered device according to the first time and the second time, and sending the rising time to a processing unit; the processing unit is respectively connected with the identification unit and the switch unit, the power supply input end is connected with the switch unit, and the switch unit is connected with an external interface; the processing unit is configured to receive the rise time sent by the identification unit, determine whether the rise time is within a set time length, determine that the powered device is a POC device if the rise time is within the set time length, control the switch unit to be turned on, and supply power to the powered device through the switch unit at the power input end; if not, determining that the powered device is a non-POC device, and controlling the switch unit to be switched off without supplying power to the powered device. In the embodiment of the invention, according to the fact that the difference of the rising time lengths of the voltage values of the POC equipment and the non-POC equipment is large, when the POC equipment and the non-POC equipment are in a non-power-supply state, the power supply equipment can acquire the partial pressure value of the powered equipment in real time, and according to the partial pressure value of the powered equipment, the rising time length of the partial pressure value of the powered equipment can be determined, so that the type of the powered equipment is determined, and the problem that the powered equipment is burnt due to the wrong type.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a power supply device provided in embodiment 1 of the present invention;

fig. 2 is a circuit diagram of an identification unit provided in embodiment 1 of the present invention;

fig. 3 is a schematic diagram illustrating a change in a partial pressure value of a powered device according to embodiment 1 of the present invention;

fig. 4 is a schematic structural diagram of a power supply device provided in embodiment 2 of the present invention;

fig. 5 is a circuit diagram of a blocking video signal according to embodiment 2 of the present invention;

fig. 6 is a schematic structural diagram of a power supply device provided in embodiment 3 of the present invention;

fig. 7 is a schematic structural diagram of a video processing unit according to embodiment 3 of the present invention;

fig. 8 is a circuit diagram for determining whether there is a video signal with a larger voltage amplitude and filtering out the video signal with a larger voltage amplitude according to embodiment 3 of the present invention;

fig. 9A is a schematic view of a video signal when a video signal with a large unfiltered voltage amplitude is provided in embodiment 3 of the present invention;

fig. 9B is a schematic diagram of a video signal after a video signal with a larger voltage amplitude is filtered according to embodiment 3 of the present invention;

fig. 10 is a schematic structural diagram of a video processing unit according to embodiment 4 of the present invention;

fig. 11 is a circuit diagram for extracting the coaxial counter control signals and performing superposition processing on the coaxial counter control signals according to embodiment 4 of the present invention;

fig. 12 is a schematic structural diagram of a power supply device provided in embodiment 5 of the present invention;

fig. 13 is a circuit diagram of an overcurrent protection circuit according to embodiment 5 of the present invention;

fig. 14 is a circuit diagram of a pull-out protection circuit of a power receiving device according to embodiment 5 of the present invention;

fig. 15 is a schematic structural diagram of a power supply system according to embodiment 6 of the present invention;

fig. 16 is a schematic structural diagram of a power receiving apparatus according to embodiment 7 of the present invention;

fig. 17 is a schematic diagram of bias voltages of a powered device before adjustment according to embodiment 8 of the present invention;

fig. 18 is a schematic diagram of the adjusted bias voltage of the powered device according to embodiment 8 of the present invention;

fig. 19 is a circuit diagram for implementing fast discharge provided in embodiment 9 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the attached drawings, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

fig. 1 is a schematic structural diagram of a power supply device according to an embodiment of the present invention, where the power supply device includes a power input end 11, an identification unit 12, a processing unit 13, a switch unit 14, and an external interface 15; wherein,

the identification unit 12 is connected to the external interface 15 and the processing unit 13, respectively, and the external interface 15 is used for connecting a powered device; the identification unit 12 is configured to obtain a voltage division value of the powered device in real time when the powered device is in a non-power-supply state, determine that the powered device is connected to the external interface 15 when the voltage division value is a preset first voltage division value, and use a current time as a first time; determining the moment when the partial pressure value is a preset second partial pressure value as a second moment; determining a rising time of the voltage division value of the powered device according to the first time and the second time, and sending the rising time to the processing unit 13;

the processing unit 13 is respectively connected with the identification unit 12 and the switch unit 14, the power input end 11 is connected with the switch unit 14, and the switch unit 14 is connected with an external interface 15; the processing unit 13 is configured to receive the rise time period sent by the identifying unit 12, determine whether the rise time period is within a set time length, if so, determine that the powered device is a POC device, control the switch unit 14 to be closed, and enable the power input end 11 to supply power to the powered device through the switch unit 14; if not, determining that the powered device is a non-POC device, controlling the switch unit 14 to be turned off, and not supplying power to the powered device.

In the embodiment of the present invention, the identification unit 12 is connected to the external interface 15 and the processing unit 13, respectively, the external interface 15 is used for connecting to the powered device through a coaxial cable, the switch unit 14 is connected to the power input terminal 11, the processing unit 13 and the external interface 15, respectively, when the switch unit 14 is closed, the power supply device is in a power supply state, and if the external interface 15 is connected to the powered device at this time, the power input terminal 11 can supply power to the powered device. In order to prevent the connected powered device from being burned when it is a non-POC device, the switch unit 14 needs to be turned off when determining whether the powered device is a POC device or a non-POC device, that is, whether the powered device is a POC device or a non-POC device in the unpowered state.

When in the unpowered state, the identification unit 12 may acquire the voltage division value of the powered device in real time. The identification unit 12 may obtain the voltage division value of the powered device according to a software program, or may be implemented by building a hardware circuit. When the external interface 15 is not connected to the powered device, the identification unit 12 cannot form a path with the powered device through the external interface 15, and at this time, the identification unit 12 obtains the voltage division value of the powered device as a larger voltage value, and when the external interface 15 is connected to the powered device, the identification unit 12 forms a path with the powered device through the external interface 15, and at this time, the identification unit 12 obtains the voltage division value of the powered device as a smaller voltage value, so that the identification unit 12 can store a preset first voltage division value, where the first voltage division value is a voltage value capable of indicating the time when the external interface 15 is connected to the powered device, and when the voltage division value of the powered device obtained by the identification unit 12 is the preset first voltage division value, it is determined that the powered device is connected to the external interface, and the current time is taken as the first time.

The powered device includes a capacitor, and after the external interface 15 is connected to the powered device, the voltage division value of the powered device increases within a certain time period. The identification unit 12 may store a preset second voltage division value, where the second voltage division value is greater than the first voltage division value, and when the voltage division value of the powered device acquired by the identification unit 12 is the preset second voltage division value, it is determined that the current time is the second time. From the first time and the second time, a rise time of the power receiving apparatus voltage division value may be determined, and the identification unit 12 may transmit the rise time to the processing unit 13.

Specifically, in the embodiment of the present invention, the identifying unit 12 may obtain the voltage division value of the powered device in real time through the circuit diagram shown in fig. 2. At the moment when the external interface 15 is connected to the powered device, a voltage of 3.3V in the circuit diagram shown in fig. 2 is transmitted to the powered device through the resistor R and the diode D, a step signal with a very high frequency is generated at the moment of transmission, and since the frequency of the step signal is very high, the impedance presented by the capacitor in the powered device to the step signal is 0, and thus, at the moment when the external interface 15 is connected to the powered device, the voltage division value of the powered device obtained by the identification unit 12 is 0. When the power receiving apparatus is not connected, the identification unit 12 cannot form a path with the power receiving apparatus, and thus the acquired divided voltage value is 3.3V as shown in fig. 2.

The preset first voltage division value stored in the recognition unit 12 may be 0. When the voltage division value of the powered device obtained by the identification unit 12 is 0, it is determined that the powered device is connected to the external interface 15, and the current time is taken as the first time. The identification unit 12 stores a preset second voltage division value, where the second voltage division value is greater than the first voltage division value and smaller than the voltage value output by the identification unit 12, for example, the voltage value output by the identification unit 12 is 3.3V, and the preset second voltage division value may be 2.2V, 2.3V, or the like. When the voltage division value of the powered device acquired by the identification unit 12 is a preset second voltage division value, it is determined that the current time is a second time. The identification unit 12 may determine a rise time period of the voltage division value of the power receiving apparatus from the first time and the second time, and transmit the rise time period to the processing unit 13.

The processing unit 13 may receive the rise time period sent by the identification unit 12. Since the capacitance of the non-POC device is relatively small, if the connected powered device is a non-POC device, the time for the powered device to increase the divided voltage value from the first divided voltage value to the second divided voltage value is very short and is substantially instantaneous, whereas the capacitance of the POC device is relatively large, and therefore, if the connected powered device is a POC device, the time for the powered device to increase the divided voltage value from the first divided voltage value to the second divided voltage value is relatively long compared to the non-POC device. As shown in fig. 3, the time t3 for the partial pressure value of the non-POC device to increase from the first partial pressure value to the second partial pressure value is very short, close to 0; the time t2 for increasing the voltage division value of the POC device with the capacitance of 220uF from the first voltage division value to the second voltage division value is close to 0.1 second; the time t1 for the voltage division value of the POC device with the capacitance of 470uF to increase from the first voltage division value to the second voltage division value is close to 0.2 seconds.

Therefore, the processing unit 13 may store the set time length, and after receiving the ascending time length sent by the identifying unit 12, determine whether the ascending time length is within the set time length, if so, determine that the powered device is a POC device, otherwise, determine that the powered device is a non-POC device. The set time period may be, for example, 0.08 to 0.22 seconds.

If it is determined that the powered device is a POC device, supplying power to the powered device does not burn the powered device, so the processing unit 13 may send a close signal to the switch unit 14, control the switch unit 14 to close, and the power input terminal 11 supplies power to the powered device through the switch unit 14. If the powered device is determined to be a non-POC device, the processing unit 13 may send an off signal to the switching unit 14, and control the switching unit 14 to turn off, so that the power input terminal 11 does not supply power to the powered device, and thus, the powered device may be prevented from being burned.

In the embodiment of the present invention, when the power receiving device is in the unpowered state, the identification unit may obtain the voltage division value of the power receiving device in real time, and according to the voltage division value of the power receiving device, may determine a rising time duration of the voltage division value of the power receiving device, and send the rising time duration to the processing unit, where a difference between rising times of the voltage values of the POC device and the non-POC device is large, and when the processing unit determines that the rising time duration is within a set time duration, the processing unit determines that the power receiving device is a POC device, controls the switch unit to be turned on, and supplies power to the power receiving device, and otherwise, determines that the power receiving device is a non-POC device, and controls the switch unit. Therefore, the problem that the powered device is burnt out if the powered device is powered when the non-POC device is mistaken as the POC device is solved.

Example 2:

on the basis of the foregoing embodiment, in the embodiment of the present invention, fig. 4 is a schematic structural diagram of a power supply device provided in the embodiment of the present invention, where the power supply device further includes: a power supply processing unit 21, a video processing unit 22, and a video receiving terminal 23;

the power processing unit 21 is respectively connected to the power input terminal 11 and the switch unit 14, and is configured to block transmission of the video signal sent by the powered device to the power input terminal 11 when the switch unit 14 is closed;

the video processing unit 22 is connected to the video receiving terminal 23 and the external interface 15, and is configured to receive the video signal sent by the powered device, perform compensation processing on the video signal, and send the video signal after compensation processing to the video receiving terminal 23.

The power sourcing equipment may supply power to the powered device via the power input 11, and the powered device may transmit a video signal to the power sourcing equipment. In the embodiment of the present invention, the power supply apparatus includes a video receiving end 23 for receiving a video signal transmitted by the power receiving apparatus, and in order to improve the quality of the video signal received by the video receiving end 23, the power supply apparatus further includes a power processing unit 21 and a video processing unit 22. The power processing unit 21 is respectively connected to the power input terminal 11 and the switch unit 14, when the switch is closed, the power input terminal 11 supplies power to the powered device through the power processing unit 21, and the power processing unit 21 can also block the transmission of the video signal sent by the powered device to the power input terminal 11, so as to reduce the attenuation of the video signal, and enable the video signal to be transmitted to the video receiving terminal 23.

In addition, the video signal inevitably has a certain attenuation in the process of being transmitted from the powered device to the video receiving end 23, and in order to ensure the quality of the video signal received by the video receiving end 23, the video processing unit 22 in the power supply device may perform compensation processing on the video signal transmitted by the powered device, and transmit the video signal after the compensation processing to the video receiving end 23. The process of performing compensation processing on a video signal belongs to the prior art, and is not described herein again.

In the embodiment of the present invention, the power processing unit 21 may block the video signal sent by the powered device from being transmitted to the power input end 11 by software, or may build a hardware circuit. Fig. 5 is a circuit diagram for blocking a video signal, the power processing unit 21 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a first triode Q1, a second triode Q2, an inductor L, and a magnetic bead FB;

one end of a first resistor R1 is connected with a power supply input end, one end of a second resistor R2 is connected with a series connection point of the first resistor R1 and the power supply input end, and the other end of the second resistor R2 is connected with an emitting electrode of a first triode Q1; the end of the first resistor R1 which is not connected with the power supply input end is respectively connected with the emitter of the second triode Q2 and one end of the fourth resistor R4; one end of a first capacitor C1 is connected with the serial connection point of the first resistor R1 and the power supply input end, and the other end is respectively connected with a third resistor R3, the base electrode of the first triode Q1 and the base electrode of the second triode Q2;

one end of the third resistor R3, which is not connected with the first capacitor C1, the collector of the first triode Q1, the collector of the second triode Q2 and one end of the fourth resistor R4, which is not connected with the first resistor R1, are respectively connected with one end of the magnetic bead FB; the other end of the magnetic bead FB is respectively connected with the inductor L and the fifth resistor R5; the end of the inductance L and the fifth resistor R5 not connected to the magnetic bead FB is connected to the switching unit 14.

In the circuit diagram shown in fig. 5, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first capacitor C1, the first transistor Q1, and the second transistor Q2 function as low-frequency signal isolation. Specifically, since the voltage across the first capacitor C1 is not abrupt, the voltage Vbe1 between the base and the emitter of the first transistor Q1 and the voltage Vbe2 between the base and the emitter of the second transistor Q2 can be clamped by charging and discharging the first capacitor C1, and the current between the base and the emitter of the first transistor Q1 and the current between the base and the emitter of the second transistor Q2 can be controlled by controlling the voltage Vbe1 between the base and the emitter of the first transistor Q1 and the voltage Vbe2 between the base and the emitter of the second transistor Q2.

Therefore, for low-frequency signals in the video signal transmitted by the powered device, the first capacitor C1 is charged and discharged through the third resistor R3, and at this time, the voltage Vbe1 between the base and the emitter of the first transistor Q1 and the voltage Vbe2 between the base and the emitter of the second transistor Q2 change, so that the current flowing between the base and the emitter of the first transistor Q1 and the current flowing between the base and the emitter of the second transistor Q2 change, that is, the response time of the circuit to the low-frequency signals can be controlled by controlling the charging and discharging time constants of the third resistor R3 and the first capacitor C1. When the resistance value of the third resistor R3 is larger or the first capacitor C1 is larger, the response time to the low-frequency signal is slower, and the equivalent impedance is larger; when the third resistor R3 or the first capacitor C1 is smaller, the response time to the low frequency signal is faster, and the equivalent impedance is smaller. Therefore, in the embodiment of the present invention, the third resistor R3 or the first capacitor C1 may be increased to increase the equivalent impedance, thereby playing a role in isolating low-frequency signals.

The inductor L and the fifth resistor R5 in the circuit diagram shown in fig. 5 perform medium-high frequency isolation, and are represented by the inductance formula: x_L2 pi Lf, in which X_LSince L is inductance and f is frequency, it can be seen that the inductance L shown in fig. 5 is large due to high frequency when the inductance L is applied to the medium-high frequency signal in the video signal transmitted from the power receiving device, and further, the medium-high frequency signal isolation function is performed. In addition, since the inductance L of the circuit needs a certain amount of current, and the inductance L needs a larger amount of inductance in order to present a higher impedance to the middle and high frequency signals, the self-resonant frequency of the inductance L becomes very low. Therefore, the isolation impedance of the high-frequency signal can be increased by adding the magnetic bead FB.

Example 3:

when the powered device has large power fluctuation, for example, an infrared lamp is switched, zooming is performed, and the like, a video signal with a voltage amplitude much higher than that of a normal video signal may exist in a video signal sent by the powered device, and the frequency of the video signal with the higher voltage amplitude is lower, so that the video signal is identified by the power supply device in a problem due to the existence of the video signal with the higher voltage amplitude, and finally the video signal is lost. In order to ensure that a received video signal can be identified when a power receiving device has large power fluctuation, on the basis of the foregoing embodiments, in an embodiment of the present invention, fig. 6 is a schematic structural diagram of a power supply device according to an embodiment of the present invention, where the power supply device further includes: a fluctuation detection unit 31;

the fluctuation detection unit 31 is connected to the video processing unit 22 and the external interface 15, respectively, and the fluctuation detection unit 31 is configured to perform low-pass filtering processing on the video signal sent by the powered device, detect a voltage value of the video signal after the low-pass filtering processing, determine whether the voltage value is within a preset voltage value range, and if not, send a control signal to the video processing unit 22;

the video processing unit 22 is further configured to, when receiving the control signal sent by the fluctuation detection unit 31, filter a video signal in the video signal, where the voltage value of the video signal is not within a preset voltage value range, perform compensation processing on the filtered video signal, and send the video signal after the compensation processing to the video receiving end 23.

In the embodiment of the present invention, when the power receiving device has a large power fluctuation, in order to ensure that the power supply device can identify the received video signal, the video signal with a large voltage amplitude generated by the power receiving device having a large power fluctuation needs to be filtered. Before filtering out a video signal with a large voltage amplitude, it is necessary to determine whether the video signal has a video signal with a large voltage amplitude. The fluctuation detection unit 31 in the power supply apparatus is used to determine whether a video signal having a large voltage amplitude exists in the video signal.

Specifically, the fluctuation detection unit 31 can receive a video signal transmitted by the power receiving apparatus, and since the frequency of the video signal having a large voltage amplitude is low, it is not necessary to determine the middle-high frequency signal, and therefore the fluctuation detection unit 31 performs low-pass filtering processing on the video signal transmitted by the power receiving apparatus. Since the voltage amplitude of the video signal having a larger voltage amplitude is much higher than that of the normal video signal, the voltage value of the video signal having a larger voltage amplitude is different from that of the normal video signal. The fluctuation detection unit 31 may store a preset voltage value range, detect the voltage value of the video signal after the low-pass filtering processing is performed on the video signal, determine whether the voltage value is within the preset voltage value range, if so, determine that no video signal with a large voltage amplitude exists in the video signal, and the video processing unit 22 directly performs the compensation processing on the video signal sent by the powered device and sends the video signal after the compensation processing to the video receiving end 23. If the voltage value is not within the preset voltage value range, it is determined that a video signal with a larger voltage amplitude exists in the video signal, and in order to ensure that the power supply device can identify the received video signal, the video signal with the larger amplitude needs to be filtered out, specifically, the fluctuation detection unit 31 sends a control signal to the video processing unit 22 after determining that the voltage value is not within the preset voltage value range, that is, after determining that the video signal with the larger voltage amplitude exists in the video signal, and controls the video processing unit 22 to filter the video signal with the larger voltage amplitude.

When receiving the control signal sent by the fluctuation detection unit 31, the video processing unit 22 filters out a video signal of which the voltage value is not within a preset voltage value range, that is, a video signal with a larger voltage amplitude, performs compensation processing on the filtered video signal, and sends the video signal after compensation processing to the video receiving end 23. As shown in fig. 7, the video processing unit 22 includes a fluctuation filtering subunit 221 and a video signal compensation subunit 222, the fluctuation filtering subunit 221 is connected to the fluctuation detection unit 31, the fluctuation filtering subunit 221 filters a video signal with a large voltage amplitude after receiving the control signal sent by the fluctuation detection unit 31, and sends the filtered video signal to the video signal compensation subunit 222, and the video signal compensation subunit 222 is connected to the video receiving end 23, and can perform compensation processing on the filtered video signal and send the compensated video signal to the video receiving end 23.

In the embodiment of the present invention, when determining whether there is a video signal with a large voltage amplitude and filtering out a video signal with a large voltage amplitude, the video signal with a large voltage amplitude may be implemented by software, or implemented by building a hardware circuit as shown in fig. 8.

As shown in fig. 8, the video signal transmitted by the power receiving apparatus is transmitted to the fluctuation detection unit 31 and the fluctuation filter subunit 221, the video driver U3 in the fluctuation detection unit 31 plays a role of isolating the video signal and filtering the video signal of a predetermined frequency band, and the resistor and the capacitor in the fluctuation detection unit 31 constitute a low-pass filter circuit for performing low-pass filter processing on the video signal. The video signal after the low-pass filtering processing is respectively input to a positive input end of the comparator U4 and a negative input end of the comparator U5, and the voltage value provided by the VH end is larger than that provided by the VL end. If the voltage value of the video signal after the low-pass filtering is greater than the voltage value provided by VH, it is determined that a video signal with a large voltage amplitude exists in the video signal, the comparator U4 outputs a high-level signal, the comparator U5 outputs a low-level signal, the diode D3 is turned on, the diode D4 is turned off, and at this time, the high-level signal output to the fluctuation filtering subunit 211 by the fluctuation detecting unit 31 is the control signal. If the voltage value of the video signal after the low-pass filtering processing is smaller than the voltage value provided by VL, it is determined that a video signal with a larger voltage amplitude exists in the video signal, the comparator U4 outputs a low-level signal, the comparator U5 outputs a high-level signal, the diode D3 is turned off, the diode D4 is turned on, and at this time, the high-level signal output to the fluctuation filtering subunit 211 by the fluctuation detection unit 31 is the control signal. If the voltage value of the video signal after the low-pass filtering processing is greater than the voltage value supplied by VL and less than the voltage value supplied by VH, it is determined that there is no video signal with a large voltage amplitude in the video signal, both the comparators U4 and U5 output low-level signal diodes D3 and D4 to be turned off, and the fluctuation detecting unit 31 outputs a low-level signal to the fluctuation filtering subunit 211.

The control signal sent by the fluctuation detection unit 31 to the fluctuation filtering subunit 221 is a high-level signal, the high-level signal controls the MOS transistor M3 in the fluctuation filtering subunit 221 to be closed, at this time, the resistor Rd and the capacitor Cd in the fluctuation filtering subunit 221 form a high-pass filter, and by adjusting the resistor Rd and the capacitor Cd, the fluctuation filtering subunit 221 can filter out a video signal with a large voltage amplitude from the video signal sent by the powered device.

When the powered device has large power fluctuation, that is, there is a video signal with a large voltage amplitude, before the video signal with the large voltage amplitude is filtered, the video signal sent by the powered device is as shown in fig. 9A, the video signal sent by the powered device includes a normal video signal and a video signal with a large voltage amplitude, and the video signal after the video signal with the large voltage amplitude is filtered is as shown in fig. 9B.

In the embodiment of the present invention, when the power receiving device has a large power fluctuation, that is, when there is a video signal with a large voltage amplitude, the fluctuation detection unit 31 may determine that there is a video signal with a large voltage amplitude, and send a control signal to the video processing unit 22, control the video processing unit 22 to filter the video signal with a large voltage amplitude, and after the video processing unit 22 filters the video signal with a large voltage amplitude, perform compensation processing on the filtered video signal, and send the video signal after the compensation processing to the video receiving end 23, so that when the power receiving device has a large power fluctuation, it is ensured that the power supply device can identify the received video signal.

Example 4:

on the basis of the foregoing embodiments, in the embodiment of the present invention, the video processing unit 22 is further configured to extract a coaxial anti-control signal sent by the video receiving end 23, perform superposition processing on the coaxial anti-control signal, and send the superposed coaxial anti-control signal to a powered device through the external interface 15.

In this embodiment of the present invention, the video receiving end 23 may further send a coaxial inverse control signal to a powered device, and the video processing unit 22 may extract the coaxial inverse control signal sent by the video receiving end 23, as shown in fig. 10, the video processing unit 22 further includes an inverse control signal extracting subunit 223, the inverse control signal extracting subunit 223 is connected to the video receiving end 23, and the inverse control signal extracting subunit 223 may extract the coaxial inverse control signal sent by the video receiving end 23. Generally, the signal driving capability of the inverse control signal extracting subunit 223 is poor, in order to ensure that the extracted coaxial inverse control signal can be transmitted to the power receiving device, as shown in fig. 10, the video processing unit 22 further includes an inverse control signal superimposing subunit 224, the inverse control signal superimposing subunit 224 is respectively connected to the inverse control signal extracting subunit 223 and the external interface 15, and is configured to perform superposition processing on the coaxial inverse control signal extracted by the inverse control signal extracting subunit 223, improve the signal driving capability, and further send the superimposed coaxial inverse control signal to the power receiving device through the external interface 15.

In the embodiment of the present invention, when the coaxial anti-control signal sent by the video receiving end 23 is extracted and the coaxial anti-control signal is subjected to superposition processing, the coaxial anti-control signal may be implemented by software, or may be implemented by building a hardware circuit as shown in fig. 11.

As shown in fig. 11, the coaxial inversion control signal is sent from the video receiving terminal 23, the voltage amplitude of the coaxial inversion control signal after passing through the resistor Rs is reduced due to the voltage division of Rs, as shown in fig. 11, the coaxial inversion control signal can be extracted by the voltage difference between the two input terminals of the comparator U1, and after passing through the RC low pass filter composed of the resistor and the capacitor, the coaxial inversion control signal is sent to the input terminal of the comparator U2, and the comparator U2 outputs the switching signal, which is a high level signal and a low level signal, by comparing the coaxial inversion control signal with the comparison level Vref. The switching signal can control the on or off of the MOS transistors M2 and M1, wherein the high level signal controls the MOS transistors M2 and M1 to be on, and the low level signal controls the MOS transistors M2 and M1 to be off. After the MOS tube M2 is conducted, the coaxial inverse control signal can be superposed on the external interface 15 through the resistor Rc; the MOS transistor M1 is turned on, and can pull the video signal sent by the power receiving device to the ground through the resistor, so as to prevent the coaxial inverse control signal at the external connection buckle 15 from being fed back to the video output end 23. Thus, the extraction and superposition of the coaxial inverse control signals can be completed. The process of extracting the coaxial counter control signal sent by the video receiving end 23 through the circuit diagram shown in fig. 11 and performing superposition processing on the coaxial counter control signal belongs to the prior art, and is not described herein again.

Example 5:

on the basis of the foregoing embodiments, in an embodiment of the present invention, fig. 12 is a schematic structural diagram of a power supply device provided in an embodiment of the present invention, where the power supply device further includes: a protection unit 41;

the protection unit 41 is respectively connected with the switch unit 14, the processing unit 13 and the external interface 15, and is configured to determine whether a current value of the protection unit is within a preset current range, and if not, send a disconnection signal to the processing unit 13;

the processing unit 13 is further configured to control the switch unit 14 to be turned off after receiving the turn-off signal.

The power supply unit is at the in-process to the powered device power supply, the condition that the overcurrent condition or powered device pull out is likely to appear, if the overcurrent condition appears, power supply unit still is in the power supply state, then the components and parts in the power supply unit or the powered device that burns out, if the powered device pulls out the back, power supply unit still is in the power supply state, high pressure can appear in external interface 15 department, when the powered device reconnection, probably has the unable problem of discerning being connected with the powered device.

In the embodiment of the present invention, in order to avoid burning components in the power supply device or burning the powered device, and avoid the problem that the connection with the powered device may not be recognized when the powered device is connected again, the power supply device further includes a protection unit 41. The protection unit 41 can detect whether an overcurrent condition or a condition of unplugging the powered device occurs.

Specifically, when an overcurrent condition occurs, the current value of the protection unit 41 itself is too large, and when the powered device is pulled out, the current value of the protection unit 41 itself is 0, and the current value of the protection unit 41 itself under these two abnormal conditions is different from the current value of the protection unit 41 itself when the power supply device normally supplies power to the powered device, so that the protection unit 41 can store a preset current range, and the protection unit 41 determines whether the current value of the protection unit is within the preset current range, and if so, it indicates that the power supply device normally supplies power to the powered device; if not, the abnormal situation is shown, and a disconnection signal is sent to the processing unit 13. After receiving the turn-off signal, the processing unit 13 sends a turn-off signal to the switching unit 14, and controls the switching unit 14 to turn off. The power supply equipment is in a non-power supply state, the problem that components in the power supply equipment or the powered equipment are possibly burnt when an overcurrent condition occurs is avoided, and the problem that the powered equipment is possibly connected with the powered equipment cannot be identified when the powered equipment is connected again is avoided.

In the embodiment of the present invention, sending a disconnection signal to the processing unit when an overcurrent condition occurs may be implemented by software, or may be implemented by building a circuit diagram shown in fig. 13; when the current of the resistor Rs is too large, the voltage drop of the resistor Rs is increased, the voltage drop of the base and the emitter of the triode Q5 is increased, the voltage division value of the ground resistor Rg is increased, the level signal sent to the processing unit 13 by the ungrounded end of the resistor Rg is increased, after the level signal is sent to the processing unit 13, the processing unit 13 sends a disconnection signal to the switch unit 14 according to the received level signal, the switch unit 14 is controlled to be disconnected, and overcurrent short-circuit protection is completed. The process of implementing overcurrent protection through the circuit diagram shown in fig. 13 belongs to the prior art, and is not described herein again.

The sending of the disconnection signal to the processing unit when the power receiving device is unplugged may be implemented by software, or may be implemented by building a circuit diagram shown in fig. 14. When the powered device is pulled out, the self current becomes 0, at this time, the diode D2 is turned off, the base and the emitter of the triode Q6 are disconnected, the voltage drop across the ground resistor Rg 'becomes 0, the ungrounded end of the resistor Rg' sends a level signal to the processing unit 13, after the level signal is sent to the processing unit 13, the processing unit 13 sends a disconnection signal to the switching unit 14 according to the received level signal, the switching unit 14 is controlled to be disconnected, and the pull-out protection of the powered device is completed. The process of implementing the pull-out protection of the powered device through fig. 14 belongs to the prior art, and is not described herein again.

Example 6:

fig. 15 is a schematic structural diagram of a power supply system according to an embodiment of the present invention, where the system includes the power supply apparatus 151 and a powered apparatus 152; wherein,

the power supply device 151 is connected to the powered device 152, and is configured to obtain a voltage division value of the powered device 152 in real time when the powered device is in a non-power-supply state, determine that the powered device 152 is connected to the external interface when the voltage division value is a preset first voltage division value, and use a current time as a first time; determining the moment when the partial pressure value is a preset second partial pressure value as a second moment; determining a rising time length of the voltage division value of the powered device 152 according to the first time and the second time, judging whether the rising time length is within a set time length, if so, determining that the powered device 152 is a POC device, and supplying power to the powered device 152; if not, it is determined that the powered device 152 is a non-POC device and no power is supplied to the powered device.

In order to prevent the connected powered device 152 from being burned when the powered device 152 is a non-POC device, the power supply device 151 needs to determine whether the powered device 152 is a POC device or a non-POC device in a non-power supply state when determining whether the powered device 152 is a POC device or a non-POC device.

When in the non-power-supplied state, the power supply apparatus 151 can acquire the voltage division value of the power receiving apparatus 152 in real time. When the external interface 15 is not connected to the external device 152, the power supply device 151 cannot form a path with the powered device 152, and at this time, the power supply device 151 obtains the voltage division value of the powered device 152 as a larger voltage value, and when the power supply device 151 is connected to the powered device 152, the power supply device 151 forms a path with the powered device 152, and at this time, the power supply device 151 obtains the voltage division value of the powered device 152 as a smaller voltage value, so that the preset first voltage division value can be stored in the power supply device 151, and when the voltage division value of the powered device 152 obtained by the power supply device 151 is the preset first voltage division value, it is determined that the powered device 152 is connected to the power supply device 151, and the current time is taken as the first time. The power supply apparatus 151 may further store a preset second voltage division value, where the second voltage division value is greater than the first voltage division value, and when the voltage division value of the powered apparatus 152 acquired by the power supply apparatus 151 is the preset second voltage division value, it is determined that the current time is the second time. From the first timing and the second timing, a rise time period of the voltage division value of the power receiving apparatus 152 can be determined. The power supply apparatus 151 stores a set time length, determines whether the rising time length is within the set time length after determining the rising time length of the voltage division value of the powered apparatus 152, and if so, determines that the powered apparatus 152 is a POC apparatus, otherwise, determines that the powered apparatus 152 is a non-POC apparatus. If the powered device 152 is determined to be a POC device, power is supplied to the powered device 152. If the powered device 152 is determined to be a non-POC device, no power is supplied to the powered device 152, thereby avoiding burning the powered device 152.

Example 7:

in addition to the above embodiments, in the embodiment of the present invention, the power receiving apparatus 152 is configured to perform isolation processing on a video signal, and transmit the video signal after the isolation processing to the power supply apparatus 151.

As shown in fig. 16, the powered device 152 includes a video output terminal 1521 and a load terminal 1522, the video output terminal 1521 can transmit a video signal to the power supply device 151, and in order to reduce the attenuation of the video signal and improve the quality of the video signal received by the power supply device 151, the powered device 152 can perform an isolation process on the video signal transmitted by the video output terminal 1521, wherein the video signal can be isolated from being transmitted to the load terminal 1522 by using the circuit diagram shown in fig. 5. And transmits the video signal after the isolation process to the power supply apparatus 151. The process of performing the isolation processing on the video signal through the circuit diagram shown in fig. 5 is not described herein again.

Example 8:

on the basis of the foregoing embodiments, in an embodiment of the present invention, the power supply device 151 is further configured to extract a coaxial counter control signal, perform superposition processing on the coaxial counter control signal, and send the superposed coaxial counter control signal to the power receiving device 152;

the powered device 152 is further configured to adjust a bias voltage of the device itself, determine a target coaxial inverse control signal according to the adjusted bias voltage and the received coaxial inverse control signal, and execute a corresponding function according to the target coaxial inverse control signal.

In the power supply system according to the embodiment of the present invention, the power supply device 151 and the power receiving device 152 are connected by a coaxial cable, two ends of the coaxial cable are respectively provided with a dc blocking capacitor, and the dc blocking capacitor at the end of the power receiving device 152 is connected to the video output end 1521, and is used for blocking current sent by the power supply device 151. However, the presence of the dc blocking capacitance changes its bias voltage. As shown in fig. 17, if the resistance in both the power supply apparatus 151 and the power receiving apparatus 152 is 75 ohms, the voltage output from the video output terminal 1521 in the power receiving apparatus 152 is Vdc, when there is no blocking capacitor, the bias voltage at the point P is Vdc/2 due to the voltage division of the 75 ohm resistance in the power supply apparatus 151, and when there is a blocking capacitor, the voltage output from the video output terminal 1521 in the power receiving apparatus 152 cannot be transmitted to the power supply apparatus 151, when the bias voltage at the point P is Vdc. The bias voltage at point P changes, but the comparison level Vref does not change in the load terminal 1522, so that the coaxial inversion control signal extracted by the comparator will be in error.

In order to ensure that the extracted coaxial inverse control signal is accurate, the powered device 152 may adjust its own bias voltage, as shown in fig. 18, the powered device 152 may adjust the bias voltage of the point P by adjusting a voltage Va and an adjusting resistor Ra, and may adjust the bias voltage of the point P to an accurate value by adjusting values of Va and Ra, and the adjusted accurate bias voltage and the received coaxial inverse control signal are transmitted to a comparator, and the comparator extracts the target coaxial inverse control signal, and the powered device 152 may perform a corresponding function according to the target coaxial inverse control signal.

In addition, if the comparison level Vref in the load end 1522 is already adjusted according to the power supply system, for example, the comparison level is adjusted to Vref + Vdc/2, so that the powered device 152 does not need to adjust its own bias voltage, and can also ensure that a correct coaxial inverse control signal is extracted.

Example 9:

in addition to the above embodiments, in the embodiment of the present invention, the power receiving apparatus 152 is further configured to quickly discharge itself when recognizing that itself is disconnected from the power supply apparatus 151.

When disconnecting itself from the power supply apparatus 151, in order to prevent the problem of excessive current of itself occurring when reconnecting to the power supply apparatus 151 in a short time, it is necessary to rapidly discharge itself upon recognizing that itself is disconnected from the power supply apparatus 151. Wherein a fast discharge can be realized by the circuit diagram described in fig. 19.

As shown in fig. 19, the powered device 152 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third transistor Q3, a fourth transistor Q4, and a second capacitor C2;

one end of the sixth resistor R6 is connected to the power supply 151, one end of the eighth resistor R8 is connected to a serial connection point of the sixth resistor R6 and the power supply 151, and the other end of the eighth resistor R8 is connected to a collector of the third triode Q3 and a base of the fourth triode Q4, respectively; one end of the ninth resistor R9 is connected to the series connection point of the sixth resistor R6 and the power supply device 151, and the other end is connected to the collector of the fourth triode Q4; one end of the second capacitor C2 is connected to the series connection point of the sixth resistor R6 and the power supply device 151, and the other end is grounded; one end of the sixth resistor R6, which is not connected with the power supply 151, is connected with the base electrodes of the seventh resistor R7 and the third triode Q3 respectively; the end of the seventh resistor R7 which is not connected with the sixth resistor R6 is grounded; the emitter of the third transistor Q3 and the emitter of the fourth transistor Q4 are grounded.

As shown in fig. 19, when the self is disconnected from the power supply device 151, since the second capacitor C2 discharges slowly, the current of the self decreases slowly, when the current of the self is high, the collector and the emitter of the third transistor Q3 are turned on, the base of the fourth transistor Q4 is pulled down to the ground, when the current of the self decreases to a certain value, the collector and the emitter of the third transistor Q3 are turned off, the base of the fourth transistor Q4 is pulled up, the collector and the emitter of the fourth transistor Q4 are turned on, and at this time, the ninth resistor R9 is grounded through the collector and the emitter of the fourth transistor Q4, so that the current decreases rapidly, that is, the self discharges rapidly.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The power supply equipment is characterized by comprising a power supply input end, an identification unit, a processing unit, a switch unit and an external interface; wherein,

2. The power supply device according to claim 1, wherein the power supply device further comprises: the system comprises a power supply processing unit, a video processing unit and a video receiving end;

3. The power supply device according to claim 2, wherein the power supply processing unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a first triode, a second triode, an inductor, and a magnetic bead;

4. The power supply device according to claim 2, characterized in that the power supply device further comprises: a fluctuation detection unit;

5. The power supply device according to claim 2 or 4, wherein the video processing unit is further configured to extract a coaxial anti-control signal sent by the video receiving end, perform superposition processing on the coaxial anti-control signal, and send the superposed coaxial anti-control signal to a powered device through the external interface.

6. The power supply device according to any one of claims 1 to 5, characterized in that the power supply device further comprises: a protection unit;

7. A power supply system characterized in that the system comprises a power receiving apparatus and the power supply apparatus according to any one of claims 1 to 6; wherein,

8. The system of claim 7, wherein the powered device is configured to isolate the video signal and send the isolated video signal to the power sourcing equipment.

9. The system of claim 7, wherein the power supply device is further configured to extract a coaxial counter control signal, perform superposition processing on the coaxial counter control signal, and send the superposed coaxial counter control signal to a powered device;

10. The system of claim 7, wherein the powered device is further configured to rapidly discharge itself upon identifying that it is disconnected from the power sourcing equipment.

11. The system of claim 10, wherein the powered device comprises a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third transistor, a fourth transistor, and a second capacitor;