CN205921601U - Ethernet power supply system and control circuit thereof - Google Patents
Ethernet power supply system and control circuit thereof Download PDFInfo
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- CN205921601U CN205921601U CN201620701202.3U CN201620701202U CN205921601U CN 205921601 U CN205921601 U CN 205921601U CN 201620701202 U CN201620701202 U CN 201620701202U CN 205921601 U CN205921601 U CN 205921601U
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Abstract
The utility model provides an ethernet power supply system and control circuit thereof. The ethernet power supply system include: power adapter provide a power supply voltage between power adapter's positive terminal and the negative pole end, the power supply unit provide the 2nd power supply voltage between the positive terminal of power supply unit and the negative pole end, terminal equipment receive between terminal equipment's power end and the earthing terminal first power supply press with one of the 2nd power supply voltage is as mains voltage, control circuit is used for when satisfying power demand, breaks off power adapter the power supply unit power adapter disconnection or insert when under -voltage the power supply unit. This ethernet power supply system detects power adapter voltage, with its turn into with the 2nd power supply voltage's reference ground is as the on -off control signal of referring to ground to switching between control power supply unit and the power adapter.
Description
Technical field
This utility model belongs to electronic technology field, relates more specifically to POE system and its control circuit.
Background technology
POE (poe, power over ehernet) technology refers to connect up architecture in existing Ethernet
On the basis of, the technology of direct current supply is provided for some network-termination devices by netting twine.In power over Ethernet, netting twine is simultaneous
There ares transmission data signal and direct current supply.This technology makes terminal unit need not rely on external power adapter to power, from
And power supply adaptor, power cable and plug can be saved, save wiring and hardware cost.POE is extensively applied
In fields such as voip phone, wireless ap, video monitorings.
In a lot of application scenarios, user wishes that terminal unit both can adopt POE, it would however also be possible to employ individually
Power supply adaptor is powered.Namely it is desirable to POE system can compatible power supply adaptor be powered.Fig. 1 illustrates according to existing
The schematic block diagram of the POE system of technology.This POE system includes power supply unit pse (power
Sourcing equipment), power receiving equipment pd (power device) and power supply adaptor apd.Power supply unit pse is via net
Line is connected with power receiving equipment pd, and power supply adaptor apd is connected with power receiving equipment pd via power line.Power receiving equipment pd selects
Property ground obtain supply voltage from one of power supply unit pse and power supply adaptor apd.
Power receiving equipment pd includes control circuit pdc and terminal unit pdt.Terminal unit pdt connects via control circuit pdc
Power supply unit pse, thus obtaining electric energy using POE mode, and is converted into the voltage needed for terminal unit pdt.This
Outward, terminal unit pdt is directly connected to power supply adaptor apd, thus obtaining electric energy using independently-powered mode.Control circuit pdc
Generally include a switching tube q1.When there are the abnormal conditions such as surge or excessively stream in power receiving equipment pd, control circuit pdc can be controlled
The supply path to disconnect power supply unit pse for the switching tube q1 processed, to carry out current-limiting protection.
In control circuit pdc, the source electrode of switching tube q1 connects power supply unit pse negative pole end vss, and drain electrode connects terminal and sets
The ground gnd of standby pdt.When the systems are operating normally, switching tube q1 conducting, power supply unit pse negative pole end vss and terminal unit pdt
Ground gnd voltage essentially identical.Control circuit pdc is by the input voltage v of power supply unit psepseAlmost all is transferred to and is set by electricity
Standby pd.If power supply adaptor apd is connected to the two ends of terminal unit pdt, the grid of switching tube q1 applies power supply first
Supply voltage vapdSo that switching tube q1 disconnects, thus power supply adaptor apd directly powers.
Due to the presence of control circuit pdc, the POE mode of power supply unit pse is more only than power supply adaptor apd
Vertical power supply mode many one-levels energy conversion, efficiency is lower, therefore, is connected with power supply unit pse in power receiving equipment pd and power supply is fitted
During both orchestration apd, preferentially adopt the independently-powered mode of power supply adaptor apd.
However, in above-mentioned power supply mode, because the switching control mode of switching tube q1 is simple, it is understood that there may be power supply
The electric voltage exception of adapter apd leads to switching tube q1 to fail the problem disconnecting as a result, power supply unit pse and power supply adaptor apd
Between will produce path so that electric current recharge occurs therebetween, thus lead to circuit damage.
Therefore, it is desirable to improve POE system and its control circuit further, to keep away in POE system
Exempt from the electric current recharge between power supply unit and power supply adaptor, thus improving the reliability of circuit.
Utility model content
In view of this, the purpose of this utility model is to provide a kind of POE system and its control circuit, is used for
The POE system of compatible power supply adaptor, wherein adopts detection module to detect the supply voltage of power supply adaptor, according to
Detection signal is switched in or out power supply unit, thus controlling the switching between power supply unit and power supply adaptor.
According to one side of the present utility model, provide a kind of POE system, comprising: power supply adaptor, described
First supply voltage is provided between the positive terminal of power supply adaptor and negative pole end；Power supply unit, in the positive pole of described power supply unit
The second supply voltage is provided between end and negative pole end；Terminal unit, respectively with described power supply adaptor and described power supply unit phase
Connect, receive between the power end and earth terminal of described terminal unit described first voltage supplied and described second supply voltage it
One as supply voltage；Control circuit, is connected between described power supply unit and described terminal unit, for fitting in described power supply
Orchestration meets and disconnects described power supply unit during power demands, disconnects or accesses described power supply when under-voltage in described power supply adaptor and sets
Standby, wherein, described control circuit includes detection module and switching tube, and the outfan of described detection module connects to described switching tube
Control end, for the detection signal of described first supply voltage is converted to switch controlling signal, thus controlling described switch
The conducting of pipe and disconnection, described detection signal using the reference ground of described first supply voltage as reference ground, described on-off control
Signal is using the reference ground of described second supply voltage as reference ground.
Preferably, also include voltage sample module, described voltage sample module is connected to the positive pole of described power supply adaptor
Between end and negative pole end, for producing described detection signal.
Preferably, described voltage sample module is resistance pressure-dividing network, and described resistance pressure-dividing network includes being connected in series
First resistor and second resistance.
Preferably, also include the first diode, the positive terminal of described power supply adaptor connects via described first diode
To the power end of described terminal unit, thus forming the power end from the positive terminal of described power supply adaptor to described terminal unit
Unidirectional current path.
Preferably, also include the second diode, the negative pole end of described power supply unit via described second diode connect to
The earth terminal of described terminal unit, thus formation is from the negative pole end of described power supply unit to described end when described switching tube disconnects
The unidirectional current path of the earth terminal of end equipment.
Preferably, described switching tube has body diode, and the negative pole end of described power supply unit is via described body diode even
It is connected to the earth terminal of described terminal unit, thus formation is from the negative pole end of described power supply unit to institute when described switching tube disconnects
State the unidirectional current path of the earth terminal of terminal unit.
Preferably, also include rectifier bridge, the first input end of described rectifier bridge and the second input connect described confession respectively
The positive terminal of electric equipment and negative pole end, the first outfan of described rectifier bridge and the second outfan are respectively connecting to described terminal and set
Standby power end and earth terminal.
Preferably, described detection module includes inverting amplifier, phase inverter and the logic circuit being sequentially connected, described detection
Module receives the detection signal of described first supply voltage, and described logic circuit provides described switch controlling signal.
Preferably, described inverting amplifier includes being sequentially connected in series in the power end of described terminal unit and described power supply
The first transistor between the negative pole end of equipment, 3rd resistor and the 4th resistance, and be connected with described 4th resistor coupled in parallel
First Zener diode, the control end described detection signal of reception of described the first transistor, the two of described first Zener diode
End obtains first voltage signal, and described phase inverter and described logic circuit carry out to described first voltage signal anti-phase respectively and patrol
Collect and control thus obtaining described switch controlling signal.
Preferably, described the first transistor is p-type metal oxide semiconductor field-effect transistor.
Preferably, described inverting amplifier include being sequentially connected in series the power end of described terminal unit and earth terminal it
Between the 5th resistance, the 6th resistance and transistor seconds, and be sequentially connected in series in the power end of described terminal unit and institute
State third transistor between the negative pole end of power supply unit, the 7th resistance and the 8th resistance, and with described 5th resistor coupled in parallel
The 3rd Zener diode that the second Zener diode connecting is connected with described 8th resistor coupled in parallel, described transistor seconds
Control end receives described detection signal, and the control end of described third transistor connects to described 5th resistance and described 6th resistance
Intermediate node, the two ends of described 3rd Zener diode obtain first voltage signal, described phase inverter and described logic circuit
Respectively anti-phase and logic control is carried out thus obtaining described switch controlling signal to described first voltage signal.
Preferably, described transistor seconds is n-type metal oxide semiconductor field-effect transistor, described third transistor
For p-type metal oxide semiconductor field-effect transistor.
According to another aspect of the present utility model, provide a kind of POE control circuit, be connected to power supply unit and
Between terminal unit, for the first supply voltage according to power supply adaptor, it is switched in or out described power supply unit, described power supply
Equipment provides the second supply voltage, and described POE control circuit includes: detection module；And switching tube, wherein, described
The outfan of detection module connects to the control end of described switching tube, for changing the detection signal of described first supply voltage
For switch controlling signal, thus controlling conducting and the disconnection of described switching tube, described detection signal is with described first supply voltage
Reference ground as reference ground, described switch controlling signal is using the reference ground of described second supply voltage as reference ground.
Preferably, described detection module includes inverting amplifier, phase inverter and the logic circuit being sequentially connected, described detection
Module receives the detection signal of described first supply voltage, and described logic circuit provides described switch controlling signal.
Preferably, described inverting amplifier includes being sequentially connected in series in the power end of described terminal unit and described power supply
The first transistor between the negative pole end of equipment, 3rd resistor and the 4th resistance, and be connected with described 4th resistor coupled in parallel
First Zener diode, the control end described detection signal of reception of described the first transistor, the two of described first Zener diode
End obtains first voltage signal, and described phase inverter and described logic circuit carry out to described first voltage signal anti-phase respectively and patrol
Collect and control thus obtaining described switch controlling signal.
Preferably, described the first transistor is p-type metal oxide semiconductor field-effect transistor.
Preferably, described inverting amplifier include being sequentially connected in series the power end of described terminal unit and earth terminal it
Between the 5th resistance, the 6th resistance and transistor seconds, and be sequentially connected in series in the power end of described terminal unit and institute
State third transistor between the negative pole end of power supply unit, the 7th resistance and the 8th resistance, and with described 5th resistor coupled in parallel
The 3rd Zener diode that the second Zener diode connecting is connected with described 8th resistor coupled in parallel, described transistor seconds
Control end receives described detection signal, and the control end of described third transistor connects to described 5th resistance and described 6th resistance
Intermediate node, the two ends of described 3rd Zener diode obtain first voltage signal, described phase inverter and described logic circuit
Respectively anti-phase and logic control is carried out thus obtaining described switch controlling signal to described first voltage signal.
Preferably, described transistor seconds is n-type metal oxide semiconductor field-effect transistor, described third transistor
For p-type metal oxide semiconductor field-effect transistor.
According to the third aspect of the present utility model, provide a kind of POE control method, comprising: detection first power supply
Voltage, to produce the detection signal of described first supply voltage；The detection signal of described first supply voltage is converted to switch
Control signal；And the second supply voltage is switched in or out using described switch controlling signal, wherein, described detection signal is with institute
The reference ground stating the first supply voltage as reference ground, made with the reference ground of described second supply voltage by described switch controlling signal
For reference ground.
POE system according to this utility model is implemented, when described power supply adaptor meets power demands
Disconnect described power supply unit, disconnect in described power supply adaptor or access described power supply unit when under-voltage.This POE system
System detection power adapter voltage, is translated into the on-off control letter using the reference ground of power supply unit voltage as reference ground
Number, it is achieved thereby that floating ground voltage detection function.Therefore, this POE system detectio power adapter voltage, by its turn
Turn to the switch controlling signal using the reference ground of described second supply voltage as reference ground, thus controlling power supply unit and power supply
Switching between adapter, such that it is able to improve the reliability of circuit, and the quiescent current reducing control circuit.
In a preferred embodiment, formed from the positive terminal of described power supply adaptor to described terminal using the first diode
The unidirectional current path of the power end of equipment, thus preventing the electric current recharge to power supply adaptor from power supply unit, and adopts
Second diode, forms the earth terminal from the negative pole end of described power supply unit to described terminal unit when described switching tube disconnects
Unidirectional current path, thereby may be ensured that control circuit still in power supply holding state.When power supply adaptor power-off or under-voltage
Afterwards, can the equipment of restoring electricity power in time.
Brief description
By the description to this utility model embodiment referring to the drawings, of the present utility model above-mentioned and other mesh
, feature and advantage will be apparent from.
Fig. 1 is the schematic block diagram of the POE system according to prior art.
Fig. 2 is the schematic block diagram of the POE system according to this utility model embodiment.
Fig. 3 is a kind of schematic circuit of control circuit used in the POE system of Fig. 2.
Fig. 4 is the schematic circuit of another kind of control circuit used in the POE system of Fig. 2.
Specific embodiment
It is more fully described this utility model hereinafter with reference to accompanying drawing.In various figures, identical element is using similar
Reference representing.For the sake of clarity, the various pieces in accompanying drawing are not necessarily to scale.Furthermore, it is possible to it is not shown
Some known parts.
Describe hereinafter many specific details of the present utility model, the structure of such as device, material, size, place
Science and engineering skill and technology, to be more clearly understood that this utility model.But just as the skilled person will understand,
This utility model can not be realized according to these specific details.
This utility model people notices in POE system if it is desired to power supply adaptor is powered simultaneously, then with
Too net electric power system needs to solve following problem: in power supply unit voltage vpseWith the first supply voltage vapdIn the presence of simultaneously, should
When avoiding producing path between two power supply units, prevent electric current recharge.In addition, the detection module in POE system,
The power adapter voltage as reference with the ground gnd of terminal unit pdt should be detected, detection signal is converted into power supply unit
Negative pole end vss is the switch controlling signal of reference.This POE system should include being applied to the detection module on floating ground.
In order to solve the above problems, this utility model people proposes the POE that a kind of compatibility power supply adaptor is powered
System, wherein, when detection module pdc detects power adapter voltage and meets power demands, power supply unit is disconnected, and adopts
Power supply adaptor is powered, and when detection module pdc detects power supply adaptor and disconnects or be under-voltage, power supply unit is accessed.Due to
There is no current path between power supply unit and power supply adaptor, influence each other thus without because the phenomenon of electric current recharge occurs.
This utility model people additionally provides two kinds of detection modules being applied in POE system, for detecting power supply adaptor electricity
Pressure, and detection signal is converted into the switch controlling signal as reference with power supply unit negative pole end vss, thus controlling power supply to fit
Being switched in or out of orchestration.
This utility model can present in a variety of manners, some of them example explained below.
Fig. 2 is the schematic block diagram of the POE system according to this utility model embodiment.This POE system
System includes power supply unit pse, power receiving equipment pd and power supply adaptor apd.Power supply unit pse is via netting twine and power receiving equipment pd phase
Connect, power supply adaptor apd is connected with power receiving equipment pd via power line.Power receiving equipment pd is optionally from power supply unit
One of pse and power supply adaptor apd obtain supply voltage, and wherein power supply adaptor apd provides the first supply voltage vapd, power supply
Equipment pse provides the second supply voltage vpse.Power supply unit pse can carry out communication with control circuit pdc and be mutually distinguishable.
Power receiving equipment pd includes control circuit pdc and terminal unit pdt.Terminal unit pdt connects via control circuit pdc
Power supply unit pse, obtains electric energy using POE mode.Additionally, terminal unit pdt is directly connected to power supply adaptor apd,
Electric energy is obtained using independently-powered mode.
When power receiving equipment pd is connected with both power supply unit pse and power supply adaptor apd, preferentially adopt power supply adaptor
The independently-powered mode of apd.When power supply adaptor apd disconnects or be under-voltage, power supply unit pse is accessed and is powered.
Further, POE system also includes voltage sample module apds, the first filter capacitor cin, the second filter
Ripple electric capacity co, the first diode d1 and the second diode d2.
Voltage sample module apds is connected between positive terminal and the negative pole end of power supply adaptor apd, for fitting to power supply
The first supply voltage v that orchestration apd providesapdSampled, thus obtaining for characterizing the first supply voltage vapdDetection letter
Number vs.For example, voltage sample module apds is resistance pressure-dividing network, including resistance r1 and r2, Yi Ji that are serially connected
The intermediate node of resistance r1 and r2 produces and the first supply voltage vapdDetection signal vs.
First filter capacitor cin is connected between positive terminal and the negative pole end of power supply unit pse, for power supply unit
The supply voltage that pse provides is filtered.Second filter capacitor co is connected to power end vdd and the earth terminal of terminal unit pdt
Between gnd, for being filtered to the supply voltage of terminal unit pdt.
The anode of the first diode d1 connects to the positive terminal of power supply adaptor apd, and negative electrode connects to terminal unit pdt's
Power end vdd.The anode of the second diode d2 connects to the negative pole end of power supply unit pse, and negative electrode connects to terminal unit pdt's
Earth terminal vdd.First diode d1 and the second diode d2 one-way conduction, thus, add diode in position shown in Fig. 2, can
Will not be interacted with guarantee power supply unit pse and power supply adaptor apd.
The positive terminal of the first diode d1 formation power supply adaptor apd is unidirectional to the power end vdd's of terminal unit pdt
Path, such that it is able to prevent electric current recharge from entering in power supply adaptor apd.Second diode d2 forms the negative of power supply unit pse
The one-way conduction path of the earth terminal gnd of extreme vss to terminal unit pdt, such that it is able to prevent electric current recharge from entering power supply unit
In pse.
When power supply adaptor apd powers, the second diode d2 allows the negative pole end vss of power supply unit pse to set to terminal
There is current path in the earth terminal gnd of standby pdt, thereby may be ensured that control circuit pdc still in power supply holding state.Work as power supply
Adapter power-off or under-voltage after, the equipment pse that can restore electricity in time powers.
Control circuit pdc is connected with voltage sample module apds, to receive detection signal vs.Control circuit pdc includes
Detection module apdd and switching tube q1.In this application, switching tube q1 is, for example, hotswap pipe (i.e. hot-swap pipe).Switching tube
Q1 is connected between the earth terminal gnd of terminal unit pdt and the negative pole end vss of power supply unit pse, by the confession of control circuit pdc
The earth terminal gnd of the negative pole end vss and terminal unit pdt of electric equipment pse separates, and plays isolation and current-limiting protection effect.
In control circuit pdc, the input of detection module apdd receives detection signal vs, and outfan provides on-off control
Signal apd_en.Detection module apdd is according to sampled voltage vs, judge whether power adapter voltage meets condition of power supply.If electric
Source adapter voltage reaches power reguirements, then disconnect switching tube q1, thus by power supply unit pse power switching to power adaptation
Device apd powers.If power adapter voltage is not up to power reguirements, switching tube q1 is turned on, thus by power supply adaptor apd
Power switching is powered to electric power supply unit pse.
In a preferred embodiment, POE system also includes rectifier bridge rb.This rectifier bridge rb is connected to power supply and sets
For between pse and the first filter capacitor cin.No matter power supply unit pse accesses or anti-phase access for positive, is input to control electricity
The voltage of the power end vdd of road pdc is positive voltage.Two inputs of rectifier bridge rb connect to the positive pole of power supply unit pse
End and negative pole end, provide the second supply voltage v between two outfanspse.
Additionally, in the above-described embodiment, it is used for being formed the negative pole of power supply unit pse using single second diode d2
The one-way conduction path of the earth terminal gnd of end vss to terminal unit pdt.In alternate embodiments, if the body of switching tube q1
Diode d3 can replace the effect of the second diode d2, then can save the second diode d2.
The first supply voltage being provided according to the POE system of this utility model embodiment, power supply adaptor apd
vapdNeed to reach certain voltage value and could meet terminal unit pdt and require, detection module pdc sends switch controlling signal afterwards,
Switching tube q1 is disconnected, the standby locking of control circuit pdc, now power supply unit pse current supply circuit disconnects, turn by power supply adaptor
Power supply.
In POE system, power supply adaptor apd and control circuit pdc are not ground altogether.In control circuit pdc
Detection module apdd be floating ground voltage detection module, such that it is able to by with the sampled voltage v as reference for the power supply adaptor grounds
Change into the switch controlling signal as reference for the control circuit ground.In addition, in POE system, control circuit pdc
Quiescent current very little, thus do not interfere with featured resistance detection function in power supply unit pse detection power receiving equipment pd.
Fig. 3 is a kind of schematic circuit of control circuit used in the POE system of Fig. 2.Voltage sample
Module apds includes resistance r1 and r2 being serially connected, and control circuit pdc includes detection module apdd and switching tube q1.Inspection
Survey module apdd and obtain detection signal vs from the intermediate node of resistance r1 and r2, and on-off control is produced according to detection signal vs
Signal apd_en.
Detection module apdd includes inverting amplifier 101, phase inverter u1 and logic circuit apdc.Inverting amplifier 101 wraps
Include the p-type mosfet (gold being sequentially connected in series between the power end vdd and the negative pole end vss of power supply unit pse of terminal unit pdt
Belong to oxide semiconductor field effect transistor) m1, resistance r3 and r4, and the Zener diode d3 being connected in parallel with resistance r4.
Produce first voltage signal v at the two ends of Zener diode d3d3.Phase inverter u1 and logic circuit apdc is sequentially connected.Phase inverter
U1 receives first voltage signal vd3, the outfan of logic circuit apdc then provides switch controlling signal apd_en.This detection module
The detection signal vs that apdd receives is with the ground gnd of terminal unit pdt as reference.
Switch controlling signal vapd_enDetermined by following formula:
Wherein, vthpRepresent the threshold voltage of p-type mosfetm1.
As the first supply voltage vapd(with the ground gnd of terminal unit pdt) reaches the supply voltage threshold of power supply adaptor apd
During value, p-type mosfetm1 in detection module pdc turns on, Zener diode d3The first voltage signal v at two endsd3Uprised by low,
Inverted device u1 delivers to logic circuit apdc, after logical transition, switch controlling signal apd_en is put 1.Control circuit pdc connects
After receiving apd_en signal, switching tube q1 is disconnected, enter holding state, system becomes power supply to fit by power supply unit pse power switching
Orchestration apd powers.
As the first supply voltage vapdUnder-voltage or disconnect when, p-type mosfetm1 in detection module pdc is off,
First voltage signal vd3By high step-down, switch controlling signal apd_en sets to 0.Now control circuit pdc conducting switching tube q1, with confession
Electric equipment pse re-starts communication identification, and the equipment pse of restoring electricity powers.
This detection module apdd receives to float the detection signal as reference for the ground terminal (i.e. the earth terminal gnd of terminal unit pdt)
Vs, detection signal vs is converted into the switch controlling signal apd_en as reference with the negative pole end vss of power supply unit pse, thus
Achieve floating ground voltage detection function.Power supply adaptor under-voltage or disconnect when, this detection module apdd will not produce extra
Quiescent current, does not produce any impact to power supply unit pse power supply process.
Fig. 4 is the schematic circuit of another kind of control circuit used in the POE system of Fig. 2.Voltage is adopted
Egf block apds includes resistance r1 and r2 being serially connected, and control circuit pdc includes detection module apdd and switching tube q1.
Detection module apdd obtains detection signal vs from the intermediate node of resistance r1 and r2, and produces switch control according to detection signal vs
Signal apd_en processed.
Detection module apdd includes inverting amplifier 201, phase inverter u1 and logic circuit apdc.Inverting amplifier 201 wraps
Include resistance r5 and r6 being sequentially connected in series between the power end vdd and the ground gnd of terminal unit pdt of terminal unit pdt, N-shaped
Mosfet (mos field effect transistor) m2, and the Zener diode d5 being connected in parallel with resistance r5, also
Including p-type mosfet being sequentially connected in series between the power end vdd and the negative pole end vss of power supply unit pse of terminal unit pdt
(mos field effect transistor) m3, resistance r7 and r8, and the Zener diode being connected in parallel with resistance r8
d3.Produce second voltage signal v at the two ends of Zener diode d6d6.Phase inverter u1 and logic circuit apdc is sequentially connected.Anti-phase
Device u1 receives second voltage signal vd6, the outfan of logic circuit apdc then provides switch controlling signal apd_en.This detection mould
The detection signal vs that block apdd receives is with the ground gnd of terminal unit pdt as reference.
Switch controlling signal vapd_enDetermined by following formula:
Wherein, vthnRepresent the threshold voltage of N-shaped mosfetm2.
As the first supply voltage vapd(with the ground gnd of terminal unit pdt) reaches the supply voltage threshold of power supply adaptor apd
During value, N-shaped mosfetm2 in detection module pdc conducting is so that Zener diode d5Conducting.The tertiary voltage at resistance r5 two ends
Signal vd5Uprised by low.Tertiary voltage signal vd5Reach Zener diode d5 breakdown reverse voltage when, p-type mosfetm3 is led
Logical.The second voltage signal v at resistance r8 two endsd6Uprise so that Zener diode d by low6Conducting.Second voltage signal vd6Through anti-
Phase device u1 delivers to logic circuit apdc, after logical transition, switch controlling signal apd_en is put 1.Control circuit pdc receives
After apd_en signal, switching tube q1 is disconnected, enter holding state, system becomes power supply adaptor by power supply unit pse power switching
Apd powers.
As the first supply voltage vapdUnder-voltage or when disconnecting, the N-shaped mosfetm2 in detection module pdc and p-type mosfetm3
It is in off-state, second voltage signal vd6By high step-down, switch controlling signal apd_en sets to 0.Now control circuit pdc is led
Logical switching tube q1, re-starts communication identification with power supply unit pse, the equipment pse of restoring electricity powers.
This detection module apdd receives to float the detection signal as reference for the ground terminal (i.e. the earth terminal gnd of terminal unit pdt)
Vs, detection signal vs is converted into the switch controlling signal apd_en as reference with the negative pole end vss of power supply unit pse, thus
Achieve floating ground voltage detection function.Power supply adaptor under-voltage or disconnect when, this detection module apdd will not produce extra
Quiescent current, does not produce any impact to power supply unit pse power supply process.
The control circuit of two above example power supply adaptor under-voltage or disconnect when, the mosfet in detection module pdc
It is in off-state, extra quiescent current will not be produced.Therefore to the detection process in power supply unit pse power supply process not
Impact can be produced, be suitable for POE system.
In sum, this patent proposes the POE system that a kind of compatibility power supply adaptor apd powers, and works as control
When circuit pdc detects power adapter voltage and meets power demands, power supply unit pse power switching is power supply adaptor
Apd powers, and returns power supply unit pse when power supply adaptor disconnects or be under-voltage and powers；Ensure power supply unit pse and power adaptation
There is no current path between device, be not in the phenomenon of electric current recharge.This utility model additionally provides two different form of answering
For the detection module pdc in POE system, the power supply adaptor as reference with power supply adaptor negative pole can be detected
Voltage, is translated into the switch controlling signal as reference with power supply unit pse negative pole, controls control circuit pdc to power supply electricity
Source switches over.This circuit power supply adaptor under-voltage or disconnect when will not produce extra quiescent current, to power supply unit pse
Power supply process does not produce any impact.
It should be noted that herein, such as first and second or the like relational terms are used merely to a reality
Body or operation are made a distinction with another entity or operation, and not necessarily require or imply these entities or deposit between operating
In any this actual relation or order.And, term " inclusion ", "comprising" or its any other variant are intended to
Comprising of nonexcludability, wants so that including a series of process of key elements, method, article or equipment and not only including those
Element, but also include other key elements being not expressly set out, or also include for this process, method, article or equipment
Intrinsic key element.In the absence of more restrictions, the key element that limited by sentence "including a ..." it is not excluded that
Also there is other identical element including in the process of described key element, method, article or equipment.
According to embodiment of the present utility model as described above, these embodiments do not have all of details of detailed descriptionthe,
Do not limit the specific embodiment that this utility model is only described yet.Obviously, as described above, a lot of modifications and change can be made
Change.This specification is chosen and is specifically described these embodiments, is to preferably explain that principle of the present utility model and reality should
With so that skilled artisan can be well using this utility model and repairing on the basis of this utility model
Change use.This utility model is only limited by claims and its four corner and equivalent.
Claims (18)
1. a kind of POE system is it is characterised in that include:
Power supply adaptor, provides the first supply voltage between the positive terminal and negative pole end of described power supply adaptor；
Power supply unit, provides the second supply voltage between the positive terminal and negative pole end of described power supply unit；
Terminal unit, is connected with described power supply adaptor and described power supply unit respectively, in the power end of described terminal unit
Receive one of described first voltage supplied and described second supply voltage as supply voltage and earth terminal between；
Control circuit, is connected between described power supply unit and described terminal unit, supplies for meeting in described power supply adaptor
Disconnect described power supply unit during electric demand, disconnect in described power supply adaptor or access described power supply unit when under-voltage,
Wherein, described control circuit includes detection module and switching tube, and the outfan of described detection module connects to described switch
The control end of pipe, for the detection signal of described first supply voltage is converted to switch controlling signal, thus open described in controlling
Close conducting and the disconnection of pipe,
, using the reference ground of described first supply voltage as reference ground, described switch controlling signal is with described for described detection signal
The reference ground of two supply voltages is as reference ground.
2. POE system according to claim 1 is it is characterised in that also include voltage sample module, described electricity
Pressure sampling module is connected between positive terminal and the negative pole end of described power supply adaptor, for producing described detection signal.
3. POE system according to claim 2 is it is characterised in that described voltage sample module is electric resistance partial pressure
Network, described resistance pressure-dividing network includes the first resistor being connected in series and second resistance.
4. POE system according to claim 1 is it is characterised in that also include the first diode, described power supply
The positive terminal of adapter connects to the power end of described terminal unit via described first diode, thus being formed from described power supply
The unidirectional current path of the positive terminal of the adapter extremely power end of described terminal unit.
5. POE system according to claim 1 is it is characterised in that also include the second diode, described power supply
The negative pole end of equipment connects to the earth terminal of described terminal unit via described second diode, thus disconnecting in described switching tube
When form the unidirectional current path of earth terminal from the negative pole end of described power supply unit to described terminal unit.
6. POE system according to claim 1 is it is characterised in that described switching tube has body diode, institute
The negative pole end stating power supply unit connects via described body diode to the earth terminal of described terminal unit, thus in described switching tube
Form the unidirectional current path of the earth terminal from the negative pole end of described power supply unit to described terminal unit during disconnection.
7. POE system according to claim 1 is it is characterised in that also include rectifier bridge, described rectifier bridge
First input end and the second input connect positive terminal and the negative pole end of described power supply unit respectively, and the first of described rectifier bridge is defeated
Go out end and the second outfan is respectively connecting to power end and the earth terminal of described terminal unit.
8. POE system according to claim 1 is it is characterised in that what described detection module included being sequentially connected
Inverting amplifier, phase inverter and logic circuit, described detection module receives the detection signal of described first supply voltage, described patrols
Collecting circuit provides described switch controlling signal.
9. POE system according to claim 8 is it is characterised in that described inverting amplifier includes being sequentially connected in series
It is connected to the first transistor between the power end of described terminal unit and the negative pole end of described power supply unit, 3rd resistor and
Four resistance, and the first Zener diode being connected with described 4th resistor coupled in parallel,
The control end of described the first transistor receives described detection signal, and the two ends of described first Zener diode obtain the first electricity
Pressure signal, described phase inverter and described logic circuit carry out anti-phase and logic control thus obtaining to described first voltage signal respectively
Obtain described switch controlling signal.
10. POE system according to claim 9 is it is characterised in that described the first transistor is p-type metal oxygen
Compound semiconductor field effect transistor.
11. POE systems according to claim 8 are it is characterised in that described inverting amplifier includes going here and there successively
Join the 5th resistance being connected between the power end of described terminal unit and earth terminal, the 6th resistance and transistor seconds, and
Be sequentially connected in series third transistor between the power end and the negative pole end of described power supply unit of described terminal unit, the 7th
Resistance and the 8th resistance, and the second Zener diode of being connected with described 5th resistor coupled in parallel and described 8th resistor coupled in parallel
The 3rd Zener diode connecting,
The control end of described transistor seconds receives described detection signal, and the control end of described third transistor connects to described the
Five resistance and the intermediate node of described 6th resistance,
The two ends of described 3rd Zener diode obtain first voltage signal, and described phase inverter and described logic circuit are respectively to institute
State first voltage signal and carry out anti-phase and logic control thus obtaining described switch controlling signal.
12. POE systems according to claim 11 are it is characterised in that described transistor seconds is N-shaped metal
Oxide semiconductor field effect transistor, described third transistor is p-type metal oxide semiconductor field-effect transistor.
A kind of 13. POE control circuits, are connected between power supply unit and terminal unit, for according to power supply adaptor
The first supply voltage, be switched in or out described power supply unit, described power supply unit provides the second supply voltage, its feature exists
In described POE control circuit includes:
Detection module；And
Switching tube,
Wherein, the outfan of described detection module connects to the control end of described switching tube, for by described first supply voltage
Detection signal be converted to switch controlling signal, thus controlling conducting and the disconnection of described switching tube,
, using the reference ground of described first supply voltage as reference ground, described switch controlling signal is with described for described detection signal
The reference ground of two supply voltages is as reference ground.
14. POE control circuits according to claim 13 are it is characterised in that described detection module is included successively
Inverting amplifier, phase inverter and the logic circuit connecting, described detection module receives the detection signal of described first supply voltage,
Described logic circuit provides described switch controlling signal.
15. POE control circuits according to claim 14 it is characterised in that described inverting amplifier include according to
The secondary the first transistor being connected in series between the power end of described terminal unit and the negative pole end of described power supply unit, the 3rd electricity
Resistance and the 4th resistance, and the first Zener diode being connected with described 4th resistor coupled in parallel,
The control end of described the first transistor receives described detection signal, and the two ends of described first Zener diode obtain the first electricity
Pressure signal, described phase inverter and described logic circuit carry out anti-phase and logic control thus obtaining to described first voltage signal respectively
Obtain described switch controlling signal.
16. POE control circuits according to claim 15 are it is characterised in that described the first transistor is p-type
Mos field effect transistor.
17. POE control circuits according to claim 14 it is characterised in that described inverting amplifier include according to
The 5th resistance between the secondary power end being connected in series in described terminal unit and earth terminal, the 6th resistance and transistor seconds,
And be sequentially connected in series third transistor between the power end and the negative pole end of described power supply unit of described terminal unit,
7th resistance and the 8th resistance, and the second Zener diode of being connected with described 5th resistor coupled in parallel and described 8th resistance
The 3rd Zener diode being connected in parallel,
The control end of described transistor seconds receives described detection signal, and the control end of described third transistor connects to described the
Five resistance and the intermediate node of described 6th resistance,
The two ends of described 3rd Zener diode obtain first voltage signal, and described phase inverter and described logic circuit are respectively to institute
State first voltage signal and carry out anti-phase and logic control thus obtaining described switch controlling signal.
18. POE control circuits according to claim 17 are it is characterised in that described transistor seconds is N-shaped
Mos field effect transistor, described third transistor is p-type metal oxide semiconductor field-effect transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620701202.3U CN205921601U (en) | 2016-06-29 | 2016-06-29 | Ethernet power supply system and control circuit thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620701202.3U CN205921601U (en) | 2016-06-29 | 2016-06-29 | Ethernet power supply system and control circuit thereof |
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| Publication Number | Publication Date |
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| CN205921601U true CN205921601U (en) | 2017-02-01 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106899453A (en) * | 2017-03-02 | 2017-06-27 | 北京星网锐捷网络技术有限公司 | The detection method and device of power supply adaptor failure |
| CN107147080A (en) * | 2017-06-12 | 2017-09-08 | 深圳市共进电子股份有限公司 | A kind of charger and its protection circuit based on POE |
| CN107425598A (en) * | 2017-09-12 | 2017-12-01 | 上海剑桥科技股份有限公司 | The power selection circuit powered for adapter and POE |
-
2016
- 2016-06-29 CN CN201620701202.3U patent/CN205921601U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106899453A (en) * | 2017-03-02 | 2017-06-27 | 北京星网锐捷网络技术有限公司 | The detection method and device of power supply adaptor failure |
| CN107147080A (en) * | 2017-06-12 | 2017-09-08 | 深圳市共进电子股份有限公司 | A kind of charger and its protection circuit based on POE |
| CN107147080B (en) * | 2017-06-12 | 2019-04-19 | 深圳市共进电子股份有限公司 | A kind of charger and its protection circuit based on Power over Ethernet |
| CN107425598A (en) * | 2017-09-12 | 2017-12-01 | 上海剑桥科技股份有限公司 | The power selection circuit powered for adapter and POE |
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