CN103634542B - A kind of power circuit of LCD TV - Google Patents
A kind of power circuit of LCD TV Download PDFInfo
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- CN103634542B CN103634542B CN201310543543.3A CN201310543543A CN103634542B CN 103634542 B CN103634542 B CN 103634542B CN 201310543543 A CN201310543543 A CN 201310543543A CN 103634542 B CN103634542 B CN 103634542B
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- 230000009467 reduction Effects 0.000 claims abstract description 19
- 238000001514 detection method Methods 0.000 claims abstract description 13
- 230000005669 field effect Effects 0.000 claims description 11
- 239000003990 capacitor Substances 0.000 claims description 6
- 230000000694 effects Effects 0.000 claims description 6
- 230000006641 stabilisation Effects 0.000 claims 1
- 238000011105 stabilization Methods 0.000 claims 1
- 230000002829 reductive effect Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 2
- 230000006837 decompression Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000003276 anti-hypertensive effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Abstract
The invention discloses a kind of power circuits of LCD TV, it is arranged between LED backlight, machine core and external input power, and the power circuit includes: filter rectifier, main topological circuit, load voltage detection and feed circuit, pwm control circuit and reduction voltage circuit；After external input power enters main topological circuit by filter rectifier, it is divided into two-way, is input to LED backlight all the way；Another way is input to machine core by reduction voltage circuit；The load voltage is connect with LED backlight, pwm control circuit respectively with feed circuit, for detecting the voltage of LED backlight and feeding back to pwm control circuit, is adjusted PWM and is exported and then adjust the voltage for being input to LED backlight.Compared with prior art, efficiency increases substantially, while power device cost is substantially reduced, and has good popularization and application foreground.
Description
Technical field
The present invention relates to liquid crystal tv technology field more particularly to a kind of power circuits of LCD TV.
Background technique
This year, LCD TV (LCD TV) technology have developed rapidly, image quality, image definition and screen size,
All it is far superior to currently marketed any other display technology.Currently, China has become the worldwide production base of LCD Related product
Ground.The fast development in the market LCD TV, higher technological challenge is also faced to power supply product, is needed to designed power supply product
Power consumption, overall performance and efficiency implement more stringent requirement.
Power supply is a kind of device to electronic equipment offer power, also referred to as power supply unit.The size of power, electric current
It is whether stable with voltage, the working performance and service life of electronic equipment will be directly affected.
As shown in Figure 1, the power circuit of existing LCD TV generally comprises: EMC filter circuit 10, rectification circuit 20,
Main topological circuit 30 and DC-DC booster circuit 40；Specifically, 110V or 220V alternating current is input to by power input port
EMC filter circuit 10, is then input to main topological circuit 30 after rectification circuit 20 is rectified, and main topological circuit 30 exports
Voltage be divided into two-way, provide the voltage of 12V all the way to Core of TV set, the voltage that another way provides 24V is electric to DC-DC boosting
Road 40 is supplied to backlight LED power supply and uses after being boosted by DC-DC booster circuit 40.
In existing power circuit, LED backlight power supply need to be converted by DC-DC booster circuit to complete, and there are efficiency
It is low, it is at high cost the disadvantages of, adverse effect, Jin Erzhi can be generated to the degree of belief of the safety of product, reliability and client
Connect the benefit for influencing manufacturer.
In view of this, the prior art has much room for improvement and improves.
Summary of the invention
There is provided the content of present invention is in order to which simplified form introduction will further describe in the following specific embodiments
Some concepts.The content of present invention is not intended to the key feature or substantive characteristics for identifying theme claimed, is not intended to
It is used to help determine the range of theme claimed.
The technical problem to be solved in the present invention is that in view of the deficiencies of the prior art, providing a kind of power supply of LCD TV
Circuit, solve LED backlight power supply in the prior art using low efficiency present in DC-DC booster circuit, it is at high cost the problems such as.
The technical proposal for solving the technical problem of the invention is as follows:
A kind of power circuit of LCD TV is arranged between LED backlight, machine core and external input power, wherein described
Power circuit includes: filter rectifier, main topological circuit, load voltage detection and feed circuit, pwm control circuit and decompression
Circuit；
Wherein, after external input power enters main topological circuit by filter rectifier, it is divided into two-way, is input to all the way
LED backlight；Another way is input to machine core by reduction voltage circuit；The load voltage and feed circuit respectively with LED backlight, PWM
Control circuit connection adjusts PWM and exports and then adjust input for detecting the voltage of LED backlight and feeding back to pwm control circuit
To the voltage of LED backlight.
The power circuit of the LCD TV, wherein the reduction voltage circuit includes a field-effect tube, a diode, one
Inductance and a capacitor；
The drain electrode of field-effect tube connects the voltage input end of main topological circuit, and source electrode is defeated to machine core power supply by inductance connection
Outlet, grounded-grid；Between the source electrode and inductance of one end setting scene effect pipe of diode, other end ground connection；The one of capacitor
End connection machine core power output end, other end ground connection.
The power circuit of the LCD TV, wherein the field-effect tube is N-channel field-effect tube.
The power circuit of the LCD TV, wherein the voltage of the voltage input end of the main topological circuit arrives for 13V
18V, the voltage of machine core power output end are 12V.
The power circuit of the LCD TV, wherein the load voltage detection and feed circuit include a LED constant current
Chip.
The power circuit of LCD TV provided by the present invention, by main topological circuit direct voltage output to LED backlight,
Load voltage detection and the voltage and feedback of the voltage detecting LED backlight of feed circuit detection LED backlight arrive pwm control circuit,
PWM is adjusted, export and then adjusts the voltage for being input to LED backlight；In addition, leading in the voltage output variation of main topological circuit
It crosses reduction voltage circuit and guarantees that the voltage for being input to machine core is constant.Compared with prior art, efficiency increases substantially, while power device
Cost is substantially reduced, and has good popularization and application foreground.
Detailed description of the invention
Fig. 1 is the schematic diagram of the power circuit of the LCD TV of the prior art.
Fig. 2 is the structural block diagram of the power circuit of LCD TV of the invention.
Fig. 3 is the circuit diagram of the main topological circuit of the embodiment of the power circuit of LCD TV of the invention.
Fig. 4 is the circuit diagram of the reduction voltage circuit of the embodiment of the power circuit of LCD TV of the invention.
Specific embodiment
The power circuit of a kind of LCD TV provided by the invention, to make the objectives, technical solutions, and advantages of the present invention more
Add clear, clear, the present invention is described in more detail as follows in conjunction with drawings and embodiments.It should be appreciated that described herein
Specific embodiment be only used to explain the present invention, be not intended to limit the present invention.On the contrary, inventor's imagination is claimed
Theme may also be combined with other present or future technologies and embody otherwise, to include the steps that different or be similar to this
The combination of the step of described in the text.
Referring to Fig. 2, its structural block diagram for the power circuit of LCD TV of the invention.As shown, the power supply
Circuit is arranged between LED backlight 600, machine core 700 and external input power 800 comprising: filter rectifier 100, master open up
Flutter circuit 200, load voltage detection and feed circuit 300, pwm control circuit 400 and reduction voltage circuit 500.
Wherein, wherein after external input power 800 enters main topological circuit 200 by filter rectifier 100, be divided into
Two-way is input to LED backlight 600 all the way；Another way is input to machine core 700 by reduction voltage circuit 500；The load voltage and anti-
Current feed circuit 300 is connect with LED backlight 600, pwm control circuit 400 respectively, and the voltage and feedback for detecting LED backlight 600 arrive
Pwm control circuit 400, adjustment PWM are exported and then are adjusted the voltage for being input to LED backlight 600.
Specifically, external input power 800 is generally 110V-220V alternating current, passes through the power input of LCD TV
End is input to filter rectifier 100 and is filtered rectification, then by the voltage input after filter rectification to main topological circuit 200
In, as shown in figure 3, its circuit signal for the main topological circuit 200 of the embodiment of the power circuit of LCD TV of the invention
Figure.The voltage that main topological circuit 200 exports is directly inputted all the way to LED backlight, without using booster circuit；Another output
Voltage passes through the antihypertensive effect of reduction voltage circuit 500 to machine core 700, it is ensured that being input to machine core is stable 12V voltage.And it loads
Voltage and feed circuit 300 are used to detect the voltage of LED backlight and feed back to pwm control circuit.In an embodiment of the present invention,
The load voltage and feed circuit 300 include a LED constant current chip, are the prior art.The voltage of detection LED light can be crossed
It can be directly fed back to primary power supply, adjust primary side PWM, and then adjust transformer and export LED voltage, realize LED constant current.Separately
Outside, primary side is fed back to after detecting LED light bar voltage due to LED constant current chip, transformer output voltage is adjusted, leads to machine core power supply
12V, which is exported, becomes a variation voltage of 13~18V, needs one reduction voltage circuit of increase thus, provide stable 12V export to
Machine core.
As shown in figure 4, its circuit signal for the reduction voltage circuit of the embodiment of the power circuit of LCD TV of the invention
Figure.The reduction voltage circuit includes a field-effect tube Q1, a diode D1, an inductance L and a capacitor C0；The drain electrode of field-effect tube Q1
The voltage input end of main topological circuit is connected, source electrode is connected to machine core power output end, grounded-grid by inductance L；Diode
Between the source electrode and inductance L of one end setting scene effect pipe Q1 of D1, other end ground connection；One end of capacitor C0 connects machine core power supply
Output end (+12V), other end ground connection.Further, the field-effect tube can be N-channel field-effect tube.
Further, EMI suppression can also be set between the filter rectifier 100 and external input power 800
Circuit processed, for inhibiting electromagnetic interference.
Since machine core 12V output power is substantially stationary (30~40W), and the more high-power LED backlight power size the bigger, such as
55 cun, straight-down negative power has a 100W, and boost power (100W) is higher than buck power (40W) more than 2.5 times, and cost can also be higher by 2 times.
Novel circuit can directly reduce cost and raising efficiency by changing original topological form.The output of another winding of transformer
A variation voltage of 13~18V provides 12V to machine core by a reduction voltage circuit, due to this partial power only has 30~
40W, this is compared with the 24V in old technology is supplied to backlight 100W by boosting, and small 1.5 times or so, so new topological circuit effect
Rate can be improved, while power device cost is substantially reduced.
In conclusion the power circuit of LCD TV provided by the present invention, setting is in LED backlight, machine core and outside
Between input power, wherein the power circuit includes: filter rectifier, main topological circuit, load voltage detection and feedback
Circuit, pwm control circuit and reduction voltage circuit；After external input power enters main topological circuit by filter rectifier, it is divided into
Two-way is input to LED backlight all the way；Another way is input to machine core by reduction voltage circuit；The load voltage and feed circuit point
It is not connect with LED backlight, pwm control circuit, for detecting the voltage of LED backlight and feeding back to pwm control circuit, adjusts PWM
It exports and then adjusts the voltage for being input to LED backlight.By main topological circuit direct voltage output to LED backlight, load voltage
Detection and the voltage and feedback of the voltage detecting LED backlight of feed circuit detection LED backlight arrive pwm control circuit, adjust PWM,
It exports and then adjusts the voltage for being input to LED backlight；In addition, passing through decompression electricity in the voltage output variation of main topological circuit
Road guarantees that the voltage for being input to machine core is constant.Compared with prior art, efficiency increases substantially, at the same power device cost have it is bright
It is aobvious to reduce, there is good popularization and application foreground.
It should be understood that the application of the present invention is not limited to the above for those of ordinary skills can
With improvement or transformation based on the above description, all these modifications and variations all should belong to the guarantor of appended claims of the present invention
Protect range.
Claims (4)
1. a kind of power circuit of LCD TV is arranged between LED backlight, machine core and external input power, which is characterized in that
The power circuit include: filter rectifier, main topological circuit, load voltage detection with feed circuit, pwm control circuit and
Reduction voltage circuit；
Wherein, after external input power enters main topological circuit by filter rectifier, it is divided into two-way, is input to LED all the way
Backlight；Another way is input to machine core by reduction voltage circuit；The load voltage and feed circuit are controlled with LED backlight, PWM respectively
Circuit connection, for detecting the voltage of LED backlight and feeding back to pwm control circuit, adjustment PWM output adjusts in turn to be input to
The voltage of LED backlight；
The load voltage detection and feed circuit include a LED constant current chip, after LED constant current chip detects LED light bar voltage
Primary power supply is fed back, transformer output voltage is adjusted;
Wherein, feedback arrives primary power supply after the LED constant current chip detection LED light bar voltage, when adjusting transformer output voltage,
Guarantee the voltage stabilization for being output to machine core by the reduction voltage circuit.
2. the power circuit of LCD TV according to claim 1, which is characterized in that the reduction voltage circuit includes an effect
Ying Guan, a diode, an inductance and a capacitor；
The drain electrode of field-effect tube connects the voltage input end of main topological circuit, and source electrode is exported by inductance connection to machine core power supply
End, grounded-grid；Between the source electrode and inductance of one end setting scene effect pipe of diode, other end ground connection；One end of capacitor
Connect machine core power output end, other end ground connection.
3. the power circuit of LCD TV according to claim 2, which is characterized in that the field-effect tube is N-channel field
Effect pipe.
4. the power circuit of LCD TV according to claim 2, which is characterized in that the voltage of the main topological circuit is defeated
The voltage for entering end is 13V to 18V, and the voltage of machine core power output end is 12V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310543543.3A CN103634542B (en) | 2013-11-06 | 2013-11-06 | A kind of power circuit of LCD TV |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310543543.3A CN103634542B (en) | 2013-11-06 | 2013-11-06 | A kind of power circuit of LCD TV |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103634542A CN103634542A (en) | 2014-03-12 |
| CN103634542B true CN103634542B (en) | 2019-08-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310543543.3A Active CN103634542B (en) | 2013-11-06 | 2013-11-06 | A kind of power circuit of LCD TV |
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| Country | Link |
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| CN (1) | CN103634542B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN107948747B (en) * | 2017-12-07 | 2020-06-23 | 海信视像科技股份有限公司 | Power supply management method and unit and television |
| CN110634448B (en) * | 2019-08-23 | 2021-03-23 | 深圳康佳电子科技有限公司 | Backlight lamp strip protection circuit and TV set |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201418034Y (en) * | 2009-04-14 | 2010-03-03 | 青岛海信电器股份有限公司 | Power supply circuit and TV possessing the power supply circuit |
| CN102740562A (en) * | 2012-06-13 | 2012-10-17 | 青岛海信电器股份有限公司 | Power control circuit, backlight module and liquid crystal display device |
| CN102883512A (en) * | 2012-11-01 | 2013-01-16 | 东莞市奥源电子科技有限公司 | LED (light-emitting diode) backlight control circuit |
-
2013
- 2013-11-06 CN CN201310543543.3A patent/CN103634542B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201418034Y (en) * | 2009-04-14 | 2010-03-03 | 青岛海信电器股份有限公司 | Power supply circuit and TV possessing the power supply circuit |
| CN102740562A (en) * | 2012-06-13 | 2012-10-17 | 青岛海信电器股份有限公司 | Power control circuit, backlight module and liquid crystal display device |
| CN102883512A (en) * | 2012-11-01 | 2013-01-16 | 东莞市奥源电子科技有限公司 | LED (light-emitting diode) backlight control circuit |
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| Publication number | Publication date |
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| CN103634542A (en) | 2014-03-12 |
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Effective date of registration: 20190612 Address after: 518053 Kangjia R&D Building 2301, 28 South 12 Road, Science and Technology Community, Yuehai Street High-tech Zone, Nanshan District, Shenzhen City, Guangdong Province Applicant after: Shenzhen Xiaojia Technology Co., Ltd. Applicant after: Konka Group Co., Ltd. Address before: 518053 Shennan Avenue 9008, Overseas Chinese Town, Nanshan District, Shenzhen City, Guangdong Province Applicant before: Konka Group Co., Ltd. |
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