CN103118470A - LED parallel circuit with equalized branch current - Google Patents
LED parallel circuit with equalized branch current Download PDFInfo
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- CN103118470A CN103118470A CN2013100554991A CN201310055499A CN103118470A CN 103118470 A CN103118470 A CN 103118470A CN 2013100554991 A CN2013100554991 A CN 2013100554991A CN 201310055499 A CN201310055499 A CN 201310055499A CN 103118470 A CN103118470 A CN 103118470A
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Abstract
The invention relates to electronic circuit technology, in particular to an LED parallel circuit with equalized branch current. The LED parallel circuit comprises a constant current source and LED units, and is characterized by further comprising a current equalizing unit. The constant current source is connected with the LED units and the current equalizing unit respectively, and the LED units are connected with the current equalizing unit. The LED parallel circuit has the advantages that current flowing through different LED light strings which are in parallel connection is equalized, and inconsistency of current due to individual difference of the LEDs is eliminated, and beneficial conditions are provided for constant-current drive of the LED light strings. In addition, the technical scheme is particularly applicable to the LED parallel circuit driven by the constant-current source.
Description
Technical field
The present invention relates to electronic circuit technology, relate to concretely a kind of LED parallel circuits of branch current equilibrium.
Background technology
Along with popularizing of semiconductor light-emitting-diode LED, all realized the generally application of LED at present in a plurality of fields such as LED LCD TV, LED illuminating lamps.In actual application, be generally LED lamp with some carry out certain string and connect after as light emitting source, for controlling cost, when the LED of numerous quantity lamp is gone here and there and connected, often adopt many or multi-string LED lamp to carry out mode in parallel and realize.But the LED lamp string of traditional circuit is after parallel connection, if between LED lamp string in parallel, property difference is larger, the situation of current-unbalance between the lamp string easily appears, take the LED LCD TV as example, current unevenness can cause that the screen intensity uniformity is relatively poor, and serious meeting impact is normally watched.So when parallel connection LED lamp string being carried out the constant current driving, must guarantee that the drive current on each road is as far as possible consistent.
Summary of the invention
Technical problem to be solved by this invention proposes a kind of can reducing under the constant current drive condition, the LED parallel circuits of the branch current equilibrium of the current difference between parallel connection LED lamp string exactly.
The present invention solves the problems of the technologies described above the technical scheme that adopts: a kind of LED parallel circuits of branch current equilibrium, comprise constant-current source and LED unit, it is characterized in that, also comprise the current-sharing unit, described constant-current source is connected with the current-sharing unit with the LED unit respectively, and described LED unit is connected with the current-sharing unit.
Concrete, described LED unit be the LED lamp string of parallel connection, and described LED lamp string is at least two, and described LED lamp string is composed in series by single or plurality of LEDs lamp.
Concrete, described current-sharing unit is the flows resistance device, and described flows resistance device quantity equates with LED lamp string quantity, and contacts with each LED lamp respectively and connect.
Concrete, described flows resistance device is one or more in carbon film resistor, metal film resistor, wire wound resistor and metal glass uranium resistor.
Beneficial effect of the present invention is, can make the electric current of each LED lamp string in parallel of flowing through consistent, eliminates the inconsistent situation of electric current of bringing due to the LED individual difference, provides advantage for the constant current of LED lamp string drives.
Description of drawings
Fig. 1 is the schematic diagram of the LED parallel circuits of embodiment.
Embodiment
Below in conjunction with drawings and Examples, describe technical scheme of the present invention in detail:
The LED parallel circuits of branch current equilibrium of the present invention, the main technical schemes of proposition are for arranging the current-sharing unit on every branch road of parallel connection, thereby the electric current of effectively balanced each branch road is eliminated because the current-unbalance phenomenon that LED difference causes.
Embodiment
As shown in Figure 1, this example comprises a constant-current source, a parallel connection LED lamp string location and a resistance flow equalizing circuit unit.This parallel connection LED lamp string location 11 comprises at least two LED lamp strings, and each LED lamp string is composed in series by single or plurality of LEDs, in the middle of the present embodiment, is composed in series as example by 2 LED lamp take 3 paths of LEDs lamp strings in parallel, each LED lamp string and describes.Described flow equalizing circuit unit 12 is comprised of the flows resistance device, and quantity equates with LED lamp string quantity, and with corresponding being connected in series of described LED lamp string.The flows resistance device can be connected in series and LED positive pole or negative pole, in the middle of the present embodiment, is serially connected in negative pole take the flows resistance device and describes as example.Constant-current source 10 provides constant total current to carry out constant current to the LED lamp string of parallel connection and drives.Wherein LED lamp string location in parallel comprises 3 LED lamp strings, and each LED lamp string is composed in series by single or plurality of LEDs, that LED can comprise is little, in, each high power LED such as high-power.
Constant-current source 10 is used for providing parallel connection LED lamp string drive current, guarantees that the total current of LED lamp string keeps constant.
Flow equalizing circuit unit 12 is comprised of the flows resistance device, traditional design does not have this flow equalizing circuit, directly carries out the connection in series-parallel of LED lamp, and the voltage during normal operation on each LED lamp string equates, due to the individual character difference of parallel connection LED lamp, the electric current that flows through each lamp string can occur inconsistent.Flow equalizing circuit in the present invention is comprised of resistor, is serially connected in each LED lamp string, is serially connected with in an embodiment LED lamp string negative pole.After each LED lamp string series resistor device, can effectively eliminate current difference between the lamp string that brings because of each string LED individual character difference, after selecting the resistor serial connection of suitable resistance, can reach between each parallel connection LED lamp string electric current consistent.
Flow equalizing circuit method for designing in the present invention can be by the mathematical method proof of deriving, be illustrated take embodiment at this: total constant drive current that setting constant-current source 10 provides is I=120mA, 3 paths of LEDs lamp strings in parallel are due to individual character difference, namely when identical current work, each LED pressure drop is different, therefore in the situation that do not increase flow equalizing circuit, when each LED lamp string pressure drop in parallel was identical, the electric current that flows through was unequal; Set LED lamp string 1, lamp string 2, when lamp string 3 work in same current, the LED pressure drop successively reduces, when identical pressure drop work, each successively increase of crosstalk stream; Each lamp string increases the flow equalizing circuit in the present invention, i.e. series resistor device on each LED lamp string, gang up on the road at the relatively large lamp of electric current, resistor by selected suitable resistance, make the resistor dividing potential drop relatively many, LED lamp string pressure drop less on corresponding path, corresponding LED lamp string stream reduces, and reaches the purpose that reduces current difference between each LED lamp string; For different LED lamp string characteristics, the resistor of selected suitable resistance on each alternate path can reach and makes the consistent purpose of each LED lamp string stream.But in actual production process, can't analyze and choose suitable resistance for each LED lamp string characteristic, so the general resistor string of choosing similar resistance that adopts is received each LED lamp string to reach the purpose that subtracts current difference between small lamp string.
Claims (4)
1. the LED parallel circuits of a branch current equilibrium comprises constant-current source and LED unit, it is characterized in that, also comprises the current-sharing unit, and described constant-current source is connected with the current-sharing unit with the LED unit respectively, and described LED unit is connected with the current-sharing unit.
2. the LED parallel circuits of a kind of branch current equilibrium according to claim 1, is characterized in that, described LED unit is LED lamp string in parallel, and described LED lamp string is at least two, and described LED lamp string is composed in series by single or plurality of LEDs lamp.
3. the LED parallel circuits of a kind of branch current equilibrium according to claim 2, is characterized in that, described current-sharing unit is the flows resistance device, and described flows resistance device quantity equates with LED lamp string quantity, and connects with each LED lamp series winding respectively.
4. the LED parallel circuits of a kind of branch current equilibrium according to claim 3, is characterized in that, described flows resistance device is one or more in carbon film resistor, metal film resistor, wire wound resistor and metal glass uranium resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100554991A CN103118470A (en) | 2013-02-21 | 2013-02-21 | LED parallel circuit with equalized branch current |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2013100554991A CN103118470A (en) | 2013-02-21 | 2013-02-21 | LED parallel circuit with equalized branch current |
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| CN103118470A true CN103118470A (en) | 2013-05-22 |
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| CN2013100554991A Pending CN103118470A (en) | 2013-02-21 | 2013-02-21 | LED parallel circuit with equalized branch current |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103260313A (en) * | 2013-05-23 | 2013-08-21 | 中山市德源照明电器有限公司 | Shunting-type LED dimming drive system and method thereof |
| CN104065247A (en) * | 2013-03-21 | 2014-09-24 | 力博特公司 | Diode parallel circuit |
| CN104994619A (en) * | 2015-06-10 | 2015-10-21 | 晶正照明科技有限公司 | LED driving circuit with high light effect |
| WO2024104353A1 (en) * | 2022-11-16 | 2024-05-23 | 深圳市明九州照明科技有限公司 | Direct-current centralizedly-driven lighting system |
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| CN101668365A (en) * | 2008-09-05 | 2010-03-10 | 李旭明 | Constant-current source driver circuit and device |
| CN102022655A (en) * | 2010-12-24 | 2011-04-20 | 鸿富锦精密工业（深圳）有限公司 | LED serial-parallel circuit and LED illumination device |
| CN102737601A (en) * | 2012-06-21 | 2012-10-17 | 深圳市华星光电技术有限公司 | Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method |
| CN203086826U (en) * | 2013-02-21 | 2013-07-24 | 四川长虹光电有限公司 | LED (Light-Emitting Diode) parallel circuit for branch current equalization |
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2013
- 2013-02-21 CN CN2013100554991A patent/CN103118470A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101668365A (en) * | 2008-09-05 | 2010-03-10 | 李旭明 | Constant-current source driver circuit and device |
| CN102022655A (en) * | 2010-12-24 | 2011-04-20 | 鸿富锦精密工业（深圳）有限公司 | LED serial-parallel circuit and LED illumination device |
| CN102737601A (en) * | 2012-06-21 | 2012-10-17 | 深圳市华星光电技术有限公司 | Light emitting diode (LED) backlight driving circuit, liquid crystal display device and manufacturing method |
| CN203086826U (en) * | 2013-02-21 | 2013-07-24 | 四川长虹光电有限公司 | LED (Light-Emitting Diode) parallel circuit for branch current equalization |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104065247A (en) * | 2013-03-21 | 2014-09-24 | 力博特公司 | Diode parallel circuit |
| CN103260313A (en) * | 2013-05-23 | 2013-08-21 | 中山市德源照明电器有限公司 | Shunting-type LED dimming drive system and method thereof |
| CN103260313B (en) * | 2013-05-23 | 2015-12-09 | 中山市德源照明电器有限公司 | A kind of shunting LED dimming drive system and method thereof |
| CN104994619A (en) * | 2015-06-10 | 2015-10-21 | 晶正照明科技有限公司 | LED driving circuit with high light effect |
| WO2024104353A1 (en) * | 2022-11-16 | 2024-05-23 | 深圳市明九州照明科技有限公司 | Direct-current centralizedly-driven lighting system |
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Application publication date: 20130522 |