WO2018045696A1 - 开关电源及电视机 - Google Patents

开关电源及电视机 Download PDF

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Publication number
WO2018045696A1
WO2018045696A1 PCT/CN2017/070308 CN2017070308W WO2018045696A1 WO 2018045696 A1 WO2018045696 A1 WO 2018045696A1 CN 2017070308 W CN2017070308 W CN 2017070308W WO 2018045696 A1 WO2018045696 A1 WO 2018045696A1
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WO
WIPO (PCT)
Prior art keywords
circuit
constant current
transformer
output
voltage
Prior art date
Application number
PCT/CN2017/070308
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English (en)
French (fr)
Inventor
陈建忠
杨寄桃
Original Assignee
深圳创维－Rgb电子有限公司
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Filing date
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Application filed by 深圳创维－Rgb电子有限公司 filed Critical 深圳创维－Rgb电子有限公司
Priority to EP17847872.3A priority Critical patent/EP3471512B1/en
Priority to US16/313,049 priority patent/US20200187328A1/en
Publication of WO2018045696A1 publication Critical patent/WO2018045696A1/zh

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Classifications

    • 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
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208—Arrangements for improving power factor of AC input
    • H02M1/4258—Arrangements for improving power factor of AC input using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage
    • 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
    • H02M3/22—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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/63—Generation or supply of power specially adapted for television receivers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • 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
    • H05B45/34—Voltage stabilisation; Maintaining constant voltage
    • 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
    • H05B45/345—Current stabilisation; Maintaining constant current
    • 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
    • H05B45/355—Power factor correction [PFC]; Reactive power compensation
    • 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
    • H05B45/36—Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
    • 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
    • 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
    • H05B45/3725—Switched mode power supply [SMPS]
    • 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
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/382—Switched mode power supply [SMPS] with galvanic isolation between input and output
    • 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
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/385—Switched mode power supply [SMPS] using flyback topology
    • 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]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/46—Details of LED load circuits with an active control inside an LED matrix having LEDs disposed in parallel lines
    • 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
    • H02M3/33561—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 having more than one ouput with independent control
    • 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
    • H05B45/32—Pulse-control circuits
    • H05B45/325—Pulse-width modulation [PWM]
    • 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
    • H05B45/395—Linear regulators
    • H05B45/397—Current mirror circuits
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present invention relates to the field of power supply technologies, and in particular, to a switching power supply and a television set using the same.
  • the traditional TV power supply architecture is shown in Figure 1.
  • the power supply needs to be corrected for power factor before DC-DC conversion to make constant voltage.
  • the 24V output power output needs to be powered by the BOOST boost to supply the backlight strip, which will make the power conversion efficiency low, and increase the cost of the constant current board and the cost of the PFC circuit.
  • this power supply architecture alternates with constant current and constant voltage, making the dynamic load of constant voltage and constant current susceptible to interference.
  • the main object of the present invention is to provide a switching power supply, which aims to improve power conversion efficiency, improve stability of constant voltage constant current output, and reduce power supply cost.
  • the present invention provides a switching power supply including a constant current switching circuit, a first single-stage PFC circuit, a first transformer, and a constant current feedback circuit; the switching power supply further includes a constant voltage switching circuit and a second single Level PFC circuit, and second transformer; among them,
  • the constant current feedback circuit samples the current output by the first transformer, and feeds the sampling current to the first single-stage PFC circuit;
  • the first single-stage PFC circuit outputs a switching signal according to the sampling current, drives the constant current switching circuit to be turned on or off, and controls the load current to be constant;
  • the second single-stage PFC circuit outputs a switching signal to drive the constant voltage switch circuit to be turned on or off;
  • the second single-stage PFC circuit samples the output voltage of the second transformer to obtain a sampling voltage, and adjusts a duty ratio of the switching signal according to the sampling voltage to adjust a voltage output to the main board, and controls the load voltage to be constant.
  • the switching power supply further includes a constant current switch and a constant current control circuit, wherein the load is an LED light bar.
  • the constant current switch adjusts the brightness of the LED light bar according to the PWM brightness signal output by the main board
  • the constant current control circuit controls the LED strip to be turned on or off according to an enable signal outputted by the main board.
  • the constant current control circuit controls the flow of current through the respective LED strips to be the same when the LED strip is still operating.
  • an input end of the constant current switching circuit is connected to a direct current, and an output end of the constant current switching circuit is connected to an output end of the first transformer; a sampling end of the first transformer and the first single a zero current detecting end of the PFC circuit is connected; an output end of the first transformer is connected to an input end of the LED light bar, and an output end of the LED light bar is connected to an input end of the constant current switch, a controlled end of the constant current switch is connected to the main board, and an output end of the constant current switch is connected to an input end of the constant current control circuit; an output end of the constant current control circuit and an input end of the constant current feedback circuit Connected, the controlled end of the constant current control circuit receives an enable signal input by the main board; the output end of the constant current feedback circuit is connected to the feedback end of the first single-stage PFC circuit;
  • An input end of the constant voltage switch circuit is connected to a direct current, an output end of the constant voltage switch circuit is connected to an input end of the second transformer, and a sampling end of the second transformer and the second single-stage PFC circuit The zero current detecting end is connected; the output end of the second transformer is electrically connected to the main board.
  • the constant current feedback circuit turns off the first single-stage PFC circuit when the constant current feedback circuit detects that the LED light bar stops working.
  • the switching power supply further includes a DC-DC conversion circuit, an input end of the DC-DC conversion circuit is connected to an output end of the second transformer, and an output end of the DC-DC conversion circuit is electrically connected to the main board .
  • the constant current control circuit includes a start-up circuit, a constant current reference source circuit, and a plurality of mirrored constant current circuits; an input end of the start-up circuit is connected to the main board, and receives an enable signal; The output end is connected to the controlled end of the constant current reference source circuit, the input end of the constant current reference source circuit is connected to the output end of an LED light bar; and the controlled end of the mirror constant current circuit is connected to the constant current The output terminals of the reference source circuit are connected, and the input ends of the mirror constant current circuit are respectively connected to the output ends of the other LED strips.
  • the starting circuit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth triode, and a fifth triode;
  • the first end of the eleventh resistor is connected to the direct current power source, the second end of the eleventh resistor is connected to the emitter of the fourth triode, and the collector of the fourth triode and the controlled end of the constant current reference source circuit Connecting, the base of the fourth triode is connected to the collector of the fifth triode through the twelfth resistor, the emitter of the fifth triode is grounded, and the base of the fifth triode is connected to the thirteenth resistor
  • the motherboard is connected to receive the enable signal from the motherboard.
  • the constant current reference source circuit includes a fourteenth resistor, a second voltage reference chip, and a sixth transistor; an input end of the second voltage reference chip is connected to a collector of the fourth transistor, and the second voltage The output end of the reference chip is grounded, the reference end of the second voltage reference chip is connected to the controlled end of the mirror constant current circuit, and the reference end of the second voltage reference chip is also connected to the base of the sixth triode, the sixth three
  • the base of the pole tube is also connected to the collector of the fourth transistor, the collector of the sixth transistor is connected to the output end of the LED strip, and the emitter of the sixth transistor is grounded via the fourteenth resistor.
  • the mirror constant current circuit includes a fifteenth resistor and a seventh triode; a collector of the seventh triode is connected to an output end of the other LED strip, and an emitter of the seventh triode is subjected to a fifteenth resistor Ground.
  • the switching power supply further includes an overvoltage adjusting circuit, wherein the number of overvoltage adjusting circuits corresponds to the number of LED strips; the input end of each overvoltage adjusting circuit is connected to the output end of the corresponding constant current switch, and the overvoltage The output of the adjustment circuit is connected to the adjustment terminal of the constant current feedback circuit.
  • an overvoltage adjusting circuit wherein the number of overvoltage adjusting circuits corresponds to the number of LED strips; the input end of each overvoltage adjusting circuit is connected to the output end of the corresponding constant current switch, and the overvoltage The output of the adjustment circuit is connected to the adjustment terminal of the constant current feedback circuit.
  • the switching power supply further includes a first secondary rectification filter circuit and a second secondary rectification filter circuit; the first secondary rectification filter circuit rectifies and filters the pulsating direct current outputted by the first transformer; The second secondary rectifying and filtering circuit rectifies and filters the pulsating direct current outputted by the second transformer.
  • the present invention also provides a television set comprising an LED light bar, a main board, and a switching power supply as described above, wherein the switching power supply is electrically connected to the LED light bar and the main board, and the main board is further connected to the LED The light bar is electrically connected.
  • the switching power supply further includes a constant current switch and a constant current control circuit, wherein the load is an LED light bar.
  • the constant current switch adjusts the brightness of the LED light bar according to the PWM brightness signal output by the main board
  • the constant current control circuit controls the LED strip to be turned on or off according to an enable signal outputted by the main board.
  • the constant current control circuit controls the flow of current through the respective LED strips to be the same when the LED strip is still operating.
  • an input end of the constant current switching circuit is connected to a direct current, and an output end of the constant current switching circuit is connected to an output end of the first transformer; a sampling end of the first transformer and the first single a zero current detecting end of the PFC circuit is connected; an output end of the first transformer is connected to an input end of the LED light bar, and an output end of the LED light bar is connected to an input end of the constant current switch, a controlled end of the constant current switch is connected to the main board, and an output end of the constant current switch is connected to an input end of the constant current control circuit; an output end of the constant current control circuit and an input end of the constant current feedback circuit Connected, the controlled end of the constant current control circuit receives an enable signal input by the main board; the output end of the constant current feedback circuit is connected to the feedback end of the first single-stage PFC circuit;
  • An input end of the constant voltage switch circuit is connected to a direct current, an output end of the constant voltage switch circuit is connected to an input end of the second transformer, and a sampling end of the second transformer and the second single-stage PFC circuit The zero current detecting end is connected; the output end of the second transformer is electrically connected to the main board.
  • the constant current feedback circuit turns off the first single-stage PFC circuit when the constant current feedback circuit detects that the LED light bar stops working.
  • the switching power supply further includes a DC-DC conversion circuit, an input end of the DC-DC conversion circuit is connected to an output end of the second transformer, and an output end of the DC-DC conversion circuit is electrically connected to the main board .
  • the technical scheme of the invention forms a switching power supply by providing a constant current switching circuit, a first single-stage PFC circuit, a first transformer, a constant current feedback circuit, a constant voltage switching circuit, a second single-stage PFC circuit, and a second transformer. .
  • the invention adopts a single-stage PFC type output without secondary boost conversion.
  • the first single-stage PFC circuit controls the operation of the first transformer, directly converts the AC-DC, outputs the constant current source, and eliminates the high-voltage electrolytic capacitor, thereby improving the power factor of the power supply and reducing the system formation; meanwhile, the constant current switch
  • the circuit, the first single-stage PFC circuit, the first transformer, and the constant current feedback circuit form a constant current output circuit, and the constant voltage switch circuit, the second single-stage PFC circuit, and the second transformer constitute a constant voltage output circuit.
  • the constant voltage source and the constant current source of the switching power supply output are respectively controlled so that the constant voltage and the constant current output do not interfere with each other during the dynamic load, and the constant voltage source is not affected by the crossover of the electrical parameter deviation of the LED lamp itself, thereby improving the system. Stability.
  • Figure 1 shows a conventional TV power supply architecture
  • FIG. 2 is a functional block diagram of an embodiment of a switching power supply of the present invention
  • FIG. 3 is a functional block diagram of a further embodiment of a switching power supply of the present invention.
  • FIG. 4 is a schematic structural view of an embodiment of a switching power supply according to the present invention.
  • first, second, and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated.
  • features defining “first” or “second” may include at least one of the features, either explicitly or implicitly.
  • the technical solutions between the various embodiments may be combined with each other, but must be based on the realization of those skilled in the art, and when the combination of the technical solutions is contradictory or impossible to implement, it should be considered that the combination of the technical solutions does not exist. It is also within the scope of protection required by the present invention.
  • the invention provides a switching power supply.
  • the switching power supply includes a constant current switching circuit 1, a first single-stage PFC circuit 2, a first transformer T1, and a constant current feedback circuit 4.
  • the switching power supply further includes a constant The voltage switch circuit 5, the second single-stage PFC circuit 6, and the second transformer T2.
  • the constant current feedback circuit 4 samples the current output by the first transformer T1, and feeds the sampling current to the first single-stage PFC circuit 2; the first single-stage PFC circuit 2, and outputs a switching signal according to the sampling current.
  • the constant current switching circuit 1 is driven to be turned on or off to control the load current to be constant.
  • the constant current switching circuit 1 converts the input direct current into a pulsating direct current and outputs it to the first transformer T1.
  • the first transformer T1 converts the input pulsating direct current into a voltage and outputs the voltage to the load.
  • the second single-stage PFC circuit 6 outputs a switching signal to drive the constant voltage switching circuit 5 to be turned on or off;
  • the second single-stage PFC circuit 6 further samples the output voltage of the second transformer T2 to obtain a sampling voltage, and adjusts the duty ratio of the switching signal according to the sampling voltage to adjust the voltage output to the main board. Control the load voltage to be constant.
  • the constant voltage switch circuit 5 converts the input DC power into a pulsating DC power and outputs it to the second transformer T2.
  • the second transformer T2 converts the input pulsating DC power to a main board.
  • the switching power supply is applied to a television set, wherein the first transformer supplies power to the LED strips in the television set, and the second transformer supplies power to the main board of the television set.
  • the switching power supply further includes an EMI filter circuit 10 and a pre-stage rectification filter circuit 11.
  • the AC power outputted by the external power source is filtered by the EMI filter circuit 10 to filter out the electromagnetic disturbance, and then input to the pre-stage rectification and filtering circuit, and is rectified and filtered by the pre-stage rectification and filtering circuit 11 and output to the first transformer T1.
  • the first single-stage PFC circuit 2 includes a control chip and a corresponding peripheral circuit.
  • the control chip adopts the HVLED001A chip of ST semiconductor, and can automatically control the working mode of the power switch frequency to enter the jump cycle during standby light load. Improve standby light load efficiency, eliminate the need for standby transformers, and save costs.
  • the constant current switch M can be a MOS tube, an IGBT tube, a thyristor or the like. In this embodiment, a MOS tube is used.
  • the technical solution of the present invention forms a switching power supply by providing a constant current switching circuit 1, a first single-stage PFC circuit 2, a first transformer T1, and a constant current feedback circuit 4.
  • the invention adopts a single-stage PFC type output without secondary boost conversion.
  • the first single-stage PFC circuit 2 controls the operation of the first transformer T1, directly performs AC-DC conversion, outputs a constant current source, and eliminates the high-voltage electrolytic capacitor, thereby improving the power factor of the power supply and reducing the system cost;
  • the flow switching circuit 1, the first single-stage PFC circuit 2, the first transformer T1, and the constant current feedback circuit 4 constitute a constant current output circuit, and the constant voltage switching circuit 5, the second single-stage PFC circuit 6, and the second transformer T2 constitutes a constant voltage output circuit.
  • the constant voltage source and the constant current source of the switching power supply output are respectively controlled so that the constant voltage and the constant current output do not interfere with each other during the dynamic load, and the constant voltage source is not affected by the crossover of the electrical parameter deviation of the LED lamp itself, thereby improving the system. Stability.
  • the switching power supply further includes a constant current switch M and a constant current control circuit 3.
  • the constant current switch M adjusts the brightness of the LED light bar according to the PWM brightness signal output by the main board.
  • the constant current control circuit 3 controls the LED strip to be turned on or off according to an enable signal outputted by the main board.
  • the number of LED strips is plural.
  • the constant current control circuit controls the flow of current flowing through each LED strip while the LED strip is working, so that the LED is The illumination display is enhanced in consistency.
  • the input end of the constant current switching circuit 1 is connected to a direct current
  • the output end of the constant current switching circuit 1 is connected to the output end of the first transformer T1
  • the sampling end of the first transformer T1 is The zero current detecting end of the first single stage PFC circuit 2 is connected
  • the output end of the first transformer T1 is connected to the input end of the LED light bar, the output end of the LED light bar and the constant current switch M
  • the input end of the constant current switch M is connected to the main board, and the output end of the constant current switch M is connected to the input end of the constant current control circuit 3;
  • the output of the constant current control circuit 3 The end is connected to the input end of the constant current feedback circuit 4, and the controlled end of the constant current control circuit 3 receives an enable signal input by the main board; the output end of the constant current feedback circuit 4 and the first single stage The feedback terminal of the PFC circuit 2 is connected.
  • the input end of the constant voltage switch circuit 5 is connected to a direct current, the output end of the constant voltage switch circuit 5 is connected to the input end of the second transformer T2, and the sampling end of the second transformer T2 is opposite to the second
  • the zero current detecting end of the single stage PFC circuit 6 is connected; the output end of the second transformer T2 is electrically connected to the main board.
  • the zero current detecting ends of the first single-stage PFC circuit 2 and the second single-stage PFC circuit 6 are also respectively connected to the auxiliary windings of the first transformer T1 and the second transformer T2 to detect the zero-crossing point of the current or voltage. Therefore, the corresponding switch tube is controlled to be turned on or off at the zero crossing point to reduce loss and improve power consumption efficiency.
  • the first single-stage PFC circuit 2 adjusts a duty ratio of the switch signal to adjust a current output to the LED strip according to a feedback level of the optocoupler U2; the second single-stage PFC circuit 6, The sampling the output voltage of the second transformer T2 to obtain a sampling voltage, and adjusting the duty ratio of the switching signal according to the sampling voltage to adjust the voltage output to the main board.
  • the first single-stage PFC circuit 2 is controlled by the constant current feedback circuit 4, and the operating frequency or duty ratio of the first single-stage PFC circuit 2 is adjusted. Further, the constant current switching circuit 1 is further controlled to make the voltage outputted by the flyback transformer small, so that the voltage outputted by the first transformer T1 matches the operating voltage of the LED light bar, thereby reducing the temperature rise of the constant current control circuit 3. The problem of large difference in output voltage caused by large voltage deviation of the same screen LED lamp in mass production is solved.
  • the first single-stage PFC circuit 2 also makes the voltage of the auxiliary winding constant by the auxiliary winding of the first transformer T1, thereby limiting the voltage output by the first transformer T1 within a prescribed range.
  • the constant voltage switch circuit 5 further controls the second transformer T2 under the control of the second single-stage PFC current, and after rectifying and filtering, outputs a stable constant voltage source.
  • the constant voltage feedback loop is the primary side feedback, that is, the voltage of the auxiliary winding is constant through the auxiliary winding of the second transformer T2, so that the voltage outputted by the second transformer T2 is constant.
  • the switching power supply further includes a first secondary rectifying and filtering circuit 7 and a second secondary rectifying and filtering circuit 8; the first secondary rectifying and filtering circuit 7 rectifies and filters the pulsating direct current outputted by the first transformer T1
  • the second secondary rectifying and filtering circuit 8 rectifies and filters the pulsating direct current output by the second transformer T2.
  • the constant current feedback circuit 4 when the constant current feedback circuit 4 detects that the LED light bar is off, that is, when the LED light bar is detected to be inoperative, the constant current feedback circuit 4 turns off the first single-stage PFC circuit. 2, thereby reducing the loss of the first single-stage PFC circuit 2.
  • the switching power supply further includes a DC-DC conversion circuit 9, an input terminal of the DC-DC conversion circuit 9 is connected to an output terminal of the second secondary rectification filter circuit 8, and an output of the DC-DC conversion circuit 9 The terminal is electrically connected to the motherboard.
  • the switching power supply includes a plurality of constant current switches M, and the input ends and the output ends of the plurality of constant current switches M are respectively connected in series with the LED light strips. Between the output end and the input end of the constant current control circuit 3, the controlled ends of the plurality of constant current switches M receive the PWM luminance signal output by the main board.
  • the constant current control circuit 3 includes a start circuit 31, a constant current reference source circuit 32, and a plurality of mirror constant current circuits 33.
  • the input end of the start circuit 31 is connected to the main board to receive an enable signal.
  • An output end of the start-up circuit 31 is connected to a controlled end of the constant current reference source circuit 32, and an input end of the constant current reference source circuit 32 is connected to an output end of an LED strip; the image constant current circuit 33 is controlled
  • the terminals are connected to the output of the constant current reference source circuit 32, and the input ends of the mirrored constant current circuit 33 are respectively connected to the output ends of the remaining LED strips.
  • the enable signal sent by the main board includes an enable signal and a shutdown signal.
  • the start-up circuit 31 receives the turn-on signal, the start-up circuit 31 outputs a high level, the constant current reference source circuit 32 is turned on, and the constant current reference source circuit 32 supplies a current reference for each of the mirror-image constant current circuits 33 of the subsequent stage, and each mirror image of the subsequent stage is constant.
  • the stream circuit 33 replicates the current in the constant current reference source circuit 32 such that the current of each of the mirror constant current circuits 33 is equal to the current of the constant current reference source circuit 32, so that the luminance of each LED strip does not shift.
  • the switching power supply further includes an overvoltage adjustment circuit (not shown), wherein the number of overvoltage adjustment circuits corresponds to the number of LED strips.
  • the input end of each overvoltage adjusting circuit is connected to the output end of the corresponding constant current switch M, and the output end of the overvoltage adjusting circuit is connected to the adjusting end of the constant current feedback circuit 4.
  • the overvoltage adjustment circuit is configured to control the first single-stage PFC circuit 2 through the constant current feedback circuit 4 when the output voltage of the transformer exceeds the voltage of the LED light bar, adjust the switching frequency of the first MOS tube, and reduce the output of the transformer to the LED light bar. Voltage.
  • the constant current mode of the present invention is controlled by the series constant current reference source circuit 32, so that the current flowing through the LED strip is constant, and when the ripple is large, the constant current reference source circuit 32 can automatically adjust the voltage division to reduce the current ripple.
  • the first single-stage PFC circuit 2 of the primary side is controlled by the overvoltage adjustment, thereby lowering the output voltage, so that the voltage across the constant current source is lowered.
  • the first transformer T1 includes a primary winding, a secondary winding, and an auxiliary winding, wherein the auxiliary winding is disposed at a primary of the transformer;
  • the first single-stage PFC circuit 2 includes a first resistor R1, a second resistor R2, a third resistor R3, and a first control chip U1;
  • the constant current switching circuit 1 includes a first MOS transistor K1 and a fourth resistor R4;
  • the first control chip U1 includes an overvoltage protection terminal HVSU, a power terminal VCC, a driver terminal GATE, a ground terminal GND, an overcurrent detection terminal CS, a zero-cross detection terminal ZCD, a feedback terminal FB, and a control terminal CTRL;
  • the first end of the first resistor R1 is connected to the output end of the pre-rectifier filter circuit 11, and the second end of the first resistor R1 is connected to the overvoltage protection end of the first control chip U1;
  • the first end of the auxiliary winding is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the third resistor R3, and the third resistor R3
  • the second end is grounded, the second end of the auxiliary winding of the first transformer T1 is grounded, the zero-cross detecting end of the first control chip U1 is connected to the first end of the third resistor R3;
  • the primary winding of the first transformer T1 The first end is connected to the output end of the pre-stage rectification filter circuit, the second end of the primary coil of the first transformer T1 is connected to the drain of the first MOS transistor K1, and the source of the first MOS transistor K1 is passed through the fourth resistor R4 is grounded, the gate of the first MOS transistor K1 is connected
  • the first secondary rectifying and filtering circuit 7 includes a first diode D1 and a first capacitor C1; an anode of the first diode D1 is connected to a first end of the secondary winding, and a cathode of the first diode D1 is The first end of the LED strip is connected, and the second end of the secondary winding is grounded; the first end of the first capacitor C1 is connected to the cathode of the first diode D1, and the second end of the first capacitor C1 is grounded.
  • the constant current feedback circuit 4 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a first optocoupler U2, a second optocoupler U3,
  • the first DC source VCC1 is supplied by the voltage output from the second transformer T2.
  • the side of the photocoupler provided with the illuminator is the control side.
  • the side with the light receiver is the executive side.
  • the first end of the fifth resistor R5 is connected to the cathode of the first diode D1, and the second end of the fifth resistor R5 is connected to the control side input end of the first optocoupler U2, and the control side output end of the first optocoupler U2 Connected to the input end of the first voltage reference chip WZ1, the output end of the first voltage reference chip WZ1 is grounded, the reference end of the first voltage reference chip WZ1 is connected to the output end of the constant current switch M; the first optocoupler U2 performs the side input The terminal is grounded, and the output end of the first optocoupler U2 is connected to the feedback end of the first control chip U1.
  • the first end of the sixth resistor R6 is connected to the first DC source VCC1, the second end of the sixth resistor R6 is connected to the collector of the first transistor Q1, and the emitter of the first transistor Q1 is connected to the seventh resistor.
  • R7 is grounded, the base of the first transistor Q1 is connected to the base of the second transistor Q2;
  • the first end of the eighth resistor R8 is connected to the first DC source VCC1, and the second end of the eighth resistor R8 is The collector of the second transistor Q2 is connected, the emitter of the second transistor Q2 is grounded via the second capacitor C2;
  • the first end of the ninth resistor R9 is connected to the first DC source VCC1, and the ninth resistor R9 is
  • the two ends are connected to the execution input end of the second photocoupler U3, the execution output end of the second photocoupler U3 is connected to the base of the second transistor Q2, and the control side input end of the second optocoupler U3 is connected to the tenth resistor R10.
  • the control side output of the second optocoupler U3 is connected to the collector of the third transistor Q3, the emitter of the third transistor Q3 is grounded, and the base of the third transistor Q3 is Electrically connected to the motherboard to receive the power-on signal and shutdown signal output from the motherboard.
  • the constant current switch M includes a first constant current switch M1 and a second constant current switch M2.
  • the input end of the first constant current switch M1 and an LED strip The output end of the first constant current switch M1 is connected to the input end of the constant current reference source circuit 32, and the input end of the second constant current switch M2 is connected to the output end of the other LED strip, the second constant current
  • the output end of the switch M2 is connected to the input end of the constant current reference source circuit 32, and the controlled end of the first constant current switch M1 and the controlled end of the second constant current switch M2 are electrically connected to the main board to receive the PWM output of the main board. Brightness signal.
  • the starting circuit 31 includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourth triode Q4, and a fifth triode Q5;
  • the first end of the eleventh resistor R11 is connected to the 12V DC power supply, the second end of the eleventh resistor R11 is connected to the emitter of the fourth transistor Q4, and the collector and constant current reference source of the fourth transistor Q4
  • the controlled end of the circuit 32 is connected, the base of the fourth transistor Q4 is connected to the collector of the fifth transistor Q5 via the twelfth resistor R12, and the emitter of the fifth transistor Q5 is grounded, the fifth three pole
  • the base of the tube Q5 is connected to the main board via the thirteenth resistor R13 to receive the enable signal EN of the main board.
  • the constant current reference source circuit 32 includes a fourteenth resistor R14, a second voltage reference chip WZ2, and a sixth transistor Q6; the input end of the second voltage reference chip WZ2 is connected to the collector of the fourth transistor Q4. The output end of the second voltage reference chip WZ2 is grounded, the reference end of the second voltage reference chip WZ2 is connected to the controlled end of the mirror constant current circuit 33, and the reference end of the second voltage reference chip WZ2 is also connected to the sixth transistor Q6. a base connection, the base of the sixth transistor Q6 is also connected to the collector of the fourth transistor Q4, and the collector of the sixth transistor Q6 is connected to the output end of the first constant current switch M1, The emitter of the six transistor Q6 is grounded via the fourteenth resistor R14.
  • the mirror constant current circuit 33 includes a fifteenth resistor R15 and a seventh transistor Q7; the collector of the seventh transistor Q7 is connected to the output end of the second constant current switch M2, and the seventh transistor Q7 is emitted.
  • the pole is grounded via the fifteenth resistor R15.
  • the second single-stage PFC circuit 6 includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a third capacitor C3, and a second diode.
  • the second transformer T2 includes a primary winding, a secondary winding, and An auxiliary winding, wherein the auxiliary winding is disposed at a primary of the transformer;
  • the second control chip U4 includes an overvoltage protection terminal HVSU, a power terminal VCC, a driver terminal GATE, a ground terminal GND, an overcurrent detection terminal CS, a zero crossing detection terminal ZCD, And the control terminal CTRL.
  • the first end of the sixteenth resistor R16 is connected to the cathode of the second diode D2, the anode of the second diode D2 is connected to the first end of the auxiliary winding of the second transformer T2, and the second end of the auxiliary winding is grounded,
  • the second end of the sixteen resistor R16 is connected to the collector of the eighth transistor Q8, the emitter of the eighth transistor Q8 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is
  • the power terminal of the second control chip U4 is connected, the first end of the fourth capacitor C4 is connected to the cathode of the third diode D3, the second end of the fourth capacitor C4 is grounded, and the base of the eighth transistor Q8 is tenth.
  • the seventh resistor R17 is connected to the cathode of the second diode D2; the first end of the third capacitor C3 is connected to the cathode of the second diode D2, and the second end of the third capacitor C3 is grounded; the first Zener diode Z1 The anode is connected to the base of the eighth transistor Q8, the cathode of the first Zener diode Z1 is grounded, the first end of the eighteenth resistor R18 is connected to the base of the eighth transistor Q8, and the eighteenth resistor R18 The second end is grounded; the overvoltage protection end of the second control chip U4 is connected to the second end of the first resistor R1, and the ground end of the second control chip U4 is grounded; The first end of the nine resistor R19 is connected to the anode of the second diode D2, the second end of the nineteenth resistor R19 is grounded via the twentieth resistor R20; the zero crossing detecting end of the second control chip U4 and the nineteenth resistor The second end of R19 is connected
  • the constant current switching circuit 1 includes a second eleventh resistor R21 and a second MOS transistor K2; a first end of the second winding of the second transformer T2 is connected to an output end of the pre-stage rectifying and filtering circuit, and a drain of the second MOS transistor K2 Connected to the second end of the primary winding of the second transformer T2, the source of the second MOS transistor K2 is grounded via the second eleventh resistor R21, and the gate of the second MOS transistor K2 is connected to the driving end of the second control chip U4, The overcurrent detecting end of the second control chip U4 is connected to the source of the second MOS transistor K2.
  • the second secondary rectifying and filtering circuit 8 includes a fourth diode D4 and a fifth capacitor C5.
  • the anode of the fourth diode D4 is connected to the first end of the secondary winding of the second transformer T2.
  • the second terminal is grounded, and the cathode of the fourth diode D4 is connected to the input end of the DC-DC conversion circuit 9, and is output to the main board after voltage conversion.
  • the overvoltage adjustment circuit includes a first overvoltage adjustment circuit (not labeled) and a second overvoltage adjustment circuit (not labeled), and the first overvoltage adjustment circuit includes a twenty-second resistor R22, a twenty-third resistor R23, and a second a fifth diode D5 and a sixth capacitor C6;
  • the second overvoltage adjusting circuit comprises a twenty-fourth resistor R24, a twenty-fifth resistor R25, a sixth diode D6 and a seventh capacitor C7; wherein, the fifth two The cathode of the pole tube D5 is connected to the voltage reference end of the first voltage reference chip WZ1, and the anode of the fifth diode D5 is connected to the first end of the twenty-fourth resistor R24 via the twenty-third resistor R23, second The second end of the resistor of the fourteenth is connected to the output end of the first constant current switch M1, the first end of the sixth capacitor C6 is connected to the first end of the twenty-second resist
  • the cathode of the sixth diode D6 is connected to the voltage reference terminal of the first voltage reference chip WZ1, and the anode of the sixth diode D6 is connected to the first end of the second sixteen resistor via the twenty-fifth resistor R25.
  • the second end of the twenty-sixth resistor is connected to the output end of the first constant current switch M1
  • the first end of the seventh capacitor C7 is connected to the first end of the twenty-fourth resistor R24
  • the second end of the seventh capacitor C7 is Grounded at the end.
  • the power supply is processed by the EMI filter circuit 10 and the pre-stage rectification filter circuit 11 and then supplied to the first transformer T1 and the second transformer T2, respectively, without large electrolytic capacitor filtering, the first MOS transistor K1 and the second MOS transistor K2.
  • the transformer is further controlled, so that the first transformer T1 is processed by the first secondary rectifying and filtering circuit 7 and then supplied to the LED strip to supply power; after the second transformer T2 is processed by the second secondary rectifying and filtering circuit 8 Power is supplied to the motherboard.
  • the above-mentioned single-stage PFC controls the constant current switching circuit 1 and the constant voltage switching circuit 5, and further controls the first converter and the second transformer T2, respectively, so that the design does not require a high voltage electrolytic capacitor, thereby saving PCB area and cost. Since the constant current source outputted by the first transformer T1 and the constant voltage source outputted by the second transformer T2 are respectively controlled, the constant voltage and the constant current output do not interfere with each other under dynamic load, and the constant voltage is not affected by the crossover of the LED lamp deviation. Improve the stability of the system.
  • the third transistor Q3 When the power-on signal is high, the third transistor Q3 is turned on, and the second transistor Q2 is turned on by the second photocoupler U3, and the first DC source VCC1 is output to the first control via the eighth resistor R8.
  • the power supply end of the chip U1 supplies power to the first control chip U1, and the first transistor Q1 is turned on, and the voltage is sampled by the sixth resistor R6 and the seventh resistor R7, and then connected to the control end of the first control chip U1, so that the first A control chip U1 starts working.
  • the enable signal EN when the enable signal EN is at a high level, the constant current reference source circuit 32 starts to operate, and the sixth transistor Q6 is turned on, and a current flows through the LED strip to be in a bright state.
  • the brightness of the LED light bar is adjusted by the PWM bright spot signal outputted by the main board, specifically by controlling the on-time of the first constant current switch M1 to adjust the brightness of the LED light bar.
  • the duty ratio of the PWM brightness signal is large, The LED strip light is brighter.
  • the duty cycle of the PWM luminance signal is small, the LED strip is dark.
  • the constant current reference source circuit 32 stops operating, and the sixth transistor Q6 is turned off, and no current flows through the LED strip, and is in a state of being off.
  • the third transistor Q3 When the output signal of the main board is low, the third transistor Q3 is turned off, and the second transistor Q2 is turned off by the second photocoupler U3, so that the power of the second control chip U4 is cut off, and the first The transistor Q1 is turned off, and the control terminal of the first control chip U1 stops working after the seventh resistor is pulled low. At this time, the constant current output of the switching power supply stops working, so that the standby power consumption is low.
  • the constant current control circuit 3 is controlled by a series constant current reference source, and the second voltage reference chip WZ2, the sixth transistor Q6, and the fourteenth resistor R14 form a constant current reference source circuit 32, and the second voltage reference chip WZ2 is The constant current supplies a reference voltage, and the sixth transistor Q6 is controlled so that the voltage across the fourteenth resistor R14 is constant, so that the current flowing through the LED strip is constant.
  • the sixth transistor Q6 operates in the amplification region, and the second voltage reference chip WZ2 controls the sixth transistor Q6 to automatically adjust the voltage division of the collector and the emitter. It makes the current more precise and reduces the current ripple.
  • the collector voltage of the sixth transistor Q6 increases due to the constant output voltage of the first transformer T1, and passes through the twenty-fourth resistor R24, the seventh capacitor C7, and the twenty-fifth.
  • a second overvoltage adjusting circuit composed of a resistor R25 and a sixth diode D6 controls the current flowing through the first photocoupler U2 through the first voltage reference chip WZ1, thereby controlling the operating frequency of the first control chip U1, and further The output voltage of the first transformer T1 is lowered, so that the voltage between the collector and the emitter of the sixth transistor Q6 is lowered.
  • Another mirror constant current circuit 33 composed of a seventh transistor Q7 and a fifteenth resistor R15, the mirror constant current circuit 33 is a current mirror body with a constant current reference source circuit 32, such that the constant current circuit and the current mirror body The current is the same, and the subsequent stage can replicate any of the same constant current sources, so that the constant current output can match any number of channels of LED strips.
  • the voltage of the rectified and filtered voltage is pre-activated by the first resistor R1 to the overvoltage protection terminals of the first control chip U1 and the second control chip U4, so that the voltages of the respective power terminals reach the turn-on voltage.
  • the first control chip U1 and the second control chip U4 start to oscillate.
  • the output voltage of the auxiliary winding of the second transformer T2 is via the eighth transistor Q8, the third diode D3, the sixteenth resistor R16, the seventeenth resistor R17, the first Zener diode Z1, and the eighteenth resistor R18.
  • the linear regulator circuit constituting the power supply of the second control chip U4 provides a stable operating voltage for the second control chip U4.
  • the overvoltage protection end of the first control chip U1 and the second control chip U4 detects the full-wave voltage signal of the rectified and filtered voltage as a reference signal, and respectively detects the primary through the fourth resistor R4 and the second eleventh resistor R21 of the current sampling resistor.
  • the current of the winding is compared with the reference signal to control the operating frequency and duty ratio of the first MOS transistor K1 and the second MOS transistor K2.
  • the full-wave voltage When the full-wave voltage is large, the operating frequency is high and the duty ratio is small; when the full wave When the voltage is small, the operating frequency is low, and the duty ratio is large, the full-wave voltage signal and the current flowing through the primary winding of the corresponding transformer are in phase, and finally the power factor is improved, and the AC-DC conversion is also realized.
  • the constant current source for supplying the LED strip and the constant voltage source for supplying power to the main board are separately controlled, and the first transformer T1, the second transformer T2, the first MOS transistor K1, and the second MOS are reduced.
  • the working temperature rise of the tube K2 also improves the stability of the system independent control.
  • the constant current control circuit 3 further controls the first MOS transistor K1 by the operating frequency and the duty ratio of the first control chip U1 becoming smaller.
  • the voltage output from the first transformer T1 becomes small, so that the voltage output from the first transformer T1 matches the operating voltage of the LED strip, thereby reducing the temperature rise of the constant current control circuit 3.
  • the problem of large difference in output voltage caused by large voltage deviation of the same screen LED strip in mass production is solved.
  • the fifth resistor R5 serves as a current limiting resistor of the first photocoupler U2.
  • the fourth resistor R4 samples the current in the primary winding and connects to the overcurrent detecting end of the first control chip U1.
  • the voltage sampled in the fourth resistor R4 is greater than the overcurrent detection of the first control chip U1.
  • the internal reference voltage of the terminal causes the first control chip U1 to be overload protected and activated.
  • the sampling resistor second resistor R2 and the third resistor R3 sample the voltage of the auxiliary winding of the transformer, so that the voltage of the auxiliary winding is limited to a safe range, and the voltage output from the first transformer T1 is prevented from being excessively large.
  • the second MOS transistor K2 further controls the second transformer T2 under the control of the second single-stage PFC circuit 6, rectifies through the fourth diode D4, and filters the fourth capacitor to output a stable constant voltage source.
  • the constant voltage feedback loop is the primary side feedback, that is, the voltage of the auxiliary winding of the second transformer T2 is sampled by the sampling resistor 19th resistor R19 and the twentieth resistor R20, so that the voltage of the auxiliary winding is constant, and the output voltage is constant.
  • the DC-DC conversion circuit can be added at the output to make the output voltage ripple smaller.
  • the mirror constant current circuit 33 can be arbitrarily expanded according to the number of channels of the LED light bar, so that the solution achieves the requirement of matching the number of LED strips of any channel, and realizes the low cost and high power factor of the large-size TV power supply. design.
  • the present invention also provides a television set comprising an LED light bar, a main board and the above-mentioned switching power supply.
  • the specific structure of the switching power supply refers to the above embodiment, and since the television set adopts all the technical solutions of all the above embodiments, At least the advantages of the technical solutions of the above embodiments are not repeated here.
  • the switching power supply is respectively electrolyzed with the LED light bar and the main board to provide a constant current source and a constant voltage source, respectively.
  • the motherboard is also electrically connected to the LED strip to control the brightness of the LED strip.

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Abstract

本发明公开一种开关电源及电视机，其中该开关电源包括恒流开关电路、第一单级PFC电路、第一变压器、恒流反馈电路、恒压开关电路、第二单级PFC电路、及第二变压器；恒流反馈电路对第一变压器输出的电流进行采样，并将采样电流反馈至第一单级PFC电路；第一单级PFC电路，并根据采样电流输出开关信号，驱动恒流开关电路导通或关断，控制负载电流恒定；第二单级PFC电路，输出开关信号，驱动恒压开关电路导通或关断; 第二单级PFC电路，对第二变压器输出电压进行采样得到采样电压，并根据采样电压，调节开关信号的占空比以调节输出至主板的电压，控制主板电压恒定。本发明技术方案提高电源转换效率、稳定性、降低成本。

Description

开关电源及电视机
技术领域
本发明涉及电源技术领域，特别涉及一种开关电源及应用该开关电源的电视机。
背景技术
当负载功率需求大于75W时，因国家标准要求功率因素需大于0.9，传统的电视机电源架构如图1所示，电源需先进行功率因素校正后，再进行DC-DC的转换，使得恒压输出电源输出的24V需经过BOOST升压后给背光灯条供电，这会使得电源转换效率低，且增加了恒流板的成本及PFC电路的成本。同时这种电源架构恒流恒压交替输出，使得恒压和恒流的动态负载时容易受到干扰。
发明内容
本发明的主要目的是提供一种开关电源，旨在提高电源转换效率、提高恒压恒流输出的稳定性、降低电源成本。
为实现上述目的，本发明提出了一种开关电源，包括恒流开关电路、第一单级PFC电路、第一变压器、恒流反馈电路；所述开关电源还包括恒压开关电路、第二单级PFC电路、及第二变压器； 其中，
所述恒流反馈电路对第一变压器输出的电流进行采样，并将采样电流反馈至第一单级PFC电路；
所述第一单级PFC电路，并根据采样电流输出开关信号，驱动恒流开关电路导通或关断，控制负载电流恒定；
所述第二单级PFC电路，输出开关信号，驱动恒压开关电路导通或关断; 所述第二单级PFC电路，对所述第二变压器输出电压进行采样得到采样电压，并根据所述采样电压，调节开关信号的占空比以调节输出至主板的电压，控制负载电压恒定。
优选地，所述开关电源还包括恒流开关、及恒流控制电路，其中，所述负载为LED灯条，
所述恒流开关，根据主板输出的PWM亮度信号调节LED灯条的亮度；
所述恒流控制电路，根据主板输出的使能信号，控制LED灯条点亮或熄灭。
优选地，所述恒流控制电路在还在LED灯条工作时，控制流过各个LED灯条中流过电流相同。
优选地，所述恒流开关电路的输入端接入直流电，所述恒流开关电路的输出端与所述第一变压器的输出端连接；所述第一变压器的采样端与所述第一单级PFC电路的零电流检测端连接；所述第一变压器的输出端与所述LED灯条的输入端连接，所述LED灯条的输出端与所述恒流开关的输入端连接，所述恒流开关的受控端连接至主板，所述恒流开关的输出端与所述恒流控制电路的输入端连接；所述恒流控制电路的输出端与所述恒流反馈电路的输入端连接，所述恒流控制电路的受控端接收主板输入的使能信号；所述恒流反馈电路的输出端与所述第一单级PFC电路的反馈端连接；
所述恒压开关电路的输入端接入直流电，所述恒压开关电路的输出端与所述第二变压器的输入端连接，所述第二变压器的采样端与所述第二单级PFC电路的零电流检测端连接；所述第二变压器的输出端与所述主板电连接。
优选地，在所述恒流反馈电路检测到LED灯条停止工作时，恒流反馈电路关断所述第一单级PFC电路。
优选地，所述开关电源还包括DC-DC转换电路，所述DC-DC转换电路的输入端与所述第二变压器的输出端连接，所述DC-DC转换电路的输出端与主板电连接。
优选地，所述恒流控制电路包括启动电路、恒流基准源电路、及多个镜像恒流电路；所述启动电路的输入端与所述主板连接，接收使能信号；所述启动电路的输出端与所述恒流基准源电路的受控端连接，所述恒流基准源电路的输入端与一LED灯条的输出端连接；镜像恒流电路的受控端均与所述恒流基准源电路的输出端连接，镜像恒流电路输入端分别与其它LED灯条的输出端连接。
优选地，所述启动电路包括第十一电阻、第十二电阻、第十三电阻、第四三极管、第五三极管；
第十一电阻的第一端连接至直流电源，第十一电阻的第二端与第四三极管的发射极连接，第四三极管的集电极与恒流基准源电路的受控端连接，第四三极管的基极经第十二电阻与第五三极管的集电极连接，第五三极管的发射极接地，第五三极管的基极经第十三电阻与主板连接，以接收主板的使能信号。
优选地，所述恒流基准源电路包括第十四电阻、第二电压基准芯片、第六三极管；第二电压基准芯片的输入端与第四三极管的集电极连接，第二电压基准芯片的输出端接地，第二电压基准芯片的参考端与镜像恒流电路的受控端连接，且第二电压基准芯片的参考端还与第六三极管的基极连接，第六三极管的基极同时还与第四三极管的集电极连接，第六三极管的集电极与LED灯条的输出端连接，第六三极管的发射极经第十四电阻接地。
所述镜像恒流电路包括第十五电阻、第七三极管；第七三极管的集电极与另一LED灯条的输出端连接，第七三极管的发射极经第十五电阻接地。
优选地，该开关电源还包括过压调整电路，其中过压调整电路的数量与LED灯条的数量对应；每一过压调整电路的输入端与对应地恒流开关的输出端连接，过压调整电路的输出端均与恒流反馈电路的调整端连接。
优选地，所述开关电源还包括第一次级整流滤波电路及第二次级整流滤波电路；所述第一次级整流滤波电路，对第一变压器输出的脉动直流电进行整流滤波；所述第二次级整流滤波电路，对第二变压器输出的脉动直流电进行整流滤波。
本发明还提出了一种电视机，包括LED灯条、主板、及如上所述的开关电源，所述开关电源分别所述LED灯条及所述主板电连接，所述主板还与所述LED灯条电连接。
优选地，所述开关电源还包括恒流开关、及恒流控制电路，其中，所述负载为LED灯条，
所述恒流开关，根据主板输出的PWM亮度信号调节LED灯条的亮度；
所述恒流控制电路，根据主板输出的使能信号，控制LED灯条点亮或熄灭。
优选地，所述恒流控制电路在还在LED灯条工作时，控制流过各个LED灯条中流过电流相同。
优选地，所述恒流开关电路的输入端接入直流电，所述恒流开关电路的输出端与所述第一变压器的输出端连接；所述第一变压器的采样端与所述第一单级PFC电路的零电流检测端连接；所述第一变压器的输出端与所述LED灯条的输入端连接，所述LED灯条的输出端与所述恒流开关的输入端连接，所述恒流开关的受控端连接至主板，所述恒流开关的输出端与所述恒流控制电路的输入端连接；所述恒流控制电路的输出端与所述恒流反馈电路的输入端连接，所述恒流控制电路的受控端接收主板输入的使能信号；所述恒流反馈电路的输出端与所述第一单级PFC电路的反馈端连接；
所述恒压开关电路的输入端接入直流电，所述恒压开关电路的输出端与所述第二变压器的输入端连接，所述第二变压器的采样端与所述第二单级PFC电路的零电流检测端连接；所述第二变压器的输出端与所述主板电连接。
优选地，在所述恒流反馈电路检测到LED灯条停止工作时，恒流反馈电路关断所述第一单级PFC电路。
优选地，所述开关电源还包括DC-DC转换电路，所述DC-DC转换电路的输入端与所述第二变压器的输出端连接，所述DC-DC转换电路的输出端与主板电连接。
本发明技术方案通过设置恒流开关电路、第一单级PFC电路、第一变压器、恒流反馈电路、恒压开关电路、第二单级PFC电路、及第二变压器，形成了一种开关电源。本发明采用单级PFC式输出，无需二次升压转换。即通过第一单级PFC电路控制第一变压器工作，直接进行AC-DC的转换，输出恒流源，省去了高压电解电容，提高了电源功率因素，降低了***成；同时，恒流开关电路、第一单级PFC电路、第一变压器、及恒流反馈电路组成了恒流输出电路，而恒压开关电路、第二单级PFC电路、及第二变压器则组成了恒压输出电路。如此，开关电源输出的恒压源和恒流源各自控制，使得恒压和恒流输出在动态负载时互不干扰，且恒压源不受LED灯本身电气参数偏差的交叉影响，提高了***的稳定性。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图示出的结构获得其他的附图。
图1为传统的电视机电源架构；
图2为本发明开关电源一实施例的功能模块图；
图3为本发明开关电源进一步实施例的功能模块图；
图4为本发明开关电源一实施例的结构示意图。
附图标号说明：
标号 名称 标号 名称
1 恒流开关电路 T1 第一变压器
2 第一单级PFC电路 T2 第二变压器
3 恒流控制电路 R1~R25 第一电阻至第二十五电阻
31 启动电路 D1~D6 第一二极管至第六二极管
32 恒流基准源电路 C1~C7 第一电容至第七电容
33 镜像恒流电路 Q1~Q8 第一三极管至第八三极管
4 恒流反馈电路 U1 第一控制芯片
5 恒压开关电路 U2 第一光耦U2
6 第二单级PFC电路 U3 第二光耦
7 第一次级整流滤波电路 U4 第二控制芯片
8 第二次级整流滤波电路 K1 第一MOS管
9 DC-DC转换电路 K2 第二MOS管
10 EMI滤波电路 M 恒流开关
11 前级整流滤波电路 M1 第一恒流开关
WZ1 第一电压基准芯片 M2 第二恒流开关
WZ2 第二电压基准芯片 VCC1 第一直流源
Z1 第一稳压管 VDD 第二直流源
本发明目的的实现、功能特点及优点将结合实施例，参照附图做进一步说明。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
需要说明，本发明实施例中所有方向性指示（诸如上、下、左、右、前、后……）仅用于解释在某一特定姿态（如附图所示）下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
另外，在本发明中涉及“第一”、“第二”等的描述仅用于描述目的，而不能理解为指示或暗示其相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。另外，各个实施例之间的技术方案可以相互结合，但是必须是以本领域普通技术人员能够实现为基础，当技术方案的结合出现相互矛盾或无法实现时应当认为这种技术方案的结合不存在，也不在本发明要求的保护范围之内。
本发明提出一种开关电源。
参照图2及图3，在本发明实施例中，该开关电源包括恒流开关电路1、第一单级PFC电路2、第一变压器T1、恒流反馈电路4；所述开关电源还包括恒压开关电路5、第二单级PFC电路6、及第二变压器T2。
所述恒流反馈电路4对第一变压器T1输出的电流进行采样，并将采样电流反馈至第一单级PFC电路2；所述第一单级PFC电路2，并根据采样电流输出开关信号，驱动恒流开关电路1导通或关断，控制负载电流恒定。
其中，恒流开关电路1，将输入的直流电转换成脉动直流电后输出至第一变压器T1。所述第一变压器T1，将输入的脉动直流电进行电压转换后输出至负载。
所述第二单级PFC电路6，输出开关信号，驱动恒压开关电路5导通或关断; 所述第二单级PFC电路6，还对所述第二变压器T2输出电压进行采样得到采样电压，并根据所述采样电压，调节所述开关信号的占空比以调节输出至主板的电压，控制负载电压恒定。
其中，所述恒压开关电路5，将输入的直流电转换成脉动直流电后输出至第二变压器T2；所述第二变压器T2，将输入的脉动直流电进行电压转换后输出至主板。
本实施例中，该开关电源应用与电视机中，其中第一变压器给电视机中的LED灯条供电，第二变压器给电视机中主板供电。
需要说明的是，本实施例中，该开关电源还包括EMI滤波电路10及前级整流滤波电路11。外部电源输出的交流电经EMI滤波电路10滤除电磁骚扰后，再输入至前级整流滤波电路，经前级整流滤波电路11整流滤波后输出至第一变压器T1。
第一单级PFC电路2包括控制芯片及相应的***电路，本实施例中，该控制芯片采用ST半导体的HVLED001A芯片，在待机轻载时，可自动控制电源开关频率转入跳周期的工作方式，提高待机轻载效率，无需待机变压器，节省成本。所述恒流开关M可以采用MOS管、IGBT管、可控硅等，本实施例中采用MOS管实现。
本发明技术方案通过设置恒流开关电路1、第一单级PFC电路2、第一变压器T1、恒流反馈电路4，形成了一种开关电源。本发明采用单级PFC式输出，无需二次升压转换。即通过第一单级PFC电路2控制第一变压器T1工作，直接进行AC-DC的转换，输出恒流源，省去了高压电解电容，提高了电源功率因素，降低了***成本；同时，恒流开关电路1、第一单级PFC电路2、第一变压器T1、及恒流反馈电路4组成了恒流输出电路，而恒压开关电路5、第二单级PFC电路6、及第二变压器T2则组成了恒压输出电路。如此，开关电源输出的恒压源和恒流源各自控制，使得恒压和恒流输出在动态负载时互不干扰，且恒压源不受LED灯本身电气参数偏差的交叉影响，提高了***的稳定性。
所述开关电源还包括恒流开关M、及恒流控制电路3。所述恒流开关M，根据主板输出的PWM亮度信号调节LED灯条的亮度。所述恒流控制电路3，根据主板输出的使能信号，控制LED灯条点亮或熄灭。
本实施例中，LED灯条的数量为多个，在LED灯条工作时，所述恒流控制电路在还在LED灯条工作时，控制流过各个LED灯条中流过电流相同，使得LED发光显示一致性增强。
具体地，所述恒流开关电路1的输入端接入直流电，所述恒流开关电路1的输出端与所述第一变压器T1的输出端连接；所述第一变压器T1的采样端与所述第一单级PFC电路2的零电流检测端连接；所述第一变压器T1的输出端与所述LED灯条的输入端连接，所述LED灯条的输出端与所述恒流开关M的输入端连接，所述恒流开关M的受控端连接至主板，所述恒流开关M的输出端与所述恒流控制电路3的输入端连接；所述恒流控制电路3的输出端与所述恒流反馈电路4的输入端连接，所述恒流控制电路3的受控端接收主板输入的使能信号；所述恒流反馈电路4的输出端与所述第一单级PFC电路2的反馈端连接。
所述恒压开关电路5的输入端接入直流电，所述恒压开关电路5的输出端与所述第二变压器T2的输入端连接，所述第二变压器T2的采样端与所述第二单级PFC电路6的零电流检测端连接；所述第二变压器T2的输出端与所述主板电连接。
本实施例中，第一单级PFC电路2和第二单级PFC电路6的零电流检测端还分别与第一变压器T1和第二变压器T2的辅助绕组连接，以检测电流或电压的过零点，从而控制对应的开关管在过零点时导通或关断，以减少损耗，提高电能使用效率。
进一步，所述第一单级PFC电路2，根据所述光耦U2的反馈电平，调节开关信号的占空比以调节输出至LED灯条的电流；所述第二单级PFC电路6，所述对所述第二变压器T2输出电压进行采样得到采样电压，并根据所述采样电压，调节开关信号的占空比以调节输出至主板的电压。
需要说明的是，当LED灯条电压比第一变压器T1输出的电压小时，通过恒流反馈电路4控制第一单级PFC电路2，调整第一单级PFC电路2的工作频率或占空比，进一步控制恒流开关电路1，使反激变压器输出的电压变小，使得第一变压器T1输出的电压和LED灯条工作电压相匹配，进而可降低恒流控制电路3的温升。解决了在量产中相同屏体LED灯的电压偏差较大造成的输出电压差异大问题。
第一单级PFC电路2还通过第一变压器T1的辅助绕组使辅助绕组的电压恒定，进而使第一变压器T1输出的电压限制在规定范围内。
恒压开关电路5在第二单级PFC电流的控制下，进一步控制第二变压器T2，经过整流滤波后使得输出稳定的恒压源。其恒压反馈环路为原边反馈，即通过第二变压器T2的辅助绕组使辅助绕组的电压恒定，进而使第二变压器T2输出的电压恒定。
进一步地，所述开关电源还包括第一次级整流滤波电路7及第二次级整流滤波电路8；所述第一次级整流滤波电路7，对第一变压器T1输出的脉动直流电进行整流滤波；所述第二次级整流滤波电路8，对第二变压器T2输出的脉动直流电进行整流滤波。
为进一步地提高开关电源的效率，在所述恒流反馈电路4检测到LED灯条熄灭时，即检测到LED灯条不工作时，恒流反馈电路4关断所述第一单级PFC电路2，从而降低了第一单级PFC电路2的损耗。
当负载对纹波要求较高时，可以在输出增加DC-DC转换电路，使输出的电压低频纹波较小。因此该开关电源还包括DC-DC转换电路9，所述DC-DC转换电路9的输入端与所述第二次级整流滤波电路8的输出端连接，所述DC-DC转换电路9的输出端与主板电连接。
当开关电源驱动的LED灯条为多组时，易于理解的是，对应地所述开关电源包括多个恒流开关M，多个恒流开关M的输入端和输出端分别串联于LED灯条的输出端及恒流控制电路3的输入端之间，多个恒流开关M的受控端则接收主板输出的PWM亮度信号。
其中，上述恒流控制电路3包括启动电路31、恒流基准源电路32、及多个镜像恒流电路33；所述启动电路31的输入端与所述主板连接，接收使能信号；所述启动电路31的输出端与所述恒流基准源电路32的受控端连接，所述恒流基准源电路32的输入端与一LED灯条的输出端连接；镜像恒流电路33的受控端均与所述恒流基准源电路32的输出端连接，镜像恒流电路33输入端分别与剩下的LED灯条的输出端连接。
需要说明的是，主板发出的使能信号包括开启信号和关断信号。在启动电路31接收到开启信号时，启动电路31输出高电平，恒流基准源电路32开启，恒流基准源电路32为后级各个镜像恒流电路33提供电流基准，后级各个镜像恒流电路33复制恒流基准源电路32中电流，使得各个镜像恒流电路33的电流与恒流基准源电路32的电流相等，从而各LED灯条发光亮度不出现偏移。
进一步地，该开关电源还包括过压调整电路（未标示），其中过压调整电路的数量与LED灯条的数量对应。每一过压调整电路的输入端与对应地恒流开关M的输出端连接，过压调整电路的输出端均与恒流反馈电路4的调整端连接。过压调整电路用于检测到变压器输出电压超过LED灯条电压时，通过恒流反馈电路4控制第一单级PFC电路2，调整第一MOS管的开关频率，减小变压器输出至LED灯条的电压。
本发明的恒流方式采用串联恒流基准源电路32控制，使得流过LED灯条的电流恒定，当纹波较大时，恒流基准源电路32可自动调整分压降低电流纹波，当LED灯条压差差异大时，LED灯条压差过大，通过过压调整，控制原边的第一单级PFC电路2，进而使输出电压降低，使得恒流源两端的电压降低。
参照图3，现结合开关电源的具体电路图对本发明作进一步说明：
第一变压器T1包括初级绕组、次级绕组及辅助绕组，其中辅助绕组设置于变压器的初级；
所述第一单级PFC电路2包括第一电阻R1、第二电阻R2、第三电阻R3、第一控制芯片U1；所述恒流开关电路1包括第一MOS管K1及第四电阻R4；所述第一控制芯片U1包括过压保护端HVSU、电源端VCC、驱动端GATE、接地端GND、过流检测端CS、过零检测端ZCD、反馈端FB、及控制端CTRL；
其中，第一电阻R1的第一端与前级整流滤波电路11的输出端连接，第一电阻R1的第二端与第一控制芯片U1的过压保护端连接；所述第一变压器T1的辅助绕组的第一端与所述第二电阻R2的第一端连接，所述第二电阻R2的第二端与所述第三电阻R3的第一端连接，所述第三电阻R3的第二端接地，所述第一变压器T1的辅助绕组的第二端接地，第一控制芯片U1的过零检测端与第三电阻R3的第一端连接；所述第一变压器T1的初级线圈的第一端与前级整流滤波电路的输出端连接，所述第一变压器T1的初级线圈的第二端与第一MOS管K1的漏极连接，第一MOS管K1的源极经第四电阻R4接地，第一MOS管K1的门极与第一控制芯片U1的驱动端连接，第一控制芯片U1的过流检测端与第一MOS管K1的源极连接，第一MOS端的接地端接地。
所述第一次级整流滤波电路7包括第一二极管D1及第一电容C1；第一二极管D1的阳极与次级绕组的第一端连接，第一二极管D1的阴极与LED灯条的第一端连接，次级绕组的第二端接地；第一电容C1的第一端与第一二极管D1的阴极连接，第一电容C1的第二端接地。
所述恒流反馈电路4包括第五电阻R5、第六电阻R6、第七电阻R7、第八电阻R8、第九电阻R9、第十电阻R10、第一光耦U2、第二光耦U3、第一电压基准芯片WZ1、第一三极管Q1、第二三极管Q2、第三三极管Q3、第二电容C2、第一直流源VCC1及第二直流源VDD；本实施例中，第一直流源VCC1由第二变压器T2输出的电压提供。需要说明的是，光耦设有发光器的一侧为控制侧。设有受光器的一侧则为执行侧。
第五电阻R5的第一端与第一二极管D1的阴极连接，第五电阻R5的第二端与第一光耦U2的控制侧输入端连接，第一光耦U2的控制侧输出端与第一电压基准芯片WZ1的输入端连接，第一电压基准芯片WZ1的输出端接地，第一电压基准芯片WZ1的参考端与恒流开关M的输出端连接；第一光耦U2执行侧输入端接地，第一光耦U2执行侧输出端与第一控制芯片U1的反馈端连接。
第六电阻R6的第一端与第一直流源VCC1连接，第六电阻R6的第二端与第一三极管Q1的集电极连接，第一三极管Q1的发射极经第七电阻R7接地，第一三极管Q1的基极与第二三极管Q2的基极连接；第八电阻R8的第一端与第一直流源VCC1连接，第八电阻R8的第二端与第二三极管Q2的集电极连接，第二三极管Q2的发射极经第二电容C2接地；第九电阻R9的第一端与第一直流源VCC1连接，第九电阻R9的第二端与第二光耦U3的执行输入端连接，第二光耦U3的执行输出端与第二三极管Q2的基极连接；第二光耦U3的控制侧输入端经第十电阻R10与第二直流源VDD连接，第二光耦U3的控制侧输出端与第三三极管Q3的集电极连接，第三三极管Q3的发射极接地，第三三极管Q3的基极与主板电连接，以接收主板输出的开机信号和关机信号。
本实施例中，以两路LED灯条为例进行说明，则恒流开关M包括第一恒流开关M1及第二恒流开关M2；第一恒流开关M1的输入端与一LED灯条的输出端连接，第一恒流开关M1的输出端与恒流基准源电路32的输入端连接，第二恒流开关M2的输入端与另一LED灯条的输出端连接，第二恒流开关M2的输出端与恒流基准源电路32的输入端连接，第一恒流开关M1的受控端及第二恒流开关M2的受控端均与主板电连接，以接收主板输出的PWM亮度信号。
所述启动电路31包括第十一电阻R11、第十二电阻R12、第十三电阻R13、第四三极管Q4、第五三极管Q5；
第十一电阻R11的第一端连接至12V直流电源，第十一电阻R11的第二端与第四三极管Q4的发射极连接，第四三极管Q4的集电极与恒流基准源电路32的受控端连接，第四三极管Q4的基极经第十二电阻R12与第五三极管Q5的集电极连接，第五三极管Q5的发射极接地，第五三极管Q5的基极经第十三电阻R13与主板连接，以接收主板的使能信号EN。
所述恒流基准源电路32包括第十四电阻R14、第二电压基准芯片WZ2、第六三极管Q6；第二电压基准芯片WZ2的输入端与第四三极管Q4的集电极连接，第二电压基准芯片WZ2的输出端接地，第二电压基准芯片WZ2的参考端与镜像恒流电路33的受控端连接，且第二电压基准芯片WZ2的参考端还与第六三极管Q6的基极连接，第六三极管Q6的基极同时还与第四三极管Q4的集电极连接，第六三极管Q6的集电极与第一恒流开关M1的输出端连接，第六三极管Q6的发射极经第十四电阻R14接地。
所述镜像恒流电路33包括第十五电阻R15、第七三极管Q7；第七三极管Q7的集电极与第二恒流开关M2的输出端连接，第七三极管Q7的发射极经第十五电阻R15接地。
所述第二单级PFC电路6包括第十六电阻R16、第十七电阻R17、第十八电阻R18、第十九电阻R19、第二十电阻R20、第三电容C3、第二二极管D2、第三二极管D3、第八三极管Q8、第一稳压管Z1、第四电容C4、及第二控制芯片U4；所述第二变压器T2包括初级绕组、次级绕组、及辅助绕组，其中辅助绕组设置于变压器的初级；所述第二控制芯片U4包括过压保护端HVSU、电源端VCC、驱动端GATE、接地端GND、过流检测端CS、过零检测端ZCD、及控制端CTRL。
第十六电阻R16的第一端与第二二极管D2的阴极连接，第二二极管D2的阳极与第二变压器T2辅助绕组的第一端连接，辅助绕组的第二端接地，第十六电阻R16的第二端与第八三极管Q8的集电极连接，第八三极管Q8的发射极与第三二极管D3的阳极连接，第三二极管D3的阴极与第二控制芯片U4的电源端连接，第四电容C4的第一端与第三二极管D3的阴极连接，第四电容C4的第二端接地；第八三极管Q8的基极经第十七电阻R17与第二二极管D2的阴极连接；第三电容C3的第一端与第二二极管D2的阴极连接，第三电容C3的第二端接地；第一稳压管Z1的阳极与第八三极管Q8的基极连接，第一稳压管Z1的阴极接地，第十八电阻R18的第一端与第八三极管Q8的基极连接，第十八电阻R18的第二端接地；第二控制芯片U4的过压保护端与第一电阻R1的第二端连接，第二控制芯片U4的接地端接地；第十九电阻R19的第一端与第二二极管D2的阳极连接，第十九电阻R19的第二端经第二十电阻R20接地；第二控制芯片U4的过零检测端与第十九电阻R19的第二端连接。
所述恒流开关电路1包括第二十一电阻R21、第二MOS管K2；第二变压器T2初级绕组的第一端与前级整流滤波电路的输出端连接，第二MOS管K2的漏极与第二变压器T2初级绕组的第二端连接，第二MOS管K2的源极经第二十一电阻R21接地，第二MOS管K2的门极与第二控制芯片U4的驱动端连接，第二控制芯片U4的过流检测端与第二MOS管K2的源极连接。
所述第二次级整流滤波电路8包括第四二极管D4、第五电容C5，第四二极管D4的阳极与第二变压器T2的次级绕组的第一端连接，次级绕组的第二端接地，第四二极管D4的阴极与DC-DC转换电路9输入端连接，在进行电压变换后输出至主板。
过压调整电路则包括第一过压调整电路（未标示）及第二过压调整电路（未标示），第一过压调整电路包括第二十二电阻R22、第二十三电阻R23、第五二极管D5、及第六电容C6；第二过压调整电路包括第二十四电阻R24、第二十五电阻R25、第六二极管D6及第七电容C7；其中，第五二极管D5的阴极与第一电压基准芯片WZ1的电压参考端连接，第五二极管D5的阳极经第二十三电阻R23与所述第二十四电阻R24的第一端连接，第二十四的电阻的第二端与第一恒流开关M1的输出端连接，第六电容C6的第一端与第二十二电阻R22的第一端连接，第六电容C6的第二端接地。
第六二极管D6的阴极与第一电压基准芯片WZ1的电压参考端连接，第六二极管D6的阳极经第二十五电阻R25与所述第二十六电阻的第一端连接，第二十六的电阻的第二端与第一恒流开关M1的输出端连接，第七电容C7的第一端与第二十四电阻R24的第一端连接，第七电容C7的第二端接地。
继续参照图2，电源经EMI滤波电路10和前级整流滤波电路11处理后分别输送给第一变压器T1和第二变压器T2，无需大电解电容滤波，第一MOS管K1和第二MOS管K2在各自的控制芯片控制下，进一步控制变压器，使得第一变压器T1经第一次级整流滤波电路7处理后输送给LED灯条供电；第二变压器T2经第二次级整流滤波电路8处理后输送给主板供电。上述采用单级PFC控制恒流开关电路1和恒压开关电路5，并进一步分别控制第一变换器和第二变压器T2，使得设计无需高压电解电容，节省了PCB面积和成本。因第一变压器T1输出的恒流源和第二变压器T2输出的恒压源各自控制，使得恒压和恒流输出在动态负载时互不干扰，且恒压不受LED灯偏差的交叉影响，提高了***的稳定性。
当开机信号为高电平时，第三三极管Q3导通，通过第二光耦U3使第二三极管Q2导通，第一直流源VCC1经第八电阻R8后输出至第一控制芯片U1的电源端，为第一控制芯片U1供电，同时第一三极管Q1导通，经第六电阻R6和第七电阻R7分压取样后接第一控制芯片U1的控制端，使第一控制芯片U1开始工作。此外，当使能信号EN为高电平时，恒流基准源电路32开始工作，第六三极管Q6导通，则LED灯条中有电流通过，为亮的状态。LED灯条的亮暗程度通过主板输出的PWM亮点信号进行调节，具体是通过控制第一恒流开关M1的导通时间，调LED灯条的亮度，当PWM亮度信号的占空比大时，LED灯条灯较亮，当PWM亮度信号占空比小时，LED灯条则较暗。
当使能信号EN为低电平时，恒流基准源电路32停止工作，第六三极管Q6截止，则LED灯条中没有电流通过，为灭的状态。
当主板输出关机信号为低电平时，控制第三三极管Q3关断，通过第二光耦U3使第二三极管Q2关断，为第二控制芯片U4的电源被切断，同时第一三极管Q1关断，第一控制芯片U1的控制端在第七的电阻拉低后停止工作，此时开关电源的恒流输出停止工作，使得待机功耗低。
进一步，恒流控制电路3采用串联恒流基准源控制,由第二电压基准芯片WZ2、第六三极管Q6，第十四电阻R14组成恒流基准源电路32，第二电压基准芯片WZ2为恒流提供基准电压，控制第六三极管Q6，使得第十四电阻R14的两端电压恒定，进而使得流过LED灯条的电流恒定。当第一变压器T1输出电压纹波较大时，因第六三极管Q6工作在放大区，第二电压基准芯片WZ2控制第六三极管Q6可自动调整集电极与发射极的分压，使得电流更精密，降低了电流纹波。当LED灯条电压偏小时，因第一变压器T1输出电压不变，则第六三极管Q6的集电极电压增大，通过由第二十四电阻R24、第七电容C7、第二十五电阻R25、及第六二极管D6组成的第二过压调整电路，通过第一电压基准芯片WZ1来控制流过第一光耦U2的电流，进而控制第一控制芯片U1的工作频率，进而使第一变压器T1输出电压降低，使得第六三极管Q6的集电极与发射极之间的电压降低。
由第七三极管Q7和第十五电阻R15组成的另一镜像恒流电路33，该镜像恒流电路33以恒流基准源电路32为电流镜本体，使得像恒流电路与电流镜本体电流相同，后级可复制任意个相同的恒流源，使得该恒流输出可匹配任意数量通道的LED灯条。
进一步，当开关电源上电后，通过整流滤波后的电压通过第一电阻R1对第一控制芯片U1和第二控制芯片U4的过压保护端进行预启动，使得各自电源端的电压达到开启电压，第一控制芯片U1和第二控制芯片U4开始振荡工作。稳定后，第二变压器T2辅助绕组输出电压经由第八三极管Q8、第三二极管D3、第十六电阻R16、第十七电阻R17、第一稳压管Z1、第十八电阻R18构成第二控制芯片U4电源的线性稳压电路，为第二控制芯片U4提供稳定的工作电压。
同时第一控制芯片U1和第二控制芯片U4的过压保护端通过检测整流滤波后电压的全波电压信号作为参考信号，分别通过电流取样电阻第四电阻R4和第二十一电阻R21检测初级绕组的电流，与参考信号做对比，进而控制第一MOS管K1和第二MOS管K2的工作频率和占空比，当全波电压大时，工作频率高，占空比小；当全波电压小时，工作频率低，占空比大，使得全波电压信号和流过对应变压器初级绕组的电流同相位，最终提高了功率因素，也实现了AC-DC的变换。
进一步如上所述，将给LED灯条供电的恒流源和给主板供电的恒压源分离单独控制，既降低了第一变压器T1、第二变压器T2、第一MOS管K1、及第二MOS管K2的工作温升，也提高了***独立控制的稳定性。
进一步，当LED灯条电压比第一变压器T1次级绕组输出的电压小时，恒流控制电路3通过第一控制芯片U1的工作频率和占空比变小，进一步控制第一MOS管K1，使第一变压器T1输出的电压变小，使得第一变压器T1输出的电压和LED灯条工作电压匹配，进而可降低恒流控制电路3的温升。解决了在量产中相同屏体LED灯条的电压偏差较大造成的输出电压差异大问题。第五电阻R5作为第一光耦U2的限流电阻， 第四电阻R4对初级绕组中电流取样后接至第一控制芯片U1的过流检测端，当输出功率过大时，在第四电阻R4取样的电压会大于第一控制芯片U1的过流检测端的内部参考电压，使第一控制芯片U1过载保护启动。采样电阻第二电阻R2和第三电阻R3采样变压器的辅助绕组的电压，使辅助绕组的电压限制在安全范围，避免使第一变压器T1输出的电压过大。
进一步，第二MOS管K2在第二单级PFC电路6控制控制下，进一步控制第二变压器T2，经过第四二极管D4整流，并经过第四电容滤波后使得输出稳定的恒压源。其恒压反馈环路为原边反馈，即通过采样电阻第十九电阻R19和第二十电阻R20采样第二变压器T2的辅助绕组的电压，使辅助绕组的电压恒定，进而使输出的电压恒定，当对纹波要求较高时，可以在输出增加DC-DC的转换电路，使输出的电压纹波较小。
需要说明的是，镜像恒流电路33可根据LED灯条的通道数量任意扩展，使得本方案实现了可匹配任意通道数量LED灯条的需求，实现了大尺寸电视电源的低成本，高功率因素设计。
本发明还提出一种电视机，该电视机包括LED灯条、主板和上述开关电源，该开关电源的具体结构参照上述实施例，由于本电视机采用了上述所有实施例的全部技术方案，因此至少具有上述实施例的技术方案所带来的所有有益效果，在此不再一一赘述。
其中开关电源分别与LED灯条和主板电解，以分别提供恒流源及恒压源。主板还与LED灯条电连接，以控制LED灯条的亮度。
以上所述仅为本发明的优选实施例，并非因此限制本发明的专利范围，凡是在本发明的发明构思下，利用本发明说明书及附图内容所作的等效结构变换，或直接/间接运用在其他相关的技术领域均包括在本发明的专利保护范围内。

Claims (17)

  1. 一种开关电源，其特征在于，包括恒流开关电路、第一单级PFC电路、第一变压器、恒流反馈电路；所述开关电源还包括恒压开关电路、第二单级PFC电路、及第二变压器；其中，
    所述恒流反馈电路对第一变压器输出的电流进行采样，并将采样电流反馈至第一单级PFC电路；
    所述第一单级PFC电路，根据采样电流输出开关信号，驱动恒流开关电路导通或关断，控制负载电流恒定；
    所述第二单级PFC电路，输出开关信号，驱动恒压开关电路导通或关断; 所述第二单级PFC电路，对所述第二变压器输出电压进行采样得到采样电压，并根据所述采样电压，调节开关信号的占空比以调节输出至主板的电压，控制主板电压恒定。
  2. 如权利要求1所述的开关电源，其特征在于，所述开关电源还包括恒流开关、及恒流控制电路，其中，所述负载为LED灯条，
    所述恒流开关，根据主板输出的PWM亮度信号调节LED灯条的亮度；
    所述恒流控制电路，根据主板输出的使能信号，控制LED灯条点亮或熄灭。
  3. 如权利要求2所述的开关电源，其特征在于，所述恒流控制电路在还在LED灯条工作时，控制流过各个LED灯条中流过电流相同。
  4. 如权利要求1所述的开关电源，其特征在于，所述恒流开关电路的输入端接入直流电，所述恒流开关电路的输出端与所述第一变压器的输出端连接；所述第一变压器的采样端与所述第一单级PFC电路的零电流检测端连接；所述第一变压器的输出端与所述LED灯条的输入端连接，所述LED灯条的输出端与所述恒流开关的输入端连接，所述恒流开关的受控端连接至主板，所述恒流开关的输出端与所述恒流控制电路的输入端连接；所述恒流控制电路的输出端与所述恒流反馈电路的输入端连接，所述恒流控制电路的受控端接收主板输入的使能信号；所述恒流反馈电路的输出端与所述第一单级PFC电路的反馈端连接；
    所述恒压开关电路的输入端接入直流电，所述恒压开关电路的输出端与所述第二变压器的输入端连接，所述第二变压器的采样端与所述第二单级PFC电路的零电流检测端连接；所述第二变压器的输出端与所述主板电连接。
  5. 如权利要求2所述的开关电源，其特征在于，在所述恒流反馈电路检测到LED灯条停止工作时，恒流反馈电路关断所述第一单级PFC电路。
  6. 如权利要求5所述的开关电源，其特征在于，所述开关电源还包括DC-DC转换电路，所述DC-DC转换电路的输入端与所述第二变压器的输出端连接，所述DC-DC转换电路的输出端与主板电连接。
  7. 如权利要求6所述的开关电源，其特征在于，所述恒流控制电路包括启动电路、恒流基准源电路、及多个镜像恒流电路；所述启动电路的输入端与所述主板连接，接收使能信号；所述启动电路的输出端与所述恒流基准源电路的受控端连接，所述恒流基准源电路的输入端与一LED灯条的输出端连接；镜像恒流电路的受控端均与所述恒流基准源电路的输出端连接，镜像恒流电路输入端分别与其它LED灯条的输出端连接。
  8. 如权利要求7所述的开关电源，其特征在于，所述启动电路包括第十一电阻、第十二电阻、第十三电阻、第四三极管、第五三极管；
    第十一电阻的第一端连接至直流电源，第十一电阻的第二端与第四三极管的发射极连接，第四三极管的集电极与恒流基准源电路的受控端连接，第四三极管的基极经第十二电阻与第五三极管的集电极连接，第五三极管的发射极接地，第五三极管的基极经第十三电阻与主板连接，以接收主板的使能信号。
  9. 如权利要求8所述的开关电源，其特征在于，所述恒流基准源电路包括第十四电阻、第二电压基准芯片、第六三极管；第二电压基准芯片的输入端与第四三极管的集电极连接，第二电压基准芯片的输出端接地，第二电压基准芯片的参考端与镜像恒流电路的受控端连接，且第二电压基准芯片的参考端还与第六三极管的基极连接，第六三极管的基极同时还与第四三极管的集电极连接，第六三极管的集电极与LED灯条的输出端连接，第六三极管的发射极经第十四电阻接地。
    所述镜像恒流电路包括第十五电阻、第七三极管；第七三极管的集电极与另一LED灯条的输出端连接，第七三极管的发射极经第十五电阻接地。
  10. 如权利要求9所述的开关电源，其特征在于，该开关电源还包括过压调整电路，其中过压调整电路的数量与LED灯条的数量对应；每一过压调整电路的输入端与对应地恒流开关的输出端连接，过压调整电路的输出端均与恒流反馈电路的调整端连接。
  11. 如权利要求1所述的开关电源，其特征在于，所述开关电源还包括第一次级整流滤波电路及第二次级整流滤波电路；所述第一次级整流滤波电路，对第一变压器输出的脉动直流电进行整流滤波；所述第二次级整流滤波电路，对第二变压器输出的脉动直流电进行整流滤波。
  12. 一种电视机，包括LED灯条及主板，其特征在于，所述电视机还包括如权利要求1所述的开关电源；所述开关电源分别所述LED灯条及所述主板电连接，所述主板还与所述LED灯条电连接。
  13. 如权利要求12所述的电视机，其特征在于，所述开关电源还包括恒流开关、及恒流控制电路，其中，所述负载为LED灯条，
    所述恒流开关，根据主板输出的PWM亮度信号调节LED灯条的亮度；
    所述恒流控制电路，根据主板输出的使能信号，控制LED灯条点亮或熄灭。
  14. 如权利要求13所述的电视机，其特征在于，所述恒流控制电路在还在LED灯条工作时，控制流过各个LED灯条中流过电流相同。
  15. 如权利要求12所述的电视机，其特征在于，所述恒流开关电路的输入端接入直流电，所述恒流开关电路的输出端与所述第一变压器的输出端连接；所述第一变压器的采样端与所述第一单级PFC电路的零电流检测端连接；所述第一变压器的输出端与所述LED灯条的输入端连接，所述LED灯条的输出端与所述恒流开关的输入端连接，所述恒流开关的受控端连接至主板，所述恒流开关的输出端与所述恒流控制电路的输入端连接；所述恒流控制电路的输出端与所述恒流反馈电路的输入端连接，所述恒流控制电路的受控端接收主板输入的使能信号；所述恒流反馈电路的输出端与所述第一单级PFC电路的反馈端连接；
    所述恒压开关电路的输入端接入直流电，所述恒压开关电路的输出端与所述第二变压器的输入端连接，所述第二变压器的采样端与所述第二单级PFC电路的零电流检测端连接；所述第二变压器的输出端与所述主板电连接。
  16. 如权利要求13所述的电视机，其特征在于，在所述恒流反馈电路检测到LED灯条停止工作时，恒流反馈电路关断所述第一单级PFC电路。
  17. 如权利要求16所述的电视机，其特征在于，所述开关电源还包括DC-DC转换电路，所述DC-DC转换电路的输入端与所述第二变压器的输出端连接，所述DC-DC转换电路的输出端与主板电连接。
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108966435A (zh) * 2018-09-26 2018-12-07 江苏优为视界科技有限公司 低纹波led控制装置的保护电路
CN110018413A (zh) * 2019-01-12 2019-07-16 广东省民防协会 一种多功能电气性能测试仪
CN110971850A (zh) * 2019-12-05 2020-04-07 深圳创维－Rgb电子有限公司 一种恒压恒流的开关电源和电视机
CN112105122A (zh) * 2020-09-23 2020-12-18 浙江华丰电动工具有限公司 一种锂电led灯的恒流控制与过放电保护电路
CN113110125A (zh) * 2021-03-15 2021-07-13 三门康创电子科技有限公司 一种果蔬机控制电路、果蔬机及果蔬机控制方法
EP3726833A4 (en) * 2018-12-25 2021-09-08 Shenzhen Skyworth-RGB Electronic Co., Ltd. TELEVISION AND TELEVISION POWER SUPPLY CONTROL DEVICE
CN113741605A (zh) * 2021-08-05 2021-12-03 大族激光科技产业集团股份有限公司 一种线性稳压电源
CN115395636A (zh) * 2022-08-08 2022-11-25 桂林电子科技大学 冗余备份恒流转恒压电源电路及控制方法

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106954315A (zh) * 2017-05-08 2017-07-14 深圳创维－Rgb电子有限公司 一种串并联led灯条网络的驱动电源和电视机
CN208273313U (zh) * 2018-05-17 2018-12-21 珠海市圣昌电子有限公司 一种单进单出触摸切相调光控制器
CN108809064B (zh) * 2018-06-07 2020-02-14 青岛浩海网络科技股份有限公司 一种用于森林防火一体机的电源
CN109274910B (zh) * 2018-11-07 2020-11-17 深圳创维－Rgb电子有限公司 一种开关电源及电视
CN109362157B (zh) * 2018-12-04 2021-05-25 深圳创维－Rgb电子有限公司 恒流控制电路及电视机
CN111314678A (zh) * 2018-12-12 2020-06-19 深圳光峰科技股份有限公司 供电***
CN111724747B (zh) * 2019-03-20 2021-10-22 海信视像科技股份有限公司 显示装置及电源启动方法
CN110010099B (zh) * 2019-04-29 2020-08-04 深圳市华星光电技术有限公司 一种稳压电路、控制方法及显示装置
CN110031660A (zh) * 2019-05-17 2019-07-19 吴忌 一种多功能维修检测仪
JP2021048523A (ja) * 2019-09-19 2021-03-25 株式会社東芝 Ｌｅｄ駆動制御回路、電子回路及びｌｅｄ駆動制御方法
CN112003241B (zh) * 2020-07-14 2022-11-11 宁波安信数控技术有限公司 一种用于开关电源的过流过压保护电路
CN113824340B (zh) * 2021-10-15 2024-07-19 厦门市科力电子有限公司 一种过功率线性调压的开关电源
DE102022200429A1 (de) * 2022-01-17 2023-07-20 Osram Gmbh Zweistufiges betriebsgerät mit isolierbarem getakteten konverter als leistungsfaktorkorrektor und regelungsverfahren für das betriebsgerät
CN114865900B (zh) * 2022-07-05 2022-10-04 安思疆科技(南京)有限公司 一种过冲抑制电路和恒流驱动装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120025735A1 (en) * 2010-08-02 2012-02-02 Microsemi Corporation Flyback with switching frequency responsive to load and input voltage
CN104377971A (zh) * 2014-12-04 2015-02-25 青岛歌尔声学科技有限公司 一种基于电压反馈的反激直驱led电源电路及电视机
CN104935843A (zh) * 2015-06-16 2015-09-23 康佳集团股份有限公司 一种led电视二合一电源电路及led电视机
CN205040065U (zh) * 2015-09-24 2016-02-17 惠州市西顿工业发展有限公司 一种可调输出电流的恒压恒流驱动电路
CN105813263A (zh) * 2016-04-22 2016-07-27 深圳创维－Rgb电子有限公司 开关电源和电视机
CN105934017A (zh) * 2016-03-17 2016-09-07 上海遍发电子科技有限公司 一种开关电源反馈控制电路以及单级pfc高效恒流电源驱动电路

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6441590B1 (en) * 1999-03-26 2002-08-27 Sarnoff Corporation Two stage architecture for a monitor power supply
US20050242751A1 (en) * 2004-04-28 2005-11-03 Zippy Technology Corp. Inverter circuit with a power factor corrector
US20060061216A1 (en) * 2004-09-17 2006-03-23 Chin-Wen Chou Power supply circuit for eliminating electrical interference
US20060061930A1 (en) * 2004-09-17 2006-03-23 Zippy Technology Corp. Power supply circuit device for eliminating electrical interference
TW200849200A (en) * 2007-06-01 2008-12-16 Mitac Technology Corp Split-type power supply circuit for LCD TV
JP2010035270A (ja) * 2008-07-25 2010-02-12 Sanken Electric Co Ltd 電力変換装置
US8575863B2 (en) * 2011-11-08 2013-11-05 Atmel Corporation Color correcting device driver
US9013110B2 (en) * 2011-11-30 2015-04-21 Atmel Corporation Circuit for driving light emitting elements
CN102523406B (zh) * 2011-12-07 2014-01-08 青岛海信电器股份有限公司 电源电路结构以及led液晶电视
CN202475621U (zh) * 2011-12-31 2012-10-03 青岛海信电器股份有限公司 Led液晶电视
CN103023352B (zh) * 2012-12-11 2015-07-08 矽力杰半导体技术(杭州)有限公司 一种交流-直流功率变换器
US9866117B2 (en) * 2013-03-11 2018-01-09 Cree, Inc. Power supply with adaptive-controlled output voltage
CN203243211U (zh) * 2013-04-01 2013-10-16 青岛海信电器股份有限公司 开关变换电路、待机电路、待机电源及液晶电视
CN103219901B (zh) * 2013-04-19 2015-12-09 矽力杰半导体技术(杭州)有限公司 Ac/dc变换器控制电路以及应用其的ac/dc变换器
CN203289702U (zh) * 2013-05-16 2013-11-13 深圳创维－Rgb电子有限公司 背光供电电路、电源装置和电视机
CN203279282U (zh) * 2013-05-17 2013-11-06 深圳Tcl新技术有限公司 Led显示模块的供电电路及平板电视机
CN103889118B (zh) * 2014-03-18 2016-02-10 深圳创维－Rgb电子有限公司 一种oled驱动电源装置
CN103997237B (zh) * 2014-05-27 2016-07-06 深圳创维－Rgb电子有限公司 大功率电源供电***
US9961728B2 (en) * 2014-08-07 2018-05-01 Philips Lighting Holding B.V. Driver device and driving method
CN106685242B (zh) * 2015-11-09 2018-11-09 光宝科技股份有限公司 单级交流至直流转换器
CN205160358U (zh) * 2015-11-09 2016-04-13 创维电子器件（宜春）有限公司 电子终端及其llc供电电源

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120025735A1 (en) * 2010-08-02 2012-02-02 Microsemi Corporation Flyback with switching frequency responsive to load and input voltage
CN104377971A (zh) * 2014-12-04 2015-02-25 青岛歌尔声学科技有限公司 一种基于电压反馈的反激直驱led电源电路及电视机
CN104935843A (zh) * 2015-06-16 2015-09-23 康佳集团股份有限公司 一种led电视二合一电源电路及led电视机
CN205040065U (zh) * 2015-09-24 2016-02-17 惠州市西顿工业发展有限公司 一种可调输出电流的恒压恒流驱动电路
CN105934017A (zh) * 2016-03-17 2016-09-07 上海遍发电子科技有限公司 一种开关电源反馈控制电路以及单级pfc高效恒流电源驱动电路
CN105813263A (zh) * 2016-04-22 2016-07-27 深圳创维－Rgb电子有限公司 开关电源和电视机

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3471512A4 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108966435A (zh) * 2018-09-26 2018-12-07 江苏优为视界科技有限公司 低纹波led控制装置的保护电路
EP3726833A4 (en) * 2018-12-25 2021-09-08 Shenzhen Skyworth-RGB Electronic Co., Ltd. TELEVISION AND TELEVISION POWER SUPPLY CONTROL DEVICE
CN110018413A (zh) * 2019-01-12 2019-07-16 广东省民防协会 一种多功能电气性能测试仪
CN110018413B (zh) * 2019-01-12 2024-06-11 广东人防工程质量检测有限公司 一种多功能电气性能测试仪
CN110971850A (zh) * 2019-12-05 2020-04-07 深圳创维－Rgb电子有限公司 一种恒压恒流的开关电源和电视机
CN110971850B (zh) * 2019-12-05 2022-05-03 深圳创维－Rgb电子有限公司 一种恒压恒流的开关电源和电视机
CN112105122B (zh) * 2020-09-23 2024-05-03 浙江华丰电动工具有限公司 一种锂电led灯的恒流控制与过放电保护电路
CN112105122A (zh) * 2020-09-23 2020-12-18 浙江华丰电动工具有限公司 一种锂电led灯的恒流控制与过放电保护电路
CN113110125A (zh) * 2021-03-15 2021-07-13 三门康创电子科技有限公司 一种果蔬机控制电路、果蔬机及果蔬机控制方法
CN113110125B (zh) * 2021-03-15 2022-04-01 三门康创电子科技有限公司 一种果蔬机控制电路、果蔬机及果蔬机控制方法
CN113741605A (zh) * 2021-08-05 2021-12-03 大族激光科技产业集团股份有限公司 一种线性稳压电源
CN115395636B (zh) * 2022-08-08 2024-04-30 桂林电子科技大学 冗余备份恒流转恒压电源电路及控制方法
CN115395636A (zh) * 2022-08-08 2022-11-25 桂林电子科技大学 冗余备份恒流转恒压电源电路及控制方法

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