CN110460013A - A kind of intrinsic safety electric source overcurrent and short-circuit protection circuit - Google Patents
A kind of intrinsic safety electric source overcurrent and short-circuit protection circuit Download PDFInfo
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- CN110460013A CN110460013A CN201910873148.9A CN201910873148A CN110460013A CN 110460013 A CN110460013 A CN 110460013A CN 201910873148 A CN201910873148 A CN 201910873148A CN 110460013 A CN110460013 A CN 110460013A
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- 230000004224 protection Effects 0.000 title claims abstract description 38
- 238000005070 sampling Methods 0.000 claims abstract description 12
- 230000008030 elimination Effects 0.000 claims abstract description 7
- 238000003379 elimination reaction Methods 0.000 claims abstract description 7
- 238000001514 detection method Methods 0.000 claims description 25
- 230000005669 field effect Effects 0.000 claims description 9
- 230000005611 electricity Effects 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 3
- 230000009977 dual effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000003245 coal Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000034994 death Effects 0.000 description 1
- 231100000517 death Toxicity 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000013024 troubleshooting Methods 0.000 description 1
- 230000003245 working effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
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Abstract
A kind of intrinsic safety electric source overcurrent and short-circuit protection circuit, comprising: principal current switching circuit, current mirror pair circuit, secondary circuital current sampling resistor, sampled voltage shift circuit, short-circuit detecting feed circuit, hysteresis loop comparator circuit, micro-current switching circuit composition.Main road electric current is replicated by current mirror pair circuit in certain proportion, the size of current by detecting current mirroring circuit obtains main road size of current；It is shifted by the sampled voltage to mirror image circuit; and the input terminal of hysteresis loop comparator is respectively connected to short-circuit detecting feedback; hysteresis comparator output signal when overcurrent or short circuit occur; turn off principal current switch cut-off load principal current; realize overcurrent or short-circuit protection; start micro-current switch simultaneously, circuit after Failure elimination is enabled to restore normal automatically.
Description
Technical field
The invention patent relates to the designs of the power protecting circuit of intrinsic safety, are specifically for use in underground coal mine essential safety
The power supply protection of portable measuring instrument device.
Background technique
Intrinsicallysafecircuit refers under standard rated condition the generation (including working normally and defined fault condition)
Any spark or any fuel factor cannot light the circuit of explosive gas atmosphere.It is deposited in coal, petroleum, natural gas extraction etc.
In the power supply of the system equipments such as all kinds of communications, monitoring, measuring instrument, instrument and the automation of the dangerous industry of inflammable, explosion hazard gases
Power supply must satisfy requirement of explosion proof, since intrinsically safe power supply is explosion-proof optimised form, so higher to its performance requirement.
Intrinsic safety electric source fully considers power circuit output voltage and electric current and power situation in the design, prevents over-voltage
Or the spark that overcurrent generates lights underground fuel gas, causes the damage and injures and deaths of equipment and personnel.According to national standard
The various indexs of GB3836.4-2000 prescribed requirement, essence safety type circuits mainly have: output voltage or electric current cannot be lighted week
Enclose imflammable gas；Must there are reliable electrical isolation or even some fields between intrinsicallysafecircuit and immaterial safety circuit
The required safety coefficient to be worked using dual or triple over-voltage over-current protection circuits, raising circuit.In addition, some appliance workings
Self-recovering function is required, i.e., can automatically revert to normal operating conditions after troubleshooting.
Currently used intrinsically safe power supply protection circuit form includes current-limiting type protection, subtracts flow pattern protection, cut-off type
Protection.The source of spark energy quickly can be thoroughly truncated in overcurrent or short trouble in cut-off type current foldback circuit, tool
There is limit energy effect well.
Summary of the invention
The purpose of the present invention is to provide a kind of guarantors of the principal current of simple, safe and reliable quick truncation spark energy
Protection circuit, while micro-current being provided, circuit after Failure elimination is resumed work automatically.
To achieve the goals above, the technical solution adopted by the present invention includes: principal current switching circuit, the secondary electricity of current mirror
Road, secondary circuital current sampling resistor, sampled voltage shift circuit, short-circuit detecting feed circuit, hysteresis loop comparator circuit, micro-current
Switching circuit composition.Main road electric current is replicated by current mirror pair circuit in certain proportion, by the electricity for detecting current mirroring circuit
It flows size and obtains main road size of current；It is respectively connected to by the sampled voltage displacement to mirror image circuit, and with short-circuit detecting feedback
Hysteresis comparator output signal when the input terminal of hysteresis loop comparator, overcurrent or short circuit occur, shutdown principal current switch cut-off load
Principal current realizes overcurrent or short-circuit protection, while starting micro-current switch, and circuit after Failure elimination is restored just automatically
Often.
The principal current switching circuit is to control loaded work piece current switch, source electrode by high-power PMOS field-effect tube
S connection power supply, drain D connect load.
The current mirror pair circuit is by the concatenation detection resistance realization of small-power PMOS field-effect tube, middle low power
PMOS fet gate G docks the high-power PMOS fet gate G of main road, and source S connects power supply, small-power PMOS
FET drain D connects detection resistance, then access load, to obtain one more small than loaded work piece electric current times of micro- electricity
Stream source.
The current sampling circuit is the concatenation detection resistance of above-mentioned small-power PMOS field-effect tube, passes through detection resistance
The purpose for calculating principal current size is realized in voltage drop.
The level shift function is completed by transistor combination network, realizes the voltage of mirror current source detection resistance
It is displaced to 1/2 or so, short-circuit detecting circuit feedback level when working normally lower than load.It is used in voltage shift circuit simultaneously
Current potential latch function guarantees that circuit detection resistance no current state during short circuit locks current potential, so that compare can be steady for hysteresis
Fixed work.
The level shift and short-circuit detecting circuit output end is respectively connected to the "+" pole and "-" pole of hysteresis loop comparator.Electricity
When road works normally, short-circuit detecting circuit exports the voltage shift that terminal potential is greater than detection resistance, and comparator exports low level；If
Short circuit occurs, short-circuit detecting circuit exports the voltage shift that terminal potential is less than detection resistance, and voltage comparator exports high level.
Equally, if principal current increases, current mirror electric current increases in proportion, and the detection voltage of sampling resistor is increase accordingly,
If being more than the "-" input terminal of hysteresis comparison circuit, so that hysteresis loop comparator exports low level, reach short-circuit detecting circuit output
Terminal potential is greater than the voltage shift of detection resistance, and comparator exports low level.
The high-power PMOS field-effect tube of above-mentioned hysteresis loop comparator output high level signal shutdown main road, realizes short circuit event
Hinder the effect of cut-off current, while opening micro-current and switching and concatenate a set current limiting diode access load guarantee short circuit inspection
Slowdown monitoring circuit works normally, and realizes that Failure elimination back loading output terminal potential is greater than the voltage shift of detection resistance, voltage comparator
Again output low level opens the high-power PMOS field-effect tube of main road, and circuit restores normal shape after realizing short trouble elimination
State, while ensuring to turn off the high reliability of P power tube during short trouble.
The comparator uses hysteresis loop comparator, can ensure that overcurrent and short-circuit protection circuit work using hysteresis loop comparator
Stability, i.e. shutdown protection and recovery have certain voltage threshold between working normally, it is ensured that overcurrent and short-circuit protection circuit work
Make stability.
The beneficial effect of the technology of the present invention is: compared with prior art, first is that on limitation intrinsic safety electric source size of current basis
On, it is ensured that be supported under short trouble can switch-off power MOS pipe, reduce short circuit occur when system loss power consumption；Second is that
Using the main road electric current of current mirroring circuit small scale duplication main power tube control, main road size of current is obtained by detection resistance,
Since current mirroring circuit electric current is smaller, reduce the pyrotoxin in circuit；Third is that circuit has short-circuit detecting and over-current detection double
Weight function cuts and can achieve adjustment overcurrent threshold size by adjusting current mirror resistance sizes；Fourth is that circuit has action response
Fastly, restore automatically, intrinsic safety output protection can be effectively realized there are much noise, can guarantee that power supply is accurately reliable
The advantages of work；Fifth is that by sharing short-circuit detecting circuit or hysteresis loop comparator circuit and series connection principal current switch, or pass through
Intrinsic safety electric source overcurrent of connecting and short-circuit protection circuit realize dual or triple overcurrent short-circuit protection purposes.
Detailed description of the invention
Present invention will be further explained below with reference to the attached drawings and examples.
Fig. 1 is schematic block circuit diagram of the invention.
Fig. 2 is a kind of circuit diagram of specific implementation of the present invention.
Fig. 3 is a kind of integrated circuit diagram of specific implementation of the present invention.
Specific embodiment
The present invention will be further described with embodiment with reference to the accompanying drawing.
As shown in Figure 1, a kind of intrinsic safety electric source overcurrent and short-circuit protection circuit, comprising: principal current switching circuit, current mirror
Secondary circuit, current sampling circuit, sampled voltage shift circuit, short-circuit detecting feed circuit, hysteresis loop comparator circuit, micro-current are opened
Powered-down road composition obtains overcurrent and short-circuit protection signal from the anode of power supply, i.e. input current and output electric current is total to cathode.
As shown in Fig. 2, a kind of intrinsic safety electric source overcurrent and short-circuit protection circuit, wherein principal current switching circuit is high-power P
Channel MOS pipe Q2, current mirror pair circuit are small-power P-channel MOS pipe Q5, and Q5 pipe replicates big rate pipe in certain proportion
The electric current of Q2 is converted into detection voltage by current sampling resistor POT；By transistor Q6, Q8, Q9, Q10, Q11, Q12 and
Q13 completes level shift function and latch function, then accesses the "+" pole input terminal of hysteresis comparison circuit；R1, R2 and R6 are short
Feed circuit is detected on road, then accesses the "-" pole input terminal of hysteresis comparison circuit；Q6 and Q7 composition diode type of attachment is total to
Source level amplifying circuit controls micro-current switching circuit Q1, and wherein the diode of micro-current switching circuit limits size of current, so
It is switched afterwards by Q3 inverter cricuit control principal current switch and its current mirror.
As shown in Fig. 2, the grid grade current potential of MOS pipe Q2 and Q5 are high level, the normal work of circuit system when working normally
Make, since sampling resistor POT accesses secondary current, therefore flows through that electric current is smaller, realize the purpose for reducing the pyrotoxin in circuit.
As shown in Fig. 2, short circuit once occurs, short-circuit detecting circuit will be fed back to low level, hysteresis loop comparator "-" input terminal
Current potential is 0 V, and because the "+" input terminal potential of comparator is greater than 0 V, the output of final comparator is high level, and then is turned off
MOS pipe Q2 and Q5, while micro-current switch Q1 is opened, so that entire load is limited to micro-current size, realize intrinsic safety electricity
The short-circuit protection in source.
As shown in Fig. 2, Q2 and Q5 pipe will turn off after realizing short-circuit protection；Q8, Q9 of voltage shift circuit, Q10,
Q11, Q12 and Q13 form current potential latch function, guarantee that hysteresis compares "+" to circuit under Q5 pipe off state during short circuit
The voltage of input terminal is consistently higher than the "-" input terminal voltage of comparator, even if there are circuit noise, so that comparator output voltage
It is always low level, ensures that circuit can turn off P power tube always during short circuit occurs, realizes the reliable of protection circuit
Property.
As shown in Fig. 2, micro-current switching circuit is opened when short circuit occurs, so that have certain current direction load, and
Ensure that short-circuit detecting circuit will be fed back to low level.
As shown in Fig. 2, once generating over-current phenomenon avoidance, image current also amplifies electric current in proportion, and sampling resistor POT is converted into
Detection voltage is increase accordingly, and the "+" input terminal of hysteresis comparison circuit has been more than the "-" input of hysteresis comparison circuit after voltage shift
End again such that hysteresis loop comparator exports low level, and then turns off MOS pipe Q2 and Q5, while opening micro-current switch Q1, from
And entirely to load to be limited to micro-current size, realize the overcurrent protection of intrinsic safety electric source.
As shown in Fig. 2, controlling overcurrent threshold size by the size for adjusting sampling resistor POT.
As shown in Fig. 2, once short circuit or over current fault are eliminated, i.e., under load resistance normal condition, micro-current switching circuit
To charge to load, short-circuit detecting circuit increase feedback voltage, and hysteresis loop comparator exports high level, open MOS pipe Q2 and
Q5, simultaneously closes off micro-current switch Q1, and circuit restores normal condition automatically.
Equally, restore under over-current state to current threshold hereinafter, the "+" input terminal of hysteresis comparison circuit is small after voltage shift
In the "-" input terminal of hysteresis comparison circuit, again such that hysteresis loop comparator exports high level, MOS pipe Q2 and Q5 is opened, together
When close micro-current switch Q1, circuit restores normal condition automatically.
If Fig. 3 is a kind of intrinsic safety overcurrent and the integrated circuit of short-circuit protection circuit, only by current sampling resistor, short-circuit detecting
Resistance makees peripheral circuit, is integrated into single chip architecture convenient for intrinsic safety electric source overcurrent and short-circuit protection circuit.
For the special occasions for requiring intrinsic safety electric source that there are dual or triple overcurrent short-circuit protections, by of the present invention
Principal current switching circuit in series, share short-circuit feedback circuit, current mirror pair circuit in parallel, current sampling circuit series connection or it is stagnant
It returns comparison circuit etc. and realizes dual or triple overcurrents and short-circuit protection purpose.Equally, overcurrent of the present invention of directly connecting and
Short-circuit protection circuit is also able to achieve dual or triple overcurrents and short-circuit protection purpose.
Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention., rather than its limitations；To the greatest extent
Pipe present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: its according to
So be possible to modify the technical solutions described in the foregoing embodiments, or to some or all of the technical features into
Row equivalent replacement；And these are modified or replaceed, various embodiments of the present invention technology that it does not separate the essence of the corresponding technical solution
The range of scheme.
Claims (5)
1. a kind of intrinsic safety electric source overcurrent and short-circuit protection circuit, comprising: principal current switching circuit, current mirror pair circuit, electric current
Sample circuit, sampled voltage shift circuit, short-circuit detecting feed circuit, hysteresis loop comparator circuit, micro-current switching circuit composition,
It is characterized by: main road electric current is replicated by current mirror pair circuit in certain proportion, it is big by the electric current for detecting current mirroring circuit
Small acquisition main road size of current；Hysteresis is respectively connected to by the sampled voltage displacement to mirror image circuit, and with short-circuit detecting feedback
Comparator, if overcurrent or short trouble, shutdown principal current switch realizes the protection of power supply road, while starting set current limiting micro-current
Switch, enables circuit after Failure elimination to restore normal automatically.
2. a kind of intrinsic safety electric source overcurrent according to claim 1 and short-circuit protection circuit, it is characterised in that: main power tube control
The main road electric current of system is that loaded work piece current switch is controlled by high-power PMOS field-effect tube, and source S connects power supply, and drain D connects
Load, current mirror pair circuit is by the concatenation detection resistance realization of small-power PMOS field-effect tube, middle low power PMOS field-effect
Tube grid G docks the high-power PMOS fet gate G of main road, and source S connects power supply, the leakage of small-power PMOS field-effect tube
Pole D connects detection resistance, then access load, to obtain one more small than loaded work piece electric current times of micro-current source.
3. a kind of intrinsic safety electric source overcurrent according to claim 1 and short-circuit protection circuit, it is characterised in that: current sample electricity
Road is realized by being connected on the detection resistance of current mirror pair circuit, calculates principal current size by detection resistance voltage drop, and
By completing level shift to detection resistance voltage 1/2 or so, when which is less than load normal work by transistor combination network
Short-circuit detecting feedback level.
4. a kind of intrinsic safety electric source overcurrent according to claim 1 and short-circuit protection circuit, it is characterised in that: the level
Displacement is respectively connected to the "+" pole and "-" pole of hysteresis loop comparator with short-circuit detecting circuit output end, when circuit works normally, short circuit
Detection circuit exports the voltage shift that terminal potential is greater than detection resistance, and comparator exports low level；If short circuit, short-circuit detecting occurs
Circuit output terminal potential is less than the voltage shift of detection resistance, and voltage comparator exports high level, equally, if principal current increases,
Current mirror electric current increases in proportion, and the detection voltage of sampling resistor is increase accordingly, if be more than hysteresis comparison circuit "-" it is defeated
Enter end, so that hysteresis loop comparator exports low level, reaches the voltage shift that short-circuit detecting circuit output terminal potential is greater than detection resistance
Position, comparator export low level.
5. a kind of intrinsic safety electric source overcurrent according to claim 1 and short-circuit protection circuit, it is characterised in that: comparator is defeated
High level signal shutdown principal current switch out, realizes the effect of short trouble cut-off current, while opening micro-current switch and ensureing
Short-circuit detecting circuit works normally, and circuit restores normal condition after realizing short trouble elimination, can ensure that using hysteresis loop comparator
Overcurrent and short-circuit protection circuit job stability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910873148.9A CN110460013B (en) | 2019-09-17 | 2019-09-17 | Intrinsic safety power supply overcurrent and short-circuit protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910873148.9A CN110460013B (en) | 2019-09-17 | 2019-09-17 | Intrinsic safety power supply overcurrent and short-circuit protection circuit |
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| Publication Number | Publication Date |
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| CN110460013A true CN110460013A (en) | 2019-11-15 |
| CN110460013B CN110460013B (en) | 2024-07-02 |
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| CN201910873148.9A Active CN110460013B (en) | 2019-09-17 | 2019-09-17 | Intrinsic safety power supply overcurrent and short-circuit protection circuit |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112130029A (en) * | 2020-10-10 | 2020-12-25 | 中车青岛四方机车车辆股份有限公司 | Train network fault detection tool and detection method |
| CN116031830A (en) * | 2023-03-28 | 2023-04-28 | 深圳市德晟达电子科技有限公司 | Load switch protection circuit adopting impedance detection |
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| JP2004248452A (en) * | 2003-02-14 | 2004-09-02 | Auto Network Gijutsu Kenkyusho:Kk | Overcurrent protection circuit |
| US7042280B1 (en) * | 2003-12-15 | 2006-05-09 | National Semiconductor Corporation | Over-current protection circuit |
| RU2432656C1 (en) * | 2010-08-23 | 2011-10-27 | Учреждение Российской академии наук Конструкторско-технологический институт вычислительной техники Сибирского отделения РАН | Electronic fuse with self-recovery |
| CN109390916A (en) * | 2017-08-14 | 2019-02-26 | 河南理工大学 | Pulse tracking formula power supply broadband short-circuit protection circuit |
-
2019
- 2019-09-17 CN CN201910873148.9A patent/CN110460013B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004248452A (en) * | 2003-02-14 | 2004-09-02 | Auto Network Gijutsu Kenkyusho:Kk | Overcurrent protection circuit |
| US7042280B1 (en) * | 2003-12-15 | 2006-05-09 | National Semiconductor Corporation | Over-current protection circuit |
| RU2432656C1 (en) * | 2010-08-23 | 2011-10-27 | Учреждение Российской академии наук Конструкторско-технологический институт вычислительной техники Сибирского отделения РАН | Electronic fuse with self-recovery |
| CN109390916A (en) * | 2017-08-14 | 2019-02-26 | 河南理工大学 | Pulse tracking formula power supply broadband short-circuit protection circuit |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112130029A (en) * | 2020-10-10 | 2020-12-25 | 中车青岛四方机车车辆股份有限公司 | Train network fault detection tool and detection method |
| CN112130029B (en) * | 2020-10-10 | 2024-03-01 | 中车青岛四方机车车辆股份有限公司 | Train network fault detection tool and detection method |
| CN116031830A (en) * | 2023-03-28 | 2023-04-28 | 深圳市德晟达电子科技有限公司 | Load switch protection circuit adopting impedance detection |
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| CN110460013B (en) | 2024-07-02 |
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