CN114664242A - Backlight constant-current control circuit and television - Google Patents
Backlight constant-current control circuit and television Download PDFInfo
- Publication number
- CN114664242A CN114664242A CN202210390437.5A CN202210390437A CN114664242A CN 114664242 A CN114664242 A CN 114664242A CN 202210390437 A CN202210390437 A CN 202210390437A CN 114664242 A CN114664242 A CN 114664242A
- Authority
- CN
- China
- Prior art keywords
- voltage
- module
- backlight
- power supply
- constant current
- 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.)
- Pending
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 71
- 239000003990 capacitor Substances 0.000 claims description 47
- 238000001914 filtration Methods 0.000 claims description 47
- 230000005669 field effect Effects 0.000 claims description 30
- 230000000087 stabilizing effect Effects 0.000 claims description 30
- 238000012545 processing Methods 0.000 claims description 28
- 230000009466 transformation Effects 0.000 claims description 20
- 239000004973 liquid crystal related substance Substances 0.000 claims description 12
- 230000006641 stabilisation Effects 0.000 claims description 11
- 238000011105 stabilization Methods 0.000 claims description 11
- 238000009499 grossing Methods 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000013461 design Methods 0.000 abstract description 10
- 238000005192 partition Methods 0.000 description 13
- 239000000243 solution Substances 0.000 description 8
- 238000010586 diagram Methods 0.000 description 5
- 230000011664 signaling Effects 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 230000001131 transforming effect Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection 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
- 230000008569 process Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
Abstract
The invention provides a backlight constant current control circuit, which relates to the technical field of electronic display and power supply, and comprises: the power supply management module is also connected with a power supply, and the constant current driving module is also connected with the mainboard module and the backlight module; the power supply management module is used for converting the output voltage of the power supply into a first power supply voltage and a second power supply voltage; the voltage conversion module is used for converting the first power supply voltage into backlight module voltage; the mainboard module works according to the second power supply voltage to generate a backlight driving signal; and the constant current driving module outputs the backlight module voltage to the backlight module when receiving the backlight driving signal. The television split box system is formed by the power management module and the mainboard module, so that the structure of the backlight constant current control circuit on the traditional television screen is simplified, and the thin design on the television screen is realized.
Description
Technical Field
The invention relates to the technical field of electronic display and power supply, in particular to a backlight constant-current control circuit and a television.
Background
In the related art, LED (Light-emitting Diode) televisions are increasingly developing toward large size and ultra-thin, and meanwhile, with the rapid development and popularization of the Mini-LED technology, multi-partition constant current has become a backlight control mode of the Mini-LED televisions, a traditional backlight constant current control circuit adopts a control structure of a box power supply and a constant current board, and the structure of the box power supply in the traditional backlight constant current control circuit is complex, so that the structure of the traditional backlight constant current control circuit is complex, and the whole thickness of the television is difficult to be extremely thin.
Disclosure of Invention
The main purposes of the invention are as follows: the utility model provides a backlight constant current control circuit and TV set, aims at solving the technical problem that traditional backlight constant current control circuit's structure is complicated.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a backlight constant current control circuit, the backlight constant current control circuit is respectively connected to a power supply and a backlight module, and the backlight constant current control circuit includes: the power supply management module is also connected with a power supply, and the constant current driving module is also connected with the main board module and the backlight module;
the power supply management module is used for converting the output voltage of the power supply into a first power supply voltage and a second power supply voltage;
the voltage conversion module is used for converting the first power supply voltage into the backlight module voltage;
the main board module is used for generating a backlight driving signal according to the work of the second power supply voltage and sending the backlight driving signal to the constant current driving module;
and the constant current driving module is used for outputting the backlight module voltage to the backlight module when receiving the backlight driving signal.
Optionally, the power management module includes a dc conversion unit, a first power conversion unit and a second power conversion unit respectively connected to the dc conversion unit;
the direct current conversion unit is used for converting the output voltage of the power supply into direct current voltage;
the first power supply conversion unit is used for converting the direct-current voltage into a first power supply voltage;
and the second power supply conversion unit is used for converting the direct-current voltage into a second power supply voltage.
Optionally, the voltage conversion module includes a resonant filtering unit and a feedback voltage stabilizing unit, an input end of the resonant filtering unit is connected to output ends of the power management module and the feedback voltage stabilizing unit, an output end of the resonant filtering unit is connected to input ends of the constant current driving module and the feedback voltage stabilizing unit, and an input end of the feedback voltage stabilizing unit is further connected to the constant current driving module;
the constant current driving module is also used for receiving a first feedback voltage of the backlight module to generate a feedback signal;
the feedback voltage stabilizing unit is used for outputting a second feedback voltage according to the backlight module voltage and the feedback signal;
and the resonance filtering unit is used for sequentially carrying out integral resonance processing, voltage transformation processing and rectification filtering processing on the first power supply voltage according to the second feedback voltage to obtain the backlight module voltage.
Optionally, the resonant filtering unit includes a first LLC resonant circuit, a voltage transformation circuit, and a first rectification filtering circuit;
the first LLC resonant circuit comprises a field effect transistor Q1, a field effect transistor Q2 and a resonant controller U1;
the drain of the field-effect transistor Q1 is connected with the positive electrodes of the power management module and the filter capacitor C1, the negative electrode of the filter capacitor C1 is grounded, the gate of the field-effect transistor Q1 is connected with the first pin of the resonant controller U1 through a resistor R1, the source is connected with the second pin of the resonant controller U1, the drain of the field-effect transistor Q2 and the transformer circuit, the gate of the field-effect transistor Q2 is connected with the third pin of the resonant controller U1 through a resistor R2, the source is connected with the transformer circuit through a capacitor C2 and is grounded, the fourth pin of the resonant controller U1 is connected with the transformer circuit through a capacitor C3, the fifth pin of the resonant controller U1 is connected with the positive electrode of the filter capacitor C4 and the negative electrode of the diode D1, the negative electrode of the filter capacitor C4 is grounded, the positive electrode of the diode D1 is connected with the transformer circuit, and the sixth pin of the controller 1 is connected with the feedback voltage stabilizing unit.
Optionally, the transformation circuit comprises a transformer T1;
the first input end of the transformer T1 is connected with the source electrode of the field effect transistor Q1, the second input end is respectively connected with one end of the capacitor C2 close to the transformer T1 and one end of the capacitor C3 close to the transformer T1, the third input end is connected with the anode of the diode D1, the fourth input end is grounded, and the output end is respectively connected with the first rectifying and filtering circuit.
Optionally, the first rectifying and filtering circuit comprises a diode D2, a diode D3, a diode D4 and a diode D5;
the anode of the diode D2 is connected to the first output terminal of the transformer T1, the anode of the diode D3 is connected to the second output terminal of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3, and is connected to the anode of the filter capacitor C5, the feedback voltage stabilizing unit and the backlight module, the first ground terminal of the transformer T1 is connected to the cathode of the filter capacitor C5, and is grounded, the anode of the diode D4 is connected to the third output terminal of the transformer T1, the anode of the diode D5 is connected to the fourth output terminal of the transformer T1, the cathode of the diode D4 is connected to the cathode of the diode D5, and is connected to the anode of the filter capacitor C6 and the constant current driving module, and the second ground terminal of the transformer T1 is connected to the cathode of the filter capacitor C6, and is grounded.
Optionally, the constant current driving module comprises a direct current power supply unit, a micro control unit and a backlight control unit, the micro control unit and the backlight control unit are respectively connected with the direct current power supply unit, the direct current power supply unit is connected with the voltage conversion module, the micro control unit is also respectively connected with the backlight control unit and the main board module, and the backlight control unit is connected with the backlight module;
the voltage conversion module is also used for converting the first power supply voltage into a constant current driving voltage;
the direct current power supply unit is used for converting the constant current driving voltage into a third power supply voltage and a fourth power supply voltage when receiving an enabling signal sent by the mainboard module, and respectively supplying power to the micro control unit and the backlight control unit;
the micro control unit is used for working according to the third power supply voltage, analyzing the backlight driving signal and outputting a micro control signal;
and the backlight control unit is used for working according to the fourth power supply voltage and outputting the voltage of the backlight module to the backlight module when receiving the micro control signal.
Optionally, the backlight constant current control circuit further comprises a logic board module connected with the main board module;
the mainboard module is also used for generating a low-voltage differential signal;
and the logic board module is used for carrying out time sequence control on the low-voltage differential signals, outputting row and column driving signals and controlling the liquid crystal screen to work.
Optionally, the backlight constant current control circuit further comprises a sound production module connected with the main board module;
the power supply management module is also used for converting the output voltage of the power supply into the power amplifier voltage of the mainboard;
the mainboard module is also used for outputting a sound production control signal according to the mainboard power amplifier voltage and controlling the sound production module to work.
In a second aspect, the present invention further provides a television, including:
the backlight constant current control circuit according to any one of the above;
the backlight module and the liquid crystal screen are respectively connected with the backlight constant current control circuit.
The invention provides a backlight constant current control circuit, which comprises a voltage management module, a main board module, a backlight module, a constant current driving module, a voltage output module and a power supply module, wherein the voltage output module converts the output voltage of a power supply into a first power supply voltage, the voltage conversion module converts the first power supply voltage into the voltage of the backlight module to the backlight module, the power supply management module converts the output voltage of the power supply into a second power supply voltage to supply power to the main board module, the main board module works according to the second power supply voltage to generate a backlight driving signal, and finally the constant current driving module outputs the voltage of the backlight module to the backlight module according to the backlight driving signal to enable the backlight module to work; the power management module is arranged in the split box system of the television, so that the structure of a box power supply in a traditional backlight constant-current control circuit and a connecting wire between the split box system and the on-screen system are simplified, the problem of complex structure of the traditional backlight constant-current control circuit is solved, and the thin and thin modeling design on the screen of the television is realized.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a connection schematic diagram of a backlight constant current control circuit according to a first embodiment of the invention;
FIG. 2 is a schematic connection diagram of a power management module of a backlight constant-current control circuit according to a first embodiment of the invention;
fig. 3 is a schematic connection diagram of a voltage conversion module according to a second embodiment of the backlight constant-current control circuit of the present invention;
fig. 4 is a schematic circuit diagram of a backlight constant current control circuit according to a second embodiment of the present invention;
fig. 5 is a connection diagram of a backlight constant current control circuit according to a third embodiment of the invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
In the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a device or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such device or system. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a device or system that comprises the element.
In addition, in the present invention, unless otherwise explicitly stated or limited, the terms "connected", "fixed", and the like are to be construed broadly, e.g., "connected" may be a fixed connection, a detachable connection, or an integral body; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. If there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.
In the present invention, suffixes such as "module", "part", or "unit" used to represent elements are used only for facilitating the description of the present invention, and have no specific meaning in themselves. Thus, "module", "component" or "unit" may be used mixedly. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. In addition, the technical solutions of the respective embodiments may be combined with each other, but must be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should be considered to be absent and not be within the protection scope of the present invention.
In the prior art, LED televisions are increasingly developing towards large size and ultra-thin, and with rapid development and popularization of the Mini-LED technology, multi-partition constant current has become a backlight control mode of the Mini-LED television. However, the current slimness of large-sized Mini-LED tv still has some problems:
1. if a traditional Power supply and constant current control framework is adopted, the whole thickness of the television is difficult to be thinned, because key components such as a Power supply, a constant current, a main board and a loudspeaker are assembled on a screen body, when AC 100 and 240V are input, key Power devices such as a Power supply EMI (electromagnetic Interference) circuit, a rectifier bridge and a PFC (Power Factor Correction) circuit are adopted, when AC 100V is input, the volumes of a common mode inductor, the rectifier bridge and the PFC inductor of the Power supply are large due to thermal design consideration, and when a Power supply board, a constant current board (or a lamp panel), the main board and the loudspeaker are assembled on a screen, the thickness of the whole television is greatly increased, so that the whole television is difficult to be thinned.
2. The large-size Mini-LED television is subjected to Localdim backlight control of hundreds of partitions or more than one thousandth of partitions, the backlight power of the module is high, the partition voltage is low (generally 12V-36V), if a box power supply and constant current plate mode is adopted, the transmission current of the backlight part is high, the appearance design of the whole machine is not facilitated, and the thinning and appearance connection design of a high-end machine is influenced. Taking a 75-inch Mini-LED television with a partition voltage of 36V as an example, the current of the connection line between the power supply of the split box and the constant current board is at least 7A (if 12V partition is adopted, the same backlight module is adopted, the current carried by the transmission line is larger), a transmission line with a larger volume needs to be adopted, which is not beneficial to the modeling design of the split television.
3. Because the power of the large-size Mini-LED television backlight module is larger, if the constant current system adopts a traditional BUCK (BUCK) or BOOST (BOOST) mode, the cost and the thermal design difficulty of a BUCK (BUCK) or BOOST (BOOST) circuit are extremely high, and the cost is very high.
In summary, the structure of the box power supply in the conventional backlight constant current control circuit is complex, so that the structure of the conventional backlight constant current control circuit is complex, and the whole thickness of the television is difficult to be thinned.
In view of the technical problem of complex structure of the traditional backlight constant current control circuit, the invention provides a backlight constant current control circuit, which has the following general idea:
backlight constant current control circuit is connected with power and backlight unit respectively, and backlight constant current control circuit includes: the power supply management module is also connected with a power supply, and the constant current driving module is also connected with the mainboard module and the backlight module; the power supply management module is used for converting the output voltage of the power supply into a first power supply voltage and a second power supply voltage; the voltage conversion module is used for converting the first power supply voltage into the backlight module voltage; the main board module is used for generating a backlight driving signal according to the work of the second power supply voltage; and the constant current driving module is used for outputting the backlight module voltage to the backlight module according to the backlight driving signal.
The invention provides a backlight constant current control circuit, which comprises a voltage management module, a power supply, a main board module, a backlight module, a constant current driving module and a power supply module, wherein the voltage management module is used for converting the output voltage of the power supply into a first power supply voltage, the voltage conversion module is used for converting the first power supply voltage into the voltage of the backlight module to the backlight module, the power supply management module is used for converting the output voltage of the power supply into a second power supply voltage to supply power to the main board, the main board module works according to the second power supply voltage to generate a backlight driving signal, and finally, the constant current driving module is used for outputting the voltage of the backlight module to the backlight module according to the backlight driving signal to enable the backlight module to work; the power management module is arranged in the split box system of the television, so that the structure of a box power supply in a traditional backlight constant-current control circuit and a connecting line between the split box system and the on-screen system are simplified, the problem of complex structure of the traditional backlight constant-current control circuit is solved, and the thin and thin design on the television screen is realized.
The structured query language injection detection method of the present invention is described in detail below with reference to the accompanying drawings and the detailed description.
Example one
Referring to fig. 1, the present embodiment provides a backlight constant current control circuit 1000, the backlight constant current control circuit 1000 is respectively connected to a power supply 2000 and a backlight module 3000, the backlight constant current control circuit 1000 includes: the power management module 100, the voltage conversion module 200 and the motherboard module 400 which are respectively connected with the power management module 100, and the constant current driving module 300 which is connected with the voltage conversion module 200, the power management module 100 is also connected with the power supply 2000, and the constant current driving module 300 is also connected with the motherboard module 400 and the backlight module 3000;
a power management module 100, configured to convert an output voltage of a power supply into a first power supply voltage and a second power supply voltage;
a voltage conversion module 200, configured to convert the first power supply voltage into a backlight module voltage;
the main board module 400 is configured to operate according to the second power supply voltage to generate a backlight driving signal;
the constant current driving module 300 is configured to output the backlight module voltage to the backlight module according to the backlight driving signal.
In this embodiment, the main board module 400 can be a main board system of a liquid crystal television, and the power supply can be 100-plus 240V or 220V ac power supply; the first power supply voltage can be 200-400V high-voltage output, and the second power supply voltage can be +12V low-voltage output to supply power for the mainboard system; the backlight module voltage is generally 12V-36V, and the low-voltage output supplies power for the backlight module 3000; the backlight driving signal may be a serial signal SPI, and is used to control the constant current driving module 300, so that the constant current driving module 300 controls the backlight module voltage to access the backlight module 3000 according to the serial signal SPI, and controls the backlight module 3000 to operate.
In specific implementation, after the television is turned on, the voltage management module 100 converts the output voltage of the power supply into a first power supply voltage and outputs the first power supply voltage to the voltage conversion module 200, the voltage conversion module 200 converts the first power supply voltage into a backlight module voltage and outputs the backlight module voltage to the backlight module to provide a working voltage of the backlight module 3000, the power management module 100 converts the output voltage of the power supply into a second power supply voltage and outputs the second power supply voltage to the main board module 400 to supply power to the main board module 400, the main board module 400 starts to work to generate a backlight driving signal and sends the backlight driving signal to the constant current driving module 300, and finally the constant current driving module 300 outputs the backlight module voltage to the backlight module 3000 according to the backlight driving signal, so that the backlight module 3000 works.
Specifically, as shown in fig. 2, the power management module 100 includes a dc conversion unit 110, a first power conversion unit 120 and a second power conversion unit 130 respectively connected to the dc conversion unit 110;
a dc conversion unit 110 for converting an output voltage of a power supply into a dc voltage;
a first power conversion unit 120 for converting the dc voltage into a first power supply voltage;
the second power conversion unit 130 is configured to convert the dc voltage into a second power supply voltage.
In this embodiment, as shown in fig. 2, the dc conversion unit 110 includes an EMI circuit 111 (filter circuit), a rectifier bridge 112, and a PFC circuit 113 (power factor correction circuit): the EMI circuit 111 is arranged between a power supply alternating current inlet wire and the rectifier bridge 112 and is used for filtering voltage transient and high-frequency interference in the commercial power grid, and simultaneously preventing high-frequency interference generated by a switching tube in the switching power supply from being transmitted into the commercial power grid to form high-frequency interference on other electric appliances; the rectifier bridge 112 converts the ac power to dc power; the PFC circuit 113 continuously adjusts the input current waveform to approach a sine wave through a suitable control circuit and maintain the same phase as the input grid voltage, thereby greatly improving the power factor, reducing the grid load, improving the output power, and significantly reducing the pollution of the power adapter to the grid.
As shown in fig. 2, the first power conversion unit 120 includes a second LLC resonant circuit 121, a main transformer 122, a second rectification filter circuit 123 and a second feedback voltage stabilizing circuit 124, which are connected in sequence, the second LLC resonant circuit 121 is connected to the dc conversion unit 110, the second rectification filter circuit 123 is connected to the voltage conversion module 124, and the second LLC resonant circuit 121, the main transformer 122 and the second rectification filter circuit 123 are connected in sequence to perform resonance processing, transformation processing and rectification filter processing on the dc voltage to obtain a first power supply voltage; the second feedback voltage stabilizing circuit 123 is further connected to the second LLC resonant circuit 121, and is configured to output a first adjusting voltage according to the first power supply voltage, adjust the first power supply voltage output by the first power conversion unit, and ensure that the first power supply voltage is output stably. For example, taking a module power of 300W for a 75-inch Mini-LED television as an example, if the voltage of the light bar (or the lamp panel) is 36V, the current of the transmission line in the conventional manner is 8.33A, whereas if the first power supply voltage in this embodiment is 400V, the current of the connection line is only 0.75A, and the volume of the connection line can be greatly reduced.
As shown in fig. 2, the second power conversion unit 130 includes a third LLC resonant circuit 131, an auxiliary transformer 132, a third rectification filter circuit 133, and a third feedback voltage stabilizing circuit 135, which are connected in sequence, where the third LLC resonant circuit 131 is connected to the dc conversion unit 110, the third rectification filter circuit 133 is connected to the motherboard module 400, and the third LLC resonant circuit 131, the auxiliary transformer 132, and the third rectification filter circuit 133 are connected in sequence to perform resonance processing, voltage transformation processing, and rectification filter processing on the dc voltage, so as to obtain a second power supply voltage; the third feedback voltage stabilizing circuit 135 is further connected to the third LLC resonant circuit 131, and is configured to output a second adjusting voltage according to the second power supply voltage, adjust the second power supply voltage output by the second power conversion unit 130, and ensure that the second power supply voltage is output stably. The second LLC resonant circuit 121 is also connected to a third LLC resonant circuit 131 and an auxiliary transformer 132, respectively.
In this embodiment, the second LLC resonant circuit 121 and the third LLC resonant circuit 131 may be the same LLC resonant circuit, the second rectifying and filtering circuit 123 and the third rectifying and filtering circuit 133 may be the same rectifying and filtering circuit, and the second feedback voltage stabilizing circuit 124 and the third feedback voltage stabilizing circuit 135 may be the same feedback voltage stabilizing circuit.
In a specific implementation, after the television is turned on, the output voltage of the power supply is converted into a dc voltage by the dc conversion unit 110, and the dc voltage is output to the first power conversion unit 120, and the dc voltage is converted into a first power supply voltage by the first power conversion unit 120, and is output to the voltage conversion module 200, and the dc voltage is further converted into a second power supply voltage by the second power conversion unit 130, so as to supply power to the motherboard module 400.
The embodiment provides a backlight constant current control circuit, which comprises a power management module and a motherboard module to form a split box system of a television, a voltage conversion module, a constant current driving module and a backlight module to form an on-screen system of the television, the power management module is arranged in the split box system of the television, key power devices such as an EMI circuit, a rectifier bridge, a PFC circuit and the like are arranged in the power management module of the split box system, the structure of the traditional backlight constant current control circuit is simplified, the output voltage of a power supply is converted by the power management module, then the voltage conversion module is switched to the constant current driving module, and a connecting wire between the voltage conversion module and the constant current driving module is simplified, the height of the split box system does not affect the thickness of the whole screen, so that the problem that the traditional backlight constant current control circuit is complex in structure is solved, and the thin modeling design on the television screen is realized.
In this embodiment, the feedback voltage stabilizing circuits are further disposed in the first power conversion unit and the second power conversion unit to adjust the output voltages of the first power conversion unit and the second power conversion unit, so as to ensure the stability of the output voltages of the first power conversion unit and the second power conversion unit.
Example two
Further, referring to fig. 3, the present embodiment provides a second embodiment of a backlight constant current control circuit, based on the first embodiment, the voltage conversion module 200 includes a resonant filtering unit 210 and a feedback voltage stabilization unit 220, an input end of the resonant filtering unit 210 is connected to output ends of the power management module 100 and the feedback voltage stabilization unit 220, an output end of the resonant filtering unit 210 is connected to input ends of the constant current driving module 300 and the feedback voltage stabilization unit 220, and an input end of the feedback voltage stabilization unit 220 is further connected to the constant current driving module 300;
the constant current driving module 300 is further configured to generate a feedback signal according to the first feedback voltage of the backlight module 3000;
a feedback voltage stabilization unit 220 for outputting a second feedback voltage according to the backlight module voltage and the feedback signal;
and the resonant filtering unit 210 is configured to perform, according to the second feedback voltage, a whole resonant processing, a voltage transformation processing, and a rectification filtering processing on the first power supply voltage in sequence, and convert the first power supply voltage into a backlight module voltage.
In this embodiment, as shown in fig. 3, the resonant filtering unit 210 may include a first LLC resonant circuit 211, a transforming circuit 212, and a first rectifying and filtering circuit 213, where the first LLC resonant circuit 211 is connected to the power management module 100, the first LLC resonant circuit 211, the transforming circuit 212, and the first rectifying and filtering circuit 213 are sequentially connected to perform resonant processing, transforming processing, and rectifying and filtering processing on the first power supply voltage output by the power management module 100, so as to obtain a backlight module voltage, and the first rectifying and filtering circuit 213 is connected to the constant current driving module 300, so as to transfer the backlight module voltage to the backlight module 3000, so as to provide a working voltage for the backlight module 3000; the feedback voltage stabilizing unit 220 is respectively connected to the first rectifying and filtering circuit 213, the constant current driving module 300, and the first LLC resonant circuit 211, and outputs a second feedback voltage to adjust the backlight module voltage output by the resonant filtering unit 210 according to the backlight module voltage and the feedback signal of the constant current driving module 300.
In specific implementation, after the television is turned on, the resonant filtering unit 210 sequentially performs resonant processing, voltage transformation processing and rectifying filtering processing on the first power supply voltage, converts the first power supply voltage into a backlight module voltage, provides a working voltage for the backlight module 3000, acquires a feedback signal from the constant current driving module 300 through the feedback voltage stabilizing unit 220, acquires the backlight module voltage from the resonant filtering unit 210, adjusts the backlight module voltage output by the resonant filtering unit 210 according to the backlight module voltage and the feedback signal, ensures the stability of the backlight module voltage, adjusts the voltage difference between the light bars (or the light panels) in the backlight module, and reduces the temperature rise of the constant current driving module 300.
Specifically, as shown in fig. 4, the resonant filtering unit 210 includes a first LLC resonant circuit 211, a transformer circuit 212, and a first rectifying and filtering circuit 213;
the first LLC resonant circuit 211 includes a field effect transistor Q1, a field effect transistor Q2, and a resonant controller U1;
the drain electrode of the field effect transistor Q1 is respectively connected with the positive electrodes of the power management module 100 and the filter capacitor C1, the cathode electrode of the filter capacitor C1 is grounded, the gate electrode of the field effect transistor Q1 is connected with the first pin HO of the resonance controller U1 through a resistor R1, the source electrode is respectively connected with the second pin HB of the resonance controller U1, the drain electrode of the field effect transistor Q2 and the transformation circuit 212, the gate electrode of the field effect transistor Q2 is connected with the third pin LO of the resonance controller U1 through a resistor R2, and the source electrode is connected with the transformation circuit 212 through a capacitor C2, and the fourth pin CS of the resonant controller U1 is connected to the voltage transformation circuit 212 through the capacitor C3, the fifth pin VCC of the resonant controller U1 is connected to the positive electrode of the filter capacitor C4 and the negative electrode of the diode D1, respectively, the negative electrode of the filter capacitor C4 is grounded, the positive electrode of the diode D1 is connected to the voltage transformation circuit 212, and the sixth pin FB of the resonant controller U1 is connected to the feedback voltage stabilization unit 220.
In this embodiment, as shown in fig. 4, the backlight module voltages Vled1+, Vled2+ … … Vledn + correspond to the first feedback voltages Vled1-, Vled2- … … Vledn-, respectively, and represent the positive and negative electrodes of the partitioned light bar (or light panel) of the backlight module, which indicates that the backlight module is divided into n partitions.
In specific implementation, after the television is turned on, the drain of the field effect transistor Q1 is connected to the positive electrodes of the power management module 100 and the filter capacitor C1, the negative electrode of the filter capacitor C1 is grounded, the first power supply voltage is received from the power management module 100, the gate of the field effect transistor Q1 is connected to the first pin HO of the resonant controller U1 through the resistor R1, the source is connected to the second pin HB of the resonant controller U1, the drain of the field effect transistor Q2 and the transformation circuit, the field effect transistor Q1 receives the high driving signal output by the first pin HO of the resonant controller U1, and is turned on according to the high driving signal to access the first power supply voltage; a gate of the field-effect transistor Q2 is connected to the third pin LO of the resonant controller U1 through a resistor R2, a source of the field-effect transistor Q2 is connected to the transformer circuit through a capacitor C2 and is grounded, the field-effect transistor Q2 receives a low driving signal output by the third pin LO of the resonant controller U1, the low driving signal is turned on according to the low driving signal, the fourth pin CS of the resonant controller U1 is connected to the transformer circuit through a capacitor C3, so as to achieve soft start of the resonant controller U1, the fifth pin VCC of the resonant controller U1 is respectively connected to an anode of the filter capacitor C4 and a cathode of the diode D1, so as to provide a working voltage of the resonant controller U1, a cathode of the filter capacitor C4 is grounded, an anode of the diode FB 1 is connected to the transformer circuit, a sixth pin of the resonant controller U1 is connected to the feedback unit 220, and the resonant controller U1 adjusts the backlight module voltage + vddn according to a signal output by the feedback regulator unit 220; the first power supply voltage is subjected to resonance processing through a field effect transistor Q1, a field effect transistor Q2 and a resonance controller U1 and then is output to the transformation circuit.
Specifically, the transformer circuit 212 includes a transformer T1;
the first input end 1 of the transformer T1 is connected to the source of the fet Q1, the second input end 2 is connected to the end of the capacitor C2 close to the transformer and the end of the capacitor C3 close to the transformer, the third input end 3 is connected to the anode of the diode D1, the fourth input end 4 is grounded, and the output end is connected to the first rectifying-filtering circuit 213.
In the concrete implementation, after the television is turned on, the first input end 1 of the transformer T1 is connected with the source electrode of the field-effect transistor Q1, the second input end 2 is connected with one end of the capacitor C2 close to the transformer and one end of the capacitor C3 close to the transformer respectively, the third input end 3 is connected with the anode of the diode D1, the fourth input end 4 is grounded, the output end is connected with the first rectifying and filtering circuit 213 respectively, and the first supply voltage is subjected to voltage transformation processing through the transformer T1 and then output to the first rectifying and filtering circuit 213.
Specifically, the first rectifying and smoothing circuit 213 includes a diode D2, a diode D3, a diode D4, and a diode D5;
the anode of the diode D2 is connected to the first output terminal 5 of the transformer T1, the anode of the diode D3 is connected to the second output terminal 6 of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3, and is connected to the anode of the filter capacitor C5, the feedback voltage stabilizing unit and the backlight module, the first ground terminal 7 of the transformer T1 is connected to the cathode of the filter capacitor C5, and is grounded, the anode of the diode D4 is connected to the third output terminal 8 of the transformer T1, the anode of the diode D5 is connected to the fourth output terminal 9 of the transformer T1, the cathode of the diode D4 is connected to the cathode of the diode D5, and is connected to the anode of the filter capacitor C6 and the constant current driving module, and the second ground terminal 10 of the transformer T1 is connected to the cathode of the filter capacitor C6, and is grounded.
In this embodiment, as shown in fig. 4, the feedback voltage stabilizing unit 220 may be a first feedback voltage stabilizing circuit 221, and the first feedback voltage stabilizing circuit 221 may be a feedback voltage stabilizing circuit identical to the second feedback voltage stabilizing circuit 124 and the third feedback voltage stabilizing circuit 135.
In specific implementation, the anode of the diode D2 is connected to the first output terminal 5 of the transformer T1, the anode of the diode D3 is connected to the second output terminal 6 of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3, and is respectively connected to the anode of the filter capacitor C5, the first feedback voltage stabilizing circuit and the backlight module, the first ground terminal 7 of the transformer T1 is connected to the cathode of the filter capacitor C5, and is grounded, so as to perform rectification filtering processing on the first power supply voltage after voltage transformation processing, output the backlight module voltage, and provide the working voltage of the backlight module; the anode of the diode D4 is connected to the third output terminal 8 of the transformer T1, the anode of the diode D5 is connected to the fourth output terminal 9 of the transformer T1, the cathode of the diode D4 is connected to the cathode of the diode D5, and is respectively connected to the anode of the filter capacitor C6 and the constant current driving module, the second ground terminal 10 of the transformer T1 is connected to the cathode of the filter capacitor C6 and is grounded, the first supply voltage after voltage transformation is rectified and filtered, and a constant current driving voltage is output. Specifically, the first feedback voltage stabilizing circuit 221 outputs a second feedback voltage according to the backlight module voltage and the feedback signal of the constant current driving module to adjust the backlight module voltage output by the resonant filtering unit, so as to ensure the stability of the output backlight module voltage and adjust the voltage difference between the light bars (or the lamp panels) of the backlight module partition, thereby reducing the temperature rise of the constant current control chip.
Specifically, the constant current driving module 300 includes a dc power supply unit 310, a micro control unit 320 and a backlight control unit 330 respectively connected to the dc power supply unit 310, the dc power supply unit 310 is connected to the voltage conversion module 200, the micro control unit 320 is further connected to the backlight control unit 330 and the main board module 400 respectively, and the backlight control unit 330 is connected to the backlight module 3000;
the voltage conversion module 200 is further configured to convert the first power supply voltage into a constant current driving voltage;
the dc power supply unit 310 is configured to convert the constant current driving voltage into a third power supply voltage and a fourth power supply voltage when receiving an enable signal sent by the motherboard module, and respectively supply power to the micro control unit 320 and the backlight control unit 330;
the micro control unit 320 is used for working according to the third power supply voltage, analyzing the backlight driving signal and outputting a micro control signal;
the backlight control unit 330 is configured to operate according to the fourth power supply voltage, and output the backlight module voltage to the backlight module when receiving the micro control signal.
In this embodiment, the micro control signal may be a micro control signal output by the micro control unit 320 after analyzing the serial signal SPI output by the main board module 400 and performing a software algorithm, and the output micro control signal may be used for controlling the light bar (or the light plate) partition and the partition current of the backlight module, so as to implement the partition dimming function of the backlight module of the whole television screen body. In addition, as shown in fig. 4, the feedback signal of the constant current driving module 300 may be a feedback signal output by the backlight control unit 330.
In the specific implementation, after the television is turned on, the voltage conversion module 200 converts the first power supply voltage into a constant current drive voltage, the dc power supply unit 310 receives the constant current drive voltage and an enable signal from the motherboard module 400, and then converts the constant current drive voltage into a third power supply voltage and a fourth power supply voltage, which respectively provide working voltages for the micro control unit 320 and the backlight control unit 330, and then the micro control unit 320 outputs a micro control signal according to the third power supply voltage and the backlight drive signal output by the motherboard module 400, and finally the backlight control unit 330 works according to the fourth power supply voltage, and when receiving the micro control signal, controls the voltage of the backlight module to be connected to the backlight module, and controls the backlight module to work; in addition, the backlight control unit 330 outputs a feedback signal to the feedback voltage stabilizing unit, so that the feedback voltage stabilizing unit outputs a second feedback voltage according to the feedback signal and the backlight module voltage.
The embodiment provides a backlight constant current control circuit, which converts a first power supply voltage into a backlight module voltage and a constant current driving voltage through a resonance filtering unit, controls the backlight module voltage to be directly connected to a backlight module through a constant current driving module according to the constant current driving voltage and a backlight driving signal output by a main board module, controls the backlight module to work, and realizes direct-drive type partition constant current driving of the backlight module.
In this embodiment, the voltage conversion module is further provided with a feedback voltage stabilization unit to obtain the backlight module voltage and the feedback signal output by the constant current driving module, so as to adjust the output backlight module voltage, ensure the stability of the output backlight module voltage, and reduce the temperature rise of the constant current control chip.
EXAMPLE III
Further, referring to fig. 5, the present embodiment provides a third embodiment of the backlight constant current control circuit 1000, and based on any one of the first to second embodiments, the backlight constant current control circuit 1000 further includes a logic board module 500 connected to the main board module 400;
the motherboard module 400 is further configured to generate a low-voltage differential signal LVDS;
and the logic board module 500 is configured to perform timing control on the low-voltage differential signaling LVDS, output a row-column driving signal, and control the operation of the liquid crystal display.
In this embodiment, the liquid crystal display may be a Mini-LED liquid crystal display, the logic board module 500 may be a T-CON board (Timing Controller), and the T-CON board may control the low voltage differential signaling LVDS sent by the main board module 400 in the logic board in time sequence and convert the low voltage differential signaling LVDS into the row and column driving signals required by the glass substrate of the liquid crystal display, so as to drive the liquid crystal display to display an image.
In a specific implementation, after the television is turned on, the main board module 400 outputs the low voltage differential signaling LVDS according to the second power supply voltage, and the logic board module 500 outputs the row-column driving signal according to the low voltage differential signaling LVDS to drive the liquid crystal display to display the image.
Specifically, as shown in fig. 5, the backlight constant current control circuit 1000 further includes a sound generating module 600 connected to the motherboard module 400;
the power management module 100 is further configured to convert an output voltage of the power supply into a main board power amplifier voltage;
the main board module 400 is further configured to output a sound generation control signal according to the main board power amplifier voltage, and control the sound generation module 600 to operate.
In this embodiment, the sound generating module 600 may be an external speaker, as shown in fig. 2, the second power conversion unit 130 further includes a fourth rectifying and filtering circuit 134, the fourth rectifying and filtering circuit 134 is respectively connected to the auxiliary transformer 132 and the motherboard module 400, and the third LLC resonant circuit 131, the auxiliary transformer 132 and the fourth rectifying and filtering circuit 134 sequentially perform resonance processing, voltage transformation processing and rectifying and filtering processing on the dc voltage to obtain the motherboard power amplifier voltage. The second rectifying and smoothing circuit 123, the third rectifying and smoothing circuit 133, and the fourth rectifying and smoothing circuit 134 may be the same rectifying and smoothing circuit.
In specific implementation, after the television is turned on, the output voltage of the power supply 2000 is converted into the main board power amplifier voltage through the power management module 100, power is supplied to the sound generating module 600, and the sound generating module 600 is controlled to generate sound by outputting a sound generating control signal through the main board module 400 according to the second power supply voltage.
The embodiment provides a backlight constant current control circuit, which simplifies the structure of the traditional backlight constant current control circuit and the connecting line between the split box system and the on-screen system by arranging the sound production module of the television in the split box system, solves the problem of complex structure of the traditional backlight constant current control circuit, and realizes the thin modeling design on the television screen.
Example four
On the basis of the foregoing embodiments, the present embodiment provides a television, which may include:
the backlight constant current control circuit 1000 according to the above embodiment;
In the specific implementation, the television is connected to a power supply 2000, after the television is turned on, the power management module 100 converts the output voltage of the power supply into a first power supply voltage, and outputs the first power supply voltage to the voltage conversion module 200, the voltage conversion module 200 converts the first power supply voltage into a backlight module voltage to provide the power supply voltage of the backlight module 3000, the main board module 400 outputs a backlight driving signal to the constant current driving module 300, and the constant current driving module 300 connects the backlight module voltage to the backlight module 3000 according to the backlight driving signal, so that the backlight module 3000 works; the output voltage of the power supply is converted into a second power supply voltage through the power management module 100, the second power supply voltage is output to the main board module 400, the main board module 400 outputs a low-voltage differential signal according to the second power supply voltage, and the logic board module 500 outputs a row-column driving signal according to the low-voltage differential signal to drive the liquid crystal display to display images.
In this embodiment, the specific structure of the backlight constant-current control circuit refers to the above embodiments, and since this embodiment adopts all technical solutions of all the above embodiments, at least all beneficial effects brought by the technical solutions of the above embodiments are achieved, and details are not repeated here.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. The utility model provides a constant current control circuit in a poor light, constant current control circuit in a poor light is connected with power and backlight unit respectively, its characterized in that, constant current control circuit in a poor light includes: the backlight module comprises a power supply management module, a voltage conversion module, a mainboard module and a constant current driving module, wherein the voltage conversion module and the mainboard module are respectively connected with the power supply management module;
the power supply management module is used for converting the output voltage of the power supply into a first power supply voltage and a second power supply voltage;
the voltage conversion module is used for converting the first power supply voltage into backlight module voltage;
the main board module is used for generating a backlight driving signal according to the second power supply voltage and sending the backlight driving signal to the constant current driving module;
and the constant current driving module is used for outputting the backlight module voltage to the backlight module when receiving the backlight driving signal.
2. The backlight constant current control circuit according to claim 1, wherein the power management module comprises a dc conversion unit, a first power conversion unit and a second power conversion unit respectively connected to the dc conversion unit;
the direct current conversion unit is used for converting the output voltage of the power supply into direct current voltage;
the first power conversion unit is used for converting the direct-current voltage into a first power supply voltage;
the second power conversion unit is used for converting the direct current voltage into a second power supply voltage.
3. The backlight constant current control circuit according to claim 1, wherein the voltage conversion module comprises a resonant filtering unit and a feedback voltage stabilization unit, an input terminal of the resonant filtering unit is connected to output terminals of the power management module and the feedback voltage stabilization unit, an output terminal of the resonant filtering unit is connected to input terminals of the constant current driving module and the feedback voltage stabilization unit, and an input terminal of the feedback voltage stabilization unit is further connected to the constant current driving module;
the constant current driving module is also used for receiving a first feedback voltage of the backlight module and generating a feedback signal;
the feedback voltage stabilizing unit is used for outputting a second feedback voltage according to the backlight module voltage and the feedback signal;
and the resonance filtering unit is used for sequentially carrying out resonance processing, voltage transformation processing and rectification filtering processing on the first power supply voltage according to the second feedback voltage to obtain backlight module voltage.
4. The backlight constant-current control circuit according to claim 3, wherein the resonance filter unit includes a first LLC resonance circuit, a voltage transformation circuit, and a first rectification filter circuit;
the first LLC resonant circuit comprises a field effect transistor Q1, a field effect transistor Q2 and a resonant controller U1;
the drain of the field effect transistor Q1 is connected to the positive electrodes of the power management module and the filter capacitor C1, the negative electrode of the filter capacitor C1 is grounded, the gate of the field effect transistor Q1 is connected to the first pin of the resonant controller U1 through a resistor R1, the source is connected to the second pin of the resonant controller U1 and the drain of the field effect transistor Q2 through a resistor R2, the gate is connected to the third pin of the resonant controller U1 through a resistor R2, the source is connected to the transformer circuit through a capacitor C2, the source of the field effect transistor Q2 is also grounded, the fourth pin of the resonant controller U1 is connected to the transformer circuit through a capacitor C3, the fifth pin of the resonant controller U1 is connected to the positive electrode of the filter capacitor C4 and the negative electrode of the diode D1, the negative electrode of the filter capacitor C4 is grounded, and the positive electrode of the diode D1 is connected to the transformer circuit, and a sixth pin of the resonance controller U1 is connected with the feedback voltage stabilizing unit.
5. The backlight constant-current control circuit according to claim 4, wherein the voltage transformation circuit includes a transformer T1;
the first input end of the transformer T1 is connected with the source electrode of the field effect transistor Q1, the second input end is connected with one end of the capacitor C2 close to the transformer T1 and one end of the capacitor C3 close to the transformer T1 respectively, the third input end is connected with the anode of the diode D1, the fourth input end is grounded, and the output end is connected with the first rectifying and filtering circuit respectively.
6. The backlight constant-current control circuit as claimed in claim 5, wherein the first rectifying and smoothing circuit includes a diode D2, a diode D3, a diode D4 and a diode D5;
the anode of the diode D2 is connected to the first output terminal of the transformer T1, the anode of the diode D3 is connected to the second output terminal of the transformer T1, the cathode of the diode D2 is connected to the cathode of the diode D3, and is respectively connected with the positive electrode of the filter capacitor C5, the feedback voltage-stabilizing unit and the backlight module, the first grounding end of the transformer T1 is connected with the negative electrode of the filter capacitor C5, and is grounded, the anode of the diode D4 is connected with the third output end of the transformer T1, the anode of the diode D5 is connected to the fourth output terminal of the transformer T1, the cathode of the diode D4 is connected to the cathode of the diode D5, and the second ground terminal of the transformer T1 is connected to the negative electrode of the filter capacitor C6 and is grounded.
7. The backlight constant current control circuit according to claim 1, wherein the constant current driving module comprises a dc power supply unit, a micro control unit and a backlight control unit respectively connected to the dc power supply unit, the dc power supply unit is connected to the voltage conversion module, the micro control unit is further connected to the backlight control unit and the motherboard module respectively, and the backlight control unit is connected to the backlight module;
the voltage conversion module is further used for converting the first power supply voltage into a constant current driving voltage;
the direct current power supply unit is used for converting the constant current driving voltage into a third power supply voltage and a fourth power supply voltage when receiving an enabling signal sent by the mainboard module, and respectively supplying power to the micro control unit and the backlight control unit;
the micro control unit is used for working according to the third power supply voltage, analyzing the backlight driving signal and outputting a micro control signal;
and the backlight control unit is used for working according to the fourth power supply voltage and outputting the voltage of the backlight module to the backlight module when receiving the micro control signal.
8. The backlight constant current control circuit according to claim 1, further comprising a logic board module connected to the main board module;
the mainboard module is also used for generating a low-voltage differential signal;
and the logic board module is used for carrying out time sequence control on the low-voltage differential signals, outputting row and column driving signals and controlling the liquid crystal screen to work.
9. The backlight constant current control circuit according to claim 1, further comprising a sound generation module connected to the motherboard module;
the power supply management module is also used for converting the output voltage of the power supply into the power amplifier voltage of the mainboard;
the mainboard module is also used for outputting a sound production control signal according to the mainboard power amplifier voltage and controlling the work of the sound production module.
10. A television set, the television set comprising:
the backlight constant current control circuit according to any one of claims 1 to 9;
the backlight module and the liquid crystal screen are respectively connected with the backlight constant current control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210390437.5A CN114664242A (en) | 2022-04-14 | 2022-04-14 | Backlight constant-current control circuit and television |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210390437.5A CN114664242A (en) | 2022-04-14 | 2022-04-14 | Backlight constant-current control circuit and television |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114664242A true CN114664242A (en) | 2022-06-24 |
Family
ID=82036156
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210390437.5A Pending CN114664242A (en) | 2022-04-14 | 2022-04-14 | Backlight constant-current control circuit and television |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114664242A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204423880U (en) * | 2014-08-26 | 2015-06-24 | 康佳集团股份有限公司 | A kind of LED backlight drive circuit of liquid crystal TV set |
| CN109547721A (en) * | 2018-12-25 | 2019-03-29 | 深圳创维－Rgb电子有限公司 | A kind of TV power supply driving device and television set |
| CN111669528A (en) * | 2020-05-11 | 2020-09-15 | 深圳创维－Rgb电子有限公司 | OLED driving power supply and OLED television |
| CN112019783A (en) * | 2020-08-11 | 2020-12-01 | 深圳创维－Rgb电子有限公司 | Television power supply and split type television |
| US20210210008A1 (en) * | 2018-09-07 | 2021-07-08 | Shenzhen Skyworth-Rgb Electronic Co., Ltd | Oled drive power supply and oled television |
| CN214591684U (en) * | 2021-03-17 | 2021-11-02 | 深圳创维－Rgb电子有限公司 | Split television power supply circuit and split television |
| CN214752884U (en) * | 2021-02-24 | 2021-11-16 | 广州视源电子科技股份有限公司 | Circuit board and display screen |
-
2022
- 2022-04-14 CN CN202210390437.5A patent/CN114664242A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204423880U (en) * | 2014-08-26 | 2015-06-24 | 康佳集团股份有限公司 | A kind of LED backlight drive circuit of liquid crystal TV set |
| US20210210008A1 (en) * | 2018-09-07 | 2021-07-08 | Shenzhen Skyworth-Rgb Electronic Co., Ltd | Oled drive power supply and oled television |
| CN109547721A (en) * | 2018-12-25 | 2019-03-29 | 深圳创维－Rgb电子有限公司 | A kind of TV power supply driving device and television set |
| CN111669528A (en) * | 2020-05-11 | 2020-09-15 | 深圳创维－Rgb电子有限公司 | OLED driving power supply and OLED television |
| CN112019783A (en) * | 2020-08-11 | 2020-12-01 | 深圳创维－Rgb电子有限公司 | Television power supply and split type television |
| CN214752884U (en) * | 2021-02-24 | 2021-11-16 | 广州视源电子科技股份有限公司 | Circuit board and display screen |
| CN214591684U (en) * | 2021-03-17 | 2021-11-02 | 深圳创维－Rgb电子有限公司 | Split television power supply circuit and split television |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1402310B1 (en) | Apparatus for supplying power and liquid crystal display having the same | |
| US8179053B2 (en) | Power supply for an LCD display | |
| CN102523406B (en) | Power circuit structure and LED liquid crystal television | |
| US8625310B2 (en) | Method of supplying power, power supply apparatus for performing the method and display apparatus having the apparatus | |
| CN107464533A (en) | A kind of constant-current drive circuit and television set | |
| JP2007508799A (en) | Power converter | |
| CN103065583A (en) | Led driving apparatus, method for driving led, and display apparatus thereof | |
| KR101026806B1 (en) | Display device, driving device of light source for display device and dc-dc converter | |
| EP3934239A1 (en) | Power supply control circuit and display device | |
| CN101409972A (en) | Driver system and method for a plurality of cold cathode fluorescent lamp and/or outer electrode florescent lamp | |
| US20070216672A1 (en) | Power driving system and liquid crystal display using same | |
| CN112019783B (en) | Television power supply and split type television | |
| US7888824B2 (en) | Independent power supply module for LCD | |
| CN114664242A (en) | Backlight constant-current control circuit and television | |
| US20080048524A1 (en) | Piezoelectric power supply | |
| CN201383895Y (en) | Power source supply device | |
| WO2008064594A1 (en) | A power supply device | |
| KR20110048309A (en) | Llc resonant converter and display device | |
| CN111724747B (en) | Display device and power supply starting method | |
| US20050242751A1 (en) | Inverter circuit with a power factor corrector | |
| CN101826803B (en) | Independent power supply module of liquid crystal display | |
| CN217690461U (en) | Multi-partition independent dimming Mini LED backlight driving device | |
| WO2018192077A1 (en) | Television power source | |
| WO2023109168A1 (en) | Display device and display control method | |
| CN114783384B (en) | Constant current driving circuit and display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |