CN105636268B - Led drive circuit and display device - Google Patents
Led drive circuit and display device Download PDFInfo
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- CN105636268B CN105636268B CN201610053072.1A CN201610053072A CN105636268B CN 105636268 B CN105636268 B CN 105636268B CN 201610053072 A CN201610053072 A CN 201610053072A CN 105636268 B CN105636268 B CN 105636268B
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- 230000009466 transformation Effects 0.000 claims abstract description 4
- 230000005611 electricity Effects 0.000 claims description 11
- 238000005286 illumination Methods 0.000 claims description 8
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Classifications
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/10—Controlling the intensity of the light
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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Abstract
The present invention is suitable for electronic technology field, provides a kind of LED drive circuit, including：Main power source module is respectively that movement and LED light bar are powered for accessing after exchange is turned direct current by Switching Power Supply, and the main power source module is provided with a transformer for power supply conversion；LED constant current module is exported after rectifying and wave-filtering again for accessing the winding of the transformer, and through the LED light bar output constant current source；The voltage value of the voltage stabilizing sampled point at the LED light bar cathode is arranged on as voltage stabilizing value, the LED light bar connection load, the load access constant voltage simultaneously passes through fixed current；Movement power supply module is powered for being exported after the processing of the transformation of the main power source module from the winding to the movement.Whereby, the present invention simplifies the driving circuit of LED, reduces cost, improves efficiency.
Description
Technical field
The present invention is suitable for electronic technology field more particularly to a kind of LED drive circuit and display device.
Background technology
The product of LED (Light Emitting Diode, light emitting diode) as backlight and with control system, such as
TV, display, illuminator.Its power unit includes direct current output all the way, powers to control system；LED backlight is given all the way
It powers (part containing LED drive circuit).By taking TV as an example, exemplified by current LED backlight TV, Power Management Design mainly includes two
Point, a part is direct current (generally 12V or 24V), is powered to core section.A part is to power to backlight portion, driving
LED backlight.
The application aspect of LED needs many LED, these LED is made on PCB, become LED light bar on television.Lamp
These LED are according to design on item, by series or in parallel, are divided into several groups (being called).LED voltage on passage, is called
Voltage.
The luminosity of LED and the electric current of LED are almost directly proportional, and control LED current can control the backlight brightness, therefore drive
Dynamic LED requirements electric current is constant controllable.LED essence is a diode, the forward voltage drop VF of diode with the variation of electric current and
Variation, changes so as to cause channel voltage with curent change.In addition because of wafer difference, its VF voltage also has difference to LED in itself
Not, therefore in TV LED channel voltage is to have a greater change scope.
Therefore, this kind of power supply has following characteristics：
First, exported all the way to LED power supplies this, there are two characteristic：It must be able to adapt to LED light bar channel voltage automatically,
Voltage changes with the voltage change of LED.It must controllable constant-current.
2nd, to the 12V voltages of system power supply, it is necessary to be voltage stabilizing output.It powers this voltage all the way to movement, because on movement
There are DC/DC conversion circuits, thus it is of less demanding to the precision of voltage regulation.
In Fig. 1, existing main power source uses reverse exciting topological framework.Transformer exports two-way, and V1 powers to movement all the way
(such as 12V), DC voltage VA (such as 48V), L2, QW11, DS31, C16, IC1, RS1, SW11 compositions BOOST boost all the way
Constant-current circuit, that is, LED drive circuit.IC1 is dedicated LED constant current boosting IC chip.VA passes through LED drive circuit, rises
It is pressed onto LED light bar voltage.LED light bar LED11 electric currents are equal to the electric current by RS1, and IC1 sets fixed voltage value on RS1, from
And RS1 becomes fixed current, external PWMDIM signals control SW11 by IC1, and electric current on LED light bar LED11 is made to become controlled
Constant current.
The feedback adjustment circuit of the secondary voltage stabilizing output of PC1 in Fig. 1, IC2, R91, R81, R71, R10, C10 and C11 composition,
It will be seen from figure 1 that the two-way voltage that transformer comes out：V1 and VA is voltage stabilizing output.VA only passes through specific BOOST liters
Constant-current circuit is pressed, can just drive LED light bar LED11.
Therefore, these current conventional methods will pass through level-one LED drive circuit, i.e. BOOST voltage increase and current constants circuit,
It can realize the constant current pressure regulation of LED drive circuit.And this level-one BOOST voltage increase and current constant circuits, efficiency generally only have 92% or so, damage
A big chunk energy is lost.In addition cost is also very high.
In summary, the existing technology has inconveniences and defects in actual use, so it is necessary to be improved.
The content of the invention
For it is above-mentioned the defects of, it is an object of the invention to provide a kind of LED drive circuit, simplify the driving electricity of LED
Road reduces cost, improves efficiency.
To achieve these goals, the present invention provides a kind of LED drive circuit, including：
Main power source module is respectively that movement and LED light bar are powered for accessing after exchange is turned direct current by Switching Power Supply, described
Main power source module is provided with a transformer for power supply conversion；
LED constant current module is exported after rectifying and wave-filtering again for accessing the winding of the transformer, and through the LED light
Output constant current source；The voltage value of the voltage stabilizing sampled point at the LED light bar cathode is arranged on as voltage stabilizing value, the LED light bar
Connection load, the load access constant voltage simultaneously pass through fixed current；
Movement power supply module, for being exported after the processing of the transformation of the main power source module from the winding to the movement
It is powered.
LED drive circuit according to the present invention, the LED drive circuit further include the feedback adjustment circuit, institute
It states feedback adjustment circuit and is used for transmission pressure regulation signal to the main power source module；
The LED constant current module further includes the control switch movement, and the LED light bar backlight illumination sends PWM in order to control
Signal, and the control switch accesses the pwm signal and realizes break-make, to control the switch of the LED light bar, the LED
Lamp bar is switched to control backlight illumination according to the duty cycle of electric current；
When the control switch conduction, the control switch and the feedback adjustment circuit in parallel, by the LED light bar
It is divided into two-way after the voltage stabilizing sampled point that output fixed current is returned at cathode, the first via is opened by the load and the control
It is grounded behind pass, the load access constant voltage becomes constant-current source, and the second tunnel is arrived by the feedback adjustment circuit output
The main power source module.
LED drive circuit according to the present invention, the movement are internally provided with DC/DC converters；And/or
The voltage stabilizing sampled point connects the feedback adjustment circuit, and the LED light bar anode is provided with output sampled point；
The voltage value of the voltage stabilizing sampled point is equal to the voltage value for setting the output sampled point and the LED light bar stagnation pressure
The difference of drop.
LED drive circuit according to the present invention, the LED light bar are that one or more LED light form, the LED
The both end voltage of lamp bar is as the overall presure drop of the multiple LED light in LED light bar changes and changes.
LED drive circuit according to the present invention, the load are fixed resistance value and are much smaller than feedback adjustment electricity
The impedance on road.
LED drive circuit according to the present invention, the main power source module includes primary circuit and secondary circuit, described
Primary circuit is the switching power circuit or LLC half-bridge resonance circuits of a reverse exciting topological framework；
The secondary circuit exports two-way, and output voltage is powered to the movement after the rectified filtering of the first via, the second tunnel
It powers to the LED light bar, the transformer output is by the voltage output after the rectifying and wave-filtering of diode and capacitance to institute
It states output sampled point and is connected to the LED light bar.
LED drive circuit according to the present invention, the movement power supply module connect while being the power supply of the movement
It connects optocoupler to be powered, the optocoupler and the feedback adjustment of the secondary voltage stabilizing output of impedance composition of the feedback adjustment circuit
Circuit, the feedback adjustment circuit is by the optocoupler by pressure regulation signal transmission to the main power source module.
LED drive circuit according to the present invention, the feedback adjustment circuit further include an optocoupler, the optocoupler connection
Electricity is taken to the voltage stabilizing sample point, the optocoupler is electrically connected on the input terminal of the movement.
LED drive circuit according to the present invention, the control switch is triode or MOS field
Effect pipe.
The present invention provides a kind of display device for including LED drive circuit described above, and the display device is LED conducts
The product with control panel of backlight, the display device include TV, display and/or illuminator.
LED light bar cathode voltage stabilizing of the present invention, directly eliminates boosting stage circuit, realizes a power supply output two-way, and one
Constant current self-pressure regulating in road drives LED, and voltage stabilizing all the way simplifies the driving circuit of LED, reduces cost, improves efficiency.
Description of the drawings
Fig. 1 is the structure diagram of the LED drive circuit of the prior art；
Fig. 2 is the structure diagram of LED drive circuit of the present invention；
Fig. 3 is the circuit theory schematic diagram of the first embodiment of LED drive circuit of the present invention；
Fig. 4 is the circuit theory schematic diagram of the second embodiment of LED drive circuit of the present invention；
Fig. 5 is the VF-IF characteristic curve schematic diagrames of the LED of one embodiment of the invention.
Specific embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to the accompanying drawings and embodiments, it is right
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.
In order to solve drawbacks described above, the present invention provides a kind of LED drive circuit 100, as shown in figs. 2 to 4, including：
Main power source module 10 is respectively that movement and LED light bar are powered for accessing after exchange is turned direct current by Switching Power Supply, institute
It states main power source module 10 and is provided with a transformer TR for power supply conversion；
LED constant current module 20 is exported after rectifying and wave-filtering again for accessing the winding of the transformer TR, and described in passing through
LED light bar LED1 output constant currents source；The voltage value for being arranged on the voltage stabilizing sampled point VB at the LED light bar LED1 cathode is voltage stabilizing
Value, the LED light bar LED1 connections load RS, and the load RS access constant voltages simultaneously pass through fixed current；
Movement power supply module 30, for being exported after the processing of the transformation of the main power source module 10 from the winding to described
Movement is powered.
In the first embodiment of LED drive circuit 100 of the present invention, further, the LED drive circuit 100 is also
Including the feedback adjustment circuit 11, the feedback adjustment circuit 11 is used for transmission pressure regulation signal to the main power source module 10；
The LED constant current module 20 further includes control switch SW1, movement LED light bar LED1 backlight illuminations in order to control
PWM (pulse width modulation, Pulse Width Modulation) signal is sent, and described in the control switch SW1 accesses
Pwm signal realizes break-make, to control the switch of the LED light bar LED1, the LED light bar LED1 according to the duty cycle of electric current into
Row switchs to control backlight illumination；
When the control switch SW1 conductings, feedback adjustment electricity of the control switch SW1 where with the load R8 and R9
Road is in parallel, is divided into two-way, the first via after the voltage stabilizing sampled point VB that LED light bar LED1 output fixed currents are returned at cathode LED-
It is grounded after overload RS and control switch SW1, the load RS access constant voltages become constant-current source, and the second tunnel passes through
Feedback adjustment circuit 11 is output to the movement.
Preferably, the movement is internally provided with DC/DC converters, after voltage increase and current constant circuit is removed, can
Ensure that the supply voltage of the movement required to precision still can be applied preferably, connected after the voltage stabilizing sampled point VB
The feedback adjustment circuit 11, the LED light bar anode are provided with output sampled point, and the voltage value of the voltage stabilizing sampled point VB is
The voltage value of the output sampled point VA and the difference of the LED light bar overall presure drop.
Further, the main power source module 10 includes primary circuit and secondary circuit, and the primary circuit is one
The switching power circuit of reverse exciting topological framework or LLC half-bridge resonance circuits；The secondary circuit exports two-way, and the first via is through whole
Output voltage is powered to the movement after stream filtering, and the second tunnel powers to the LED light bar LED1, and transformer TR outputs are by two
Voltage output after the rectifying and wave-filtering of pole pipe and capacitance is connected to the LED light bar LED1 to the output sampled point VA.
For the product of relatively high power, 10 topological structure of main power source module can use other electric source topology frameworks, such as LLC (electricity
Sense-inductor-capacitor resonance) half-bridge resonance Switching Power Supply topological structure.But it is same as described above, to the cathode voltage of LED light bar
Sampling so that cathode voltage is regulated power supply output.
As shown in figure 3, in order to be best understood from the present invention, LED drive circuit 100 of the present invention is preferably, LED light
LED1 represents lamp bar, can be a lamp bar, it is also possible to which many a LED light compositions pass through series connection and/or parallel way
Connection, characteristic is all that the LED light both end voltage of LED light bar LED1 changes as LED voltage changes, thus the LED light
The both end voltage of item is as the overall presure drop of the multiple LED light in LED light bar changes and changes, LED light current requirements constant current
Controllably.
The LED constant current module 20 compared with prior art, is eliminated from steady voltage source to the LED light bar LED1's
Voltage increase and current constant circuit between the output sampled point VA, secondary circuit all the way through DS1, C17 rectifying and wave-filtering, output voltage
V1 powers to movement；Another way passes through DS2, C13 rectifying and wave-filtering, and output voltage VA is connected to LED light bar LED1 (i.e. LED BAR)
Anode LED+, the cathode LED- of LED light bar LED1 returns to power supply, becomes voltage VB, through overload RS, under control switch SW1
Ground.
The LED light bar LED1 backlight illuminations send pwm signal to the movement in order to control, and control control switch SW1's is logical
It is disconnected, so as to control the switch of LED light bar LED1, the electric current on LED light bar LED1 is made to be switched according to certain duty cycle, and then controlled
Backlight illumination.
The LED light bar LED1 is that one or more LED light are composed in series, the LED light bar LED1 both end voltages with
The overall presure drop of the multiple LED light in LED light bar LED1 changes and changes.Preferably, it is described load be fixed resistance value and
RS is much larger than much smaller than the impedance of the feedback circuit, such as R8+R9.
It is powered with to the voltage V1 that the movement is powered to optocoupler PC1, the resistance of optocoupler PC1, IC2, feedback adjustment circuit 11
Anti- R9, R8, R7, R10 and the feedback adjustment circuit 11 of the secondary voltage stabilizing output of capacitance C10, C11 composition, the voltage stabilizing
The voltage stabilizing that sampled point VB becomes power supply exports, and VB values are determined by R9, the intrinsic standoff ratio of R8.For example the TL431 in Fig. 3 is 2.5V bases
Standard, R9, R8 sampling 4.7K Ω, then VB is 5V.If one can not be further included with alternative, the feedback adjustment circuit with V1 power supplies
Optocoupler, the optocoupler PC1 are connected to the voltage stabilizing sample point VB and take electricity, and the optocoupler PC1 is electrically connected to the input of the movement
On end.
Specifically, each LED light essence is a diode, and each LED light has certain pressure drop, the both ends electricity of lamp bar
It presses and is represented with VLED, then VB=VA-VLED.Since VB is fixed value, when control switch SW1 is closed, load RS ground connection, therefore
Voltage on RS is VB.The electric current of RS：IS=VB/RS, IS are fixed value.
Pass through the electric current ILED=IS+IR9 of LED.By value of the R9+R8 values much larger than load RS, such as 100 times of difference
More than.Therefore ILED is approximately equal to IRS, specifically：For example R9 is set as 4.7K Ω, R8 is 4.7K Ω, because of the REF feet of TL431
(PIN1) it is 2.5V, then VB is 5V.RS is set as 10 Ω.Then obtain：IRS=5V/10 Ω=500mA, ILED=500mA
Therefore when it is VB that voltage stabilizing sample point VB, which is voltage stabilizing output valve, load RS essence be a constant-current source, load RS with
Control switch SW1 forms a controlled constant-current source.
When control switch SW1 is closed, load RS is equivalent to the load of the load, i.e. regulated power supply of voltage stabilizing sampled point VB.
When SW1 is controlled to disconnect, mono- section of load RS is hanging, is equivalent to zero load, VB is still voltage stabilizing at this time, for example maintains 5V.
When the electric current ILED of LED light bar LED1 is controllable constant current value, the voltage VLED of LED light bar is as electric current is big
Small and change, according to the VF-IF characteristic curves of LED, Fig. 5 is the VF-IF characteristic curves of the LED of certain producer.
VF excursions change to 4.2V/400mA from 2.6V/0A.Can generally be controlled in entire current range ±
20%, actual LED light bar LED1 voltage VLED, actual test can be controlled ± 20%.
According to：VB=VA-VLED, then VA=VLED+VB
Therefore output sample point VA changes with curent change, and excursion is substantially also ± 20%, for direct current
Voltage.
Since two windings that V1 and VA are same transformer TR come out, V1 is directly proportional to VA.Cause
This, when VA is when maximum voltage range changes, the excursion of V1 is also controlled within ± 20%.By taking 12V as an example, maximum magnitude
Change in 12V-16.8V.This meets requirement of most movements to input voltage, and high product is required, it is necessary to have some
DC/DC conversion circuits coordinate.
It is exported all the way to LED light bar LED1 power supplies this, there are two characteristic：LED light bar LED1 powers on pressure energy and adapts to automatically
LED light bar LED1 channel voltages, which changes with the voltage change of each LED, is controllable constant-current.It is wherein each
The VF-IF characteristic curves of LED are as shown in Figure 5；To the movement power supply this export all the way, it is necessary to be voltage stabilizing output.Work as voltage stabilizing
Precision is not high enough, and when can only achieve ± 20%, high product is required, it is necessary to there is the cooperation of DC/DC conversion circuits some, and it is preferred that
Be that the movement comes with DC/DC converters.
Conventional voltage-stabilizing switch power source is exported in transformer TR windings, by diode, capacitance, after rectifying and wave-filtering
Sampling forms voltage stabilizing output.In the present invention, the characteristic for considering LED is a diode, and the voltage after rectifying and wave-filtering passes through
It crosses the decompression of LED diodes and is still direct current afterwards, voltage stabilizing sample point VB is taken in LED light bar cathode, makes LED light bar LED1 cathode
Voltage forms the output of constant voltage DC, based on this, generates constant-current source, this is made to become voltage stabilizing all the way, and fixed current
Output.And then realize a power supply output two-way, constant current self-pressure regulating drives LED all the way, and constant voltage DC exports all the way.With existing skill
Art is compared, and need not be carried out voltage stabilizing to output sample point VA, can also be obtained the constant-current source of constant-current voltage-stabilizing, without increase device into
This.
Preferably in order to be directly realized by the connection of optocoupler PC1, LED drive circuit 100, bringing onto load is not direct for the movement
Connect optocoupler PC1, the optocoupler PC1 and load R8 and R9 and the feedback tune of the secondary voltage stabilizing output of capacitance C10, C11 composition
Whole circuit 11, the feedback adjustment circuit 11 by pressure regulation signal transmission to main power source module 10, make main electricity by the optocoupler PC1
Source module 10 adjusts output voltage.
After the LED light bar LED1, direct current output and it is at the voltage stabilizing sampled point VB of LED cathode LED-
Fixed voltage, output terminal connect the load RS of a fixed resistance value over the ground, and the load RS output constant currents source is thus real
The input pwm signal of voltage stabilizing all the way is showed, when disconnecting control switch SW1, constant current is transferred to optocoupler PC1 and the movement, such as Fig. 3 institutes
Show.
Control switch SW1 can be triode or Metal-Oxide Semiconductor field-effect tube (metal-oxide
Semiconductor FET, abbreviation MOS-FET), by movement come pwm signal control switch, i.e. access in figure
PWMDIMMING。
In addition, the present invention also provides a kind of display device for including above-mentioned LED drive circuit 100, the display devices one
As refer to products with control panel of the LED as backlight, including TV, display, illuminator is also applied for purely lighting
The illuminating product of LED.This kind of product only does constant current driving to LED.Such as figure, at this time by power to movement this is suitable all the way
It in not bringing onto load, only powers to optocoupler PC1, also electricity can be taken from VB to optocoupler PC1 power supplies.The key point of the present invention is pair
Sample point of the cathode voltage of LED light bar LED1 as regulated power supply makes cathode voltage become stable voltage value, as base
Plinth generates constant-current source.
Therefore, such as Fig. 4 second embodiment alternatives, LED light bar cathode LED- voltages are passed through to the output of regulated power supply
Sampling, including increasing diode DX, the mode of resistance RX or DX+RX, such as Fig. 4 or placed in DX positions resistance etc. other
Type, essence is equivalent to forms voltage stabilizing output in cathode voltage, and constant-current source is generated with RS, in addition, load RS is represented under VB
Controlled constant-current source is formed, the load simplest modes of RS are exactly a resistance, if using other modes instead realizes constant-current source, even if
It is also the core concept for meeting the present invention that more devices are added after VB.
In conclusion LED light bar cathode voltage stabilizing of the present invention, directly cancels voltage increase and current constant circuit, a power supply output is realized
Two-way, all the way constant current self-pressure regulating driving LED, voltage stabilizing all the way.Whereby, the present invention is due to the omission of LED drive circuit almost all, essence
The driving circuit of simple LED reduces cost, improves efficiency.
Certainly, the present invention can also have other various embodiments, without deviating from the spirit and substance of the present invention, ripe
It knows those skilled in the art and makes various corresponding changes and deformation, but these corresponding changes and change in accordance with the present invention
Shape should all belong to the protection domain of appended claims of the invention.
Claims (10)
1. a kind of LED drive circuit, which is characterized in that including：
Main power source module is respectively that movement and LED light bar are powered for accessing after exchange is turned direct current by Switching Power Supply, the main electricity
Source module is provided with a transformer for power supply conversion；
LED constant current module is exported after rectifying and wave-filtering again for accessing the winding of the transformer, and defeated through the LED light bar
Go out constant-current source；The voltage value of the voltage stabilizing sampled point at the LED light bar cathode is arranged on as voltage stabilizing value, the LED light bar connection
Load, the load access constant voltage simultaneously pass through fixed current；
Movement power supply module carries out for being exported after the processing of the transformation of the main power source module from the winding to the movement
Power supply.
2. LED drive circuit according to claim 1, which is characterized in that the LED drive circuit further includes feedback adjustment
Circuit, the feedback adjustment circuit are used for transmission pressure regulation signal to the main power source module；
The LED constant current module further includes control switch, and the LED light bar backlight illumination sends PWM letters to the movement in order to control
Number, and the control switch accesses the pwm signal and realizes break-make, to control the switch of the LED light bar, the LED light
Item is switched to control backlight illumination according to the duty cycle of electric current；
When the control switch conduction, the control switch and the feedback adjustment circuit in parallel are exported by the LED light bar
It is divided into two-way after the voltage stabilizing sampled point that fixed current is returned at cathode, the first via is after the load and the control switch
Ground connection, it is described load access constant voltage become constant-current source, and the second tunnel by the feedback adjustment circuit output arrive described in
Main power source module.
3. LED drive circuit according to claim 2, which is characterized in that the movement is internally provided with DC/DC conversions
Device；And/or
The voltage stabilizing sampled point connects the feedback adjustment circuit, and the LED light bar anode is provided with output sampled point；
The voltage value of the voltage stabilizing sampled point be equal to set the output sampled point voltage value and the LED light bar overall presure drop it
Difference.
4. LED drive circuit according to claim 3, which is characterized in that the LED light bar is one or more LED light
Composition, the both end voltage of the LED light bar is as the overall presure drop of the multiple LED light in LED light bar changes and changes.
5. LED drive circuit according to claim 2, which is characterized in that the load is fixed resistance value and is much smaller than institute
State the impedance of feedback adjustment circuit.
6. LED drive circuit according to claim 1, which is characterized in that the main power source module include primary circuit and
Secondary circuit, the primary circuit are the switching power circuit or LLC half-bridge resonance circuits of a reverse exciting topological framework；
The secondary circuit exports two-way, and output voltage is powered to the movement after the rectified filtering of the first via, and the second tunnel is to institute
State LED light bar power supply, transformer output is by the voltage output after the rectifying and wave-filtering of diode and capacitance to described defeated
Go out sampled point and be connected to the LED light bar.
7. LED drive circuit according to claim 2, which is characterized in that the movement power supply module is the movement
It connects optocoupler while power supply to be powered, the optocoupler and the secondary voltage stabilizing output of impedance composition of the feedback adjustment circuit
The feedback adjustment circuit, the feedback adjustment circuit is by the optocoupler by pressure regulation signal transmission to the main power source module.
8. LED drive circuit according to claim 2, which is characterized in that the feedback adjustment circuit further includes an optocoupler,
The optocoupler is connected to the voltage stabilizing sample point and takes electricity, and the optocoupler is electrically connected on the input terminal of the movement.
9. LED drive circuit according to claim 2, which is characterized in that the control switch is triode or metal oxygen
Compound semiconductor field.
A kind of 10. display device for including such as claim 1~9 any one of them LED drive circuit, which is characterized in that institute
Display device is stated as products with control panel of the LED as backlight, the display device includes TV, display and/or photograph
Bright lamp has.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610053072.1A CN105636268B (en) | 2016-01-26 | 2016-01-26 | Led drive circuit and display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610053072.1A CN105636268B (en) | 2016-01-26 | 2016-01-26 | Led drive circuit and display device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105636268A CN105636268A (en) | 2016-06-01 |
| CN105636268B true CN105636268B (en) | 2018-05-18 |
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| CN201610053072.1A Active CN105636268B (en) | 2016-01-26 | 2016-01-26 | Led drive circuit and display device |
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| CN104935843B (en) * | 2015-06-16 | 2018-03-20 | 康佳集团股份有限公司 | A kind of LED television two-in-one electric source circuit and LED television |
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Effective date of registration: 20190612 Address after: 518000 Area B, 4th Floor, No. 1 Second Lane, Jiazitang Avenue, Jiazitang Community, Gongming Office, Guangming New District, Shenzhen City, Guangdong Province Patentee after: Shenzhen Jiaanxin Electronics Co., Ltd. Address before: 518000 Guangdong Province Nanshan District Houhai Aocheng Garden Phase II 4 21A Patentee before: Song Jiali |
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