CN115512643A - LED display power supply and display device - Google Patents

LED display power supply and display device Download PDF

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Publication number
CN115512643A
CN115512643A CN202110687350.XA CN202110687350A CN115512643A CN 115512643 A CN115512643 A CN 115512643A CN 202110687350 A CN202110687350 A CN 202110687350A CN 115512643 A CN115512643 A CN 115512643A
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CN
China
Prior art keywords
voltage
unit
subunit
backup current
output end
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Pending
Application number
CN202110687350.XA
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Chinese (zh)
Inventor
郑凌霄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangzhou Shiyuan Electronics Thecnology Co Ltd
Guangzhou Shikun Electronic Technology Co Ltd
Original Assignee
Guangzhou Shiyuan Electronics Thecnology Co Ltd
Guangzhou Shikun Electronic Technology Co Ltd
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Filing date
Publication date
Application filed by Guangzhou Shiyuan Electronics Thecnology Co Ltd, Guangzhou Shikun Electronic Technology Co Ltd filed Critical Guangzhou Shiyuan Electronics Thecnology Co Ltd
Priority to CN202110687350.XA priority Critical patent/CN115512643A/en
Priority to PCT/CN2022/099666 priority patent/WO2022268003A1/en
Publication of CN115512643A publication Critical patent/CN115512643A/en
Pending legal-status Critical Current

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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]
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
    • 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • 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
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/20—Controlling the colour of the light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits

Abstract

The invention discloses an LED display power supply and display equipment. The first power supply circuit comprises a first voltage conversion module and a first backup current-sharing module, and the second power supply circuit comprises a second voltage conversion module and a second backup current-sharing module. The output voltage of the other power supply circuit is collected through one of the backup current sharing modules, the output voltages of the two power supply circuits are compared, and then the comparison result is fed back to the voltage conversion module. When the output voltages of the two power supply circuits are not equal, the voltage conversion module adjusts the output voltage according to the feedback result, so that the output voltages of the two power supply circuits reach a balanced state, the heat productivity of the two power supply circuits is balanced, the problem that the LED lamp beads have display color difference due to unbalanced heat generation of the two power supply circuits is avoided, and the display quality is improved.

Description

LED display power supply and display device
Technical Field
The invention relates to the technical field of LED display power supplies, in particular to an LED display power supply and display equipment.
Background
The LED display has the advantages of bright color, wide dynamic range, high brightness, long service life, stable and reliable work and the like, is widely applied to commercial media, cultural performance markets, stadiums, information dissemination, news distribution, security trading and the like, and can meet the requirements of different environments.
The LED display screen is mainly divided into a display module, a control system and an LED display power supply. The display module comprises an LED lamp bead array for emitting light; the control system is used for regulating and controlling the on-off condition in the area to realize conversion of the content displayed on the screen; the LED display power supply is used for converting input voltage and current to meet the requirements of a display screen.
The LED display power supply is a power source of the LED display screen, so the service life of the LED display screen mostly lies in the stable performance of the LED display power supply. Therefore, in order to reduce the problem that the LED display screen cannot work normally due to the damage of the LED display power supply, two sets of power supplies are usually connected in parallel to supply power to the display module.
However, due to parameter errors of electronic components, the existing scheme that two sets of power supplies are connected in parallel to supply power to the display module cannot ensure that the power supply voltages of the two sets of power supplies are consistent, and the situation that one voltage is high and the other voltage is low can happen. For a power supply with a large supply voltage, the output power is large, so that the heat generation is easy to be serious, and the service life is shortened. And when one of the power supplies is shorted, it will cause the other power supply to be shorted, causing both power supplies to fail. In addition, the display effect of the display module is affected by temperature, and the LED lamp beads close to the two power supplies have display color difference due to the fact that the difference of the heat productivity of the two power supplies is large, so that the display effect is affected.
Disclosure of Invention
The embodiment of the invention provides an LED display power supply and display equipment, which can improve the stability of the LED display power supply, avoid the problem of display color difference of LED lamp beads caused by unbalanced heating of two power supply circuits and improve the display quality.
In a first aspect, an embodiment of the present invention provides an LED display power supply, including a first power supply circuit and a second power supply circuit;
the first power supply circuit comprises a first voltage conversion module and a first backup current-sharing module, and the second power supply circuit comprises a second voltage conversion module and a second backup current-sharing module;
the input end of the first voltage conversion module and the input end of the second voltage conversion module are used for being connected with an external power supply; the output end of the first voltage conversion module is connected with the input end of the first backup current-sharing module, and the output end of the second voltage conversion module is connected with the input end of the second backup current-sharing module; the output end of the first backup current-sharing module and the output end of the second backup current-sharing module are used for supplying power to the LED lamp beads;
the voltage acquisition end of the first backup current equalizing module is connected with the voltage acquisition end of the second backup current equalizing module; the feedback signal output end of the first backup current-sharing module is connected with the feedback signal input end of the first voltage conversion module, and the feedback signal output end of the second backup current-sharing module is connected with the feedback signal input end of the second voltage conversion module.
Optionally, the first voltage conversion module includes a first power conversion unit and a first DC-DC conversion unit, and the second voltage conversion module includes a second power conversion unit and a second DC-DC conversion unit;
the first backup current equalizing module comprises two backup current equalizing units which are respectively a first backup current equalizing unit and a second backup current equalizing unit, and the second backup current equalizing module comprises two backup current equalizing units which are respectively a third backup current equalizing unit and a fourth backup current equalizing unit;
the input end of the first power conversion unit and the input end of the second power conversion unit are used for being connected with an external power supply, the output end of the first power conversion unit is respectively connected with the input end of the first DC-DC conversion unit and the input end of the first backup current-sharing unit, the output end of the first backup current-sharing unit is used for supplying power to the red LED lamp beads, the output end of the first DC-DC conversion unit is connected with the input end of the second backup current-sharing unit, and the output end of the second backup current-sharing unit is used for supplying power to the green LED lamp beads, the blue LED lamp beads and the control panel;
the output end of the second power conversion unit is respectively connected with the input end of the second DC-DC conversion unit and the input end of the third backup current-sharing unit, the output end of the third backup current-sharing unit is used for supplying power to the red LED lamp beads, the output end of the second DC-DC conversion unit is connected with the input end of the fourth backup current-sharing unit, and the output end of the fourth backup current-sharing unit is used for supplying power to the green LED lamp beads, the blue LED lamp beads and the control panel;
the voltage acquisition end of the first backup current equalizing unit is connected with the voltage acquisition end of the third backup current equalizing unit; the voltage acquisition end of the second backup current equalizing unit is connected with the voltage acquisition end of the fourth backup current equalizing unit; a feedback signal output end of the first backup current equalizing unit and a feedback signal output end of the second backup current equalizing unit are respectively connected with a feedback signal input end of the first power conversion unit; and the feedback signal output end of the third backup current equalizing unit and the feedback signal output end of the fourth backup current equalizing unit are respectively connected with the feedback signal input end of the second power conversion unit.
Optionally, the backup current equalizing unit includes a backup unit and a current equalizing unit;
the backup unit comprises a switch subunit and a voltage detection subunit, the switch subunit is connected to a loop where the backup current equalizing unit is located, the voltage detection subunit is used for detecting the voltage of the switch subunit, and the output end of the voltage detection subunit is connected with the control end of the switch subunit;
the current equalizing unit comprises a voltage acquisition subunit, a voltage amplification subunit, a voltage comparison subunit and a feedback signal output subunit, wherein the voltage acquisition subunit is used for acquiring the output voltage of the backup current equalizing unit, the input end of the voltage amplification subunit is connected with the output end of the voltage acquisition subunit, the output end of the voltage amplification subunit is connected with the first input end of the voltage comparison subunit, the second input end of the voltage comparison subunit is connected with the output end of the voltage amplification subunit, the output end of the voltage comparison subunit is connected with the input end of the feedback signal output subunit, and the output end of the feedback signal output subunit is connected with the feedback signal input end of the first power conversion unit or the second power conversion unit corresponding to the backup current equalizing unit;
the output end of the voltage amplifying subunit in the current equalizing unit of the first backup current equalizing unit is connected with the first input end of the voltage comparing subunit in the current equalizing unit of the third backup current equalizing unit; the output end of the voltage amplifying subunit in the current equalizing unit of the second backup current equalizing unit is connected with the first input end of the voltage comparing subunit in the current equalizing unit of the fourth backup current equalizing unit.
Optionally, the switch subunit includes a first resistor and a first switch transistor;
the first resistor and the switch transistor are connected in series on a loop where the backup current equalizing unit is located, and the output end of the voltage detection subunit is connected with the control end of the first switch transistor.
Optionally, the voltage detection subunit includes a first voltage comparator;
the first input end of the first voltage comparator is connected with the input end of the switch subunit, the second input end of the first voltage comparator is connected with the output end of the switch subunit, and the output end of the first voltage comparator is connected with the control end of the switch subunit.
Optionally, the voltage acquisition subunit includes a second resistor, and the second resistor is connected to a loop where the backup current equalizing unit is located.
Optionally, the voltage amplifying subunit includes an amplifier;
the first input end of the amplifier is connected with the first end of the second resistor, the second input end of the amplifier is connected with the second end of the second resistor, and the output end of the amplifier is connected with the first input end of the voltage comparison subunit.
Optionally, the voltage comparison subunit includes a second voltage comparator;
a first input end of the second voltage comparator and a second input end of the second voltage comparator are respectively connected with an output end of the amplifier, and an output end of the second voltage comparator is connected with an input end of the feedback signal output subunit;
the output end of the amplifier in the current equalizing unit of the first backup current equalizing unit is connected with the first input end of the second voltage comparator in the current equalizing unit of the third backup current equalizing unit; the output end of an amplifier in the current equalizing unit of the second backup current equalizing unit is connected with the first input end of the second voltage comparator in the current equalizing unit of the fourth backup current equalizing unit.
Optionally, the feedback signal output subunit includes a second switching transistor and a third resistor;
the first end of the second switch transistor is connected with the output end of the corresponding first power conversion unit or the output end of the second power conversion unit through the lower bias sampling resistor, the second end of the second switch transistor is connected with the first end of the third resistor, the second end of the third resistor is grounded, and the control end of the second switch transistor is connected with the output end of the voltage comparison subunit.
In a second aspect, the invention also provides a display device comprising an LED display power supply as provided in the first aspect of the invention.
The LED display power supply provided by the embodiment of the invention comprises a first power supply circuit and a second power supply circuit. The first power supply circuit comprises a first voltage conversion module and a first backup current-sharing module, and the second power supply circuit comprises a second voltage conversion module and a second backup current-sharing module. The input end of the first voltage conversion module and the input end of the second voltage conversion module are used for connecting an external power supply, the output end of the first voltage conversion module is connected with the input end of the first backup current-sharing module, the output end of the second voltage conversion module is connected with the input end of the second backup current-sharing module, and the output end of the first backup current-sharing module and the output end of the second backup current-sharing module are used for supplying power for the LED lamp beads. The voltage acquisition end of the first backup current-sharing module is connected with the voltage acquisition end of the second backup current-sharing module, the feedback signal output end of the first backup current-sharing module is connected with the feedback signal input end of the first voltage conversion module, and the feedback signal output end of the second backup current-sharing module is connected with the feedback signal input end of the second voltage conversion module. The output voltage of the other power supply circuit is collected through one of the backup current sharing modules, the output voltages of the two power supply circuits are compared, and then the comparison result is fed back to the voltage conversion module. When the output voltages of the two power supply circuits are not equal, the voltage conversion module adjusts the output voltage according to the feedback result, so that the output voltages of the two power supply circuits reach a balanced state, the heat productivity of the two power supply circuits is balanced, the problem that the LED lamp beads have display color difference due to unbalanced heat generation of the two power supply circuits is avoided, and the display quality is improved.
Drawings
The invention is explained in more detail below with reference to the figures and examples.
Fig. 1 is a block diagram of an LED display power supply according to an embodiment of the present invention;
FIG. 2 is a block diagram of another LED display power supply according to an embodiment of the present invention;
fig. 3 is a block diagram of a backup current sharing unit according to an embodiment of the present invention;
FIG. 4 is a circuit diagram of a backup unit according to an embodiment of the present invention;
fig. 5 is a circuit diagram of two current equalizing units according to an embodiment of the present invention.
Detailed Description
In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all 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.
In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature. Furthermore, the terms "first" and "second" are used merely for descriptive purposes and are not intended to have any special meaning.
Fig. 1 is a block diagram of a structure of an LED display power supply according to an embodiment of the present invention, and as shown in fig. 1, the LED display power supply includes a first power supply circuit 100 and a second power supply circuit 200.
The first power circuit 100 includes a first voltage transformation module 110 and a first backup current equalizing module 120. The second power circuit 200 includes a second voltage transformation module 210 and a second backup current sharing module 220.
The input terminal of the first voltage conversion module 110 and the input terminal of the second voltage conversion module 210 are used for connecting an external power source. In some embodiments of the present invention, the external power is 220V ac, and each of the first power circuit 100 and the second power circuit 200 further includes an EMC (Electro Magnetic Compatibility) protection module for isolating external electromagnetic interference and a rectifying and filtering module for rectifying and filtering the external power incoming line to convert the external power into the power required by the first voltage transformation module 110 and the second voltage transformation module 210. The output terminal of the first voltage conversion module 110 is connected to the input terminal of the first backup current sharing module 120 through a power line L11. The output end of the second voltage transformation module 210 is connected to the input end of the second backup current equalizing module 220 through a power line L21. The output end of the first backup current equalizing module 120 and the output end of the second backup current equalizing module 220 are used for supplying power to the LED lamp beads.
The voltage collecting terminal of the first backup current equalizing module 120 is connected to the voltage collecting terminal of the second backup current equalizing module 220 through a voltage collecting line L3. The feedback signal output end of the first backup current sharing module 120 is connected to the feedback signal input end of the first voltage converting module 110 through a feedback line L12. The feedback signal output end of the second backup current sharing module 220 is connected to the feedback signal input end of the second voltage converting module 210 through a feedback line L22.
The output voltage of another power supply circuit is collected through a backup current equalizing module in one power supply circuit, and is compared with the output voltage of the own power supply circuit, and then the comparison result is fed back to a voltage conversion module of the own power supply circuit. When the output voltages of the two power supply circuits are not equal, the voltage conversion module in one power supply circuit adjusts the output voltage according to the feedback result, so that the output voltages of the two power supply circuits reach a balanced state, namely are equal or equal within a certain error range, the heat productivity of the two power supply circuits is balanced, the problem that the LED lamp beads have display color difference due to unbalanced heating of the two power supply circuits is avoided, and the display quality is improved.
The present invention is illustratively explained by taking as an example that the output voltage of the second power supply circuit 200 is higher than the output voltage of the first power supply circuit 100. The first backup current sharing module 120 collects the output voltage of the second power circuit 200 (i.e. the output voltage of the second backup current sharing module 220), and compares the output voltage with the output voltage of the first power circuit 100 (i.e. the output voltage of the first backup current sharing module 120), because the output voltage of the second power circuit 200 is higher than the output voltage of the first power circuit 100, the first backup current sharing module 120 sends a feedback signal to the first voltage transformation module 110, and the first voltage transformation module 110 responds to the feedback signal to increase the output voltage, so that the output voltages of the two power circuits reach a balanced state.
The LED display power supply provided by the embodiment of the invention comprises a first power supply circuit and a second power supply circuit. The first power supply circuit comprises a first voltage conversion module and a first backup current-sharing module, and the second power supply circuit comprises a second voltage conversion module and a second backup current-sharing module. The input end of the first voltage conversion module and the input end of the second voltage conversion module are used for being connected with an external power supply, the output end of the first voltage conversion module is connected with the input end of the first backup current-sharing module, the output end of the second voltage conversion module is connected with the input end of the second backup current-sharing module, and the output end of the first backup current-sharing module and the output end of the second backup current-sharing module are used for supplying power to the LED lamp beads. The voltage acquisition end of the first backup current-sharing module is connected with the voltage acquisition end of the second backup current-sharing module, the feedback signal output end of the first backup current-sharing module is connected with the feedback signal input end of the first voltage conversion module, and the feedback signal output end of the second backup current-sharing module is connected with the feedback signal input end of the second voltage conversion module. The output voltage of the other power supply circuit is acquired through the backup current equalizing module of one power supply circuit, the output voltages of the two power supply circuits are compared, and then the comparison result is fed back to the voltage conversion module. When the output voltages of the two power supply circuits are not equal, the voltage conversion module adjusts the output voltage according to the feedback result, so that the output voltages of the two power supply circuits reach a balanced state, the heat productivity of the two power supply circuits is balanced, the problem that the LED lamp beads have display color difference due to unbalanced heat generation of the two power supply circuits is avoided, and the display quality is improved.
In some embodiments of the invention, the first power circuit and the second power circuit are both dual-path common-ground output circuits, the dual-path common-ground output circuits have the same reference ground and output two paths of voltages, one path of voltage supplies power to the red LED lamp beads, and the other path of voltage supplies power to the blue LED lamp beads, the green LED lamp beads and the control panel of the display screen.
Fig. 2 is a block diagram of another LED display power supply according to an embodiment of the present invention, and exemplarily, as shown in fig. 2, on the basis of the above embodiment, the first voltage conversion module 110 includes a first power conversion unit 111 and a first DC-DC conversion unit 112. The second voltage conversion module 210 includes a second power conversion unit 211 and a second DC-DC conversion unit 212. The first backup current sharing module 120 includes two backup current sharing units, which are a first backup current sharing unit 121 and a second backup current sharing unit 122. The second backup current share module 220 includes two backup current share units, which are a third backup current share unit 221 and a fourth backup current share unit 222.
The input terminal of the first power conversion unit 111 and the input terminal of the second power conversion unit 211 are used for connecting an external power supply. In some embodiments of the present invention, the external power source is 220V ac, and the first power circuit 100 and the second power circuit 200 each further include an EMC (Electro Magnetic Compatibility) protection module and a rectifying and filtering module. The output end of the first power conversion unit 111 is connected to the input end of the first DC-DC conversion unit 112 and the input end of the first backup current equalizing unit 121, respectively, and the output end VO1 of the first backup current equalizing unit 121 is used for supplying power to the red LED lamp bead. The output end of the first DC-DC conversion unit 112 is connected to the input end of the second backup current equalizing unit 122, and the output end VO2 of the second backup current equalizing unit 122 is used for supplying power to the green LED lamp beads, the blue LED lamp beads and the control board.
The output end of the second power conversion unit 211 is connected to the input end of the second DC-DC conversion unit 212 and the input end of the third backup current equalizing unit 221, respectively, and the output end VO1 of the third backup current equalizing unit 221 is used for supplying power to the red LED lamp bead. The output end of the second DC-DC conversion unit 212 is connected to the input end of the fourth backup current equalizing unit 222, and the output end VO2 of the fourth backup current equalizing unit 222 is used for supplying power to the green LED lamp bead, the blue LED lamp bead and the control board.
The voltage collecting terminal of the first backup current equalizing unit 121 is connected to the voltage collecting terminal of the third backup current equalizing unit 221, and the voltage collecting terminal of the second backup current equalizing unit 122 is connected to the voltage collecting terminal of the fourth backup current equalizing unit 222. The feedback signal output end of the first backup current equalizing unit 121 and the feedback signal output end of the second backup current equalizing unit 122 are respectively connected with the feedback signal input end of the first power conversion unit 111. The feedback signal output end of the third backup current equalizing unit 221 and the feedback signal output end of the fourth backup current equalizing unit 222 are respectively connected with the feedback signal input end of the second power converting unit 211.
Specifically, in the first power circuit 100, the first power conversion unit 111 supplies power to the red LED lamp beads through the first backup current equalizing unit 121, and the first DC-DC conversion unit 112 is configured to boost the voltage output by the first power conversion unit 111, and supply power to the green LED lamp beads, the blue LED lamp beads, and the control board through the second backup current equalizing unit 122. The second power conversion unit 211 in the second power circuit 100 supplies power to the red LED lamp beads through the third backup current equalizing unit 221, and the second DC-DC conversion unit 212 is configured to boost the voltage output by the second power conversion unit 211, and supply power to the green LED lamp beads, the blue LED lamp beads, and the control board through the fourth backup current equalizing unit 222. Because the two outputs of the first power circuit 100 and the two outputs of the second power circuit 200 are provided with the backup current equalizing units, the problem that the red LED lamp beads have display color difference due to unbalanced heating of the two outputs for supplying power to the red LED lamp beads can be avoided, and the problem that the blue LED lamp beads and the green LED lamp beads have display color difference due to unbalanced heating of the two outputs for supplying power to the blue LED lamp beads and the green LED lamp beads can be avoided, so that the display quality is improved. The embodiment of the present invention is not described herein again.
Particularly, the DC-DC conversion unit usually adopts a non-isolated BUCK circuit topology, the follow current tube in the BUCK circuit usually adopts an MOS tube, and the failure of the circuit is usually caused by the fact that the output of the DC-DC conversion circuit is short-circuited due to the damage of the MOS short-circuit, so that the two DC-DC conversion circuits cannot output, and the whole LED display screen cannot normally display. According to the embodiment of the invention, the backup current equalizing unit is arranged at the output end of the DC-DC conversion unit, when one power supply circuit is short-circuited, the backup current equalizing unit of the power supply circuit cuts off a power supply loop, so that the problem that two DC-DC conversion units cannot output power due to the short-circuiting of one DC-DC conversion unit is avoided, and the stability of the LED display power supply is improved.
In some embodiments of the present invention, each backup current share unit has the same structure, including the backup unit and the current share unit. Fig. 3 is a structural block diagram of a backup current equalizing unit according to an embodiment of the present invention, and as shown in fig. 3, the backup current equalizing unit includes a backup unit 10 and a current equalizing unit 20.
The backup unit 10 includes a switch subunit 11 and a voltage detection subunit 12, the switch subunit 11 is connected to a loop where the backup current equalizing unit is located, that is, an input end of the switch subunit 11 is connected to an output end of the power conversion unit or the DC-DC conversion unit, and an output end VO of the switch subunit 11 is used for supplying power to the red LED lamp beads, or the blue LED lamp beads, the green LED lamp beads and the control board. The voltage detection subunit 12 is configured to detect a voltage of the switch subunit 11, and an output end of the voltage detection subunit 12 is connected to a control end of the switch subunit 11.
For example, the operation process of the backup unit in the present invention is exemplarily described by taking the output short circuit of the first DC-DC conversion unit 112 as an example. Normally, the voltage at the input terminal VI of the switch subunit 11 is greater than the voltage at the output terminal VO. When the output of the first DC-DC converting unit 112 is short-circuited, the voltage detecting subunit 12 detects that the voltage at the input terminal VI of the switch subunit 11 is less than the voltage at the output terminal VO, and sends a control signal to the switch subunit 11, so that the switch subunit 11 is turned off, and since the first DC-DC converting unit 112 and the second DC-DC converting unit 212 respectively supply power to the green LED lamp bead, the blue LED lamp bead, and the control board through the second backup current equalizing unit 122 and the fourth backup current equalizing unit 222, that is, the first DC-DC converting unit 112 and the second DC-DC converting unit 212 are electrically connected, it is possible to avoid that short-circuit current reversely flows into the second DC-DC converting unit 212, which may cause the second DC-DC converting unit 212 to be damaged.
The current equalizing unit 20 comprises a voltage collecting subunit 21, a voltage amplifying subunit 22, a voltage comparing subunit 23 and a feedback signal output subunit 24. The voltage acquisition subunit 21 is configured to acquire an output voltage of the backup current equalizing unit where the voltage acquisition subunit is located (that is, a voltage of the output terminal VO of the switch subunit 11), an input terminal of the voltage amplification subunit 22 is connected to an output terminal of the voltage acquisition subunit 21, an output terminal of the voltage amplification subunit 22 is connected to a first input terminal of the voltage comparison subunit 23, a second input terminal of the voltage comparison subunit 23 is connected to an output terminal of the voltage amplification subunit 22, an output terminal of the voltage comparison subunit 23 is connected to an input terminal of the feedback signal output subunit 24, and an output terminal FB of the feedback signal output subunit 24 is connected to a feedback signal input terminal of the power conversion unit corresponding to the backup current equalizing unit where the voltage acquisition subunit is located.
The output of the voltage amplifier subunit 22 in the current equalizing unit 20 of the first backup current equalizing unit 121 is connected to the first input of the voltage comparator subunit 22 in the current equalizing unit 20 of the third backup current equalizing unit 221. The output of the voltage amplification subunit 22 in the current equalizing unit 20 of the second backup current equalizing unit 122 is connected to the first input of the voltage comparison subunit 22 in the current equalizing unit of the fourth backup current equalizing unit 222.
For example, a working process of the current equalizing unit in the embodiment of the present invention is exemplarily described by taking a loop for supplying power to a red LED lamp bead as an example. When the output voltage of one of the power supply circuits is greater than the supply voltage of the other power supply circuit, for example, taking the output voltage of the second power supply circuit 200 is greater than the output voltage of the first power supply circuit 100 as an example, the voltage collecting subunit 21 in the current equalizing unit 20 in the second power supply circuit 200 collects the output voltage of the second power supply circuit 200, and after the output voltage is amplified by the voltage amplifying subunit 22, the output voltage is applied to the first input terminal of the voltage comparing subunit 22 of the current equalizing unit 20 in the first power supply circuit 100, so that the voltage of the first input terminal of the voltage comparing subunit 22 of the current equalizing unit 20 in the first power supply circuit 100 is increased, and the voltage of the second input terminal of the voltage comparing subunit 22 of the current equalizing unit 20 in the first power supply circuit 100 is unchanged, therefore, the voltage increase of the output terminal of the voltage comparing subunit 22 of the current equalizing unit 20 in the first power supply circuit 100 triggers the feedback signal output subunit 24 of the first power supply circuit 20 to send a feedback signal to the first power conversion unit 111 in the first power supply circuit 100, and the first power conversion unit 111 outputs a feedback signal to increase the output voltage of the two balanced power supply circuits, so that the two balanced power supply circuits output voltage.
Fig. 4 is a circuit diagram of a backup unit according to an embodiment of the present invention, and as shown in fig. 4, on the basis of the foregoing embodiment, the switch subunit 11 includes a first resistor R1 and a first switch transistor Q1. The voltage detection subunit 12 includes a first voltage comparator U1A.
The first resistor R1 and the first switch transistor Q1 are connected in series on a loop where the backup current equalizing unit is located, a first end VI of the first resistor R1 is connected with an output end of the power conversion unit or the DC-DC conversion unit, a second end of the first resistor R1 is connected with a first end of the first switch transistor Q1, a second end VO of the first switch transistor Q1 is used for supplying power to the red LED lamp beads or the green LED lamp beads, the blue LED lamp beads and the control panel, and a control end of the first switch transistor Q1 is connected with an output end of the first voltage comparator U1A through a resistor R2.
A first input terminal of the first voltage comparator U1A is connected to a first terminal VI of the first resistor R1 through a resistor R3, and a second input terminal of the first voltage comparator U1A is connected to a second terminal VO of the first switching transistor Q1 through a resistor R4.
Under normal conditions, due to the voltage drop effect of the first resistor R1 and the first switching transistor Q1, the voltage at the first terminal VI of the first resistor R1 is higher than the voltage at the second terminal VO of the first switching transistor Q1. When the loop in which the backup unit is located is short-circuited, for example, when the output of the first DC-DC conversion unit is short-circuited, the voltage of the first terminal VI of the first resistor R1 is lower than the voltage of the second terminal VO of the first switching transistor Q1. The first voltage comparator U1A compares the voltages of the two input terminals, and sends a control signal to the control terminal of the first switching transistor Q1 when the voltage of the first input terminal is less than the voltage of the second input terminal, so that the first switching transistor Q1 is turned off, thereby avoiding affecting the second DC-DC conversion unit 212.
Fig. 5 is a circuit diagram of two current equalizing units according to an embodiment of the present invention, and as shown in fig. 5, the present embodiment exemplifies two current equalizing units for supplying power to a red LED lamp bead, which exemplifies the present invention.
On the basis of the above embodiment, in the current equalizing unit of the first power supply circuit, the voltage collecting subunit includes the second resistor R5, the voltage amplifying subunit includes the amplifier U2A, the voltage comparing subunit includes the second voltage comparator U3A, and the feedback signal outputting subunit includes the second switching transistor Q2 and the third resistor R6.
The first end of the second resistor R5 is connected with the output end of the backup unit in the first power circuit, and the output end of the backup unit in the first power circuit is used for supplying power (4.2 VO) for the red LED lamp bead.
The first input end of the amplifier U2A is connected with the first end of the second resistor R5 through the resistor R7, the second input end of the amplifier U2A is connected with the second end of the second resistor R5 through the resistor R8, and the output end of the amplifier U2A is connected with the first input end of the second voltage comparator U3A through the voltage follower U4A, the diode D1 and the resistor R9 which are sequentially connected.
A second input terminal of the second voltage comparator U3A is connected to the output terminal of the amplifier U2A through a resistor R10, and an output terminal of the second voltage comparator U3A is connected to the control terminal of the second switching transistor Q2 through a resistor R11.
A first end of the second switching transistor Q2 is connected to the corresponding lower-biased sampling resistor of the output end of the first power conversion unit, a second end of the second switching transistor Q2 is connected to a first end of the third resistor R12, and a second end of the third resistor R12 is grounded.
Similarly, in the current equalizing unit of the second power supply circuit, the voltage collecting subunit includes a second resistor R13, the voltage amplifying subunit includes an amplifier U5A, the voltage comparing subunit includes a second voltage comparator U6A, and the feedback signal outputting subunit includes a second switching transistor Q3 and a third resistor R14. The connection relationship may refer to the connection relationship of each element in the current equalizing unit of the second power circuit, and the embodiment of the present invention is not described herein again.
In the current equalizing unit of the first power supply circuit and the current equalizing unit of the second power supply circuit, first input ends of two voltage comparators U3A and U6A are connected through a Share connecting wire. Specifically, one end of the Share connection line is connected to the first input terminal of the second voltage comparator U3A through the resistor R15, and the other end of the Share connection line is connected to the first input terminal of the second voltage comparator U6A through the resistor R16.
For example, the embodiment of the present invention is exemplarily described by taking an example that the output voltage of the second power supply circuit is greater than the output voltage of the first power supply circuit. Under normal conditions, the outputs of the first power supply circuit and the second power supply circuit are connected together to supply power (4.2 VO) for the red LED lamp beads, and the first power supply circuit and the second power supply circuit share half of load current. When the output voltage of the second power supply circuit is greater than the output voltage of the first power supply circuit, the voltage at two ends of the second resistor R13 is increased, and after the voltage is amplified by the amplifier U5A, the amplified voltage is applied to the first input end of the second voltage comparator U3A through the Share connection line, so that the voltage at the first input end of the second voltage comparator U3A is increased, and the voltage at the second input end of the second voltage comparator U3A is unchanged, therefore, the voltage at the output end of the second voltage comparator U3A is increased, when the conduction threshold of the second switching transistor Q2 is reached, the second switching transistor Q2 is conducted, so that the third resistor R6 is connected into the circuit, and the third resistor R6 is connected in parallel with the lower bias sampling resistor at the output end of the first power conversion unit, so that the output voltage of the first power conversion unit is increased, and the output voltages of the two power supply circuits reach a balanced state.
The invention further provides a display device, which includes the LED display power supply provided in any of the foregoing embodiments of the invention, and the display device may include, for example, a television, a computer monitor, a smart phone, a tablet computer, and the like, which is not limited herein.
In the description herein, it is to be understood that the terms "upper", "lower", "left", "right", and the like are used in a descriptive sense or positional relationship based on the orientation or positional relationship shown in the drawings for convenience in description and simplicity of operation, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present invention.
In the description herein, references to the description of "an embodiment," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.
Furthermore, it should be understood that although the specification describes embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and it will be understood by those skilled in the art that the specification as a whole and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
The technical principles of the present invention have been described above with reference to specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be taken in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.

Claims (10)

1. An LED display power supply is characterized by comprising a first power supply circuit and a second power supply circuit;
the first power supply circuit comprises a first voltage conversion module and a first backup current equalizing module, and the second power supply circuit comprises a second voltage conversion module and a second backup current equalizing module;
the input end of the first voltage conversion module and the input end of the second voltage conversion module are used for being connected with an external power supply; the output end of the first voltage conversion module is connected with the input end of the first backup current-sharing module, and the output end of the second voltage conversion module is connected with the input end of the second backup current-sharing module; the output end of the first backup current-sharing module and the output end of the second backup current-sharing module are used for supplying power to the LED lamp beads;
the voltage acquisition end of the first backup current equalizing module is connected with the voltage acquisition end of the second backup current equalizing module; the feedback signal output end of the first backup current-sharing module is connected with the feedback signal input end of the first voltage conversion module, and the feedback signal output end of the second backup current-sharing module is connected with the feedback signal input end of the second voltage conversion module.
2. The LED display power supply of claim 1, wherein the first voltage conversion module comprises a first power conversion unit and a first DC-DC conversion unit, and the second voltage conversion module comprises a second power conversion unit and a second DC-DC conversion unit;
the first backup current equalizing module comprises two backup current equalizing units which are respectively a first backup current equalizing unit and a second backup current equalizing unit, and the second backup current equalizing module comprises two backup current equalizing units which are respectively a third backup current equalizing unit and a fourth backup current equalizing unit;
the input end of the first power conversion unit and the input end of the second power conversion unit are used for being connected with an external power supply, the output end of the first power conversion unit is respectively connected with the input end of the first DC-DC conversion unit and the input end of the first backup current-sharing unit, the output end of the first backup current-sharing unit is used for supplying power to the red LED lamp beads, the output end of the first DC-DC conversion unit is connected with the input end of the second backup current-sharing unit, and the output end of the second backup current-sharing unit is used for supplying power to the green LED lamp beads, the blue LED lamp beads and the control panel;
the output end of the second power conversion unit is respectively connected with the input end of the second DC-DC conversion unit and the input end of the third backup current-equalizing unit, the output end of the third backup current-equalizing unit is used for supplying power to the red LED lamp beads, the output end of the second DC-DC conversion unit is connected with the input end of the fourth backup current-equalizing unit, and the output end of the fourth backup current-equalizing unit is used for supplying power to the green LED lamp beads, the blue LED lamp beads and the control panel;
the voltage acquisition end of the first backup current equalizing unit is connected with the voltage acquisition end of the third backup current equalizing unit; the voltage acquisition end of the second backup current equalizing unit is connected with the voltage acquisition end of the fourth backup current equalizing unit; the feedback signal output end of the first backup current equalizing unit and the feedback signal output end of the second backup current equalizing unit are respectively connected with the feedback signal input end of the first power conversion unit; and the feedback signal output end of the third backup current equalizing unit and the feedback signal output end of the fourth backup current equalizing unit are respectively connected with the feedback signal input end of the second power conversion unit.
3. The LED display power supply of claim 2, wherein the backup current sharing unit comprises a backup unit and a current sharing unit;
the backup unit comprises a switch subunit and a voltage detection subunit, the switch subunit is connected to a loop where the backup current equalizing unit is located, the voltage detection subunit is used for detecting the voltage of the switch subunit, and the output end of the voltage detection subunit is connected with the control end of the switch subunit;
the current equalizing unit comprises a voltage acquisition subunit, a voltage amplification subunit, a voltage comparison subunit and a feedback signal output subunit, wherein the voltage acquisition subunit is used for acquiring the output voltage of the backup current equalizing unit, the input end of the voltage amplification subunit is connected with the output end of the voltage acquisition subunit, the output end of the voltage amplification subunit is connected with the first input end of the voltage comparison subunit, the second input end of the voltage comparison subunit is connected with the output end of the voltage amplification subunit, the output end of the voltage comparison subunit is connected with the input end of the feedback signal output subunit, and the output end of the feedback signal output subunit is connected with the feedback signal input end of the first power conversion unit or the second power conversion unit corresponding to the backup current equalizing unit;
the output end of a voltage amplifying subunit in the current equalizing unit of the first backup current equalizing unit is connected with the first input end of a voltage comparing subunit in the current equalizing unit of the third backup current equalizing unit; the output end of the voltage amplifying subunit in the current equalizing unit of the second backup current equalizing unit is connected with the first input end of the voltage comparing subunit in the current equalizing unit of the fourth backup current equalizing unit.
4. The LED display power supply of claim 3, wherein the switch subunit comprises a first resistor and a first switch transistor;
the first resistor and the switch transistor are connected in series on a loop where the backup current equalizing unit is located, and the output end of the voltage detection subunit is connected with the control end of the first switch transistor.
5. The LED display power supply of claim 3, wherein the voltage detection subunit comprises a first voltage comparator;
the first input end of the first voltage comparator is connected with the input end of the switch subunit, the second input end of the first voltage comparator is connected with the output end of the switch subunit, and the output end of the first voltage comparator is connected with the control end of the switch subunit.
6. The LED display power supply according to any one of claims 3 to 5, wherein the voltage acquisition subunit comprises a second resistor, and the second resistor is connected to a loop where the backup current equalizing unit is located.
7. The LED display power supply of claim 6, wherein the voltage amplification subunit comprises an amplifier;
the first input end of the amplifier is connected with the first end of the second resistor, the second input end of the amplifier is connected with the second end of the second resistor, and the output end of the amplifier is connected with the first input end of the voltage comparison subunit.
8. The LED display power supply of claim 7, wherein the voltage comparison subunit comprises a second voltage comparator;
a first input end of the second voltage comparator and a second input end of the second voltage comparator are respectively connected with an output end of the amplifier, and an output end of the second voltage comparator is connected with an input end of the feedback signal output subunit;
the output end of an amplifier in the current equalizing unit of the first backup current equalizing unit is connected with the first input end of the second voltage comparator in the current equalizing unit of the third backup current equalizing unit; the output end of the amplifier in the current equalizing unit of the second backup current equalizing unit is connected with the first input end of the second voltage comparator in the current equalizing unit of the fourth backup current equalizing unit.
9. The LED display power supply according to any one of claims 3-5, wherein the feedback signal output subunit comprises a second switching transistor and a third resistor;
the first end of the second switch transistor is connected with the output end of the corresponding first power conversion unit or the output end of the second power conversion unit through the lower bias sampling resistor, the second end of the second switch transistor is connected with the first end of the third resistor, the second end of the third resistor is grounded, and the control end of the second switch transistor is connected with the output end of the voltage comparison subunit.
10. A display device comprising the LED display power supply according to any one of claims 1 to 9.
CN202110687350.XA 2021-06-21 2021-06-21 LED display power supply and display device Pending CN115512643A (en)

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KR100273439B1 (en) * 1998-08-11 2001-01-15 구자홍 Apparatus and method for reducing power consumption of a power supply
CN101764425B (en) * 2009-12-30 2011-11-09 福建星网锐捷网络有限公司 Single plate power backup circuit and single plate power system
CN202333882U (en) * 2011-11-21 2012-07-11 漳州科华技术有限责任公司 Direct-current power supply having redundant backup function
CN103683479A (en) * 2013-12-23 2014-03-26 大连大学 Current-sharing control method for parallel redundant power supply
CN205039620U (en) * 2015-10-27 2016-02-17 厦门市华软科技有限公司 LED display screen signal battery dual backup circuit
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