WO2018152901A1 - 一种电源电路及液晶显示器 - Google Patents

一种电源电路及液晶显示器 Download PDF

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Publication number
WO2018152901A1
WO2018152901A1 PCT/CN2017/077092 CN2017077092W WO2018152901A1 WO 2018152901 A1 WO2018152901 A1 WO 2018152901A1 CN 2017077092 W CN2017077092 W CN 2017077092W WO 2018152901 A1 WO2018152901 A1 WO 2018152901A1
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WIPO (PCT)
Prior art keywords
circuit
resistor
pfc
llc
capacitor
Prior art date
Application number
PCT/CN2017/077092
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English (en)
French (fr)
Inventor
杨勇
刘方云
Original Assignee
深圳市华星光电技术有限公司
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Filing date
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Application filed by 深圳市华星光电技术有限公司 filed Critical 深圳市华星光电技术有限公司
Priority to US15/567,527 priority Critical patent/US10305374B2/en
Publication of WO2018152901A1 publication Critical patent/WO2018152901A1/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
    • 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
    • H02M1/4241—Arrangements for improving power factor of AC input using a resonant converter
    • 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
    • H02M1/4266—Arrangements for improving power factor of AC input using passive elements
    • 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
    • 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
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/007—Plural converter units in cascade
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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 liquid crystal television technologies, and in particular, to a power supply circuit and a liquid crystal display.
  • LCD TV has become one of the indispensable electronic devices in people's lives.
  • FIG. 1 is a schematic diagram of a power supply circuit provided by the prior art.
  • the power supply circuit of the conventional liquid crystal television generally includes a rectification filter circuit 101, a flyback circuit 102, a PFC circuit 103 (power factor correction circuit), and an LLC circuit 104 (resonance circuit).
  • the flyback circuit 102 is responsible for providing the power supply of the main board or the control board, and is responsible for providing the power supply of the PFC circuit 103 and the LLC circuit 104, so that the PFC circuit 103 and the LLC circuit 104 are in an active state, and the working process is: the flyback circuit 102 provides The PFC circuit 103 and the LLC circuit 104 are powered.
  • the PFC circuit 103 and the LLC circuit 104 operate.
  • the PFC circuit 103 outputs a voltage to the LLC circuit 104 to generate a load voltage.
  • the LLC circuit 104 starts to work, which causes the current of the switching device in the LLC circuit 104 to be large and extremely burnt, which makes the power circuit fail.
  • the object of the present invention is to provide a power supply circuit and a liquid crystal display to solve the problem that the output voltage of the PFC circuit does not reach a stable value in the existing power supply circuit, and the LLC circuit starts to work, thereby causing damage to the switching device in the LLC circuit, and the power circuit is disabled.
  • Technical problem is to provide a power supply circuit and a liquid crystal display to solve the problem that the output voltage of the PFC circuit does not reach a stable value in the existing power supply circuit, and the LLC circuit starts to work, thereby causing damage to the switching device in the LLC circuit, and the power circuit is disabled.
  • the present invention provides a power supply circuit, including a rectification filter circuit, a flyback circuit, a PFC circuit, and an LLC circuit, which are sequentially connected, wherein the power supply circuit further includes: a PFC control circuit and an LLC control circuit;
  • a first input end and a second input end of the PFC control circuit are respectively connected to a first output end and a second output end of the flyback circuit, an output end of the PFC control circuit and the PFC circuit and the The first input of the LLC control circuit is connected;
  • a second input end of the LLC control circuit is connected to a first output end of the flyback circuit, an output end of the LLC control circuit is connected to the LLC circuit, a voltage collecting end of the LLC circuit and the PFC The voltage output of the circuit is connected;
  • the PFC control circuit is configured to output a stable first operating voltage to the PFC circuit to operate the PFC circuit;
  • the LLC control circuit is configured to detect a voltage value of a voltage output end of the PFC circuit, when When the voltage value reaches the preset voltage value, generating a second working voltage to the LLC circuit to operate the LLC circuit;
  • the PFC control circuit includes a first photocoupler, a first switch tube, a second switch tube, a control signal processing module, a voltage dividing module, and a clamping module;
  • An anode end of the first photocoupler is coupled to a first output end of the flyback circuit; a cathode end of the first photocoupler is coupled to a first end of the first switch transistor, the first The second end of the switch tube is grounded, and the control end of the first switch tube is connected to a control signal processing module;
  • a collector end of the first photocoupler is connected to a second output end of the flyback circuit, and an emitter terminal of the first photocoupler is respectively connected to a control end of the second switch tube through a voltage dividing module And a clamp module connection;
  • a first end of the second switch is connected to a second output of the flyback circuit, and a second end of the second switch is connected to the PFC circuit and a first input of the LLC control circuit ;
  • the control signal processing module includes a first resistor, a second resistor and a first capacitor; one end of the first resistor is connected to a control signal source, and the other end of the first resistor and one end of the second resistor, One end of the first capacitor and the control end of the first switch tube are connected; the other end of the second resistor and the other end of the first capacitor are grounded;
  • the voltage dividing module includes a third resistor and a fourth resistor; one end of the third resistor and one end of the fourth resistor are connected to an emitter terminal of the first photocoupler, and the other end of the third resistor Grounded, the other end of the fourth resistor is connected to the control end of the second switch tube;
  • the clamping module includes a Zener diode, a first diode, and a second capacitor; one end of the Zener diode, one end of the second capacitor, and a cathode end of the first diode
  • the control terminal of the second switch is connected, the other end of the Zener diode and the other end of the second capacitor are grounded, the anode end of the first diode and the second end of the second switch connection;
  • the LLC control circuit includes a second photocoupler, a controllable precision voltage regulator source, a third switch transistor, and an acquisition module;
  • An anode end of the second photocoupler is connected to one end of the fifth resistor and one end of the sixth resistor, and the other end of the fifth resistor is connected to the PFC control circuit.
  • the other end of the sixth resistor is connected to the cathode end of the second photocoupler and the anode end of the controllable precision voltage regulator source, and the cathode end of the controllable precision voltage regulator source is grounded, and the controllable a reference end of the precision voltage stabilizing source is connected to a voltage output end of the PFC circuit through an acquisition module;
  • a collector end of the second photocoupler is connected to one end of the seventh resistor and one end of the eighth resistor, and the other end of the seventh resistor is connected to the first output end of the flyback circuit, the eighth The other end of the resistor is connected to the control end of the third switch tube, and the emitter end of the second photocoupler is grounded;
  • the first end of the third switch tube is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the first output end of the flyback circuit; the second end of the third switch tube is The LLC circuit is connected;
  • the acquisition module is configured to collect a voltage value of a voltage output end of the PFC circuit to a reference end of the controllable precision voltage stabilization source.
  • the PFC control circuit further includes a third capacitor, one end of the third capacitor is connected to the PFC circuit, and the other end of the third capacitor is grounded.
  • the first switch tube and the second switch tube are NPN type transistors, and the first end, the second end, and the control end of the first switch tube and the second switch tube They are the collector, the emitter and the base.
  • the third switch tube is a PNP type transistor, and the first end, the second end, and the control end of the third switch tube are an emitter, a collector, and a base, respectively.
  • the acquisition module includes: a tenth resistor, an eleventh resistor, and a twelfth resistor;
  • One end of the tenth resistor is connected to a voltage output end of the PFC circuit, and the other end of the tenth resistor is connected to one end of the eleventh resistor, and the other end of the eleventh resistor and the first One end of the twelve resistor is connected to the reference end of the controllable precision voltage regulator, and the other end of the twelfth resistor is grounded.
  • the acquisition module includes: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a second diode, a third diode, a fourth capacitor, and a fifth capacitor;
  • One end of the thirteenth resistor is connected to a voltage output end of the PFC circuit, and the other end of the thirteenth resistor is connected to one end of the fourth capacitor; the other end of the fourth capacitor is opposite to the first Connecting an anode end of the diode and a cathode end of the third diode;
  • a cathode end of the second diode is connected to one end of the fifth capacitor and one end of the fourteenth resistor; an anode end of the third diode and another end of the fifth capacitor are grounded;
  • the other end of the fourteenth resistor and one end of the fifteenth resistor are connected to a reference end of the controllable precision voltage regulator; the other end of the fifteenth resistor is grounded.
  • the LLC control circuit further includes a sixth capacitor, one end of the sixth capacitor is connected to a reference end of the controllable precision voltage regulator source, and the other end of the sixth capacitor is grounded.
  • the present invention further provides a power supply circuit comprising a rectification filter circuit, a flyback circuit, a PFC circuit, and an LLC circuit connected in sequence, the power supply circuit further comprising: a PFC control circuit and an LLC control circuit;
  • a first input end and a second input end of the PFC control circuit are respectively connected to a first output end and a second output end of the flyback circuit, an output end of the PFC control circuit and the PFC circuit and the The first input of the LLC control circuit is connected;
  • a second input end of the LLC control circuit is connected to a first output end of the flyback circuit, an output end of the LLC control circuit is connected to the LLC circuit, a voltage collecting end of the LLC circuit and the PFC The voltage output of the circuit is connected;
  • the PFC control circuit is configured to output a stable first operating voltage to the PFC circuit to operate the PFC circuit; the LLC control circuit is configured to detect a voltage value of a voltage output end of the PFC circuit, when When the voltage value reaches the preset voltage value, a second operating voltage is generated to the LLC circuit to operate the LLC circuit.
  • the PFC control circuit includes a first photocoupler, a first switch tube, a second switch tube, a control signal processing module, a voltage dividing module, and a clamping module;
  • An anode end of the first photocoupler is coupled to a first output end of the flyback circuit; a cathode end of the first photocoupler is coupled to a first end of the first switch transistor, the first The second end of the switch tube is grounded, and the control end of the first switch tube is connected to a control signal processing module;
  • a collector end of the first photocoupler is connected to a second output end of the flyback circuit, and an emitter terminal of the first photocoupler is respectively connected to a control end of the second switch tube through a voltage dividing module And a clamp module connection;
  • a first end of the second switch is connected to a second output of the flyback circuit, and a second end of the second switch is connected to the PFC circuit and a first input of the LLC control circuit ;
  • the control signal processing module includes a first resistor, a second resistor and a first capacitor; one end of the first resistor is connected to a control signal source, and the other end of the first resistor and one end of the second resistor, One end of the first capacitor and the control end of the first switch tube are connected; the other end of the second resistor and the other end of the first capacitor are grounded;
  • the voltage dividing module includes a third resistor and a fourth resistor; one end of the third resistor and one end of the fourth resistor are connected to an emitter terminal of the first photocoupler, and the other end of the third resistor Grounded, the other end of the fourth resistor is connected to the control end of the second switch tube;
  • the clamping module includes a Zener diode, a first diode, and a second capacitor; one end of the Zener diode, one end of the second capacitor, and a cathode end of the first diode
  • the control terminal of the second switch is connected, the other end of the Zener diode and the other end of the second capacitor are grounded, the anode end of the first diode and the second end of the second switch connection.
  • the PFC control circuit further includes a third capacitor, one end of the third capacitor is connected to the PFC circuit, and the other end of the third capacitor is grounded.
  • the first switch tube and the second switch tube are NPN type transistors, and the first end, the second end, and the control end of the first switch tube and the second switch tube They are the collector, the emitter and the base.
  • the LLC control circuit includes a second photocoupler, a controllable precision voltage regulator source, a third switch transistor, and an acquisition module;
  • An anode end of the second photocoupler is connected to one end of the fifth resistor and one end of the sixth resistor, and the other end of the fifth resistor is connected to the PFC control circuit, and the other end of the sixth resistor is a cathode end of the second optocoupler and an anode end of the controllable precision voltage stabilizing source are connected, a cathode end of the controllable precision voltage stabilizing source is grounded, and a reference end of the controllable precision voltage stabilizing source passes through an acquisition module Connected to a voltage output terminal of the PFC circuit;
  • a collector end of the second photocoupler is connected to one end of the seventh resistor and one end of the eighth resistor, and the other end of the seventh resistor is connected to the first output end of the flyback circuit, the eighth The other end of the resistor is connected to the control end of the third switch tube, and the emitter end of the second photocoupler is grounded;
  • the first end of the third switch tube is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the first output end of the flyback circuit; the second end of the third switch tube is The LLC circuit is connected;
  • the acquisition module is configured to collect a voltage value of a voltage output end of the PFC circuit to a reference end of the controllable precision voltage stabilization source.
  • the third switch tube is a PNP type transistor, and the first end, the second end, and the control end of the third switch tube are an emitter, a collector, and a base, respectively.
  • the acquisition module includes: a tenth resistor, an eleventh resistor, and a twelfth resistor;
  • One end of the tenth resistor is connected to a voltage output end of the PFC circuit, and the other end of the tenth resistor is connected to one end of the eleventh resistor, and the other end of the eleventh resistor and the first One end of the twelve resistor is connected to the reference end of the controllable precision voltage regulator, and the other end of the twelfth resistor is grounded.
  • the acquisition module includes: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a second diode, a third diode, a fourth capacitor, and a fifth capacitor;
  • One end of the thirteenth resistor is connected to a voltage output end of the PFC circuit, and the other end of the thirteenth resistor is connected to one end of the fourth capacitor; the other end of the fourth capacitor is opposite to the first Connecting an anode end of the diode and a cathode end of the third diode;
  • a cathode end of the second diode is connected to one end of the fifth capacitor and one end of the fourteenth resistor; an anode end of the third diode and another end of the fifth capacitor are grounded;
  • the other end of the fourteenth resistor and one end of the fifteenth resistor are connected to a reference end of the controllable precision voltage regulator; the other end of the fifteenth resistor is grounded.
  • the LLC control circuit further includes a sixth capacitor, one end of the sixth capacitor is connected to a reference end of the controllable precision voltage regulator source, and the other end of the sixth capacitor is grounded.
  • a liquid crystal display further includes a power supply circuit including a rectification filter circuit, a flyback circuit, a PFC circuit, and an LLC circuit sequentially connected, wherein the power supply circuit further includes: a PFC control Circuit and LLC control circuit;
  • a first input end and a second input end of the PFC control circuit are respectively connected to a first output end and a second output end of the flyback circuit, an output end of the PFC control circuit and the PFC circuit and the The first input of the LLC control circuit is connected;
  • a second input end of the LLC control circuit is connected to a first output end of the flyback circuit, an output end of the LLC control circuit is connected to the LLC circuit, a voltage collecting end of the LLC circuit and the PFC The voltage output of the circuit is connected;
  • the PFC control circuit is configured to output a stable first operating voltage to the PFC circuit to operate the PFC circuit; the LLC control circuit is configured to detect a voltage value of a voltage output end of the PFC circuit, when When the voltage value reaches the preset voltage value, a second operating voltage is generated to the LLC circuit to operate the LLC circuit.
  • the PFC control circuit includes a first photocoupler, a first switching transistor, a second switching transistor, a control signal processing module, a voltage dividing module, and a clamping module;
  • An anode end of the first photocoupler is coupled to a first output end of the flyback circuit; a cathode end of the first photocoupler is coupled to a first end of the first switch transistor, the first The second end of the switch tube is grounded, and the control end of the first switch tube is connected to a control signal processing module;
  • a collector end of the first photocoupler is connected to a second output end of the flyback circuit, and an emitter terminal of the first photocoupler is respectively connected to a control end of the second switch tube through a voltage dividing module And a clamp module connection;
  • a first end of the second switch is connected to a second output of the flyback circuit, and a second end of the second switch is connected to the PFC circuit and a first input of the LLC control circuit ;
  • the control signal processing module includes a first resistor, a second resistor and a first capacitor; one end of the first resistor is connected to a control signal source, and the other end of the first resistor and one end of the second resistor, One end of the first capacitor and the control end of the first switch tube are connected; the other end of the second resistor and the other end of the first capacitor are grounded;
  • the voltage dividing module includes a third resistor and a fourth resistor; one end of the third resistor and one end of the fourth resistor are connected to an emitter terminal of the first photocoupler, and the other end of the third resistor Grounded, the other end of the fourth resistor is connected to the control end of the second switch tube;
  • the clamping module includes a Zener diode, a first diode, and a second capacitor; one end of the Zener diode, one end of the second capacitor, and a cathode end of the first diode
  • the control terminal of the second switch is connected, the other end of the Zener diode and the other end of the second capacitor are grounded, the anode end of the first diode and the second end of the second switch connection.
  • the LLC control circuit includes a second photocoupler, a controllable precision voltage regulator source, a third switch transistor, and an acquisition module;
  • An anode end of the second photocoupler is connected to one end of the fifth resistor and one end of the sixth resistor, and the other end of the fifth resistor is connected to the PFC control circuit, and the other end of the sixth resistor is a cathode end of the second optocoupler and an anode end of the controllable precision voltage stabilizing source are connected, a cathode end of the controllable precision voltage stabilizing source is grounded, and a reference end of the controllable precision voltage stabilizing source passes through an acquisition module Connected to a voltage output terminal of the PFC circuit;
  • a collector end of the second photocoupler is connected to one end of the seventh resistor and one end of the eighth resistor, and the other end of the seventh resistor is connected to the first output end of the flyback circuit, the eighth The other end of the resistor is connected to the control end of the third switch tube, and the emitter end of the second photocoupler is grounded;
  • the first end of the third switch tube is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the first output end of the flyback circuit; the second end of the third switch tube is The LLC circuit is connected;
  • the acquisition module is configured to collect a voltage value of a voltage output end of the PFC circuit to a reference end of the controllable precision voltage stabilization source.
  • the third switch tube is a PNP type transistor, and the first end, the second end, and the control end of the third switch tube are an emitter, a collector, and a base, respectively.
  • the power supply circuit and the liquid crystal display of the present invention firstly generate a first operating voltage to the PFC circuit via the PFC control circuit by setting the PFC control circuit and the LLC control circuit, thereby operating the PFC circuit, and then outputting a voltage value to the LLC circuit; then, LLC
  • the control circuit detects whether the generated voltage value reaches a preset voltage value. When the preset voltage value is reached, the LLC control circuit generates a second working voltage to the LLC circuit to operate, thereby effectively reducing the risk of damage of the switching device in the LLC circuit. Improve the reliability of the power circuit.
  • FIG. 1 is a schematic diagram of a power supply circuit provided by the prior art
  • FIG. 2 is a schematic diagram of a power supply circuit according to an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of a PFC control circuit in a power supply circuit according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of an LLC control circuit in a power supply circuit according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram 1 of an acquisition module of an LLC control circuit in a power supply circuit according to an embodiment of the present invention
  • FIG. 6 is a schematic diagram 2 of an acquisition module of an LLC control circuit in a power supply circuit according to an embodiment of the present invention.
  • FIG. 2 is a schematic diagram of a power supply circuit according to an embodiment of the present invention.
  • the power supply circuit 20 includes a rectification filter circuit 201, a flyback circuit 202, a PFC circuit 203, and an LLC circuit 204 that are sequentially connected. Meanwhile, the power supply circuit 20 further includes a PFC control circuit 205 and an LLC control circuit 206.
  • the first input terminal D and the second input terminal C of the PFC control circuit 205 are respectively connected to the first output terminal A and the second output terminal B of the flyback circuit 202, and the output terminal of the PFC control circuit 205 and the PFC circuit 203 and
  • the first input terminal E of the LLC control circuit 206 is connected;
  • the second input terminal F of the LLC control circuit 206 is connected to the first output terminal A of the flyback circuit 202, and the output of the LLC control circuit 206 is connected to the LLC circuit 204, LLC control
  • the voltage collecting terminal H of the circuit 206 is connected to the voltage output terminal G of the PFC circuit.
  • the PFC control circuit 205 is configured to output a stable first operating voltage V1 to the PFC circuit 203 to operate the PFC circuit 203; and the LLC control circuit 206 is configured to detect the voltage value V0 of the voltage output terminal G of the PFC circuit 203.
  • the second working voltage V2 is generated to the LLC circuit 204 to operate the LLC circuit 204, thereby effectively reducing the risk of damage of the switching device in the LLC circuit 204 and improving the reliability of the power circuit 20.
  • FIG. 3 is a schematic diagram of a PFC control circuit in a power supply circuit according to an embodiment of the present invention.
  • the PFC control circuit 205 includes a first photocoupler U1, a first switch transistor Q1, a second switch transistor Q2, a control signal processing module 2051, a voltage divider module 2052, and a clamp module 2053.
  • the anode terminal 1 of the first photocoupler U1 is connected to the first output terminal A of the flyback circuit, where a first one can be disposed between the anode terminal 1 of the first photocoupler U1 and the first output terminal A of the flyback circuit. Protection resistor Rx; the cathode end 2 of the first photocoupler U1 is connected to the first end of the first switch tube Q1, the second end of the first switch tube Q1 is grounded, the control end of the first switch tube Q1 and a control signal processing Module 2051 is connected;
  • the collector terminal 3 of the first photocoupler U1 is connected to the second output terminal B of the flyback circuit 202.
  • the emitter terminal 4 of the first photocoupler U1 passes through a voltage dividing module 2052 and the control terminal of the second switching transistor Q2. And a clamping module 2053 is connected;
  • the first end of the second switch Q2 is connected to the second output B of the flyback circuit 202.
  • a first switch can be disposed between the first end of the second switch Q2 and the second output B of the flyback circuit 202.
  • a protection resistor Ry; a second end of the second switching transistor Q2 is connected to the PFC circuit and the first input terminal E of the LLC control circuit 206;
  • the control signal processing module 2051 includes a first resistor R1, a second resistor R2, and a first capacitor C1.
  • One end of the first resistor R1 is connected to a control signal source PS_ON, and the other end of the first resistor R1 and one end of the second resistor R2.
  • One end of the first capacitor C1 and the control end of the first switch tube Q1 are connected; the other end of the second resistor R2 and the other end of the first capacitor C1 are grounded;
  • the voltage dividing module 2052 includes a third resistor R3 and a fourth resistor R4; one end of the third resistor R3 and one end of the fourth resistor R4 are connected to the emitter terminal 4 of the first photocoupler U1, and the other end of the third resistor R3 is grounded. The other end of the fourth resistor R4 is connected to the control end of the second switch tube Q2;
  • the clamping module 2053 includes a Zener diode ZD1, a first diode D1, and a second capacitor C2; one end of the Zener diode ZD1, one end of the second capacitor C2, and a cathode end and a second end of the first diode D1.
  • the control terminal of the switching transistor Q2 is connected, the other end of the Zener diode ZD1 and the other end of the second capacitor C2 are grounded, and the anode end of the first diode D1 is connected to the second end of the second switching transistor Q2.
  • the PFC control circuit 205 further includes a third capacitor C3. One end of the third capacitor C3 is connected to the PFC circuit, and the other end of the third capacitor C3 is grounded.
  • the first switch tube Q1 and the second switch tube Q2 are NPN type transistors. The first end, the second end, and the control end of the first switch tube Q1 and the second switch tube Q2 are respectively a collector, an emitter, and a base.
  • the working principle of the PFC control circuit is as follows: First, the first output terminal A of the flyback circuit 202 outputs a voltage, and when the control signal source PS_ON outputs a control signal, the processing of the control signal processing module 2051 is transmitted to the first switching transistor Q1.
  • the control terminal turns on the first switching transistor Q1, so that the anode terminal 1 and the cathode terminal 2 of the first photocoupler U1 are turned on; and the collector terminal 3 of the first photocoupler U1 is electrically connected to the emitter terminal 4
  • the first operating voltage V1 is output to the PFC circuit 203 via the clamping action of the clamping module 2053.
  • the second switch transistor turns on Q2, the diode D1 does not conduct, and the second output terminal of the flyback circuit 202
  • the voltage outputted by B is output to the PFC circuit 203 via the second switching transistor Q2 to operate; when the voltage output from the second output terminal B of the flyback circuit 202 is greater than the voltage regulation value of the Zener diode Z1, the second switching transistor Q2
  • the diode D1 is turned on, the voltage outputted by the second output terminal B of the flyback circuit 202 is clamped to the voltage regulator of the Zener diode ZD1 via the second switching transistor Q2.
  • FIG. 4 is a schematic diagram of an LLC control circuit in a power supply circuit according to an embodiment of the present invention.
  • the LLC control circuit 206 includes a second photocoupler U2, a controllable precision voltage regulator source U3, a third switch transistor Q3, and an acquisition module 2061.
  • the anode end 1 of the second photocoupler U2 is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6, and the other end of the fifth resistor R5 is connected to the PFC control circuit 205, and the other end of the sixth resistor and the second photoelectric
  • the cathode end 2 of the coupler U2 and the anode end 1 of the controllable precision voltage regulator source U3 are connected, and the cathode end 2 of the controllable precision voltage regulator source U3 is grounded, and the reference terminal 3 of the controllable precision voltage regulator source U3 passes through the acquisition module 2061 and The voltage output terminal G of the PFC circuit 203 is connected;
  • the collector terminal 3 of the second photocoupler U2 is connected to one end of the seventh resistor R7 and one end of the eighth resistor R8, and the other end of the seventh resistor R7 is connected to the first output terminal A of the flyback circuit 205, and the eighth resistor The other end of R8 is connected to the control end of the third switch tube Q3, and the emitter end 4 of the second photocoupler U2 is grounded;
  • the first end of the third switch tube Q3 is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is connected to the first output end A of the flyback circuit 202, and the second end of the third switch tube Q3 is connected to the LLC circuit. 204 connection;
  • the acquisition module 2061 is configured to collect the voltage value of the voltage output terminal G of the PFC circuit 203 to the reference terminal 3 of the controllable precision voltage regulator source U3.
  • the third switch tube Q3 is a PNP type transistor, and the first end, the second end, and the control end of the third switch tube Q3 are an emitter, a collector, and a base, respectively.
  • the LLC control circuit further includes a sixth capacitor C6. One end of the sixth capacitor C6 is connected to the reference terminal 3 of the controllable precision voltage regulator source U3, and the other end of the sixth capacitor C6 is grounded.
  • FIG. 5 is a schematic diagram 1 of an acquisition module of an LLC control circuit in a power supply circuit according to an embodiment of the present invention.
  • the acquisition module 2061 detects the voltage value of the voltage output end of the PFC circuit, and further detects whether the voltage value reaches a preset voltage value.
  • the acquisition module 2061 includes: a tenth resistor R10, an eleventh resistor R11, and a Twelve resistors R12;
  • One end of the tenth resistor R10 is connected to the voltage output terminal G of the PFC circuit, the other end of the tenth resistor R10 is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 and one end of the twelfth resistor R12 are The reference terminal 3 of the controllable precision voltage regulator source U3 is connected, and the other end of the twelfth resistor R12 is grounded.
  • FIG. 6 is a schematic diagram 2 of an acquisition module of an LLC control circuit in a power supply circuit according to an embodiment of the present invention.
  • the acquisition module 2061 can detect the voltage value of the voltage output terminal of the PFC circuit 203.
  • the voltage output terminal of the PFC circuit is not limited to that described in FIG. 5.
  • the PFC circuit 203 The voltage value having a proportional relationship can be output through the transformer.
  • FIG. 6 describes only another embodiment in which the voltage value is proportional to the voltage value described in FIG. 5. Those skilled in the art can set the circuit diagram of the acquisition module by the voltage proportional relationship.
  • the voltage value of the voltage output end of the PFC circuit 203 has a certain proportional relationship with that described in FIG. 5, and the acquisition module can be set to detect whether the voltage value reaches a preset voltage value, and the acquisition module includes: a thirteenth resistor. R13, the fourteenth resistor R14, the fifteenth resistor R15, the second diode D2, the third diode D3, the fourth capacitor C4 and the fifth capacitor C5;
  • One end of the thirteenth resistor R13 is connected to the voltage output terminal G of the PFC circuit, the other end of the thirteenth resistor R13 is connected to one end of the fourth capacitor C4, and the other end of the fourth capacitor C4 is opposite to the anode of the second diode D2. Extremely connected to the cathode end of the third diode D3;
  • a cathode end of the second diode D2 is connected to one end of the fifth capacitor C5 and one end of the fourteenth resistor R14; the anode end of the third diode D3 and the other end of the fifth capacitor C5 are grounded;
  • the other end of the fourteenth resistor R14 and one end of the fifteenth resistor R15 are connected to the reference terminal 3 of the controllable precision voltage stabilizing source U3; the other end of the fifteenth resistor R15 is grounded.
  • the working principle of the LLC control circuit is as follows: when the PFC circuit is working, a voltage value is outputted to the LLC circuit, and the PFC control circuit collects the voltage value through the acquisition module to the reference end of the controllable precision voltage regulator source, when the voltage value is When the preset voltage value is reached, the anode end and the cathode end of the controllable precision voltage regulator are turned on, and the first working voltage outputted by the PFC control circuit forms a conduction loop through the anode end and the cathode end of the second photocoupler, and further The collector end of the second photocoupler is electrically connected to the emitter terminal, and the voltage outputted from the first output end of the flyback circuit forms a conduction loop through the collector terminal of the second photocoupler and the emitter terminal, so that the third switch tube guide The voltage outputted by the first output terminal of the flyback circuit is outputted by the first switching transistor to the second operating voltage value LLC circuit to operate.
  • the power supply circuit of the present invention first sets a PFC control circuit and an LLC control circuit, first generates a first working voltage to the PFC circuit via the PFC control circuit, causes the PFC circuit to operate, and then outputs a voltage value to the LLC circuit; and then, the LLC control circuit detects and generates Whether the voltage value reaches the preset voltage value, when the preset voltage value is reached, the LLC control circuit generates the second working voltage to the LLC circuit to operate, thereby effectively reducing the risk of damage of the switching device in the LLC circuit, and improving the power circuit Reliability.
  • the present invention also provides a liquid crystal display comprising the power supply circuit of the above embodiment.
  • the power supply circuit has been discussed in detail in the above embodiments, and details are not described herein again.
  • the liquid crystal display of the invention provides a PFC control circuit and an LLC control circuit, firstly generates a first working voltage to the PFC circuit via the PFC control circuit, causes the PFC circuit to operate, and then outputs a voltage value to the LLC circuit; and then, the LLC control circuit detects and generates Whether the voltage value reaches the preset voltage value, when the preset voltage value is reached, the LLC control circuit generates the second working voltage to the LLC circuit to operate, thereby effectively reducing the risk of damage of the switching device in the LLC circuit, and improving the power circuit Reliability.

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Abstract

一种电源电路，包括依次连接的整流滤波电路、反激电路、ＰＦＣ电路、ＬＬＣ电路，ＰＦＣ控制电路以及ＬＬＣ控制电路；ＰＦＣ控制电路用于输出一稳定的第一工作电压至ＰＦＣ电路，使ＰＦＣ电路工作；ＬＬＣ控制电路用于检测ＰＦＣ电路生成的电压值，当电压值达到预设电压值时，生成第二工作电压至ＬＬＣ电路，使ＬＬＣ电路工作。

Description

一种电源电路及液晶显示器 技术领域
本发明涉及液晶电视技术领域，尤其涉及一种电源电路及液晶显示器。
 背景技术
随着电子技术的不断发展和人们需求的不断增加，具备各种不同功能的显示器设备逐渐被研发出来，使得人们的生活更加便捷和方便。其中，液晶电视已成为人们生活中必不可少的电子设备之一。
参阅图1，图1为现有技术提供的一种电源电路的示意图。如图1所示，现有的液晶电视的电源电路一般包括整流滤波电路101、反激电路102、PFC电路103（功率因素校正电路）、LLC电路104（谐振电路）。其中，反激电路102负责提供主板或控制板的供电，同时负责提供PFC电路103以及LLC电路104的供电，使PFC电路103以及LLC电路104处于工作状态，其工作过程为：反激电路102提供PFC电路103以及LLC电路104的供电，此时，PFC电路103以及LLC电路104工作，PFC电路103输出一电压至LLC电路104，进而生成一负载电压，然而若PFC电路103输出的电压值未达到稳定,LLC电路104就开始工作，会使得LLC电路104中的开关器件的电流很大，极易烧毁，使得电源电路失效。
故，有必要提供一种电源电路及液晶显示器，以解决现有技术所存在的问题。
 技术问题
本发明的目的在于提供一种电源电路及液晶显示器，以解决现有的电源电路在PFC电路输出电压未达到稳定值，LLC电路就开始工作，从而造成LLC电路中的开关器件损坏，电源电路失效的技术问题。
 技术解决方案
本发明提供一种电源电路，包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，其中所述电源电路还包括：PFC控制电路以及LLC控制电路；
所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作；
所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接；
所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接， 所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
在本发明的电源电路中，所述PFC控制电路还包括第三电容，所述第三电容的一端与所述PFC电路连接，所述第三电容的另一端接地。
在本发明的电源电路中，所述第一开关管以及所述第二开关管为NPN型三极管，所述第一开关管和所述第二开关管的第一端、第二端、控制端分别为集电极、发射极、基极。
在本发明的电源电路中，所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
在本发明的电源电路中，所述采集模块包括：第十电阻、第十一电阻、第十二电阻；
所述第十电阻的一端与所述PFC电路的电压输出端连接，所述第十电阻的另一端与所述第十一电阻的一端连接，所述第十一电阻的另一端以及所述第十二电阻的一端与所述可控精密稳压源的参考端连接，所述第十二电阻的另一端接地。
在本发明的电源电路中，所述采集模块包括：第十三电阻、第十四电阻、第十五电阻、第二二极管、第三二极管、第四电容以及第五电容；
所述第十三电阻的一端与所述PFC电路的电压输出端连接，所述第十三电阻的另一端与所述第四电容的一端连接；所述第四电容的另一端与所述第二二极管的阳极端以及所述第三二极管的阴极端连接；
所述第二二极管的阴极端与所述第五电容的一端以及所述第十四电阻的一端连接；所述第三二极管的阳极端以及所述第五电容的另一端接地；
所述第十四电阻的另一端以及所述第十五电阻的一端与所述可控精密稳压源的参考端连接；所述第十五电阻的另一端接地。
在本发明的电源电路中，所述LLC控制电路还包括第六电容，所述第六电容的一端与所述可控精密稳压源的参考端连接，所述第六电容的另一端接地。
本发明还提供一种电源电路，包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，所述电源电路还包括：PFC控制电路以及LLC控制电路；
所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作。
在本发明的电源电路中，所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接。
在本发明的电源电路中，所述PFC控制电路还包括第三电容，所述第三电容的一端与所述PFC电路连接，所述第三电容的另一端接地。
在本发明的电源电路中，所述第一开关管以及所述第二开关管为NPN型三极管，所述第一开关管和所述第二开关管的第一端、第二端、控制端分别为集电极、发射极、基极。
在本发明的电源电路中，所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接，所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
在本发明的电源电路中，所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
在本发明的电源电路中，所述采集模块包括：第十电阻、第十一电阻、第十二电阻；
所述第十电阻的一端与所述PFC电路的电压输出端连接，所述第十电阻的另一端与所述第十一电阻的一端连接，所述第十一电阻的另一端以及所述第十二电阻的一端与所述可控精密稳压源的参考端连接，所述第十二电阻的另一端接地。
在本发明的电源电路中，所述采集模块包括：第十三电阻、第十四电阻、第十五电阻、第二二极管、第三二极管、第四电容以及第五电容；
所述第十三电阻的一端与所述PFC电路的电压输出端连接，所述第十三电阻的另一端与所述第四电容的一端连接；所述第四电容的另一端与所述第二二极管的阳极端以及所述第三二极管的阴极端连接；
所述第二二极管的阴极端与所述第五电容的一端以及所述第十四电阻的一端连接；所述第三二极管的阳极端以及所述第五电容的另一端接地；
所述第十四电阻的另一端以及所述第十五电阻的一端与所述可控精密稳压源的参考端连接；所述第十五电阻的另一端接地。
在本发明的电源电路中，所述LLC控制电路还包括第六电容，所述第六电容的一端与所述可控精密稳压源的参考端连接，所述第六电容的另一端接地。
依据本发明的上述目的，还提供一种液晶显示器，其包括一种电源电路，其包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，其中所述电源电路还包括：PFC控制电路以及LLC控制电路；
所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作。
在本发明的液晶显示器中，所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接。
在本发明的液晶显示器中，所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接，所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
在本发明的液晶显示器中，所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
 有益效果
本发明的电源电路及液晶显示器，通过设置PFC控制电路以及LLC控制电路，首先经PFC控制电路生成第一工作电压至PFC电路，使PFC电路工作，进而输出一电压值至LLC电路；然后，LLC控制电路检测生成的电压值是否达到预设电压值，当达到预设电压值时，该LLC控制电路生成第二工作电压至LLC电路，使其工作，从而有效降低LLC电路中开关器件的损坏风险，提高电源电路的可靠性。
 附图说明
为让本发明的上述内容能更明显易懂，下文特举优选实施例，并配合所附图式，作详细说明如下：
下面结合附图，通过对本发明的具体实施方式详细描述，将使本发明的技术方案及其它有益效果显而易见。
图1为现有技术提供的一种电源电路的示意图；
图2 为本发明实施例提供的电源电路的示意图；
图3为本发明实施例提供的电源电路中PFC控制电路的示意图；
图4为本发明实施例提供的电源电路中LLC控制电路的示意图；
图5为本发明实施例提供的电源电路中LLC控制电路的采集模块的示意图一；
图6为本发明实施例提供的电源电路中LLC控制电路的采集模块的示意图二。
 本发明的最佳实施方式
为更进一步阐述本发明所采取的技术手段及其效果，以下结合本发明的优选实施例及其附图进行详细描述。显然，所描述的实施例仅仅是本发明一部分实施例，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。
参阅图2，图2为本发明实施例提供的电源电路的示意图。如图2所示，该电源电路20包括依次连接的整流滤波电路201、反激电路202、PFC电路203、LLC电路204。同时，该电源电路20还包括：PFC控制电路205以及LLC控制电路206。
其中，PFC控制电路205的第一输入端D以及第二输入端C分别与反激电路202的第一输出端A以及第二输出端B连接，PFC控制电路205的输出端与PFC电路203以及LLC控制电路206的第一输入端E连接；LLC控制电路206的第二输入端F与反激电路202的第一输出端A连接，LLC控制电路206的输出端与LLC电路204连接，LLC控制电路206的电压采集端H与PFC电路的电压输出端G连接。
具体的，PFC控制电路205用于输出一稳定的第一工作电压V1至PFC电路203，使PFC电路203工作；LLC控制电路206用于检测PFC电路203的电压输出端G的电压值V0，当电压值V0达到预设电压值时，生成第二工作电压V2至LLC电路204，使LLC电路204工作，从而有效降低LLC电路204中开关器件的损坏风险，提高该电源电路20的可靠性。
参阅图3，图3为本发明实施例提供的电源电路中PFC控制电路的示意图。结合图2、图3所示，该PFC控制电路205包括第一光电耦合器U1、第一开关管Q1、第二开关管Q2、控制信号处理模块2051、分压模块2052以及钳位模块2053；
第一光电耦合器U1的阳极端1与反激电路的第一输出端A连接，此处可在第一光电耦合器U1的阳极端1与反激电路的第一输出端A之间设置一保护电阻Rx；第一光电耦合器U1的阴极端2与第一开关管Q1的第一端连接，第一开关管Q1的第二端接地，第一开关管Q1的控制端与一控制信号处理模块2051连接；
第一光电耦合器U1的集电极端3与反激电路202的第二输出端B连接，第一光电耦合器U1的发射极端4通过一分压模块2052分别与第二开关管Q2的控制端以及一钳位模块2053连接；
第二开关管Q2的第一端与反激电路202的第二输出端B连接，此处可在第二开关管Q2的第一端与反激电路202的第二输出端B之间设置一保护电阻Ry；第二开关管Q2的第二端与PFC电路以及LLC控制电路206的第一输入端E连接；
控制信号处理模块2051包括第一电阻R1，第二电阻R2以及第一电容C1；第一电阻R1的一端与一控制信号源PS_ON连接，第一电阻R1的另一端与第二电阻R2的一端、第一电容C1的一端以及第一开关管Q1的控制端连接；第二电阻R2的另一端以及第一电容C1的另一端接地；
分压模块2052包括第三电阻R3以及第四电阻R4；第三电阻R3的一端以及第四电阻R4的一端与第一光电耦合器U1的发射极端4连接，第三电阻R3的另一端接地，第四电阻R4的另一端与第二开关管Q2的控制端连接；
钳位模块2053包括一稳压二极管ZD1、第一二极管D1以及一第二电容C2；稳压二极管ZD1的一端、第二电容C2的一端以及第一二极管D1的阴极端与第二开关管Q2的控制端连接，稳压二极管ZD1的另一端以及第二电容C2的另一端接地，第一二极管D1的阳极端与第二开关管Q2的第二端连接。
进一步的，该PFC控制电路205还包括第三电容C3，第三电容C3的一端与PFC电路连接，第三电容C3的另一端接地；第一开关管Q1以及第二开关管Q2为NPN型三极管，第一开关管Q1和第二开关管Q2的第一端、第二端、控制端分别为集电极、发射极、基极。
该PFC控制电路的工作原理如下：首先，反激电路202的第一输出端A输出电压，当控制信号源PS_ON输出一控制信号时，经控制信号处理模块2051的处理传至第一开关管Q1的控制端，使第一开关管Q1导通，从而使得第一光电耦合器U1的阳极端1与阴极端2导通；进而第一光电耦合器U1的集电极端3与发射极端4导通，经过钳位模块2053的钳位作用输出第一工作电压V1至PFC电路203。具体地，当反激电路202的第二输出端B输出的电压小于稳压二极管ZD1的稳压值时，第二开关管导通Q2，二极管D1不导通，反激电路202第二输出端B输出的电压经第二开关管Q2输出至PFC电路203，使其工作；当反激电路202的第二输出端B输出的电压大于稳压二极管Z1的稳压值时，第二开关管Q2导通，二极管D1导通，此时反激电路202第二输出端B输出的电压经第二开关管Q2被钳位在稳压二极管ZD1的稳压值上。通过本发明的PFC控制电路，使得PFC电路上的第一工作电压更加稳定，提高电路的可靠性。
参阅图4，图4为本发明实施例提供的电源电路中LLC控制电路的示意图。结合图2、图4所示，该LLC控制电路206包括第二光电耦合器U2、一可控精密稳压源U3、第三开关管Q3以及采集模块2061；
第二光电耦合器U2的阳极端1与第五电阻R5的一端以及第六电阻R6的一端连接，第五电阻R5的另一端与PFC控制电路205连接，第六电阻的另一端与第二光电耦合器U2的阴极端2以及可控精密稳压源U3的阳极端1连接，可控精密稳压源U3的阴极端2接地，可控精密稳压源U3的参考端3通过采集模块2061与PFC电路203的电压输出端G连接；
第二光电耦合器U2的集电极端3与第七电阻R7的一端以及第八电阻R8的一端连接，第七电阻R7的另一端与反激电路205的第一输出端A连接，第八电阻R8的另一端与第三开关管Q3的控制端连接，第二光电耦合器U2的发射极端4接地；
第三开关管Q3的第一端与第九电阻R9的一端连接，第九电阻R9的另一端与反激电路202的第一输出端A连接；第三开关管Q3的第二端与LLC电路204连接；
采集模块2061用于采集PFC电路203的电压输出端G的电压值至可控精密稳压源U3的参考端3。
其中，第三开关管Q3为PNP型三极管，第三开关管Q3的第一端、第二端、控制端分别为发射极、集电极、基极。LLC控制电路还包括第六电容C6，第六电容C6的一端与可控精密稳压源U3的参考端3连接，第六电容C6的另一端接地。
进一步的，参阅图5，图5为本发明实施例提供的电源电路中LLC控制电路的采集模块的示意图一。如图5所示，该采集模块2061通过检测PFC电路的电压输出端的电压值，进而检测该电压值是否达到预设电压值，采集模块2061包括：第十电阻R10、第十一电阻R11、第十二电阻R12；
第十电阻R10的一端与PFC电路的电压输出端G连接，第十电阻R10的另一端与第十一电阻R11的一端连接，第十一电阻R11的另一端以及第十二电阻R12的一端与可控精密稳压源U3的参考端3连接，第十二电阻R12的另一端接地。
另外，参阅图6，图6为本发明实施例提供的电源电路中LLC控制电路的采集模块的示意图二。如图6所示，该采集模块2061可通过检测PFC电路203的电压输出端的电压值，需要注意的是，PFC电路的电压输出端并不局限于图5所描述的，通常的，PFC电路203通过变压器可以输出具有一定比例关系的电压值，图6描述的仅为另一与图5描述的电压值成比例关系的实施例，本领域的技术人员可通过电压比例关系设置采集模块的电路图。此时，PFC电路203的电压输出端的电压值与图5描述的具有一定的比例关系，可通过设置采集模块，同样可以检测该电压值是否达到预设电压值，采集模块包括：第十三电阻R13、第十四电阻R14、第十五电阻R15、第二二极管D2、第三二极管D3、第四电容C4以及第五电容C5；
第十三电阻R13的一端与PFC电路的电压输出端G连接，第十三电阻R13的另一端与第四电容C4的一端连接；第四电容C4的另一端与第二二极管D2的阳极端以及第三二极管D3的阴极端连接；
第二二极管D2的阴极端与第五电容C5的一端以及第十四电阻R14的一端连接；第三二极管D3的阳极端以及第五电容C5的另一端接地；
第十四电阻R14的另一端以及第十五电阻R15的一端与可控精密稳压源U3的参考端3连接；第十五电阻R15的另一端接地。
该LLC控制电路的工作原理如下：当PFC电路工作时，输出一电压值至LLC电路，此时PFC控制电路通过采集模块采集该电压值至可控精密稳压源的参考端，当该电压值达到预设电压值时，可控精密稳压源的阳极端与阴极端导通，进而PFC控制电路输出的第一工作电压经第二光电耦合器的阳极端与阴极端形成导通回路，进而第二光电耦合器的集电极端与发射极端导通，反激电路的第一输出端输出的电压经第二光电耦合器的集电极端与发射极端形成导通回路，使得第三开关管导通，反激电路的第一输出端输出的电压经第一开关管输出第二工作电压值LLC电路，使其工作。
本发明的电源电路通过设置PFC控制电路以及LLC控制电路，首先经PFC控制电路生成第一工作电压至PFC电路，使PFC电路工作，进而输出一电压值至LLC电路；然后，LLC控制电路检测生成的电压值是否达到预设电压值，当达到预设电压值时，该LLC控制电路生成第二工作电压至LLC电路，使其工作，从而有效降低LLC电路中开关器件的损坏风险，提高电源电路的可靠性。
本发明还提供一种液晶显示器，包括上述实施例的电源电路，该电源电路已经在上述实施例中进行详细的论述，在此不再赘述。
本发明的液晶显示器通过设置PFC控制电路以及LLC控制电路，首先经PFC控制电路生成第一工作电压至PFC电路，使PFC电路工作，进而输出一电压值至LLC电路；然后，LLC控制电路检测生成的电压值是否达到预设电压值，当达到预设电压值时，该LLC控制电路生成第二工作电压至LLC电路，使其工作，从而有效降低LLC电路中开关器件的损坏风险，提高电源电路的可靠性。
综上，虽然本发明已以优选实施例揭露如上，但上述优选实施例并非用以限制本发明，本领域的普通技术人员，在不脱离本发明的精神和范围内，均可作各种更动与润饰，因此本发明的保护范围以权利要求界定的范围为准。

Claims (20)

  1. 一种电源电路，包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，其中所述电源电路还包括：PFC控制电路以及LLC控制电路；
    所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
    所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作；
    所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
    所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
    所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
    所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
    所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
    所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接；
    所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
    所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接， 所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
    所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
    所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
    所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
  2. 根据权利要求1所述的电源电路，其中所述PFC控制电路还包括第三电容，所述第三电容的一端与所述PFC电路连接，所述第三电容的另一端接地。
  3. 根据权利要求2所述的电源电路，其中所述第一开关管以及所述第二开关管为NPN型三极管，所述第一开关管和所述第二开关管的第一端、第二端、控制端分别为集电极、发射极、基极。
  4. 根据权利要求1所述的电源电路，其中所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
  5. 根据权利要求4所述的电源电路，其中所述采集模块包括：第十电阻、第十一电阻、第十二电阻；
    所述第十电阻的一端与所述PFC电路的电压输出端连接，所述第十电阻的另一端与所述第十一电阻的一端连接，所述第十一电阻的另一端以及所述第十二电阻的一端与所述可控精密稳压源的参考端连接，所述第十二电阻的另一端接地。
  6. 根据权利要求4所述的电源电路，其中所述采集模块包括：第十三电阻、第十四电阻、第十五电阻、第二二极管、第三二极管、第四电容以及第五电容；
    所述第十三电阻的一端与所述PFC电路的电压输出端连接，所述第十三电阻的另一端与所述第四电容的一端连接；所述第四电容的另一端与所述第二二极管的阳极端以及所述第三二极管的阴极端连接；
    所述第二二极管的阴极端与所述第五电容的一端以及所述第十四电阻的一端连接；所述第三二极管的阳极端以及所述第五电容的另一端接地；
    所述第十四电阻的另一端以及所述第十五电阻的一端与所述可控精密稳压源的参考端连接；所述第十五电阻的另一端接地。
  7. 根据权利要求5或6所述的电源电路，其中所述LLC控制电路还包括第六电容，所述第六电容的一端与所述可控精密稳压源的参考端连接，所述第六电容的另一端接地。
  8. 一种电源电路，包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，其中所述电源电路还包括：PFC控制电路以及LLC控制电路；
    所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
    所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作。
  9. 根据权利要求8所述的电源电路，其中所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
    所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
    所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
    所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
    所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
    所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接。
  10. 根据权利要求9所述的电源电路，其中所述PFC控制电路还包括第三电容，所述第三电容的一端与所述PFC电路连接，所述第三电容的另一端接地。
  11. 根据权利要求10所述的电源电路，其中所述第一开关管以及所述第二开关管为NPN型三极管，所述第一开关管和所述第二开关管的第一端、第二端、控制端分别为集电极、发射极、基极。
  12. 根据权利要求8至11任一项所述的电源电路，其中所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
    所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接， 所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
    所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
    所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
    所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
  13. 根据权利要求12所述的电源电路，其中所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
  14. 根据权利要求13所述的电源电路，其中所述采集模块包括：第十电阻、第十一电阻、第十二电阻；
    所述第十电阻的一端与所述PFC电路的电压输出端连接，所述第十电阻的另一端与所述第十一电阻的一端连接，所述第十一电阻的另一端以及所述第十二电阻的一端与所述可控精密稳压源的参考端连接，所述第十二电阻的另一端接地。
  15. 根据权利要求13所述的电源电路，其中所述采集模块包括：第十三电阻、第十四电阻、第十五电阻、第二二极管、第三二极管、第四电容以及第五电容；
    所述第十三电阻的一端与所述PFC电路的电压输出端连接，所述第十三电阻的另一端与所述第四电容的一端连接；所述第四电容的另一端与所述第二二极管的阳极端以及所述第三二极管的阴极端连接；
    所述第二二极管的阴极端与所述第五电容的一端以及所述第十四电阻的一端连接；所述第三二极管的阳极端以及所述第五电容的另一端接地；
    所述第十四电阻的另一端以及所述第十五电阻的一端与所述可控精密稳压源的参考端连接；所述第十五电阻的另一端接地。
  16. 根据权利要求14或15所述的电源电路，其中所述LLC控制电路还包括第六电容，所述第六电容的一端与所述可控精密稳压源的参考端连接，所述第六电容的另一端接地。
  17. 一种液晶显示器，其包括一种电源电路，其包括依次连接的整流滤波电路、反激电路、PFC电路、LLC电路，其中所述电源电路还包括：PFC控制电路以及LLC控制电路；
    所述PFC控制电路的第一输入端以及第二输入端分别与所述反激电路的第一输出端以及第二输出端连接，所述PFC控制电路的输出端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述LLC控制电路的第二输入端与所述反激电路的第一输出端连接，所述LLC控制电路的输出端与所述LLC电路连接，所述LLC电路的电压采集端与所述PFC电路的电压输出端连接；
    所述PFC控制电路用于输出一稳定的第一工作电压至所述PFC电路，使所述PFC电路工作；所述LLC控制电路用于检测所述PFC电路的电压输出端的电压值，当所述电压值达到预设电压值时，生成第二工作电压至所述LLC电路，使所述LLC电路工作。
  18. 根据权利要求17所述的液晶显示器，其中所述PFC控制电路包括第一光电耦合器、第一开关管、第二开关管、控制信号处理模块、分压模块以及钳位模块；
    所述第一光电耦合器的阳极端与所述反激电路的第一输出端连接；所述第一光电耦合器的阴极端与所述第一开关管的第一端连接，所述第一开关管的第二端接地，所述第一开关管的控制端与一控制信号处理模块连接；
    所述第一光电耦合器的集电极端与所述反激电路的第二输出端连接，所述第一光电耦合器的发射极端通过一分压模块分别与所述第二开关管的控制端以及一钳位模块连接；
    所述第二开关管的第一端与所述反激电路的第二输出端连接，所述第二开关管的第二端与所述PFC电路以及所述LLC控制电路的第一输入端连接；
    所述控制信号处理模块包括第一电阻，第二电阻以及第一电容；所述第一电阻的一端与一控制信号源连接，所述第一电阻的另一端与所述第二电阻的一端、第一电容的一端以及所述第一开关管的控制端连接；所述第二电阻的另一端以及所述第一电容的另一端接地；
    所述分压模块包括第三电阻以及第四电阻；所述第三电阻的一端以及所述第四电阻的一端与所述第一光电耦合器的发射极端连接，所述第三电阻的另一端接地，所述第四电阻的另一端与所述第二开关管的控制端连接；
    所述钳位模块包括一稳压二极管、第一二极管以及一第二电容；所述稳压二极管的一端、所述第二电容的一端以及所述第一二极管的阴极端与所述第二开关管的控制端连接，所述稳压二极管的另一端以及所述第二电容的另一端接地，所述第一二极管的阳极端与所述第二开关管的第二端连接。
  19. 根据权利要求18所述的液晶显示器，其中所述LLC控制电路包括第二光电耦合器、一可控精密稳压源、第三开关管以及采集模块；
    所述第二光电耦合器的阳极端与第五电阻的一端以及第六电阻的一端连接，所述第五电阻的另一端与所述PFC控制电路连接，所述第六电阻的另一端与所述第二光电耦合器的阴极端以及所述可控精密稳压源的阳极端连接，所述可控精密稳压源的阴极端接地，所述可控精密稳压源的参考端通过采集模块与所述PFC电路的电压输出端连接；
    所述第二光电耦合器的集电极端与第七电阻的一端以及第八电阻的一端连接，所述第七电阻的另一端与所述反激电路的第一输出端连接，所述第八电阻的另一端与所述第三开关管的控制端连接，所述第二光电耦合器的发射极端接地；
    所述第三开关管的第一端与第九电阻的一端连接，所述第九电阻的另一端与所述反激电路的第一输出端连接；所述第三开关管的第二端与所述LLC电路连接；
    所述采集模块用于采集所述PFC电路的电压输出端的电压值至所述可控精密稳压源的参考端。
  20. 根据权利要求19所述的液晶显示器，其中所述第三开关管为PNP型三极管，所述第三开关管的第一端、第二端、控制端分别为发射极、集电极、基极。
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