CN205883038U - Current foldback circuit and have display screen of this circuit - Google Patents
Current foldback circuit and have display screen of this circuit Download PDFInfo
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- CN205883038U CN205883038U CN201620336918.8U CN201620336918U CN205883038U CN 205883038 U CN205883038 U CN 205883038U CN 201620336918 U CN201620336918 U CN 201620336918U CN 205883038 U CN205883038 U CN 205883038U
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Abstract
The utility model provides a current foldback circuit and have display screen of this circuit, a current strength for detecting the consumer, when current strength is too high, output control power consumption device power down's truncated signal, it is the alternating current that this current foldback circuit directly is coupled what receive at the power, so need become the direct current to this ac inversion, the filtering unit is arranged in the effect of the harmonic of elimination primary circuit, prevent that the harmonic from producing the interference to this circuit, sampling unit is arranged in converting the direct current of filtering unit output to voltage provides the sample voltage that this electric current corresponds, comparing element is given in output, comparing element is used for the inside reference voltage who provides of comparison sample voltage and comparing element, , sample voltage showes that the too high meeting of consumer internal current intensity leads to the consumer to produce the trouble when being greater than reference voltage, then, comparing element outlet driving signal, drive unit falls in response to this drive signal control consumer.
Description
Technical field
This utility model relates to display screen, particularly to a kind of current foldback circuit and with the display screen of this circuit.
Background technology
Electrical appliance short circuit, refers to plug or the bad short circuit of power line quality of electrical appliance, because of defective insulation, device inside electrical equipment
Aging loosen etc. reason cause power supply short circuit, once electrical equipment is short-circuited and without safety, or safety lose work
With, directly make main line bear powerful electric current, referred to as electrical appliance short circuit.
When there is electrical short-circuit, if short circuit current is not enough to blow user's electric fuse, or make air switch trip, then can
Use the aggravation of electric line electric current, generally several ten times larger than running current, make circuit produce substantial amounts of heat at short notice
Amount, it is impossible to diffusing at once in surrounding air, temperature the most quickly raises, makes wiring sealing material be heated ignition, sometimes
Waiting short circuit and also produce spark, the incendivity thing making distance line close catches fire, and causes fire.
In prior art, if display screen is under over-current state (electrical appliance ground, short circuit and fault) for a long time
Work not only can cause burns display screen, and the person also can bring time serious the biggest danger.
Utility model content
The purpose of this utility model is to provide a kind of current foldback circuit and the display screen with this circuit, works as display screen
When being short-circuited, current foldback circuit plays the effect of protection display screen.
Above-mentioned purpose of the present utility model has the technical scheme that
A kind of current foldback circuit, for the current intensity of detection equipment, when current intensity is too high, output controls
The truncated signal of electrical equipment power-off, it is characterised in that: include
Rectification unit, is coupled to civil power, for alternating current is converted to unidirectional current；
Filter unit, is coupled to described rectification unit, for the harmonic wave in described unidirectional current being filtered off and forming an electric current；
Sampling unit, is coupled to described filter unit, is used for according to this electric current generation one with the change of this DC current
The sampled voltage of change；
Comparing unit, is coupled to described sampling unit, is used for comparing, when adopting according to a reference voltage and described sampled voltage
Sample voltage is more than output drive signal during reference voltage；
Driver element, is coupled to described comparing unit, is used for exporting described truncated signal according to described driving signal, drives
Unit includes relay coil, and described relay coil obtains electric work in response to described driving signal；
Being also coupled to amplifying unit between described filter unit and sampling unit, described amplifying unit is used for described in foundation adopting
The amplification voltage of multiple is fixed in the output of sample voltage higher than this sampled voltage, and described amplifying unit includes the amplifier of ratio in the same direction
And the protective resistance that is serially connected and Zener diode, the node that described protective resistance and Zener diode couple is put with described
The positive input terminal of big device couples.
By using technique scheme, what this current foldback circuit was directly coupled to power supply reception is alternating current, so
Needing this alternating current is converted into unidirectional current, filter unit, for filtering off the effect of the harmonic wave in primary circuit, prevents harmonic wave to this
Circuit produces interference, and sampling unit provides this electric current institute right for the DC current of output in filter unit is converted into voltage
The sampled voltage answered, exports to comparing unit, and comparing unit is for comparing sampled voltage and the internal reference provided of comparing unit
Voltage, represents that when sampled voltage is more than reference voltage the electrical equipment too high meeting of internal current intensity causes electrical equipment to produce event
Barrier, now, comparing unit output drive signal, driver element controls electrical equipment power down, protection electricity in response to this driving signal
Resistance and Zener diode have the protective effect to amplifier, prevent bigger voltage from entering and cause transport and placing device to damage.
As improvement of the present utility model, described rectification unit is bridge rectifier unit.
By using technique scheme, bridge rectifier utilizes the unidirectional general character of diode to carry out rectification, compared to half
Ripple rectification, bridge rectifier obtains sinusoidal wave positive half period, and negative half-cycle then loses, and has the advantages that energy fluctuation is little.
As improvement of the present utility model, described filter unit includes the polarized filtered electrical being coupled to described rectification unit
Hold.
By using technique scheme, on the one hand arranging of polarized filter capacitor play the effect filtering off harmonic wave, separately
On the one hand cost is reduced.
As improvement of the present utility model, described comparing unit includes that comparator, the positive input terminal of described comparator couple
Described sampling unit, the negative input end of described comparator is used for receiving reference voltage.
As improvement of the present utility model, described sampling unit includes sampling resistor, described sampling resistor and described filtering
The node output sampled voltage that unit couples.
By using technique scheme, sampling unit includes sampling resistor, and sampling resistor couples and filter unit, when
During filter unit output electric current, through sampling resistor and form a sampled voltage on sampling resistor, defeated at the node coupled
Go out.
A kind of display screen with overcurrent protection, including above-mentioned current foldback circuit.
By using technique scheme, this current foldback circuit is installed on a display screen, when display screen receives too high
Electric current time, for preventing the appliance component within electric current too high damage electric wire or display screen, institute so that display screen power down, rises
Effect to protection display screen.
In sum, this utility model has the advantages that this current foldback circuit is directly coupled to power supply and receives
Be alternating current, so needing this alternating current is converted into unidirectional current, filter unit is for filtering off the work of harmonic wave in primary circuit
With, prevent harmonic wave from this circuit is produced interference, sampling unit is for being converted into voltage the DC current of output in filter unit
Thering is provided the sampled voltage corresponding to this electric current, output is to comparing unit, and comparing unit is used for comparing sampled voltage and comparing single
When sampled voltage is more than reference voltage, the internal reference voltage provided of unit, represents that the electrical equipment too high meeting of internal current intensity is led
Causing electrical equipment and produce fault, this thing comparing unit output drive signal, driver element controls electricity consumption in response to this driving signal
Device looses power.
Accompanying drawing explanation
Fig. 1 is current foldback circuit connection circuit figure.
In figure, 1, rectification unit；2, filter unit；3, sampling unit；4, amplifying unit；5, comparing unit；6, list is driven
Unit.
Detailed description of the invention
Below in conjunction with accompanying drawing, this utility model is described in further detail.
Embodiment 1, a kind of current foldback circuit, with reference to shown in Fig. 1, including the rectification unit 1 coupled successively, filter unit
2, sampling unit 3, amplifying unit 4, comparing unit 5 and driver element 6, wherein, rectification unit 1 is set to bridge rectifier electricity
Road, this bridge rectifier utilizes the unidirectional general character of diode to carry out rectification, and compared to halfwave rectifier, bridge rectifier is just obtaining
The positive half period of string ripple, negative half-cycle then loses, and has the advantages that energy fluctuation is little, by bridge rectifier being input to
The alternating current of electrical equipment is converted into unidirectional current, by the filter capacitor C1 of filter unit 2, the harmonic wave in unidirectional current is being filtered off,
Preventing harmonic wave from circuit is produced interference, sampling unit 3 includes a sampling resistor R1, and sampling resistor chooses the resistance that resistance is relatively low,
Preventing making when current fluctuation is bigger sampling unit 3 export higher voltage signal and damage the components and parts in this circuit, sampling is single
Unit 3 couples amplifying unit 4, in order to the components and parts in this circuit are protected further, in amplifying unit 4, and series connection one protection electricity group
R2 and Zener diode D5, protective resistance R2 and Zener diode D5 have the protective effect to amplifier, prevent bigger electricity
Being pressed into into causing transport and placing device to damage, to export sampled voltage less, so putting by leading to ratio for sampling unit 3 in normal state
This signal of telecommunication is amplified by big device, and leading to proportional amplifier is that prior art is not the most done and repeated its principle, and it amplifies
Multiple determined by internal resistance, by amplifier in proportion sampled voltage amplified to be formed and amplifies voltage and export to the most single
Unit 5 compares, and the 3rd resistance R5 and the 4th resistance R6 that comparing unit 5 protection is arranged in series connect between power supply and ground, its
The node output reference voltage coupled, comparing unit 5 also includes comparator, the positive input terminal sampling unit 3 of comparator, negative input
The node that end coupling resistance R5 and resistance R6 couples, is used for comparing amplification voltage and reference voltage, when amplifying voltage more than benchmark
Represent during voltage that to input to the current intensity of sampling unit 3 too big, if this electric current is passed through in display screen, may result in aobvious
Display screen is damaged, and now, the outfan output high level signal of comparator, driver element 6 includes NPN audion VT1 and relay
Coil, the base stage of NPN audion couples the outfan of comparator, and when receiving high level signal, audion VT1 turns on, this
Place audion VT1 do switching component use, when audion VT1 turn on, with audion VT1 launch collect couple relay
Device coil obtains electric work, and relay also includes a relay normally-closed contact, and this relay normally-closed contact is coupled in electrical equipment
On, when relay coil obtains electric work, relay normally-closed contact disconnects and makes electricity consumption device looses power.
Embodiment 2, a kind of display screen with current foldback circuit, including the overcurrent protection electricity described in above-described embodiment 1
Road.
This specific embodiment is only that it is not to restriction of the present utility model, ability to explanation of the present utility model
The present embodiment can be made after reading this specification by field technique personnel as required does not has the amendment of creative contribution, but
As long as all being protected by Patent Law in right of the present utility model.
Claims (6)
1. a current foldback circuit, for the current intensity of detection equipment, when current intensity is too high, output controls to use
The truncated signal of electricity device powers down, it is characterised in that: include
Rectification unit (1), is coupled to civil power, for alternating current is converted to unidirectional current；
Filter unit (2), is coupled to described rectification unit (1), for the harmonic wave in described unidirectional current being filtered off and is formed an electricity
Stream；
Sampling unit (3), is coupled to described filter unit (2), is used for producing one with the change of this DC current according to this electric current
And the sampled voltage changed；
Comparing unit (5), is coupled to described sampling unit (3), is used for comparing according to a reference voltage and described sampled voltage, when
Sampled voltage is more than output drive signal during reference voltage；
Driver element (6), is coupled to described comparing unit (5), is used for exporting described truncated signal according to described driving signal, drives
Moving cell (6) includes relay coil, and described relay coil obtains electric work in response to described driving signal；
Being also coupled to amplifying unit (4) between described filter unit (2) and sampling unit (3), described amplifying unit (4) is used for depending on
Fix the amplification voltage of multiple higher than this sampled voltage according to the output of described sampled voltage, described amplifying unit (4) includes in the same direction
The amplifier of ratio and the protective resistance being serially connected and Zener diode, described protective resistance and Zener diode couple
Node couples with the positive input terminal of described amplifier.
A kind of current foldback circuit the most according to claim 1, it is characterised in that: described rectification unit (1) is that bridge-type is whole
Stream unit (1).
A kind of current foldback circuit the most according to claim 1, it is characterised in that: described filter unit (2) includes coupling
Polarized filter capacitor in described rectification unit (1).
A kind of current foldback circuit the most according to claim 1, it is characterised in that: described comparing unit (5) includes comparing
Device, the positive input terminal of described comparator couples described sampling unit (3), and the negative input end of described comparator is used for receiving with reference to electricity
Pressure.
A kind of current foldback circuit the most according to claim 1, it is characterised in that: described sampling unit (3) includes sampling
Resistance, described sampling resistor couples with described filter unit (2).
6. the display screen with current foldback circuit, it is characterised in that: include that any one of claim 1 to 5 is described
Current foldback circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620336918.8U CN205883038U (en) | 2016-04-20 | 2016-04-20 | Current foldback circuit and have display screen of this circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620336918.8U CN205883038U (en) | 2016-04-20 | 2016-04-20 | Current foldback circuit and have display screen of this circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205883038U true CN205883038U (en) | 2017-01-11 |
Family
ID=57686480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620336918.8U Active CN205883038U (en) | 2016-04-20 | 2016-04-20 | Current foldback circuit and have display screen of this circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205883038U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106786350A (en) * | 2017-02-13 | 2017-05-31 | 中领世能（天津）科技有限公司 | Circuit protection device and electric power system |
| CN107086554A (en) * | 2017-05-26 | 2017-08-22 | 中领世能（天津）科技有限公司 | Electric power system and its multi-stage protection device |
| CN107727977A (en) * | 2017-11-18 | 2018-02-23 | 广东电网有限责任公司清远供电局 | The overvoltage protection device wireless monitoring device that a kind of band logical severed finger shows |
| CN111026211A (en) * | 2018-10-09 | 2020-04-17 | 西安智盛锐芯半导体科技有限公司 | Conversion circuit for converting current into voltage |
-
2016
- 2016-04-20 CN CN201620336918.8U patent/CN205883038U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106786350A (en) * | 2017-02-13 | 2017-05-31 | 中领世能（天津）科技有限公司 | Circuit protection device and electric power system |
| CN107086554A (en) * | 2017-05-26 | 2017-08-22 | 中领世能（天津）科技有限公司 | Electric power system and its multi-stage protection device |
| CN107727977A (en) * | 2017-11-18 | 2018-02-23 | 广东电网有限责任公司清远供电局 | The overvoltage protection device wireless monitoring device that a kind of band logical severed finger shows |
| CN111026211A (en) * | 2018-10-09 | 2020-04-17 | 西安智盛锐芯半导体科技有限公司 | Conversion circuit for converting current into voltage |
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