CN107147080A - A kind of charger and its protection circuit based on POE - Google Patents
A kind of charger and its protection circuit based on POE Download PDFInfo
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- CN107147080A CN107147080A CN201710438389.1A CN201710438389A CN107147080A CN 107147080 A CN107147080 A CN 107147080A CN 201710438389 A CN201710438389 A CN 201710438389A CN 107147080 A CN107147080 A CN 107147080A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/02—Details
- H04L12/10—Current supply arrangements
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- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The present invention is applied to power over Ethernet field there is provided a kind of charger based on POE and its protection circuit, including：Voltage regulation unit, biasing charge/discharge unit, first switch unit and second switch unit；When the charger protection circuit based on POE is short-circuit, the secondary end of transformer can export low level, so that second switch unit no longer output level control signal, bypass of the biasing charge/discharge unit due to losing second switch unit is acted on, start to charge up, when the charging voltage for biasing charge/discharge unit reaches preset charged threshold value, when the control end of first switch unit is on level, first switch unit is blocked, therefore power supply chip is stopped, and then the concussion stopped to transformer causes the above-mentioned charger protection circuit based on POE to be stopped.High-temperature work environment is in so as to be effectively prevented from transformer and power supply chip, protects transformer and power supply chip not destroyed, circuit structure is simple, it is convenient to realize.
Description
Technical field
The invention belongs to power over Ethernet field, more particularly to a kind of charger and its guarantor based on POE
Protection circuit.
Background technology
POE (Power Over Ethernet, POE) refers to connecting up basis in existing Ethernet Cat.5
In the case that framework does not make any changes, for some IP-based terminal (such as IP telephone machines, wireless local network connecting point
The terminal devices such as AP, web camera) transmission data-signal while, the skill of direct current supply is also provided for such terminal device
Art.POE technologies can ensure the normal operation of existing network while ensuring that existing structureization wiring is safe, simplify system cloth
Line, reduces the construction cost of network infrastructure.But POE chargers are in the engineering used, there is short circuit in circuit abnormal
Situation when, POE power supply chips can enter " hiccup protections pattern ", to protect power supply chip not damage.So-called " hiccup protections
Pattern ", refers to due to the mode of operation that power supply chip is constantly restarted caused by the short-circuit exception of circuit appearance, however, working as power supply
" hiccup protections pattern ", which occur, in prolonged periods can cause transformer and power supply chip temperature to raise so that damage.
In summary, the existing charger based on POE exists due to power supply core when there is short circuit exception
There is " hiccup protections pattern " for a long time and causes the problem of transformer and power supply chip are damaged in piece.
The content of the invention
The invention provides a kind of charger based on POE and its protection circuit, it is intended to solves existing be based on
The charger of POE exists due to power supply chip appearance " hiccup protections pattern " for a long time when there is short circuit exception
Cause the problem of transformer and power supply chip are damaged.
The invention provides a kind of charger protection circuit based on POE, the confession based on POE
Protective circuit for electric appliance includes：
Voltage regulation unit, biasing charge/discharge unit, first switch unit and second switch unit；
The input of the voltage regulation unit is connected with providing the power supply of supply voltage, the output end of the voltage regulation unit
It is connected with the input of the biasing charge/discharge unit, the output end and the first switch unit of the biasing charge/discharge unit
Control end connection, the input of the first switch unit is connected with transformer, the output end of the first switch unit and
Power supply chip is connected, and the input of the second switch unit is connected with the secondary end of the transformer, the second switch list
The output end of member is connected with the biasing charge/discharge unit；
When the power supply start offer shake hands voltage when, while the power supply starts as the transformer-supplied
When, the voltage of shaking hands is not more than the breakdown voltage of the voltage regulation unit, i.e., described voltage regulation unit is not breakdown, and the biasing is filled
Discharge cell dead electricity does not work, and keeps low level output so that the first switch unit is turned on, and then makes the power supply chip
It must establish by cable and begin to carry out work of shaking hands according to professional standard and the power supply, the transformer does not obtain the power supply chip
Oscillator signal thus not output coupling output voltage, the second switch unit is not turned on, no level controling signal output, i.e., without
Bypass is acted on；
When the power supply chip and the power supply are shaken hands successfully, the voltage value recovers professional standard and big
In the breakdown voltage of the voltage regulation unit, i.e., described voltage regulation unit is breakdown, and when the voltage regulation unit is breakdown, the biasing is filled
Discharge cell originate the electric stage is equivalent to short circuit, relay output low level, so that the first switch unit is remained in that
Conducting, so make the power supply chip persistently electric work and export oscillator signal to the transformer, the transformer is obtained
The oscillator signal starts output coupling output voltage；
When the secondary end output coupling output voltage of the transformer is to when loading, the second switch unit obtains conductance
Logical, output level control signal is so that the biasing charge/discharge unit is bypassed, even if the biasing charge/discharge unit is persistently protected
Low level is held so that the first switch unit is turned on, so that the power supply chip works, the secondary end of the transformer continues
Output coupling output voltage；
When short circuit occurs for the charger output based on POE, the secondary end of the transformer is short-circuited into
Low level, the second switch unit dead electricity is not turned on, and no level controling signal output, the biasing charge/discharge unit loses side
Road acts on and then started to charge up, when the charging voltage of the biasing charge/discharge unit reaches preset charged threshold value, and described first
Switch element is blocked, so that the power supply chip dead electricity is stopped, and then stops the output oscillator signal to the transformation
Device, so that the transformer is stopped.
A kind of charger based on POE, including power supply chip and transformer, the transformer first input end
It is connected with the power supply for providing supply voltage, the second input of the transformer is connected with the power supply chip, the base
Also include the above-mentioned charger protection circuit based on POE in the charger of POE, it is described to be supplied based on Ethernet
The charger protection circuit of electricity is connected with the transformer and the power supply chip respectively.
Charger based on POE and its protection circuit that the present invention is provided, by starting to provide in power supply
Shake hands voltage when, because voltage of shaking hands is not more than the breakdown voltage of voltage regulation unit, therefore voltage regulation unit is not breakdown, regardless of distribution
Biasing charge/discharge unit, therefore biasing charge/discharge unit output low level are depressed into, so that the control end of first switch unit is low
Level, thus turn on first switch unit and then power supply chip is worked, it is state of shaking hands due to now, therefore do not export
Voltage, therefore second switch unit is not turned on due to no input voltage, no low level output, when power supply chip is held with power supply
During hand success, supply voltage is more than the breakdown voltage of voltage regulation unit, therefore voltage regulation unit is turned on, and exports voltage of voltage regulation to biasing
Charge/discharge unit, due to voltage regulation unit breakdown moment, biasing charge/discharge unit is equivalent to short circuit, therefore biasing discharge and recharge list
Member still exports low level so that the control end of first switch unit is in low level, so that power supply chip continuous firing, works as change
The normal output coupling output voltage of depressor is to when loading, and second switch unit conducting, output level control signal is filled so as to bias
Discharge cell is bypassed to low level, and then turns on first switch unit, so that the power supply chip continuous firing, the change
The secondary end of depressor continues output coupling output voltage, described when the charger protection circuit based on POE is short-circuit
The secondary end of transformer can export low level so that second switch unit no longer exports low level, biasing charge/discharge unit due to
The bypass effect of second switch unit is lost, is started to charge up, when the charging voltage of biasing charge/discharge unit reaches preset charged threshold
During value, when the control end of first switch unit is in high level, first switch unit is blocked, therefore power supply chip is stopped,
And then stop output oscillator signal to transformer so that transformer is stopped so that the above-mentioned charger based on POE
It is stopped.High-temperature work environment, protection transformer and power supply chip are in so as to be effectively prevented from transformer and power supply chip
Not destroyed, circuit structure is simple, and it is convenient to realize.
Brief description of the drawings
Technical scheme in order to illustrate the embodiments of the present invention more clearly, below will be to embodiment or description of the prior art
In required for the accompanying drawing that uses be briefly described, it should be apparent that, drawings in the following description are some implementations of the present invention
Example, for those of ordinary skill in the art, without having to pay creative labor, can also be according to these accompanying drawings
Obtain other accompanying drawings.
Fig. 1 is the structural representation of the charger protection circuit provided in an embodiment of the present invention based on POE；
Fig. 2 is the circuit structure signal of the charger protection circuit provided in an embodiment of the present invention based on POE
Figure.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.
It should be noted that term " comprising " and their any changes in description and claims of this specification
Shape, it is intended that covering is non-exclusive to be included.System, product or equipment for example comprising a series of units are not limited to arrange
The unit gone out, but alternatively also include the step of do not list or unit, or alternatively also include for these products or set
Standby intrinsic other units.In addition, term " first ", " second " and " the 3rd " etc. is to be used to distinguish different objects, not for
Particular order is described.
The embodiment of the present invention exists to solve the existing charger based on POE when there is short circuit exception
Causing the problem of transformer and power supply chip are damaged due to power supply chip appearance " hiccup protections pattern " for a long time, there is provided one
Charger and its protection circuit kind based on POE, by power supply start offer shake hands voltage when, due to holding
Torch pressure is not more than the breakdown voltage of voltage regulation unit, therefore voltage regulation unit is not breakdown, and biasing discharge and recharge list is depressed into regardless of distribution
Member, therefore biasing charge/discharge unit output low level, so that the control end of first switch unit is low level, thus make first to open
Close unit to turn on and then make power supply chip work, be state of shaking hands due to now, therefore no output voltage, therefore second switch list
Member is not turned on due to no input voltage, no low level output, when power supply chip is shaken hands successfully with power supply, supply voltage
More than the breakdown voltage of voltage regulation unit, therefore voltage regulation unit is turned on, and exports voltage of voltage regulation to charge/discharge unit is biased, due to steady
Press unit breakdown moment, biasing charge/discharge unit is equivalent to short circuit, therefore biasing charge/discharge unit remains unchanged output low level
So that the control end of first switch unit is in low level, so that power supply chip continuous firing, when the normal output coupling of transformer
Output voltage is to when loading, and second switch unit conducting, output level control signal is bypassed to so as to bias charge/discharge unit
Low level, and then first switch unit is turned on, so that the power supply chip continuous firing, the secondary end of the transformer continues
Output coupling output voltage, when the charger protection circuit based on POE is short-circuit, the secondary end meeting of the transformer
Export low level so that second switch unit no longer exports low level, and biasing charge/discharge unit is due to losing second switch unit
Bypass effect, start to charge up, when bias charge/discharge unit charging voltage reach preset charged threshold value when, first switch unit
Control end be in high level when, first switch unit is blocked, therefore power supply chip is stopped, so stop output concussion letter
Number to transformer so that transformer is stopped so that the above-mentioned charger protection circuit based on POE is stopped.
High-temperature work environment is in so as to be effectively prevented from transformer and power supply chip, protects transformer and power supply chip not destroyed,
Circuit structure is simple, and it is convenient to realize.
In order to illustrate above-mentioned a kind of charger and its protection circuit based on POE, below in conjunction with specific reality
Example is applied to be described in detail：
Fig. 1 shows the structure of the charger protection circuit provided in an embodiment of the present invention based on POE, in order to
It is easy to explanation, illustrate only the part related to the embodiment of the present invention, details are as follows：
As shown in figure 1, the charger protection circuit 10 based on POE includes：
Voltage regulation unit 110, biasing charge/discharge unit 120, first switch unit 130 and second switch unit 140.
The input of voltage regulation unit 110 is connected with providing the power supply VCC of supply voltage, the output of voltage regulation unit 110
Hold and be connected with biasing the input of charge/discharge unit 120, bias the output end and first switch unit 130 of charge/discharge unit 120
Control end connection, the input of first switch unit 130 is connected with transformer T1, the output end of first switch unit 130 and
Power supply chip U1 connections, the input of second switch unit 140 is connected with transformer T1 output end, second switch unit 140
Output end with biasing charge/discharge unit 120 be connected.
When power supply VCC start offer shake hands voltage when, while when power supply VCC is started as transformer-supplied T1,
It is not breakdown that voltage of shaking hands is not more than the breakdown voltage of voltage regulation unit 110, i.e. voltage regulation unit 110, and biasing charge/discharge unit 120 loses
Electricity does not work, and keeps low level output so that first switch unit 130 is turned on, so make power supply chip U1 must establish by cable the beginning according to
Professional standard and power supply VCC carry out work of shaking hands, transformer T1 do not obtain power supply chip U1 oscillator signal thus it is not defeated
Go out and couple output voltage, second switch unit 140 is not turned on, no level controling signal output, i.e. none-disk terminal is acted on.
When power supply chip U1 and power supply VCC shake hands successfully, voltage value recovers professional standard and more than voltage stabilizing
The breakdown voltage of unit 110, i.e. voltage regulation unit 110 are breakdown, output voltage of voltage regulation to biasing charge/discharge unit 120, voltage stabilizing list
When member 110 is breakdown, biasing charge/discharge unit 120 originate the electric stage is equivalent to short circuit, relay output low level, so that the
One switch element 130 is remained on, and then power supply chip U1 is obtained electric continuous firing and exported oscillator signal to the change
Depressor T1, transformer T1 obtain oscillator signal and start output coupling output voltage.
When transformer T1 secondary end output coupling output voltage is to when loading, second switch unit 140 must be conducted, defeated
Go out level controling signal so that biasing charge/discharge unit 120 is bypassed, even if biasing charge/discharge unit 120 persistently keeps low level
So that first switch unit 130 is turned on, so that power supply chip U1 works, transformer T1 secondary end continues output coupling output electricity
Pressure.
When short circuit occurs for the charger output based on POE, transformer T1 secondary end is short-circuited into low electricity
Flat, the dead electricity of second switch unit 140 is not turned on, and no level controling signal output, biasing charge/discharge unit 120 loses bypass effect
And then start to charge up, when the charging voltage for biasing charge/discharge unit 120 reaches preset charged threshold value, first switch unit 130
Block, so that power supply chip U1 dead electricity is stopped, and then stops output oscillator signal to transformer T1, so that transformer T1 stops
Only work.
It should be noted that the charger protection circuit 10 based on POE can be with the confession based on POE
Transformer T1 and power supply chip the U1 connection of electrical equipment, transformer T1 first input ends are connected with supply voltage VCC, transformer T1
The second input be connected with power supply chip U1, transformer T1 secondary end output coupling output voltage is to loading, power supply chip
U1 refers to POE power supply chips.
It should be noted that the biography of some control information adjoint during the transmission of practical application information between communication equipment
Pass, they work according to set communications protocol, by application message it is safe, reliable, efficient be sent to destination." shaking hands " just
Be two equipment before a communication, the action being first mutually distinguishable according to standard communication protocol, after being mutually distinguishable could mutually
Transmit information.When power supply chip and power supply are shaken hands, voltage ratio of shaking hands is relatively low, no more than the electric conduction of voltage regulation unit
Press, above-mentioned conducting voltage refers to, voltage regulation unit minimum voltage required when turning on.
It is set in advance in order that above-mentioned first switch unit it can further be stated that above-mentioned preset charged threshold value refers to
The charging voltage of biasing charge/discharge unit output when control end is in high level.
It should also be noted that, it can also be low level that above-mentioned level controling signal, which can be high level, when from different
Component when, the level controling signal be different level.
Further, in embodiments of the present invention, biasing charge/discharge unit 120 includes：Bias unit 121 and RC charge and discharges
Electric unit 122.
Bias unit 121 is connected with RC charge/discharge units 122, and the input and output end of bias unit 121 are respectively inclined
Put the input and output end of charge/discharge unit 120, the inputs of RC charge/discharge units 122 is defeated with second switch unit 140
Go out end connection.
When power supply VCC start offer shake hands voltage when, while when power supply VCC starts to power for transformer T1,
It is not breakdown that voltage of shaking hands is not more than the breakdown voltage of voltage regulation unit 110, i.e. voltage regulation unit 110, bias unit 121 and RC charge and discharges
The dead electricity of electric unit 122 does not work, and keeps low level output so that first switch unit 130 is persistently held on, and then makes power supply
Chip U1 obtains electric work, and transformer T1 does not obtain power supply chip U1 oscillator signal thus not output coupling output voltage, second
Switch element 140 is not turned on, no level controling signal output.
When power supply chip U1 and power supply VCC shake hands successfully, supply voltage is more than the breakdown potential of voltage regulation unit 110
Pressure, i.e., voltage regulation unit 110 is breakdown, output voltage of voltage regulation to bias unit 121, when voltage regulation unit 110 is breakdown, RC discharge and recharges
Unit 122 originate the electric stage is equivalent to short circuit, the relay of RC charge/discharge units 122 output low level, power time needs are more than
The power supply chip work produces the time required for concussion, so that first switch unit 130 is turned on, and then makes power supply chip U1
Persistently electric work, and export oscillator signal to transformer T1, transformer T1 obtains oscillator signal and starts output coupling output electricity
Pressure.
When transformer T1 secondary end output coupling output voltage is to when loading, second switch unit 140 must be conducted, defeated
Go out level controling signal so that bias unit 121 and RC charge/discharge units 122 are bypassed into low level, even if bias unit 121
Low level is persistently kept so that first switch unit 130 is persistently held on, so that power supply chip U1 persistently keeps work, transformation
Device T1 secondary end continues output coupling output voltage.
When short circuit occurs for the charger output based on POE, transformer T1 secondary end output low level, the
Two switch elements 140 are not turned on, no low level output, and bias unit 121 and RC charge/discharge units 122 are not bypassed, RC charge and discharges
Electric unit 122 is started to charge up, when the charging voltage of RC charge/discharge units 122 reaches preset charged threshold value, first switch unit
130 block, so that power supply chip U1 dead electricity is stopped, and then stops output oscillator signal to transformer T1, so that transformer
T1 is stopped.
Fig. 2 shows the circuit structure of the charger protection circuit provided in an embodiment of the present invention based on POE,
For convenience of description, the part related to the embodiment of the present invention is illustrate only, details are as follows：
As shown in Fig. 2 as one embodiment of the invention, first switch unit 130 includes switching tube Q1.
Switching tube Q1 control end is the control end of first switch unit 130, and switching tube Q1 input is first switch
The input of unit 130, switching tube Q1 output end is the output end of first switch unit 130.Further, of the invention real
Apply in example, above-mentioned switching tube Q1 is FET, the grid of FET is switching tube Q1 control end, the source electrode of FET
For switching tube Q1 input, the drain electrode of FET is switching tube Q1 output end.In addition, above-mentioned switching tube Q1 can also be
Triode, is not limited herein.
Second switch unit 140 includes photoelectrical coupler U2.Photoelectrical coupler U2 first input end is second switch list
The input of member 140, photoelectrical coupler U2 the second input end grounding, photoelectrical coupler U2 the first output end is opened for second
Close the output end of unit 140, photoelectrical coupler U2 the second output head grounding.
Voltage regulation unit 110 includes voltage-stabiliser tube D1.Voltage-stabiliser tube D1 negative pole is the input of voltage regulation unit 110, voltage-stabiliser tube D1
The just extremely output end of voltage regulation unit 110.
Bias unit 121 includes first resistor R1 and second resistance R2.
First resistor R1 first end is the input of bias unit 121, first resistor R1 the second end and second resistance
R2 first end connection, second resistance R2 the second end ground connection, second resistance R2 first end is the output of bias unit 121
End.Specifically, in the present embodiment, above-mentioned first resistor R1 is upper inclined resistance, second resistance R2 is lower inclined resistance.
RC charge/discharge units 122 include the first electric capacity C1 and second resistance R2.
First electric capacity C1 first end is the input of RC charge/discharge units 122, the first electric capacity C1 first end and second
Resistance R2 first end connection, the first electric capacity C1 the second end ground connection, second resistance R2 the second end ground connection.
The above-mentioned charger protection circuit based on POE is made furtherly below in conjunction with operation principle and Fig. 2
It is bright：
In application, the charger protection circuit of above-mentioned POE includes three kinds of mode of operations：It is handshake mode, normal
Powering mode and short circuit protection mode.
Handshake mode, when supply voltage VCC flows through transformer T1 to power supply chip U1, power supply chip U1 can be according to mark
Quasi- agreement carries out hand shaking, voltage of now shaking hands (power supply electricity when shaking hands with providing the power supply VCC of supply voltage
Pressure) it is not more than voltage-stabiliser tube D1 pressure voltage (i.e. supply voltage is not more than the breakdown voltage of voltage regulation unit), it is exemplary, in this reality
Apply in example, above-mentioned supply voltage when shaking hands is 10V, and above-mentioned conducting voltage is 13V, therefore voltage-stabiliser tube D1 does not have breakdown, because
This bias unit 121 and RC charge/discharge units 122 are distributed without electric charge, and the output end of biasing charge/discharge unit 120 exports low electricity
Put down, FET Q1 grids obtain low level, persistently keep the conducting of source electrode and drain electrode, power supply chip U1 is normal to obtain electric work,
It is also load supplying (i.e. transformation that the photoelectrical coupler of second switch unit 140, which detects transformer T1 secondary end, simultaneously
Device T1 secondary end is low level), second switch unit 140 keeps open-circuit condition, therefore does not influence the biasing list that is attached thereto
The working method of 121 and RC of member charge/discharge units 122.It should be noted that mode of operation of shaking hands, it is to provide for good hard
Part environment " is shaken hands " Lifetime to the charger based on POE with providing the front end of power supply.Shake hands mode of operation
Customized for the standard POE Handshake Protocol times, being capable of completely compatible different POE power supply chips.
Normal power supply pattern, when power supply chip U1 shakes hands successfully with providing the power supply VCC of supply voltage, power supply electricity
Pressure reaches normal power supply state, and during normal power supply, supply voltage is 48V, and now voltage-stabiliser tube D1 pressure voltage is less than power supply electricity
Pressure (i.e. supply voltage is more than conducting voltage), exemplary, in the present embodiment, conducting voltage is 13V, and supply voltage, which is subtracted, leads
Be powered pressure, and remaining voltage is distributed on bias unit 121, meanwhile, moment breakdown voltage-stabiliser tube D1, RC charge/discharge units
The first electric capacity C1 in 122, theoretical and reality is all equivalent to short circuit, therefore, the biasing output low level of charge/discharge unit 120, field
Effect pipe Q1 grid obtains low level, persistently keeps the conducting of source electrode and drain electrode.It should be noted that now, the first electric capacity
C1 is started to charge up, and the preset charged threshold values of charging voltage have to be lower than the operation voltage of unlatching/closing of FET, in charging
Need FET Q1 to continue pipe in time and protect conducting.It should be noted that the charging interval of RC charge/discharge units 122 is (according to T
=RC obtains the charging interval, and the first electric value R1 resistance and the first electric capacity C1 capacitance product obtain the charging interval) it have to be larger than
Power supply chip U1 is to the transformer T1 starting of oscillation working time, and charging voltage is less than FET closing motion within the charging interval
Operation voltage, now, transformer T1 output end output coupling output voltage.Because transformer T1 output end output coupling is defeated
Go out voltage, therefore second switch unit must be conducted, the first output end output low level of photoelectrical coupler, bias unit 121
The low levels that are exported by second switch unit 121 of second resistance R2 bypass, i.e. the output voltage of bias unit is limited in low
Level, therefore the first electric capacity C1 stops charging, now FET Q1 grid continues relay acquisition low level, persistently keeps source
Pole and the conducting of drain electrode, power supply chip U1 continue normal electric work, and transformer T1 output end persistently exports constant output
Voltage.
Short circuit protection mode, when the charger normal work based on POE exports constant output voltage, on
State the charger protection circuit based on POE to work according to above-mentioned normal power supply pattern, if above-mentioned be based on POE
Charger protection circuit unexpected abnormality short circuit, now transformer T1 output end output output voltage be low level, second
Switch element 140 loses input voltage, is stopped, now, and the output end of second switch unit 140 is without low level output, partially
Unit 121 and RC charge/discharge units 122 are put, photoelectrical coupler U2 low level bypass effect is lost, RC charge/discharge units 122 are opened
Beginning work, over time, the first electric capacity C1 charging voltage more and more higher, when fet gate obtains high level
When, source electrode and drain electrode are blocked, and power supply chip U1 is stopped, that is, stop the concussion to transformer T1, so that above-mentioned be based on ether
The charger protection circuit of net power supply is stopped, so that being effectively prevented from transformer is in high-temperature work environment, protects transformation
Device is not destroyed.
Charger protection circuit provided in an embodiment of the present invention based on POE is held by being provided in power supply
When torch is pressed, because voltage of shaking hands is not more than the breakdown voltage of voltage regulation unit, therefore voltage-stabiliser tube is not breakdown, biases discharge and recharge list
Member output low level, so that the grid of FET is low level so that its source electrode and drain electrode turn on and then make power supply chip work
Make, be state of shaking hands due to now, therefore without output voltage, therefore second switch unit is not turned on due to no input voltage,
Without low level output, when power supply chip is shaken hands successfully with providing the power supply of supply voltage, supply voltage is more than voltage stabilizing list
The breakdown voltage of member, therefore voltage regulation unit conducting, and voltage of voltage regulation is exported to bias unit, due to voltage regulation unit breakdown wink
Between, the first electric capacity is actual and is all equivalent to short circuit in theory, therefore biasing charge/discharge unit remains unchanged output low level so that field is imitated
Should the grid of pipe be in low level, its source electrode and drain electrode are turned on, so that power supply chip continuous firing, when transformer normally exports coupling
Output voltage is closed to when loading, the conducting of second switch unit exports low level, so that biasing charge/discharge unit output low level,
And then FET is turned on, so that the power supply chip continuous firing, the lasting output coupling of secondary end of the transformer is defeated
Go out voltage, when the charger protection circuit based on POE is short-circuit, the secondary end output low level of the transformer makes
Obtain second switch unit and no longer export low level, the bypass of bias unit and RC charge/discharge units due to losing second switch unit
Effect, the first electric capacity of RC charge/discharge units is started to charge up, when the charging voltage of the first electric capacity reaches preset charged threshold value,
When the grid of FET is in high level, its source electrode and drain electrode are blocked, therefore power supply chip is stopped, and then stop output
Oscillator signal causes the above-mentioned charger protection circuit based on POE to stop to transformer so that transformer is stopped
Work.Be in high-temperature work environment so as to be effectively prevented from transformer and power supply chip, protect transformer and power supply chip not by
Damage, circuit structure is simple, and it is convenient to realize.
The embodiment of the present invention additionally provides a kind of charger based on POE, including power supply chip and transformer,
Transformer first input end is connected with providing the power supply of supply voltage, and the second input and the power supply chip of transformer connect
Connect, the above-mentioned charger based on POE also include the above-mentioned charger protection circuit based on POE, based on
The charger protection circuit for netting very much power supply is connected with transformer and power supply chip respectively.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention
Any modifications, equivalent substitutions and improvements made within refreshing and principle etc., should be included in the scope of the protection.
Claims (8)
1. a kind of charger protection circuit based on POE, it is characterised in that the power supply based on POE
Device protection circuit includes：
Voltage regulation unit, biasing charge/discharge unit, first switch unit and second switch unit；
The input of the voltage regulation unit is connected with providing the power supply of supply voltage, the output end of the voltage regulation unit and institute
State the input connection of biasing charge/discharge unit, the output end of the biasing charge/discharge unit and the control of the first switch unit
End connection processed, the input of the first switch unit is connected with transformer, the output end and power supply of the first switch unit
Chip is connected, and the input of the second switch unit is connected with the secondary end of the transformer, the second switch unit
Output end is connected with the biasing charge/discharge unit；
When the power supply start offer shake hands voltage when, while when the power supply is started as the transformer-supplied,
The voltage of shaking hands is not more than the breakdown voltage of the voltage regulation unit, i.e., described voltage regulation unit is not breakdown, the biasing charge and discharge
Electric unit dead electricity does not work, and keeps low level output so that the first switch unit is turned on, and then obtains the power supply chip
Establish by cable and begin to carry out work of shaking hands according to professional standard and the power supply, the transformer does not obtain the shake of the power supply chip
Signal thus not output coupling output voltage are swung, the second switch unit is not turned on, no level controling signal output, i.e., without side
Road is acted on；
When the power supply chip and the power supply are shaken hands successfully, the voltage value recovers professional standard and more than institute
The breakdown voltage of voltage regulation unit is stated, i.e., described voltage regulation unit is breakdown, when the voltage regulation unit is breakdown, the biasing discharge and recharge
Unit originate the electric stage is equivalent to short circuit, relay output low level so that the first switch unit is remained on,
And then make the power supply chip persistently electric work and export oscillator signal to the transformer, the transformer obtains the shake
Swing signal and start output coupling output voltage；
When the secondary end output coupling output voltage of the transformer is to when loading, the second switch unit must be conducted, defeated
Go out level controling signal so that the biasing charge/discharge unit is bypassed, even if the biasing charge/discharge unit persistently keeps low electricity
Put down so that first switch unit conducting, so that the power supply chip works, the secondary end of the transformer persistently exports coupling
Close output voltage；
When short circuit occurs for the charger output based on POE, the secondary end of the transformer is short-circuited into low electricity
Flat, the second switch unit dead electricity is not turned on, and no level controling signal output, the biasing charge/discharge unit loses bypass and made
With so start to charge up, when it is described biasing charge/discharge unit charging voltage reach preset charged threshold value when, the first switch
Unit is blocked, so that the power supply chip dead electricity is stopped, and then stops the output oscillator signal to the transformer, with
The transformer is set to be stopped.
2. the charger protection circuit according to claim 1 based on POE, it is characterised in that the biasing is filled
Discharge cell includes：Bias unit and RC charge/discharge units；
The bias unit is connected with the RC charge/discharge units, and the input and output end of the bias unit are respectively described
The input and output end of charge/discharge unit are biased, the input of the RC charge/discharge units is defeated with the second switch unit
Go out end connection；
When the power supply start offer shake hands voltage when, while when the power supply is started as the transformer-supplied,
The voltage of shaking hands is not more than the voltage regulation unit breakdown voltage, i.e., described voltage regulation unit is not breakdown, the bias unit and
The RC charge/discharge units dead electricity does not work, and keeps low level output so that the first switch unit is persistently held on, enters
And the power supply chip is obtained electric work, the transformer does not obtain the oscillator signal of the power supply chip thus not output coupling
Output voltage, the second switch unit is not turned on, no level controling signal output；
When the power supply chip and the power supply are shaken hands successfully, the supply voltage is more than puncturing for the voltage regulation unit
Voltage, i.e., described voltage regulation unit is breakdown, and output voltage of voltage regulation is to the bias unit, when the voltage regulation unit is breakdown, institute
State RC charge/discharge units originate the electric stage is equivalent to short circuit, the RC charge/discharge units relay exports low level, during relay
Between need be more than the power supply chip work produce concussion required for time so that the first switch unit turn on, and then
Make the power supply chip persistently electric work, and export oscillator signal to the transformer, the transformer obtains the concussion
Signal starts output coupling output voltage；
When the secondary end output coupling output voltage of the transformer is to when loading, the second switch unit must be conducted, defeated
Go out level controling signal so that the bias unit and the RC charge/discharge units are bypassed into low level, even if the biasing is single
Member persistently keeps low level so that the first switch unit is persistently held on, so that the power supply chip persistently keeps work
Make, the secondary end of the transformer continues output coupling output voltage；
When short circuit occurs for the charger output based on POE, the secondary end of the transformer is short-circuited into low electricity
Flat, the second switch unit is not turned on, and no level controling signal output, bias unit and the RC charge/discharge unit is not other
Road, RC charge/discharge units are started to charge up, when the charging voltage of the RC charge/discharge units reaches that the default of first switch unit is filled
During electric threshold value, the first switch unit is blocked, so that the power supply chip dead electricity is stopped, and then stops the output shake
Signal is swung to the transformer, so that the transformer is stopped.
3. the charger protection circuit according to claim 1 based on POE, it is characterised in that described first opens
Closing unit includes switching tube；
The control end of the switching tube is the control end of the first switch unit, and the input of the switching tube is described first
The input of switch element, the output end of the switching tube is the output end of the first switch unit.
4. the charger protection circuit according to claim 1 based on POE, it is characterised in that described second opens
Closing unit includes photoelectrical coupler；
The first input end of the photoelectrical coupler is the input of the second switch unit, the second of the photoelectrical coupler
Input end grounding, the first output end of the photoelectrical coupler is the output end of the second switch unit, the photoelectric coupling
Second output head grounding of device.
5. the charger protection circuit according to claim 1 based on POE, it is characterised in that the voltage stabilizing list
Member includes voltage-stabiliser tube；
The negative pole of the voltage-stabiliser tube be the voltage regulation unit input, the just extremely described voltage regulation unit of the voltage-stabiliser tube it is defeated
Go out end.
6. the charger protection circuit according to claim 2 based on POE, it is characterised in that the biasing list
Member includes first resistor and second resistance；
The first end of the first resistor is the input of the bias unit, the second end of the first resistor and described second
The first end connection of resistance, the second end ground connection of the second resistance, the first end of the second resistance is the bias unit
Output end.
7. the charger protection circuit according to claim 2 based on POE, it is characterised in that the RC charge and discharges
Electric unit includes the first electric capacity and second resistance；
The first end of first electric capacity be the RC charge/discharge units input, the first end of first electric capacity with it is described
The first end connection of second resistance, the second end ground connection of first electric capacity, the second end ground connection of the second resistance.
8. a kind of charger based on POE, including power supply chip and transformer, the transformer first input end with
The power supply connection of supply voltage is provided, the second input of the transformer is connected with the power supply chip, and its feature exists
In, the charger based on POE also include as described in claim 1 to 7 any one based on POE
Charger protection circuit, the charger protection circuit based on POE respectively with the transformer and the power supply
Chip is connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710438389.1A CN107147080B (en) | 2017-06-12 | 2017-06-12 | A kind of charger and its protection circuit based on Power over Ethernet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710438389.1A CN107147080B (en) | 2017-06-12 | 2017-06-12 | A kind of charger and its protection circuit based on Power over Ethernet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107147080A true CN107147080A (en) | 2017-09-08 |
| CN107147080B CN107147080B (en) | 2019-04-19 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710438389.1A Active CN107147080B (en) | 2017-06-12 | 2017-06-12 | A kind of charger and its protection circuit based on Power over Ethernet |
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| Country | Link |
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| CN (1) | CN107147080B (en) |
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| CN109217255A (en) * | 2018-11-13 | 2019-01-15 | 柳州辰天科技有限责任公司 | The method and its relay power control module of goat phase failure protector relay power supply |
| CN110281787A (en) * | 2019-06-26 | 2019-09-27 | 深圳智链物联科技有限公司 | A kind of wireless charging device and its protection circuit |
| CN113872774A (en) * | 2021-09-06 | 2021-12-31 | 波达通信设备（广州）有限公司 | POE power supply control circuit and power supply method |
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| CN105703618A (en) * | 2016-03-05 | 2016-06-22 | 上海斐讯数据通信技术有限公司 | Circuit for realizing large-power power supply by using routine POE and implementation method |
| CN205921601U (en) * | 2016-06-29 | 2017-02-01 | 杭州士兰微电子股份有限公司 | Ethernet power supply system and control circuit thereof |
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| CN102074998A (en) * | 2009-11-19 | 2011-05-25 | 国基电子（上海）有限公司 | Protection circuit and Ethernet electrical equipment |
| CN102497276A (en) * | 2011-12-20 | 2012-06-13 | 青岛海信网络科技股份有限公司 | Power source conversion circuit and network camera with same |
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| CN109217255A (en) * | 2018-11-13 | 2019-01-15 | 柳州辰天科技有限责任公司 | The method and its relay power control module of goat phase failure protector relay power supply |
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| CN110281787A (en) * | 2019-06-26 | 2019-09-27 | 深圳智链物联科技有限公司 | A kind of wireless charging device and its protection circuit |
| CN110281787B (en) * | 2019-06-26 | 2024-04-12 | 深圳智链物联科技有限公司 | Wireless charging equipment and protection circuit thereof |
| CN113872774A (en) * | 2021-09-06 | 2021-12-31 | 波达通信设备（广州）有限公司 | POE power supply control circuit and power supply method |
| CN113872774B (en) * | 2021-09-06 | 2023-10-24 | 波达通信设备（广州）有限公司 | POE power supply control circuit and power supply method |
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| Publication number | Publication date |
|---|---|
| CN107147080B (en) | 2019-04-19 |
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