CN101808448A - Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter - Google Patents
Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter Download PDFInfo
- Publication number
- CN101808448A CN101808448A CN201010116227A CN201010116227A CN101808448A CN 101808448 A CN101808448 A CN 101808448A CN 201010116227 A CN201010116227 A CN 201010116227A CN 201010116227 A CN201010116227 A CN 201010116227A CN 101808448 A CN101808448 A CN 101808448A
- Authority
- CN
- China
- Prior art keywords
- switch
- high brightness
- width modulation
- current
- brightness led
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention discloses a pulse width modulation dimming method of the high-brightness light-emitting diode of a switch-type DC-DC converter, which uses a switcher, a switch-type step-down current regulator, a high-brightness light emitting diode load and an active clamping circuit, wherein the switcher is used for switching the output current of the switch-type step-down current regulator to the active lamping circuit from the high-brightness light-emitting diode load or to the high-brightness light-emitting diode load from the active lamping circuit; the switch-type step-down current regulator consist of a step-down switch SA, a freewheel diode DA and a step-down inductor L; and the active clamping circuit consist of switches S1 and S2, a capacitor Cc for absorbing the energy of the leakage inductance of the switch converter, output diodes D3 and D4 and the switch converter. The method can produce a pulse width modulation current pulse sequence which is used for the high-performance dimming of the high-brightness light-emitting diode and has a very wide variation rage of duty ratio.
Description
Technical field
The invention belongs to electronic technology field, relate to the control of high brightness LED impulse width modulation and light adjusting.More particularly, the present invention relates to a kind of high brightness LED pulse width modulation dimming method that is used for the switching mode DC-DC converter.
Background technology
The high brightness LED brightness adjustment control has two kinds of controlling schemes.That is, simulation light modulation and impulse width modulation and light adjusting.The simulation light modulation relatively easily realizes, but dimming scope is narrow and the colour temperature of band light changes.Impulse width modulation and light adjusting can realize that the colour temperature of wide dimming scope and fewer light changes.In most of performance application, as LCD TV LED-backlit, LED projecting apparatus, impulse width modulation and light adjusting are main brightness adjustment control schemes.
The linear current Source drive of high brightness LED is to realize impulse width modulation and light adjusting very easily, as it can be under 400 hertz of modulating frequencies output duty cycle less than 1%, but that it drives efficient is lower.When the electric current of required high brightness LED was high, the power consumption of this linear current Source drive was also high.This has produced sizable heat dissipation problem.
Because the conducting of switch is turn-offed, the switching mode DC-DC converter can obtain quite high efficient, and this makes heat dissipation problem solve easily.In the switching mode DC-DC converter, energy-storage travelling wave tube is arranged.It and switch combination controlledly are transferred to output with intake.Just this energy-storage travelling wave tube it make that the response speed of switching mode DC-DC converter system is slower than linear current Source drive.The impulse width modulation and light adjusting of realizing high brightness LED with the switching mode DC-DC converter is a heat subject.
In existing scheme, be typically in the output loading of buck switch converters and connect a short switch, the buck switch converters is with average-current mode control as shown in Figure 1.This short switch makes this inductive current controllably flow through high brightness LED or this short switch just.As long as this inductive current not to be changed, it can produce good impulse width modulation and light adjusting electric current in the high brightness LED load like this, and just, this load high brightness LED can obtain the electric current square wave of low duty ratio.In actual applications, when this load voltage increase, in LCD TV application backlight, the electric current square wave of this low duty ratio has suitable distortion as 200V.
Summary of the invention
The objective of the invention is with the buck switch converters serves as that the basis produces narrow pulsewidth current pulse sequence.Use the present invention can produce the pulse width modulated current pulses sequence of the non-constant width change in duty cycle scope that is used for high brightness LED high-performance dimmer application.
The present invention proposes a kind of hybrid power topological structure.It is made up of switch buck current adjuster and active clamp converter.The active clamp converter is used to absorb energy and it is recovered to input power supply or other absorption voltage sources.
The high brightness LED pulse width modulation dimming method of switching mode DC-DC converter of the present invention, it is by change over switch, switching mode buck current adjuster, high brightness LED load and active clamp circuit constitute; Described change over switch be the output current that is used for change over switch type buck current adjuster from high brightness LED load to active clamp circuit or from active clamp circuit to the high brightness LED load; Described switching mode buck current adjuster is by voltage reducing switch SA, fly-wheel diode DA, and buck inductor L constitutes; Described active clamp circuit is by switch S 1 and S2, absorbs the capacitor C c of switch transformer leakage inductance energy, and output diode D3 and D4 or full-wave rectification bridge and switch transformer T constitute; Two former limit windings of switch transformer T are contacted with switch S 1 or S2 respectively; Two former limit windings of switch transformer T are in parallel and respectively as the input of active clamp circuit with switch S 1 or the S2 formed branch road of contacting respectively; The Cc electric capacity that is used to absorb the switch transformer leakage inductance energy respectively with switch S 1 or S2 polyphone; Two of switch transformer pay limit winding or one and pay limit winding and output diode D3 and D4 or full-wave rectification bridge formation full-wave rectifying circuit; The output of full-wave rectifying circuit is input voltage source Vin or other absorption voltage sources.
Switching mode buck current adjuster is to make that by average current type current or accurate average current type current or the control of other control methods its output current is constant.
The mutual conducting of switch S 1 and S2 in the active clamp circuit, i.e. S1 conducting, S2 ends; The S2 conducting, S1 ends; The input current of active clamp circuit can former limit winding phase place flow into respectively on the contrary from two of switch transformer like this, switch transformer pay the limit through output diode D3 and the mutual conducting of D4 or through full-wave rectification bridge, output to input voltage source Vin or other absorb voltage source with fixed proportion.
The above switch S 1 and S2 are that self-excitation drives or it swashs driving.
The voltage stress of the above S1 and S2 absorbs voltage source and the decision of former pair of limit of the switch transformer turn ratio by input voltage vin or other.
The current stress of the above S1 and S2 is by the input current Io of active clamp circuit decision.
The change over switch that is in series with active clamp circuit can omit.
One of advantage of the present invention is that the switch buck current adjuster system that makes can produce output current efficiently, and this active clamp converter that part of inductive current that can will not flow through high brightness LED is fully retrieved to the input power supply just.
Two of advantage of the present invention is that the inductance condition of work of switch buck current adjuster can remain unchanged, and inductive current can be constant like this.This constant inductance electric current is crossed at one of high brightness LED load and active clamp converter alternating current and can be made the input pulse electric current of high brightness LED load very near square wave.
Three of advantage of the present invention is that this can make that the pulse-width modulation audio noise that is produced is lower because the inductance condition of work of switch buck current adjuster remains unchanged and inductive current is constant.
Description of drawings
Fig. 1 is the light modulation scheme of existing high brightness LED pulse modulation technology.
Fig. 2 is a schematic diagram of the present invention.
Fig. 3 is the high brightness LED impulse width modulation and light adjusting scheme instantiation circuit diagram that is used for the switching mode DC-DC converter of the present invention.
Fig. 4 is concrete second example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention.
Fig. 5 is concrete the 3rd example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention.
Fig. 6 is concrete the 4th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and voltage reducing switch SA drives with type of drive altogether.
Fig. 7 is concrete the 5th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and voltage reducing switch SA drives with type of drive altogether.
Fig. 8 is concrete the 6th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and voltage reducing switch SA drives with type of drive altogether.
Fig. 9 is concrete the 7th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string are impulse width modulation and light adjusting respectively.
Figure 10 is concrete the 8th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string are impulse width modulation and light adjusting respectively.
Figure 11 is concrete the 9th example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string are impulse width modulation and light adjusting respectively.
Figure 12 is concrete the tenth example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string impulse width modulation and light adjusting and voltage reducing switch SA respectively drive with type of drive altogether.
Figure 13 is concrete the 11 example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string impulse width modulation and light adjusting and voltage reducing switch SA respectively drive with type of drive altogether.
Figure 14 is concrete the 12 example circuit diagram of high brightness LED impulse width modulation and light adjusting scheme that is used for the switching mode DC-DC converter of the present invention, and two high brightness light emitting diode string impulse width modulation and light adjusting and voltage reducing switch SA respectively drive with type of drive altogether.
Embodiment
For the buck switch converters, in order to produce the complete square wave current impulse, this need a switch S K control this inductive current be by or obstructed excessive brightness light emitting diode string.Shown in Figure 1 one existing scheme.This scheme can not guarantee that the inductance condition of work remains unchanged when switch S K turns on and off, and inductive current is constant.The intensity of variation of inductive current depends on the output voltage V o of high brightness LED string and the ratio of input voltage vin.Although the buck switch converters is controlled with average-current mode, high more this inductive current of this voltage ratio changes more greatly.
High output voltage to the high brightness LED string is used, and the scheme of Fig. 1 is difficult to meet the demands.If the voltage source V rfl of an equivalence is as shown in Figure 2 arranged, it is the output voltage V o near the high brightness LED string, and the inductance condition of work can seldom change when switch S K turns on and off, so the inductive current substantially constant.This substantially invariable inductive current makes that just producing the complete square wave current pulse that is used for the high brightness LED impulse width modulation and light adjusting becomes possibility just.This equivalent voltage source V rfl is a heavy source in Fig. 2, when switch S K opens, is used for the energy storage of absorption inductor.In actual applications, this equivalent voltage source should have the ability to reclaim the inductive energy storage of this absorption and feed back to the input power supply.
Fig. 3 provides physical circuit figure of the present invention.This equivalent voltage source V rfl is by switch S 1 and S2, switch transformer T, and diode D3 and D4, the capacitor C c and the input power supply Vin that absorb the switch transformer leakage inductance energy constitute.In this equivalent voltage source V rfl, switch S 1 and S2 are with 50% duty ratio alternate conduction.Switch S 1 and S2 conducting are turn-offed just, when switch S K turn-offs, make this input inductance electric current through switch transformer, and diode D3 and D4 are recovered to input voltage source Vin.The voltage that reflects back from input voltage source is Vrfl.Vrfl＝Vin×Ns/Np。The turn ratio by transformer selects to be easy to make the output voltage V o of Vrfl near this high brightness LED string.In this equivalent voltage source V rfl, the voltage stress of S1 and S2 is 2 * Vrfl, and its current stress is an inductive current.
In this circuit, switch S K connects with high brightness LED.If Vrfl is the output voltage V o that is higher than this high brightness LED, when switch S K conducting, inductive current is by SK and high brightness LED.When switch S K turn-offed, inductive current was made a detour by the voltage source V rfl of equivalence and was absorbed and fed back to input power supply Vin.
Fig. 4 provides another physical circuit of the present invention figure, and switch S K connects with the voltage source V rfl of equivalence.If Vrfl is the output voltage V o that is lower than this high brightness LED, when switch S K turn-offed, inductive current passed through high brightness LED.When switch S K conducting, inductive current is made a detour by the voltage source V rfl of equivalence and is absorbed and feeds back to input power supply Vin.
In Fig. 5, there are two switch S K and SK1 to be in series with the voltage source V rfl of high brightness LED respectively with equivalence.Switch S K and SK1 alternate conduction are turn-offed the square wave current pulse that produces the high brightness LED impulse width modulation and light adjusting.Select Vrfl can seldom change to guarantee the inductance condition of work near the output voltage V o of high brightness LED, so the inductive current substantially constant.
Because the buffer action of switch transformer, voltage reducing switch SA can with low cost altogether type of drive drive, as Fig. 6, Fig. 7 and shown in Figure 8.
The present invention program can be used for many high brightness LEDs string impulse width modulation and light adjusting and uses.Fig. 9, the impulse width modulation and light adjusting of 10,11,12,13 and 14 demonstrations, two high brightness light emitting diode string is used.
In this class was used, current source can drive many high brightness LEDs string and each high brightness LED can separate impulse width modulation and light adjusting.In the voltage source V rfl of equivalence, switch S 1 and S2 only need with 50% duty ratio driving pulse.This impulse width modulation and light adjusting scheme is very simple, and is reliable, low cost and high efficiency.
Conversion switch S K or SK1 or SK2 and active clamp circuit are in series in Fig. 4,5,7,8,9,11,12,14.Because switch S 1 in the active clamp circuit and the equivalent switch effect of S2, this change over switch SK or SK1 or SK2 can omit with further reduction system cost.
Claims (7)
1. the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter is characterized in that by change over switch, switching mode buck current adjuster, and high brightness LED load and active clamp circuit constitute; Described change over switch be the output current that is used for change over switch type buck current adjuster from high brightness LED load to active clamp circuit or from active clamp circuit to the high brightness LED load; Described switching mode buck current adjuster is by voltage reducing switch SA, fly-wheel diode DA, and buck inductor L constitutes; Described active clamp circuit is by switch S 1 and S2, absorbs the capacitor C c of switch transformer leakage inductance energy, and output diode D3 and D4 or full-wave rectification bridge and switch transformer T constitute; Two former limit windings of switch transformer T are contacted with switch S 1 or S2 respectively; Two former limit windings of switch transformer T are in parallel and respectively as the input of active clamp circuit with switch S 1 or the S2 formed branch road of contacting respectively; The Cc electric capacity that is used to absorb the switch transformer leakage inductance energy respectively with switch S 1 or S2 polyphone; Two of switch transformer pay limit winding or one and pay limit winding and output diode D3 and D4 or full-wave rectification bridge formation full-wave rectifying circuit; The output of full-wave rectifying circuit is input voltage source Vin or other absorption voltage sources.
2. the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter according to claim 1 is characterized in that: switching mode buck current adjuster is to make that by average current type current or accurate average current type current or the control of other control methods its output current is constant.
3. the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter according to claim 1 is characterized in that: the mutual conducting of switch S 1 and S2 in the active clamp circuit, i.e. and S1 conducting, S2 ends; The S2 conducting, S1 ends; The input current of active clamp circuit can former limit winding phase place flow into respectively on the contrary from two of switch transformer like this, switch transformer pay the limit through output diode D3 and the mutual conducting of D4 or through full-wave rectification bridge, output to input voltage source Vin or other absorb voltage source with fixed proportion.
4. as the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter as described in the claim 3, it is characterized in that: switch S 1 and S2 are that self-excitation drives or its swashs and drives.
5. as the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter as described in the claim 3, it is characterized in that: the voltage stress of S1 and S2 absorbs voltage source and the decision of former pair of limit of the switch transformer turn ratio by input voltage vin or other.
6. as the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter as described in the claim 3, it is characterized in that: the current stress of S1 and S2 is by the input current Io decision of active clamp circuit.
7. the high brightness LED pulse width modulation dimming method of switching mode DC-DC converter according to claim 1 is characterized in that: will omit with the change over switch that active clamp circuit is in series.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010116227 CN101808448B (en) | 2010-03-02 | 2010-03-02 | Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010116227 CN101808448B (en) | 2010-03-02 | 2010-03-02 | Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101808448A true CN101808448A (en) | 2010-08-18 |
| CN101808448B CN101808448B (en) | 2013-01-16 |
Family
ID=42610003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010116227 Active CN101808448B (en) | 2010-03-02 | 2010-03-02 | Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101808448B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103155704A (en) * | 2010-10-23 | 2013-06-12 | 泰克尼莱克有限公司 | High efficiency led power supply |
| TWI620467B (en) * | 2017-05-26 | 2018-04-01 | Newvastek Co Ltd | Energy recovery device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070210725A1 (en) * | 2006-03-13 | 2007-09-13 | Linear Technology Corporation | LED dimming control technique for increasing the maximum PWM dimming ratio and avoiding LED flicker |
| CN101315744A (en) * | 2007-05-30 | 2008-12-03 | 霍尼韦尔国际公司 | Apparatus, systems, and methods for dimming an active matrix light-emitting diode (LED) display |
| CN101588664A (en) * | 2008-05-21 | 2009-11-25 | 原景科技股份有限公司 | Light emitting diode drive circuit and circuit for controlling power switch |
-
2010
- 2010-03-02 CN CN 201010116227 patent/CN101808448B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070210725A1 (en) * | 2006-03-13 | 2007-09-13 | Linear Technology Corporation | LED dimming control technique for increasing the maximum PWM dimming ratio and avoiding LED flicker |
| CN101315744A (en) * | 2007-05-30 | 2008-12-03 | 霍尼韦尔国际公司 | Apparatus, systems, and methods for dimming an active matrix light-emitting diode (LED) display |
| CN101588664A (en) * | 2008-05-21 | 2009-11-25 | 原景科技股份有限公司 | Light emitting diode drive circuit and circuit for controlling power switch |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103155704A (en) * | 2010-10-23 | 2013-06-12 | 泰克尼莱克有限公司 | High efficiency led power supply |
| CN103155704B (en) * | 2010-10-23 | 2016-10-19 | 泰克尼莱克有限公司 | Efficient LED supply of electric power source |
| TWI620467B (en) * | 2017-05-26 | 2018-04-01 | Newvastek Co Ltd | Energy recovery device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101808448B (en) | 2013-01-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101917804B (en) | Large-power intelligent dimming multiple-output power supply for suppressing electric surge with field-effect transistor | |
| CN103313472B (en) | LED drive circuit with dimming function and lamp | |
| JP3167927U (en) | Constant current LED lamp | |
| CN102137524B (en) | High-efficiency control method for balance-driving light-emitting diode (LED) | |
| CN103139992A (en) | Light-emitting diode (LED) dimming driving system with silicon controlled bypass dimming circuit | |
| CN102238780A (en) | Control circuit of light-emitting element | |
| CN102625548A (en) | Multi-output heavy-power LED constant-current drive power supply | |
| CN104159367A (en) | LED light modulator based on PAM and PWM and dimming method of LED light modulator based on PAM and PWM | |
| CN103155704B (en) | Efficient LED supply of electric power source | |
| CN102438377A (en) | LED (Light Emitting Diode) constant-current driving circuit with high power factor | |
| CN102685989A (en) | PWM (Pulse-Width modulation) dimming method and circuit of LED constant-current source concentratively powered by high-voltage direct current | |
| CN201386933Y (en) | ACLED illuminating light source | |
| CN104797062B (en) | Non-strobe high-efficiency LED (light-emitting diode) driving manner compatible with phase-controlled light modulator | |
| Satyakar Veeramallu et al. | Analysis and implementation of soft‐switched bidirectional buck‐boost DC‐DC converter for solar PV‐fed LED street lighting systems. | |
| CN101808448B (en) | Pulse width modulation dimming method of high-brightness light-emitting diode of switch-type DC-DC converter | |
| CN103428967B (en) | For the harmless forward voltage matching network of LED driver | |
| CN201533427U (en) | LLC self-excited half-bridge resonant LED driver | |
| CN102170732A (en) | Drive circuit topological device for MR16 (Multifaceted Reflector) light-emitting diode | |
| CN202435690U (en) | Flicker-prevention LED (light-emitting diode) pulse width modulation control circuit | |
| CN102791063A (en) | Intelligent LED module with function of automatic voltage regulation | |
| CN204145795U (en) | Have APFC function without working frequency ripple wave LED streetlamp power source | |
| CN201750601U (en) | High-power intelligent dimming multiplexed output power supply employing field-effect transistor for electric surge suppression | |
| Mounika et al. | ADC controlled half-bridge LC series resonant converter for LED lighting | |
| CN201731335U (en) | Alternating current direct-drive LED lamp tube | |
| CN104735837A (en) | LED street lamp power supply without power frequency ripples and with APFC function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20191126 Address after: 221300, Fumin Road, Pizhou hi tech Industrial Development Zone, Xuzhou, Jiangsu, 22 Patentee after: Pizhou hi tech Zone New Energy Technology Research Institute Co., Ltd. Address before: 310012 Qixia garden, Guihua Road, two West Wen Road, Hangzhou, Zhejiang, Xihu District 13-1-102 Patentee before: Wei Qicui |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210425 Address after: 221300 No.56, paoche street, Pizhou City, Xuzhou City, Jiangsu Province Patentee after: Pizhou Jingpeng Venture Capital Co., Ltd Address before: 221300, Fumin Road, Pizhou hi tech Industrial Development Zone, Xuzhou, Jiangsu, 22 Patentee before: PIZHOU HIGH-TECH ZONE NEW ENERGY TECHNOLOGY RESEARCH INSTITUTE Co.,Ltd. |
|
| TR01 | Transfer of patent right |