CN112785971B - Display device and negative-pressure step power supply circuit - Google Patents
Display device and negative-pressure step power supply circuit Download PDFInfo
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- CN112785971B CN112785971B CN202110138504.XA CN202110138504A CN112785971B CN 112785971 B CN112785971 B CN 112785971B CN 202110138504 A CN202110138504 A CN 202110138504A CN 112785971 B CN112785971 B CN 112785971B
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- 238000006243 chemical reaction Methods 0.000 claims abstract description 28
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- 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]
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
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- Circuit Arrangement For Electric Light Sources In General (AREA)
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Abstract
The application provides a display device and negative pressure ladder power supply circuit, through positive first voltage and the second voltage of negative going, be a plurality of parallel connection's voltage conversion circuit and LED drive assembly power supply simultaneously, thereby under the condition that a plurality of voltage conversion circuit can be parallelly connected, provide the required electric current of multichannel LED lamp strip by a plurality of voltage conversion circuit separately to the LED drive assembly who connects, and then can realize the ladder power supply through the circuit structure that the cost is lower, circuit structure complexity is lower.
Description
The present application claims priority from the chinese patent application filed on 18/03/2020, having application number 202010192086.8 and entitled "display device and power supply circuit", which is incorporated herein by reference in its entirety.
Technical Field
The application relates to the technical field of electronics, in particular to a display device and a negative-pressure step power supply circuit.
Background
With the development of electronic technology, the integration level of electronic equipment including display devices such as televisions is higher and higher, and thus higher and higher requirements are put on the power supply of the display devices. At present, after most display devices receive commercial power alternating current through plugs, a special power supply circuit is adopted to convert the alternating current into direct current, transform the alternating current and the like, and then the power is supplied to loads in the display devices.
In the related art, a power supply circuit for implementing a step power supply includes at least the following modules: the circuit comprises a rectifier bridge, a Power Factor Correction (PFC) module and a resonance conversion circuit (LLC) module. Meanwhile, a plurality of LED driving assemblies are further arranged in the power supply circuit, each LED driving assembly is used for supplying power to the connected multipath LED lamp strips, the secondary winding of the LLC module also supplies power to the LED driving assemblies through a voltage adjusting module (such as a buck circuit or a boost circuit), and the voltage adjusting module can adjust the voltage output to the LED driving assemblies according to the feedback signals of the LED driving assemblies, so that the LED driving assemblies can drive the connected multipath LED lamp strips to work at rated current.
By adopting the prior art, because the plurality of LED driving assemblies and the connected voltage adjusting modules can not be used in parallel, the technical problem of realizing step power supply by adding windings or diodes in the LLC module is solved, and the structure of the power supply circuit is complicated.
Disclosure of Invention
The application provides a display device and a negative-pressure stepped power supply circuit, which are used for simplifying the circuit structure of the power supply circuit.
The application provides a display device, including: a display screen configured to display an image screen; a plurality of LED drive assemblies, each LED drive assembly for powering a connected multi-channel Light Emitting Diode (LED) light bar configured to illuminate the display screen; a power supply circuit configured to supply power to the plurality of LED driving components; wherein the power supply circuit is specifically configured to generate a first voltage and a second voltage and to simultaneously power the plurality of LED drive components via the first voltage and the second voltage.
The present application further provides a negative voltage step power supply circuit configured to supply power to a plurality of LED driving components, comprising: an LLC primary winding configured to receive an input voltage; the positive electrodes of the first LLC secondary windings are respectively connected with the positive electrodes of the LED driving components, and the negative electrodes of the first LLC secondary windings are grounded; the first LLC secondary winding is configured to output the first voltage to the anodes of the plurality of LED drive components after converting the input voltage to the first voltage; the negative electrode of the first LLC secondary winding is grounded; the anode of the second LLC secondary winding is grounded, and the cathodes of the second LLC secondary windings are respectively connected with the cathodes of the LED driving assemblies; the second LLC secondary winding is configured to output a second voltage to the anodes of the plurality of LED drive components after converting the input voltage to the second voltage; the anodes of the secondary windings of the first LLC are connected with the anodes of the corresponding LED driving components through the voltage adjusting modules; the LED driving component is configured to send a feedback signal to the voltage adjusting module according to the working voltage of the connected multiple paths of LED lamp bars; the voltage adjusting module is configured to adjust the first voltage output to the multiple paths of LED driving components according to the feedback signal. Each LED driving component is connected with the corresponding voltage adjusting module through one feedback circuit; the feedback circuit is configured to receive a first feedback signal output by the LED driving component, convert the first feedback signal into a second feedback signal, and output the second feedback signal to the voltage adjusting module; wherein the first feedback signal and the second feedback signal differ in reference ground level.
In summary, the application provides a display device and negative voltage ladder power supply circuit, through positive first voltage and negative second voltage, be the power supply of a plurality of parallel connection's voltage conversion circuit and LED drive assembly simultaneously, thereby under the condition that a plurality of voltage conversion circuit can be parallelly connected, provide the required electric current of multichannel LED lamp strip by a plurality of voltage conversion circuit separately to the LED drive assembly who connects, and then can realize the ladder power supply through the circuit structure that the cost is lower, the circuit structure complexity is lower.
Drawings
In order to more clearly illustrate the embodiments of the present application or technical solutions of the related art, the drawings required to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
FIG. 1 is a schematic diagram of a display device with an independent power board;
FIG. 2 is a schematic diagram illustrating a connection relationship between a power board and a load of the display device;
FIG. 3 is a schematic diagram of a power architecture of a television;
FIG. 4 is a schematic diagram of a power supply circuit on a power board of a display device;
FIG. 5 is a schematic diagram of a power supply circuit of another display device;
FIG. 6 is a schematic diagram of a power supply circuit of another display device;
FIG. 7 is a schematic view of a display device provided herein;
fig. 8 is a schematic structural diagram of an embodiment of a feedback circuit provided in the present application;
fig. 9 is a schematic circuit diagram of a feedback circuit provided in the present application;
fig. 10 is a schematic structural diagram of another embodiment of a feedback circuit provided in the present application;
fig. 11 is a schematic diagram of an embodiment of a circuit structure of a feedback circuit provided in the present application;
fig. 12 is a schematic diagram of another embodiment of a circuit structure of a feedback circuit provided in the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, 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 application.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The following first describes a scenario in which the present application is applied and problems that may occur with reference to the drawings. As the demand for obtaining information is continuously increasing, various types of display devices, such as computers, televisions, projectors, and the like, are being developed. The power supply circuit is one of the most important circuit structures in the display device, and the power supply circuit can provide electric energy for the display device, so that the display device can normally operate. Some display devices are provided with independent power panels, and some display devices combine the power panels and the main board into a whole.
Taking a display device provided with an independent power board as an example, a structure of the display device is described, referring to fig. 1, fig. 1 is a schematic structural diagram of the display device provided with the independent power board, and as shown in fig. 1, the display device includes a display panel 1, a backlight assembly 2, a main board 3, a power board 4, a rear case 5 and a base 6. The display panel 1 is used for presenting pictures for users; the backlight assembly 2 is located below the display panel 1, usually some optical assemblies, and is used for supplying sufficient light sources with uniform brightness and distribution, so that the display panel 1 can normally display images, the backlight assembly 2 further includes a back plate 20, the main board 3 and the power board 4 are arranged on the back plate 20, usually some convex hull structures are formed by punching on the back plate 20, and the main board 3 and the power board 4 are fixed on the convex hulls through screws or hooks; the rear shell 5 is covered on the panel 1 to hide the parts of the display device such as the backlight assembly 2, the main board 3 and the power panel 4, and the like, thereby achieving the effect of beautiful appearance; and a base 6 for supporting the display device.
In some embodiments, fig. 2 is a schematic diagram of a connection relationship between a power board and a load of a display device, as shown in fig. 2, the power board 4 includes an input terminal 41 and an output terminal 42 (a first output terminal 421, a second output terminal 422, and a third output terminal 423 are shown in the figure), where the input terminal 41 is connected to a commercial power, the output terminal 42 is connected to a load in the display device, for example, the first output terminal 421 is connected to an LED light bar for lighting a display screen, the second output terminal 422 is connected to an audio, and the third output terminal 423 is connected to a main board. The power board 4 needs to convert ac power into dc power required by the load, and the dc power generally has different voltage specifications, such as 18V for sound, 12V for panel, etc.
In some embodiments, a power architecture of a display device is described by taking a television as an example, and fig. 3 is a schematic diagram of the power architecture of the television, as shown in fig. 3, the power board may specifically include: rectifier bridge, Power Factor Correction (PFC) module and resonant converter (LLC) module, including synchronous rectifier circuit (not shown in fig. 3) in the LLC module, PFC module is connected with the LLC module, and the LLC module is connected the load.
The rectifier bridge is used for rectifying the input commercial power alternating current and inputting a full-wave signal to the PFC module. An Electromagnetic Interference (EMI) filter (not shown in fig. 3) may be connected before the ac power is input into the PFC module to perform high frequency filtering on the input ac power.
The PFC module may include a PFC inductor, a switching power device, and a PFC control chip, and mainly performs power factor correction on an input ac power source to output a stable dc bus voltage (e.g., 380V) to the LLC module. The PFC module can effectively improve the power factor of a power supply and ensure the same phase of voltage and current. Alternatively, in some embodiments, the PFC module may not be provided in the power architecture shown in fig. 3.
The LLC module may adopt a double-MOS tube LLC resonant conversion circuit, and the synchronous rectification circuit is usually arranged in the LLC module, and the synchronous rectification circuit mainly may include a transformer, a controller, two MOS tubes, and a diode. In addition, the LLC module may further include a Pulse Frequency Modulation (PFM) circuit, a capacitor, an inductor, and other components. The LLC module may specifically step down or step up the dc bus voltage input by the PFC module, and output a constant voltage to the load. In general, LLC modules are capable of outputting a variety of different voltages to meet the demands of different loads. Alternatively, in other embodiments, the LLC module shown in fig. 3 may be replaced by a flyback voltage conversion module, which steps down or steps up the voltage and outputs a constant voltage to the load
More specifically, also taking the display device as a television as an example, fig. 4 shows a schematic structural diagram of a power supply circuit on a power board of the display device, wherein after commercial power alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit from the plug 11 sequentially passes through the filtering and rectifying module 12 (rectifying bridge), the PFC module 13 and the LLC module 14, power is supplied to the main board 15, the LED driving component 16 and other loads of the display device, which are not shown in fig. 4. The first secondary winding in the LLC module provides 12V voltage to the motherboard, the second secondary winding provides 18V voltage to the motherboard, and the third secondary winding provides voltage to the LED driving component 16, so that the LED driving component 16 can supply power to the multiple paths of LED light bars connected thereto, so that the multiple paths of LED light bars illuminate the display screen of the television, and the LED components in the LED light bars need to operate with a certain range of voltage drop to achieve their rated current, for example, the multiple paths of LED light bars are 16 paths of LED light bars, and under the condition that each light bar includes 9 LED components, under the condition of 120mA, the voltage range required by the multiple paths of LED light bars is 51.3V-58.5V, and the total current is 1.92A. The power supply circuit is further provided with a voltage adjusting module 17, so that the LED driving assembly 16 can also detect the working voltages of the multiple paths of LED light bars and send feedback signals to the voltage adjusting module 17 according to the voltage changes, so that the voltage adjusting module 17 can adjust the voltage output to the LED driving assembly 16 according to the feedback signals, and further, the stability of the working currents of the multiple paths of LED light bars is maintained.
It should be noted that, as shown in fig. 4, taking one LED driving component 16 as an example to provide voltages for multiple LED light bars, in a specific implementation, multiple driving components 16 may be further provided to provide voltages for different multiple LED light bars respectively. For example, fig. 5 is a schematic structural diagram of another power supply circuit of a display device, where an LLC module 14 can supply power to two LED driving assemblies 16, which are respectively denoted as an LED driving assembly 161 and an LED driving assembly 162, so that the LED driving assembly 161 and the LED driving assembly 162 can respectively supply power to multiple LED light bars connected to each other, and the LLC module 14 is connected to the LED driving assembly 161 through a voltage adjusting module 171 and connected to the LED driving assembly 162 through a voltage adjusting module 172, so that the voltage adjusting module 171 can adjust the voltage provided to the LED driving assembly 161, and the voltage adjusting module 172 can adjust the voltage provided to the LED driving assembly 162.
In addition, in the embodiment shown in fig. 4, since the voltage stress of the voltage adjustment module provided for the multiple paths of LED light bars in the power supply circuit is large, the voltage withstanding values of the components such as the switching tube and the capacitor in the voltage adjustment module are high, and thus the area of the PCB where the power supply circuit is located is large, and finally the cost of the power supply circuit is increased. Therefore, in the embodiment shown in fig. 5, the voltage range output by the two different secondary windings can be flexibly set, so that the voltage adjustment module only needs to adjust the voltage output by one of the secondary windings, and thus the multiple LED light bars are supplied with power by the fixed voltage and the variable voltage output by the two secondary windings, which may also be referred to as "step power supply," so as to reduce the requirement on the withstand voltage of the components such as the switching tube and the capacitor in the voltage adjustment module.
Specifically, as shown in fig. 5, after the LLC module 14 of the power supply circuit provided in this embodiment receives the dc voltage sent by the PFC module 13 through the primary winding 141, different secondary windings output different voltages according to the input voltage received by the primary winding 141, for example, the secondary winding 143 provides 12V of voltage to the main board 15 according to the voltage of the primary winding 141, and the secondary winding 142 provides 18V of voltage to the main board 15 according to the voltage of the primary winding 141. Meanwhile, two different LLC secondary windings are arranged in the LLC module 14 to supply power to multiple LED light bars together, where a varying voltage output by the anode of the secondary winding 144 is recorded as a first voltage, a fixed voltage output by the anode of the secondary winding 145 is recorded as a second voltage, the anode of the secondary winding 145 is connected to the cathode of the secondary winding 144, and the cathode of the secondary winding 145 is grounded. The anode of the secondary winding 144 may be connected to the LED driving assembly 161 through the voltage adjusting module 171, so as to provide a voltage, which is the sum of the second voltage and the first voltage, to the driving assembly 161, so that the LED driving assembly 161 supplies power to the multiple LED light bars connected thereto; the positive pole of the secondary winding 144 may also be connected to the LED driving assembly 162 through the voltage adjusting module 172, so as to provide the LED driving assembly 162 with a voltage that is the sum of the second voltage and the first voltage, so that the LED driving assembly 162 supplies power to the multiple LED light bars connected thereto.
At this time, the second voltage output by the secondary winding 145 is equivalent to a fixed voltage which is not changed, and the first voltage output by the secondary winding 144 is equivalent to a changed voltage, so that an adjustable first voltage output is added on the basis of the fixed second voltage, and the fixed voltage and the changed voltage output by the two secondary windings jointly supply power to the multiple paths of LED light bars, which can also be referred to as "step power supply". In some embodiments, the first voltage output by secondary winding 144 is less than the second voltage output by secondary winding 145.
For example, if the multi-path LED driving in fig. 5 is 16 LED light bars according to the sum of the first voltage and the second voltage, when each light bar includes 9 LED assemblies, under the condition of 120mA, the voltage range required by the multi-path LED light bar is 51.3V to 58.5V, and the total current is 1.92A. For the step power supply implemented by the buck structure, the fixed second voltage outputted by the secondary winding 145 may be set to 48V, the first voltage outputted by the secondary winding 144 may be set to 12V, and the voltage range adjusted by the voltage adjusting module may be set to 3.3V to 10.5V. At this time, the DC-DC parameters for the buck topology are: the input voltage is 12V, the output voltage range is 3.3V-10.5V, and the output current is 1.92A. For the step power supply implemented by adopting the boost topology, the second voltage can be set to 40V, the first voltage floating output can be set to 10V, and the DC-DC parameters for the boost topology are as follows: the input voltage is 12V, the output voltage range is 11.3V-18.5V, and the output current is 1.92A. The buck topology and the boost topology can be selected according to engineering requirements, for example, the buck topology structure has the advantage of low cost; while the boost topology has the advantage of a wider output voltage range.
In the embodiment shown in fig. 5, the multiple paths of LED driving components may also send a feedback signal to the voltage adjustment module connected thereto according to the real-time current of the multiple paths of LED light bars when supplying power to the multiple paths of LED light bars, so that the voltage adjustment module adjusts the first voltage according to the feedback signal, thereby implementing timely and effective adjustment of the voltage by the voltage adjustment module.
Two connection relations including power supply and feedback at least are arranged between the voltage regulation module and the multipath LED driving components, but when the voltage regulation module is subjected to DC-DC regulation, the grounding point of the voltage regulation module is connected with the output end of the secondary winding 144, the voltage value of the voltage regulation module is not 0V of grounding, which is equivalent to regulating the output voltage of the secondary winding 144 on the basis of the output voltage value of the secondary winding 145, therefore, feedback signals sent to the voltage regulation module by the multipath LED driving components need to pass through the optocoupler, so that the feedback signals are subjected to floating ground voltage conversion through the optocoupler, feedback signals sent to the voltage regulation module by the multipath LED driving components are subjected to optocoupler isolation, the floating ground voltage of the voltage regulation modules on two sides of the optocoupler and the actual ground voltage of the multipath LED driving components are unified, and mutual influence of the floating ground voltage and the actual ground voltage of the multipath LED driving components is prevented.
However, since the cost of the voltage adjusting module (DC-DC) increases with the increase of the current, a more economical way is to supply power to the driving components of the LED light bar by a plurality of low-current voltage adjusting modules respectively arranged in the step power supply circuit as shown in fig. 5, but in fig. 5, even if the current of each voltage adjusting module is small, after all the voltage adjusting modules are connected with the output end of the secondary winding 144, each voltage adjusting module is grounded, so that the secondary winding 144 needs to provide current to all the voltage adjusting modules through one output port thereof, so that all the voltage adjusting modules are equivalent to being connected in series with the output end of the secondary winding 144, resulting in a large current output last time by the secondary winding 144, and then a full-wave rectification or bidirectional half-wave rectification diode needs to be arranged on the secondary winding to realize the step power supply, the overall complexity of the circuit is improved.
Similarly, fig. 6 is a schematic structural diagram of a power supply circuit of another display device, and fig. 6 illustrates another implementation manner in which the power supply circuit uses step power supply, where taking the power supply circuit as an example to supply power to two LED light bars (i) and (ii), three different LLC secondary windings are arranged in the LLC module 14 to supply power to the LED light bars (i) and (ii), including: secondary winding 146, secondary windings 144 and 145; the negative electrode a of the secondary winding 146 is grounded, the positive electrode b is connected with the LED driving component 161 of the LED light bar (i) through the voltage adjusting module 171, and is connected with the driving component 162 of the LED light bar (ii) through the voltage adjusting module 172, the negative electrode c of the secondary winding 145 is connected with the voltage adjusting module 171, the positive electrode d is connected with the LED driving component 161 of the LED light bar (i), the negative electrode e of the secondary winding 144 is connected with the voltage adjusting module 172, and the positive electrode f is connected with the LED driving component 162 of the LED light bar (ii).
Then, for the voltage adjustment module 171 implemented based on the boost circuit and connected to the LED light bar (r), the voltage adjustment module 171 may be configured to adjust the voltage output by the LLC secondary winding 146, and record that the adjusted voltage is the third voltage, and the voltage adjustment module 171 may send the third voltage to the input end c of the secondary winding 145. The secondary winding 145 is configured to output a second voltage, so that an output end d of the secondary winding 145 can send the sum of the third voltage and the second voltage to the LED light bar (i) for power supply. Similarly, for the LED light bar —, the voltage adjustment module 172 implemented based on the boost circuit connected to the LED light bar —, may be configured to adjust the voltage output by the secondary winding 146, and note that the adjusted voltage is a fourth voltage, the voltage adjustment module 172 may send the fourth voltage to the input end e of the secondary winding 144, and the secondary winding 144 is configured to output a fifth voltage, so that the output end f of the secondary winding 144 can send the sum of the fourth voltage and the fifth voltage to the LED light bar — (ii) for power supply.
At this time, the second voltage output by the secondary winding 145 and the fifth voltage output by the secondary winding 144 correspond to a fixed voltage that does not change, and the voltage output by the secondary winding 146 corresponds to a changed voltage, so that an adjustable changed voltage output is added on the basis of the fixed voltage, and the fixed voltage and the changed voltage output by the two secondary windings together supply power to the LED light bar, which may also be referred to as "step power supply". In particular, each path of LED light bar can be connected with an independent voltage adjusting module and an independent LLC secondary winding, so that each voltage adjusting module can more effectively adjust the voltage of the connected LED light bar.
The power supply circuit shown in fig. 6 can also supply power to two paths of LED light bars through two secondary windings respectively, at this time, the voltage adjusting modules are connected to different secondary windings respectively, and the voltage adjusting modules are neither in parallel connection nor in series connection, it can be understood that when an LED light bar to be supplied with power is added to the power supply circuit, a voltage adjusting module of an LED light bar needs to be added, and accordingly, a winding is additionally added to the LLC module to realize step power supply, which is equivalent to adding a new power supply branch, when the number of LED light bars is large, the number of pins and the number of diodes of the LLC module are greatly increased, so that the circuit structure becomes more complex.
In summary, in the power supply circuits of the display devices shown in fig. 5 to 6, there is a technical problem that the voltage conversion circuits cannot be used in parallel, so that a winding or a diode needs to be added in the LLC module to implement step power supply, which results in a complicated structure of the power supply circuit.
Therefore, in some embodiments, the present application further provides a display device and a negative voltage ladder power supply circuit, such that the power supply circuit only needs to set one LLC secondary winding in an LLC module to provide a negative voltage, and combine another LLC secondary winding to provide a positive first voltage, and two LLC secondary windings can simultaneously provide voltages for driving components of multiple LED light bars connected to multiple voltage conversion circuits in a parallel connection manner, so that multiple voltage conversion circuits can connect outputs of the same LLC secondary winding and connect to the same negative voltage ground point, thereby implementing parallel connection of multiple voltage conversion circuits in the power supply circuit, and the LLC secondary windings simultaneously provide power for multiple LED drivers, and at this time, multiple voltage conversion circuits can respectively provide currents required by multiple LED light bars to the connected LED driving components, without completely depending on one secondary winding to provide all large currents, the current output by the secondary winding is not too large, and the step power supply can be realized without arranging more secondary windings, so that the circuit structure of the power supply circuit can be simplified.
The technical solution of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
Fig. 7 is a schematic diagram of a display device provided in the present application, which may be a specific circuit implementation of the display device shown in fig. 7 in any one of fig. 1 to 4, and fig. 7 only shows a portion of the display device relevant to the present application, and other portions of the display device not shown in fig. 7 are not limited.
The power supply circuit provided in the display device shown in fig. 7 may supply power to a plurality of LED driving components in the display device. Taking the LED driving components 161 and 162 as an example in fig. 7, each LED driving component can be used to supply power to multiple LED light bars connected thereto, and the multiple LED light bars connected to all the LED driving components can be used together to illuminate a display screen of the display device.
In the display device shown in fig. 7, the power supply circuit includes: the plug 11, the smoothing and rectifying module 12, the PFC module 13 and the LLC module 14 may be implemented in other possible ways, and the power supply circuit may further include all or part of the above modules according to different working conditions. Then, when the power supply circuit obtains the commercial power alternating current (100V-240V, 50-60Hz) from the plug 11, the commercial power alternating current is processed sequentially through the filtering rectification module 12 (rectifier bridge), the PFC module 13 and the LLC module 14, and then the direct currents with different voltages are obtained to supply power to the load. For example, after the LLC module 14 of the power supply circuit receives the dc input voltage sent by the PFC module 13 through the primary winding 141, the secondary winding 143 provides a voltage of 12V to the motherboard 18 according to the voltage of the primary winding 141, and the secondary winding 142 provides a voltage of 18V to the motherboard 18 according to the voltage of the primary winding 141. The voltages of 12V and 18V are only examples, and the secondary windings 142 and 143 may also provide voltages of other voltage values to the main board 18.
In the LLC module 14 of the power supply circuit provided in this embodiment, two different secondary windings are used to simultaneously supply power to a plurality of driving components connected in parallel, which are denoted as a first LLC secondary winding and a second LLC secondary winding, where the first LLC secondary winding is used to provide a positive first voltage to the plurality of LED driving components, and the second LLC secondary winding is used to provide a negative second voltage to the plurality of LED driving components.
In some embodiments, the first LLC secondary winding providing a forward first voltage may be the secondary winding 143 (with the first voltage being 12V) and the secondary winding 142 (with the first voltage being 18V). In the example shown in fig. 7, the first LLC secondary winding is taken as the secondary winding 143 as an example, the anodes of the first LLC secondary windings are respectively connected to the anodes of the plurality of LED driving components, that is, the anode of the first LLC secondary winding 143, and are simultaneously connected to the anode of the LED driving component 161 and the anode of the LED driving component 162, and the cathode of the first LLC secondary winding 143 is grounded, that is, the first LLC secondary winding takes the ground as the reference level.
The second LLC secondary winding 144 in the LLC module 14 may provide the negative second voltage, wherein a positive electrode a of the second LLC secondary winding is grounded, and negative electrodes b of the second LLC secondary winding are respectively connected to negative electrodes of the LED driving assemblies, that is, the negative electrode of the second LLC secondary winding is simultaneously connected to the negative electrodes of the LED driving assembly 161 and the negative electrode of the LED driving assembly 162. Then the negative pole b of the second LLC secondary winding 144 now amounts to being able to provide a second voltage in the negative direction, since the second LLC secondary winding 144 is available to convert the input voltage of the LLC primary winding 141 into the second voltage.
Meanwhile, in the embodiment shown in fig. 7, the power supply circuit further includes a plurality of voltage adjustment modules, each LED driving component is connected to a corresponding voltage adjustment module, each voltage adjustment module may be used to adjust the voltage output to the LED component, and the voltage adjustment module may be implemented by a buck or boost structure, or may be a DC-DC chip. For example, the first LLC secondary winding of the LLC module 14 is connected to the LED driver component 161 via the voltage regulation module 171 and to the LED driver component 162 via the voltage regulation module 172.
With reference to the first LLC secondary winding 143 and the second LLC secondary winding 144 of the LLC module 14 in the power supply circuit, the LED driving component 161 is taken as an example, when the primary winding 141 of the LLC module 14 receives the input voltage sent by the PFC module 13, the first LLC secondary winding 143 converts the input voltage into a first voltage (denoted as VOUT) and outputs the first voltage to the anode of the LED driving component 161 through the voltage adjustment module 171, and the second LLC secondary winding 144 converts the input voltage into a second voltage (denoted as (-VLED) and outputs the second voltage to the cathode of the LED driving component 161, at this time, for the LED driving component 161, the voltage on both sides is equal to the sum of the absolute values of the first voltage VOUT and the second voltage-VLED, where-VLED of the cathode is taken as a reference ground level. Because the second voltage-VLED output by the second LLC secondary winding 144 does not change and is recorded as "fixed voltage", the first voltage output by the first LLC secondary winding 143 can be adjusted by the voltage adjustment module 171 and is recorded as "variable voltage", so that the fixed voltage and the variable voltage output by the two secondary windings jointly supply power to the multiple LED light bars, thereby realizing step power supply.
In some embodiments, the first voltage VOUT output by the first LLC secondary winding 143 is less than the absolute value of the second voltage-VLED output by the second LLC secondary winding.
The LED driving component 161 can also determine the operating voltage of the LED light bar connected thereto, and send a feedback signal to the voltage adjusting module 171 when the operating voltage changes, so that the voltage adjusting module 171 adjusts the voltage provided to the LED driving component 161 according to the feedback signal, so that the LED driving component 161 can drive the LED light bar to maintain its rated normal operating current.
In summary, the power supply circuit provided in this embodiment can simultaneously supply power to the plurality of voltage conversion circuits and the LED driving component through the positive first voltage provided by the first LLC secondary winding and the negative second voltage provided by the second LLC secondary winding, so that at the positive output end of the plurality of voltage conversion circuits capable of the first LLC secondary winding, one end of the second LLC secondary winding providing-VLED is connected, thereby implementing parallel connection of the plurality of voltage conversion circuits in the power supply circuit, and the LLC secondary winding simultaneously supplies power to the plurality of LED drivers, at this time, the plurality of voltage conversion circuits can respectively provide currents required by the plurality of LED light bars to the connected LED driving component, compared with the embodiment shown in fig. 5, the current output by each secondary winding is not too large, and the cost of the voltage conversion circuits can be reduced, compared with the embodiment shown in fig. 6, and more secondary windings are not required to be arranged, and all the voltage conversion circuits can share the second LLC secondary winding, so that the present embodiment solves the problems in the embodiments shown in fig. 5 and 6, and can implement step power supply by using a circuit structure with low cost and low circuit structure complexity.
In some embodiments, in the embodiment shown in fig. 7, for each LED driving component and the voltage adjustment module to which the LED driving component is connected, since the reference ground level of the LED driving component is-VLED, which is different from the reference ground directly connected to the voltage adjustment module, the feedback signal generated by the constant current control chip in the LED driving component cannot be directly sent to the voltage adjustment module, so that the present application further provides a feedback circuit, which is disposed between each LED driving component and the voltage adjustment module in the embodiment shown in fig. 7, and is configured to receive the first feedback signal output by the LED driving component, convert the first feedback signal to obtain a second feedback signal corresponding to the voltage adjustment module, and finally send the second feedback signal to the voltage adjustment module.
Specifically, fig. 8 is a schematic structural diagram of an embodiment of a feedback circuit provided in the present application, and in the embodiment shown in fig. 8, a feedback circuit 20 disposed between the LED driving component 161 and the voltage adjusting module 171 in the power supply circuit of fig. 7 is taken as an example. The feedback circuit 20 includes: the LED driver circuit comprises a VI conversion circuit and a DC-DC voltage feedback circuit, wherein the VI conversion circuit is configured to convert a first feedback signal in the form of a voltage signal sent by the LED driver component 161 into a second feedback signal in the form of a current signal corresponding to the DC-DC voltage feedback circuit, and implement level conversion. The DC-DC voltage feedback circuit is configured to receive and send a second feedback signal to the voltage adjustment module 171.
Fig. 9 is a schematic circuit structure diagram of a feedback circuit provided in the present application, showing a specific circuit implementation manner of the structure shown in fig. 8, where the VI conversion circuit includes: the first input end (which can be a positive electrode) of the operational amplifier N1 is connected with the LED driving component 161, the second input end (which can be a negative electrode) of the operational amplifier N1 is connected with the first end of the transistor V1 and the first end of the first resistor R4, the output end of the operational amplifier N1 is connected with the control end of the transistor V1, and the second end of the first resistor R4 is connected with the negative electrode of the second LLC secondary winding, so that the reference ground level of the VI conversion circuit is-VLED of the negative electrode of the second LLC secondary winding.
The DC-DC feedback circuit includes: a second resistor R1, a third resistor R2, and a fourth resistor R3, wherein a first end of the second resistor R1 is connected to the output terminal VOUT of the voltage adjusting module 171, a second end of the second resistor R1 is connected to a first end of the third resistor R2, a first end of the fourth resistor R3, and a feedback input terminal of the voltage adjusting module 171, a second end of the fourth resistor R3 is connected to the second end of the transistor V1, and a second end of the third resistor R2 is grounded, so that the DC-DC feedback circuit is connected to the ground.
When the operational amplifier N1 receives the first feedback signal FB sent by the LED driving component 161, the V1 is controlled to be turned on, so that a current signal is generated from VOUT to ground and flows through the second resistor R1 and the fourth resistor R3 in the DC-DC voltage feedback circuit, and the current signal at the second end of the second resistor R1 can be used as a second feedback signal and input to the feedback input terminal of the voltage adjusting module 171, so that the voltage adjusting module 171 receives the second feedback signal and then adjusts the voltage VOUT output to the LED driving component 161.
However, in the embodiments shown in fig. 8 to 9, because the first LLC secondary winding providing a fixed voltage in the LLC module has voltage fluctuation of several kHz, the feedback speed completely depending on the feedback signal sent by the constant current control chip in the LED driving component is slow, which may cause high-frequency fluctuation of the voltage provided to the LED light bar, and further cause fluctuation of the operating current of the LED light bar.
Therefore, in order to overcome the problem of voltage fluctuation of the secondary winding, the present application also provides another feedback circuit. Fig. 10 is a schematic structural diagram of another embodiment of a feedback circuit provided in the present application, where the feedback circuit shown in fig. 10 includes: LED voltage feedback circuit 203, isolation circuit 204, and DC-DC voltage feedback circuit 201. The DC-DC voltage feedback circuit 201 is connected to a reference ground, the reference ground of the LED voltage feedback circuit remains the same as the LED driving component 161, and is connected to the negative electrode of the secondary winding of the second LLC, so that the reference ground level is-VLED, and the isolation circuit 204 is used to electrically isolate the LED voltage feedback circuit 203 and the DC-DC voltage feedback circuit 201 on both sides thereof. The LED voltage feedback circuit is configured to generate a first intermediate signal according to the first voltage VOUT and the first feedback signal, and send the first intermediate signal to the isolation circuit 204, and the isolation circuit converts the first intermediate signal of the second LED driving component 161 into a second intermediate signal and outputs the second intermediate signal to the DC-DC voltage feedback circuit 201, so that the DC-DC feedback circuit can generate a second feedback signal according to the second intermediate signal and send the second feedback signal to the voltage adjustment module, and the problem that the reference low levels of the circuits on both sides are different can be solved.
Fig. 11 is a schematic diagram of an embodiment of a circuit structure of the feedback circuit provided in the present application, showing a specific circuit implementation manner of the structure shown in fig. 10, wherein the isolation circuit 204 may be a switch transistor T1, and the switch transistor T1 may be a triode, a MOS transistor, or the like. The first end of the switching tube T1 is connected to the voltage output terminal VOUT of the voltage adjustment module 171, the second end is connected to the DC-DC voltage feedback circuit 201, and the control end is connected to the LED voltage feedback circuit 203, so that the switching tube T1 can be isolated by turning on and off the transmission signal under the control of the LED voltage feedback circuit 203.
The DC-DC voltage feedback circuit 201 includes: a second resistor R1, a third resistor R2 and a fourth resistor R3; a first end of the second resistor R1 is connected to the voltage output end of the voltage adjustment module 171, a second end of the second resistor R1 is connected to a first end of the third resistor R2, a first end of the fourth resistor R3 and the feedback input end of the voltage adjustment module 171, and a second end of the fourth resistor R3 is connected to a second end of the switch tube T1; the second terminal of the third resistor R is connected to ground, so that the DC-DC feedback circuit 201 is connected to ground. The DC-DC voltage feedback circuit 201 may implement feedback on VOUT alone, and then the R1 resistance of the second resistor should be set to be larger to satisfy that the DC-DC output voltage can reach the set maximum voltage output value, and the fourth resistor R3 may adjust the minimum output voltage value, or the resistance of the fourth resistor R3 may also be 0R.
In some embodiments, the DC-DC voltage feedback circuit 201 as shown in fig. 11 may further include: and the feedforward circuit is used for performing feedforward compensation on the whole DC-DC loop. The feedforward circuit includes a fifth resistor R11 and a second capacitor C1, wherein a first end of the fifth resistor R11 is connected to the voltage output terminal VOUT of the voltage adjustment module 171, and a second end of the fifth resistor R11 is connected to the feedback input terminal of the voltage adjustment module 171 through the second capacitor C11.
The LED voltage feedback circuit 203 includes: a reference voltage source N1, a first voltage dividing resistor (which may be one resistor, taking R7 and R8 as examples in fig. 11), a second voltage dividing resistor R9, a bias resistor R4, and a current limiting resistor R5; a first end R7 of the first voltage-dividing resistor is connected to the output terminal VOUT of the voltage adjustment module 171, a second end R8 of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor R9 and the control end of the reference voltage source N1, the first end of the reference voltage source N1 sequentially passes through the first end and the second end of the current-limiting resistor R5 and the first end and the second end of the bias resistor R4 and is connected to the output terminal VOUT of the voltage adjustment module 171, the first end of the bias resistor R4 and the second end of the current-limiting resistor R5 are connected to the control end of the switching tube T1, the second end of the reference voltage source N1 and the second end of the second voltage-dividing resistor R9 are respectively connected to the cathode of the second LLC secondary winding, so that the reference ground level of the LED voltage feedback circuit 203 is-VLED of the cathode of the second LLC secondary winding.
Wherein the reference voltage source N1 may be TL 431. The reference voltage source N1, the first voltage dividing resistor (R7 and R8) and the second voltage dividing resistor R9 in the LED voltage feedback circuit 203 can jointly realize feedback, and when VOUT varies, VOUT controls the on and off of the reference voltage source N1 while voltage division is performed by the first voltage dividing resistor and the second voltage dividing resistor. Meanwhile, the first feedback signal generated by the constant current control chip in the LED driving module 161 can also be directly sent to the control terminal of the reference voltage source N1 through the resistor R10. The bias resistor R4 is used to provide a bias current of the reference voltage source N1, and the current limiting resistor R5 is used to limit a current, when the overall voltage value of the LED voltage feedback circuit 203 is large, a voltage stabilizing circuit may be added between the output terminal VOUT of the voltage regulating module 171 and the reference voltage source N1, for example, the voltage stabilizing circuit includes: zener diode VZ 1. A voltage regulation circuit may be used to protect the reference voltage source N1.
In the circuit structure shown in fig. 11, the LED voltage feedback circuit can perform overall voltage feedback with the sum of the overall voltages (VOUT and VLED), so as to solve the influence of the voltage fluctuation of the first LLC secondary winding with fixed voltage on the voltage and the operating current of the LED light bar through the adjustment of the bandwidth output of the reference voltage source N1 in the LED feedback circuit.
Fig. 12 is a schematic diagram of another embodiment of the circuit structure of the feedback circuit provided in the present application, showing another specific circuit implementation manner of the structure shown in fig. 10, wherein the structure shown in fig. 12 is similar to that shown in fig. 11, except that the isolation circuit is replaced by the optical coupler O1 from the switching tube T1, and then the connection relationship in the LED voltage feedback circuit needs to be adaptively adjusted. The first end of the reference voltage source N1 is connected to the output terminal VOUT of the voltage adjustment module 171 through the bias resistor R4, the first end of the current-limiting resistor R5 is connected to the output terminal VOUT of the voltage adjustment module 171, the second end of the current-limiting resistor R5 is connected to the first input terminal of the optocoupler O1, the first end R8 of the first voltage-dividing resistor is connected to the second input terminal of the optocoupler O1 through the first capacitor C2, the first output terminal of the optocoupler O1 is connected to the output terminal VOUT of the voltage adjustment module 171, and the second output terminal of the optocoupler O1 is connected to the fourth resistor R3 in the DC-DC voltage feedback circuit 201.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A display device, comprising:
a display screen configured to display an image screen;
a plurality of LED drive assemblies, each LED drive assembly for powering a connected multi-channel Light Emitting Diode (LED) light bar configured to illuminate the display screen;
a power supply circuit configured to supply power to the plurality of LED driving components; wherein the power supply circuit is specifically configured to generate a first voltage and a second voltage and to simultaneously power the plurality of LED drive components by the first voltage and the second voltage;
the power supply circuit includes:
a first LLC secondary winding configured to provide a forward first voltage to the anodes of the plurality of LED drive components;
a second LLC secondary winding configured to provide a negative second voltage to a negative pole of the plurality of LED drive components.
2. The display device according to claim 1, wherein the power supply circuit comprises:
an LLC primary winding configured to receive an input voltage;
the positive electrodes of the first LLC secondary windings are respectively connected with the positive electrodes of the LED driving components, and the negative electrodes of the first LLC secondary windings are grounded; the first LLC secondary winding is specifically configured to output the first voltage to the anodes of the plurality of LED drive components after converting the input voltage to the first voltage;
the anode of the second LLC secondary winding is grounded, and the cathodes of the second LLC secondary windings are respectively connected with the cathodes of the LED driving assemblies; the second LLC secondary winding is specifically configured to output a second voltage to the cathodes of the plurality of LED drive components after converting the input voltage to the second voltage.
3. The display device according to claim 2, wherein the power supply circuit further comprises:
a plurality of voltage adjustment modules; the positive electrode of each first LLC secondary winding is connected with the positive electrode of the LED driving component through the voltage adjusting module;
the LED driving component is configured to send a feedback signal to the voltage adjusting module according to the working voltage of the connected multiple paths of LED lamp bars; the voltage adjusting module is configured to adjust the first voltage output to the plurality of LED driving components according to the feedback signal.
4. The display device according to claim 3, wherein the power supply circuit further comprises:
each LED driving component is connected with the corresponding voltage adjusting module through one feedback circuit;
the feedback circuit is configured to receive a first feedback signal output by the LED driving component, convert the first feedback signal into a second feedback signal, and output the second feedback signal to the voltage adjusting module; wherein the first feedback signal and the second feedback signal differ in reference ground level.
5. The display device according to claim 4, wherein the feedback circuit comprises:
the VI conversion circuit and the DC-DC voltage feedback circuit;
the VI conversion circuit is used for converting the first feedback signal in the form of a voltage signal into the second feedback signal in the form of a current signal and sending the second feedback signal to the DC-DC voltage feedback circuit;
the DC-DC voltage feedback circuit is used for receiving and sending the second feedback signal to the voltage adjusting module.
6. The display device according to claim 4, wherein the feedback circuit comprises:
the LED voltage feedback circuit, the isolation circuit and the DC-DC voltage feedback circuit;
the LED voltage feedback circuit is used for generating a first intermediate signal according to the first voltage and the first feedback signal;
the isolation circuit is used for receiving the first intermediate signal and generating an isolated second intermediate signal;
the DC-DC voltage feedback circuit is used for receiving the second intermediate signal, generating a second feedback signal according to the second intermediate signal, and sending the second feedback signal to the voltage adjusting module.
7. The display device according to claim 6,
the isolation circuit includes: a switching tube; alternatively, an optocoupler.
8. The display device according to claim 6 or 7, wherein the DC-DC voltage feedback circuit further comprises:
a feedforward circuit for providing feedforward compensation; the first end of the feedforward circuit is connected with the output end of the voltage adjusting module, and the second end of the feedforward circuit is connected with the feedback input end of the voltage adjusting module.
9. The display device according to claim 6 or 7, wherein the LED voltage feedback circuit further comprises:
and the voltage stabilizing circuit is arranged between the output end of the voltage adjusting module and the reference voltage source and is used for protecting the reference voltage source.
10. A negative voltage ladder power supply circuit configured to supply power to a plurality of LED drive assemblies, comprising:
an LLC primary winding configured to receive an input voltage;
the positive electrodes of the first LLC secondary windings are respectively connected with the positive electrodes of the LED driving components, and the negative electrodes of the first LLC secondary windings are grounded; the first LLC secondary winding is configured to output the first voltage to the anodes of the plurality of LED drive components after converting the input voltage to the first voltage;
the anode of the second LLC secondary winding is grounded, and the cathodes of the second LLC secondary windings are respectively connected with the cathodes of the LED driving assemblies; the second LLC secondary winding is configured to convert the input voltage to a second voltage and output the second voltage to the cathodes of the plurality of LED drive components;
the anodes of the secondary windings of the first LLC are connected with the anodes of the corresponding LED driving components through the voltage adjusting modules; the LED driving component is configured to send a feedback signal to the voltage adjusting module according to the working voltage of the connected multiple paths of LED lamp bars; the voltage adjusting module is configured to adjust the first voltage output to the plurality of LED driving components according to the feedback signal;
each LED driving component is connected with the corresponding voltage adjusting module through one feedback circuit; the feedback circuit is configured to receive a first feedback signal output by the LED driving component, convert the first feedback signal into a second feedback signal, and output the second feedback signal to the voltage adjusting module; wherein the first feedback signal and the second feedback signal differ in reference ground level.
Priority Applications (5)
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| PCT/CN2021/080257 WO2021185150A1 (en) | 2020-03-18 | 2021-03-11 | Display apparatus and display control method |
| PCT/CN2021/095347 WO2022041873A1 (en) | 2020-08-24 | 2021-05-21 | Display apparatus and step power circuit |
| US17/660,786 US11783788B2 (en) | 2020-03-18 | 2022-04-26 | Display apparatus and display control method |
| US17/900,166 US11825577B2 (en) | 2020-08-24 | 2022-08-31 | Display apparatus and step power circuit |
| US18/460,875 US20230419916A1 (en) | 2020-03-18 | 2023-09-05 | Display apparatus and display control method |
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| CN202110138504.XA Active CN112785971B (en) | 2020-03-18 | 2021-02-01 | Display device and negative-pressure step power supply circuit |
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| WO2022041873A1 (en) * | 2020-08-24 | 2022-03-03 | 海信视像科技股份有限公司 | Display apparatus and step power circuit |
| EP4451260A1 (en) * | 2021-12-14 | 2024-10-23 | Hisense Visual Technology Co., Ltd. | Display device and display control method |
| CN114267269B (en) * | 2022-01-11 | 2023-07-21 | 福州不止光电科技有限公司 | Free-mounting free combined type luminous sign |
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| CN107909969A (en) * | 2016-10-11 | 2018-04-13 | 京东方科技集团股份有限公司 | Drive circuit, backlight and display device |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN112785971A (en) | 2021-05-11 |
| CN113436571B (en) | 2022-10-18 |
| CN113436571A (en) | 2021-09-24 |
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