CN204231217U - A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set - Google Patents
A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set Download PDFInfo
- Publication number
- CN204231217U CN204231217U CN201420751218.6U CN201420751218U CN204231217U CN 204231217 U CN204231217 U CN 204231217U CN 201420751218 U CN201420751218 U CN 201420751218U CN 204231217 U CN204231217 U CN 204231217U
- Authority
- CN
- China
- Prior art keywords
- power supply
- led
- lamp bar
- type triode
- led lamp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Abstract
The utility model discloses a kind of flyback based on Voltage Feedback and directly drive LED power circuit and television set, comprise inverse excitation type converter, by inverse excitation type converter conversion output one road power supply and a paths of LEDs driving power; Described LED drive power connects the positive pole of LED lamp bar, the negative pole of LED lamp bar connects a switching circuit, the electric current flowing through LED lamp bar transfers to the reference pole of three end adjustable shunt reference sources when described switching circuit conducting, described a reference source is according to the change in voltage of power supply and LED drive power, regulate and feed back to the size of current of inverse excitation type converter, with the voltage magnitude of the constant each road power supply exported by reaction type converter.The utility model carries out Isobarically Control to LED drive power, the current constant flowing through LED lamp bar is ensured by the voltage of stable LED drive power, thus on the basis meeting LED lamp bar constant current driving requirement, effectively reduce power supply cost, simplify power supply structure.
Description
Technical field
The utility model belongs to power circuit technical field, specifically, and the circuit framework relating to a kind of inverse-excitation type LED drive power and the television set adopting described power circuit to design.
Background technology
At present, the competition of television set manufacturer is more and more fierce, and this just causes very large cost declining pressure to power supply etc. for the circuit module of television set.And the cost declining space of current components and parts is very little, it is very difficult that the one-tenth wanted by reducing components and parts lowers the cost of power supply originally.Therefore, power supply structure advantageously must just be found to complete the object of cost declining.
Through technical development in recent years, a kind of emerging inverse-excitation type AC-DC converter is widely applied on current liquid crystal and LED television product.The power module utilizing inverse-excitation type AC-DC converter to design not only can provide the power supply needed for it (being generally the DC power supply of 12V) for the system board of television set, the driving power needed for it can also be provided for the LED backlight bar in television set, the high pressure that described driving power does not normally wait from tens volts to a few hectovolt simultaneously.
In the practical application of television set, system board requires constant voltage to the 12V power supply that power module exports, and must reach higher precision; The LED drive power exported for power module then requires constant current, with stable backlight illumination.In order to obtain the LED drive power of current constant, the design that the current industry of order is popular be arrange in a power constant current drived control IC and with the metal-oxide-semiconductor of the step-up/down of described IC cooperating and fly-wheel diode, utilize described constant current drived control IC that the voltage that inverse-excitation type AC-DC converter exports is carried out to DC-DC conversion thus reaches current constant control.This traditional power circuit design due to needs use integrated chip carry out current constant control, therefore hardware cost is higher, causes the rising of power module cost, and then have impact on the market competitiveness of tv product.
Summary of the invention
The purpose of this utility model is to provide a kind of inverse-excitation type based on Voltage Feedback directly to drive LED power circuit, the voltage constant that analog circuit controls the LED drive power that inverse excitation type converter exports is built by adopting discrete component, the current constant flowing through LED lamp bar is realized by the voltage of stable LED drive power, the use of constant current drived control IC can be saved thus, reduce the hardware cost of power circuit.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
Flyback based on Voltage Feedback directly drives a LED power circuit, comprises inverse excitation type converter, is used for the LED drive power of driving LED lamp bar by described inverse excitation type converter conversion output at least one road power supply and a road; Described LED drive power connects the positive pole of LED lamp bar, the negative pole of LED lamp bar connects a switching circuit, the electric current flowing through LED lamp bar transfers to the reference pole of three end adjustable shunt reference sources when described switching circuit conducting, described switching circuit receives the control signal for regulating LED lamp bar brightness, break-make under the control of said control signal; Described power supply transfers to the reference pole of described three end adjustable shunt reference sources via the dividing potential drop that the first potential-divider network is formed, described three end adjustable shunt reference sources are according to the change in voltage of described power supply and LED drive power, regulate the size of current feeding back to described inverse excitation type converter, the voltage magnitude of each road power supply that described inverse excitation type converter regulates it to export according to the feedback current received.
As a kind of preferred circuit teaming method of described switching circuit, a N-channel MOS pipe, a NPN type triode and a PNP type triode is provided with in described switching circuit, the control signal described in grid reception of described N-channel MOS pipe, drain electrode connects the negative pole of LED lamp bar, source electrode by shunt resistance ground connection, and connects the emitter of described PNP type triode; The collector electrode of described PNP type triode connects the reference pole of described three end adjustable shunt reference sources, and base stage connects the collector electrode of described NPN type triode; The control signal described in base stage reception of described NPN type triode, the grounded emitter of NPN type triode.
As another circuit teaming method of described switching circuit, two NPN type triode and a PNP type triode is provided with in described switching circuit, the control signal described in base stage reception of first NPN type triode, collector electrode connects the negative pole of LED lamp bar, emitter by shunt resistance ground connection, and connects the emitter of described PNP type triode; The collector electrode of described PNP type triode connects the reference pole of described three end adjustable shunt reference sources, and base stage connects the collector electrode of second NPN type triode; The control signal described in base stage reception of second NPN type triode, the grounded emitter of second NPN type triode.
In order to improve the accuracy controlled switch connecting and disconnecting of the circuit, by described control signal first via after a shaping circuit process, then transfer to described switching circuit; An operational amplifier is provided with in described shaping circuit, the control signal described in in-phase input end reception of described operational amplifier, inverting input receives described power supply via the bias voltage formed after the second potential-divider network dividing potential drop, controls signal to described switching circuit after the output output Shaping of operational amplifier.
Preferably, described control signal is pwm signal, and the amplitude of described bias voltage is less than 0.8V.
Further, the plus earth of described three end adjustable shunt reference sources, negative electrode connects the emission side of an optocoupler, the inverse excitation type converter described in sensitive side connection of optocoupler; Described three end adjustable shunt reference sources change the electric current flowing through described optocoupler according to the change in voltage of described power supply and LED drive power, and then regulate by opto-coupled feedback to the size of current of inverse excitation type converter.
Further again, be parallel with a resistance at the two ends of the emission side of described optocoupler, one end of described resistance connects the negative electrode of three end adjustable shunt reference sources, the power supply described in the other end is connected by a current-limiting resistance.
Further, flyback PWM controller and switch transformer is provided with in described inverse excitation type converter, described flyback PWM controller receives the electric current of described opto-coupled feedback, and it exports the duty ratio of the pwm signal of switch transformer to according to described Current adjustment, to stablize the amplitude of power supply and the LED drive power exported by switch transformer.
Flyback based on above-mentioned Voltage Feedback directly drives the structural design of LED power circuit, and the utility model also proposed a kind of television set adopting described power circuit to design, and comprises system board and display screen, in described display screen, be provided with LED lamp bar; The flyback be also provided with in described television set based on Voltage Feedback directly drives LED power circuit, described power circuit comprises inverse excitation type converter, is used for the LED drive power of driving LED lamp bar by described inverse excitation type converter conversion output at least one road power supply and a road; Described power supply transfers to system board, for system board is powered; Described LED drive power connects the positive pole of LED lamp bar, the negative pole of LED lamp bar connects a switching circuit, the electric current flowing through LED lamp bar transfers to the reference pole of three end adjustable shunt reference sources when described switching circuit conducting, described switching circuit receives the control signal for regulating LED lamp bar brightness, break-make under the control of said control signal; Described power supply transfers to the reference pole of described three end adjustable shunt reference sources via the dividing potential drop that the first potential-divider network is formed, described three end adjustable shunt reference sources are according to the change in voltage of described power supply and LED drive power, regulate the size of current feeding back to described inverse excitation type converter, the voltage magnitude of each road power supply that described inverse excitation type converter regulates it to export according to the feedback current received.
Further, described power supply is by the standby power needed for a DC-DC pressurizer conversion generation system mainboard.
Compared with prior art, advantage of the present utility model and good effect are: the utility model employing discrete component is built constant-current control circuit and replaced traditional integrated chip, the LED drive power exported inverse excitation type converter is adopted to carry out the mode of Isobarically Control, the current constant flowing through LED lamp bar is ensured by the voltage of stable LED drive power, thus on the basis meeting LED lamp bar constant current driving requirement, effectively reduce power supply cost, simplify power supply structure.Be applied in the circuit design of television set by adopting the power module of described power supply structure design, inverse excitation type converter is utilized to export the power supply needed for system for TV set mainboard and the constant-current driving power supply needed for backlight LED in the lump, and the main board power supply power supply that inverse excitation type converter can be utilized to export is through the standby power needed for the further generation system mainboard of DC-DC pressurizer, not only can simplify the power panel design of tv product thus, reduce hardware cost, improve the market competitiveness of tv product, and can energy loss be reduced, improve the stability that power supply runs.
After reading the detailed description of the utility model execution mode by reference to the accompanying drawings, other features of the present utility model and advantage will become clearly.
Accompanying drawing explanation
Fig. 1 is the overall architecture block diagram of the power circuit that the utility model proposes;
Fig. 2 is the circuit theory diagrams of a kind of embodiment of LED drive power feedback fraction in voltage feedback circuit shown in Fig. 1;
Fig. 3 is the circuit theory diagrams of another embodiment of LED drive power feedback fraction in voltage feedback circuit shown in Fig. 1;
Fig. 4 is the circuit theory diagrams of the third embodiment of LED drive power feedback fraction in voltage feedback circuit shown in Fig. 1;
Fig. 5 is the circuit theory diagrams of a kind of embodiment of power supply and LED drive power common sparing in voltage feedback circuit shown in Fig. 1.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in more detail.
In the design of existing power circuit, inverse excitation type converter is usually used to generate driving power OUT_LED(needed for LED lamp bar hereinafter referred to as LED drive power), the DC power supply of such as 150V, shown in Figure 1.In order to ensure the stability of LED lamp bar luminosity, need the current constant keeping flow through LED lamp bar, therefore, necessary specialized designs LED constant-current control circuit, carries out current constant control to the LED drive power OUT_LED exported by inverse excitation type converter.
The present embodiment is in order to reduce the hardware cost of power circuit, changing tradition adopts constant current drived control IC to build power circuit, realize the design of current constant control, propose a kind of voltage feedback circuit adopting discrete component to set up, by described voltage feedback circuit, voltage stabilizing control is carried out to the LED drive power that inverse excitation type converter exports, by the voltage magnitude of stable LED drive power, current constant control is realized to the electric current flowing through LED lamp bar, and then under the prerequisite to require at the constant current drived control meeting LED lamp bar, the use of LED constant current drived control IC can be saved, realize the remarkable reduction of power circuit hardware cost, for electronic product (the such as television set using such power circuit to design, computer etc.) larger cost declining space is provided.
The voltage feedback circuit of the present embodiment receives the two-way DC power supply exported by inverse excitation type converter: a road is low-voltage dc power supply, and such as, power supply OUT_12V needed for system for TV set mainboard, is generally the DC power supply of+12V; Another road is high-voltage DC power supply, such as, LED drive power OUT_LED needed for the backlight of television display screen.Described voltage feedback circuit is according to the change in voltage of the two-way DC power supply received, it is regulated to feed back to the size of current of inverse excitation type converter, the amplitude of each road DC power supply that inverse excitation type converter regulates it to export according to the curent change received, and then make the voltage magnitude of described power supply OUT_12V and LED drive power OUT_LED remain stable.
In order to reduce costs, the voltage feedback circuit of the present embodiment adopts discrete component to build, and shown in composition graphs 2, Fig. 5, comprises a switching circuit, three end adjustable shunt reference source U3 and first potential-divider network.The LED drive power OUT_LED exported by inverse excitation type converter is transferred to the positive pole of LED lamp bar, the negative pole LED-of LED lamp bar is connected to described switching circuit, control current supply circuit conducting or the cut-out of LED lamp bar by controlling described switching circuit break-make, and then realize the accurate control to the switching sequence of LED lamp bar.
Illustrate for the television product being configured with LED backlight bar, when user needs the backlight illumination regulating display screen, corresponding operational order can be inputted by remote controller or the keypad be arranged in television body, controller on system board generates the control signal for regulating the brightness of LED backlight bar according to the operational order that user inputs, the pwm signal that such as duty ratio is adjustable, by regulating the switching sequence of LED backlight bar, change the backlight illumination of display screen.
The present embodiment for described control signal for pwm signal is described.Described pwm signal is transferred to the control end of switching circuit, the break-make sequential of switching circuit is controlled.When the controlled conducting of described switching circuit, the current supply circuit of LED lamp bar is communicated with, gather the electric current flowing through LED lamp bar, and transfer to the reference pole of described three end adjustable shunt reference source U3, the curent change of LED lamp bar is flow through by three end adjustable shunt reference source U3 perception, and then correspondingly regulate it to feed back to the electric current of inverse excitation type converter, to stablize the voltage magnitude of the LED drive power exported by inverse excitation type converter.
In order in the process of voltage magnitude regulating LED drive power, the voltage stabilization of power supply OUT_12V can be maintained, to meet the power reguirements of system for TV set mainboard, the power supply OUT_12V exported by inverse excitation type converter is also transferred to the reference pole of described three end adjustable shunt reference source U3 by the present embodiment via the dividing potential drop that the first potential-divider network is formed.Described three end adjustable shunt reference source U3 consider the change in voltage of power supply OUT_12V and LED drive power OUT_LED, with the size of current regulating it to feed back to described inverse excitation type converter.The voltage magnitude of each road power supply that described inverse excitation type converter regulates it to export according to the feedback current received, stablizes with the voltage magnitude maintaining each road power supply.
As wherein a kind of preferred circuit teaming method of described switching circuit, shown in Figure 2, the present embodiment is provided with a N-channel MOS pipe Q7, a NPN type triode Q14 and PNP type triode Q13 in described switching circuit.The control signal (being described for pwm signal below) being used for adjusting backlight luminance that system board exports is transferred to the grid of N-channel MOS pipe Q7 and the base stage of NPN type triode Q14 respectively, the drain electrode of N-channel MOS pipe Q7 is connected to the negative pole of LED lamp bar, source electrode leads up to shunt resistance R56 ground connection, and another road is connected to the emitter of PNP type triode Q13.The collector electrode of described PNP type triode Q13 is connected to the reference pole of three end adjustable shunt reference source U3, base stage is connected to the collector electrode of NPN type triode Q14 by resistance R73, the grounded emitter of described NPN type triode Q14.
In the present embodiment, the resistance selection principle of described shunt resistance R56 should meet: I
lED* R56=Vref.Wherein, Vref is the reference pole tension of three end adjustable shunt reference source U3; I
lEDfor requiring the constant current flowing through LED lamp bar.
When pwm signal is in high level, the controlled saturation conduction of N-channel MOS pipe Q7 and NPN type triode Q14, the conducting of N-channel MOS pipe Q7 makes the current supply circuit of LED lamp bar be communicated with, the a part of drain electrode by N-channel MOS pipe Q7 of electric current and the source electrode that flow through LED lamp bar flow to shunt resistance R56, and another part flows to the emitter of PNP type triode Q13.After described NPN type triode Q14 saturation conduction, drag down the base potential of PNP type triode Q13, make PNP type triode Q13 saturation conduction, then make the electric current of the emitter of inflow PNP type triode Q13 flow to the reference pole of three end adjustable shunt reference source U3 by the collector electrode of PNP type triode Q13.When there is fluctuation in the electric current flowing through LED lamp bar, the electric current being transferred to three end adjustable shunt reference source U3 by PNP type triode Q13 is changed, the electric current of the negative electrode and anode flowing through three end adjustable shunt reference source U3 is changed, described curent change is fed back to inverse excitation type converter, and then realizes the corresponding adjustment of the voltage magnitude to each road power supply that inverse excitation type converter exports.
When pwm signal proceeds to low level, N-channel MOS pipe Q7 and NPN type triode Q14 cut-off, PNP type triode Q13 turns off, and stops the reference pole feedback current to three end adjustable shunt reference source U3.
In order to improve the accuracy controlled LED lamp bar switching sequence, first the present embodiment carries out Shape correction to the waveform of the pwm signal that system board exports, and then transfers to described switching circuit.As shown in Figure 3, the pwm signal that system board is exported via current-limiting resistance R53 transfer to the in-phase input end of an operational amplifier U5+, the power supply OUT_12V that inverse excitation type converter is exported via after the second potential-divider network dividing potential drop, formed bias voltage be applied to the inverting input of described operational amplifier U5-.In the present embodiment, described second potential-divider network preferably adopts resistance pressure-dividing network, the bleeder circuit be such as formed by connecting by divider resistance R58 and R57.Described bleeder circuit is connected between power supply OUT_12V and ground, its divider node be connected to the inverting input of described operational amplifier U5-, reasonably configure the resistance of described divider resistance R58 and R57, to limit the amplitude of described bias voltage at below 0.8V, produce misoperation to ensure operational amplifier U5 to be unlikely to unsettled.The pwm signal exported by operational amplifier U5 shaping is transferred to the grid of N-channel MOS pipe Q7 by resistance R55, and acted on the base stage of NPN type triode Q14 by resistance R74, to realize the accurate control to N-channel MOS pipe Q7 and NPN type triode Q14 switching sequence.
Certainly, when designing described switching circuit, also NPN type triode Q8 can be utilized to replace N-channel MOS pipe Q7 (the good metal-oxide-semiconductor of preferred radiating effect) in Fig. 2, and triode Q13 and Q14 described in coordinating build described switching circuit, as shown in Figure 4.Now, only the collector electrode of NPN type triode Q8 need be connected to the negative pole LED-of LED lamp bar; Resistance R55 of the base stage of NPN type triode Q8 being leaded up to is connected to the output of operational amplifier U5, and current-limiting resistance R74 of separately leading up to is connected to the base stage of NPN type triode Q14; By the emitter of NPN type triode Q8 by shunt resistance R56 ground connection, and be connected with the emitter of PNP type triode Q13, the switching circuit formed thus is while realization controls LED lamp bar switching sequence, gather the electric current flowing through LED lamp bar, and feed back to the reference pole of three end adjustable shunt reference source U3, and then realize the Isobarically Control to the LED drive power that inverse excitation type converter exports.
Certainly, described PNP type triode Q13 and NPN type triode Q14 also can select metal-oxide-semiconductor to replace, and the switching circuit formed thus can meet design requirement equally.The concrete establishment form of the present embodiment to switching circuit is not limited in above citing.
In the present embodiment, described inverse excitation type converter preferably adopts inverse-excitation type AC-DC converter, as shown in Figure 1.Current rectifying and wave filtering circuit Z1, flyback PWM controller and switch transformer T1 is provided with in described inverse-excitation type AC-DC converter, described current rectifying and wave filtering circuit Z1 receives outside alternating current input power supplying AC, and after rectifying conversion and filtering process are carried out to described alternating current input power supplying AC, export DC power supply DC and transfer to the elementary of flyback PWM controller and switch transformer T1 respectively.The described flyback PWM controller current supply circuit elementary to switch transformer T1 carries out break-make control, by the switching sequence of by-pass cock transformer T1, regulates the voltage magnitude of each road DC power supply of the secondary output by switch transformer T1.
Certainly, power supply for outside input is the situation of DC power supply, inverse-excitation type DC-DC converter can be selected to replace the inverse-excitation type AC-DC converter shown in Fig. 1 when designing described power circuit, design the overall architecture of described power circuit, the concrete type selecting of the present embodiment to inverse excitation type converter does not do concrete restriction.
Carrying out in the process of current stabilization control to the electric current flowing through LED lamp bar, the voltage magnitude of the power supply OUT_12V that inverse excitation type converter can be caused to export fluctuates, in order to the voltage magnitude of stable power-supplying power supply OUT_12V, to meet the constant voltage requirement of system for TV set mainboard to power supply, the present embodiment by the power supply OUT_12V that exported by inverse excitation type converter via after the first potential-divider network dividing potential drop, also feed back to the reference pole of described three end adjustable shunt reference source U3, jointly realize regulating to the electric current flowing through a reference source U3.
In the present embodiment, described first potential-divider network preferably adopts resistance pressure-dividing network, such as be in series by two resistance R23, R24, one end connects the output of inverse excitation type converter, receive power supply OUT_12V, other end ground connection, connects the reference pole of three end adjustable shunt reference source U3 by the divider node of potential-divider network, the plus earth of three end adjustable shunt reference source U3, negative electrode connects the flyback PWM controller of inverse excitation type converter.For the purpose of design of protection inverse excitation type converter; the negative electrode of three end adjustable shunt reference source U3 is preferably connected to the emission side of an optocoupler PC1 by the present embodiment; the negative electrode of such as connecting luminous diode; power supply OUT_12V described in light-emitting diodes tube anode is connected by current-limiting resistance R21, can also further parallel resistance R20 at the two ends of described light-emitting diode.The sensitive side of optocoupler PC1 is connected to the flyback PWM controller of inverse excitation type converter, such as, the collector electrode of illuminated triode can be connected flyback PWM controller, grounded emitter.When there is fluctuation in the power supply OUT_12V exported by inverse excitation type converter or LED drive power OUT_LED, reference pole tension due to three end adjustable shunt reference source U3 keeps constant, therefore the electric current flowing through three end adjustable shunt reference source U3 is caused to change, and then cause the electric current flowing through optocoupler PC1 to change, and described curent change is fed back to the flyback PWM controller in inverse excitation type converter.Described flyback PWM controller is according to the feedback current received, the duty ratio of the pwm signal regulating it to export, by changing the switching sequence of switch transformer T1, adjust the voltage magnitude that it exports, stablize to keep power supply OUT_12V and LED drive power OUT_LED, and then while meeting the constant voltage power reguirements of system board, the constant current being met LED lamp bar by the voltage stabilization controlling LED drive power drives requirement.
In order to improve the stability of voltage feedback circuit work, can also cross-over connection filter capacitor C5 and the series arm that is formed by connecting by electric capacity C6 and resistance R22 further between the negative electrode and the divider node of the first potential-divider network of described three end adjustable shunt reference source U3, as shown in Figure 5, to be used for adjusting the response speed fed back, ensure the stability of circuit.
For the standby power that system for TV set mainboard is required when standby, the DC power supply of such as+5V, can utilize DC-DC pressurizer directly to change generation to the power supply OUT_12V that inverse excitation type converter exports, as shown in Figure 1, to simplify circuit design further, reduce hardware cost.
The above is the situation based on single-string LED lamp bar.The design that the present embodiment proposes equally also is applicable to the situation of many cluster of lamps, ornamental bar parallel connection, because the conduction voltage drop of every cluster of lamps, ornamental bar of parallel connection is identical, therefore, only identical way need be adopted the reference pole of the Voltage Feedback of each cluster of lamps, ornamental bar to described three end adjustable shunt reference source U3.
Flyback of the present utility model is directly driven LED power circuit and is especially applicable to being applied in below 100W, has on the two-in-one power supply (power supply is two-in-one with driving) of the anti exciting converter that two-way exports.This source nominal power is generally less than 75W, therefore without the need to designing PFC power factor correction loop.This new architecture has compared with traditional switch power supply that structure is simple, low cost and other advantages, and the framework of low-power television power supply can be made to be improved.This new architecture is apparent in the advantage of cost and reliability, and realizes than being easier to, and therefore promotes relatively easy.
Certainly; above-mentioned explanation is not to restriction of the present utility model; the utility model is also not limited in above-mentioned citing, the change that those skilled in the art make in essential scope of the present utility model, remodeling, interpolation or replacement, also should belong to protection range of the present utility model.
Claims (10)
1. the flyback based on Voltage Feedback directly drives a LED power circuit, comprises inverse excitation type converter, is used for the LED drive power of driving LED lamp bar by described inverse excitation type converter conversion output at least one road power supply and a road; It is characterized in that: described LED drive power connects the positive pole of LED lamp bar, the negative pole of LED lamp bar connects a switching circuit, the electric current flowing through LED lamp bar transfers to the reference pole of three end adjustable shunt reference sources when described switching circuit conducting, described switching circuit receives the control signal for regulating LED lamp bar brightness, break-make under the control of said control signal;
Described power supply transfers to the reference pole of described three end adjustable shunt reference sources via the dividing potential drop that the first potential-divider network is formed, described three end adjustable shunt reference sources are according to the change in voltage of described power supply and LED drive power, regulate the size of current feeding back to described inverse excitation type converter, the voltage magnitude of each road power supply that described inverse excitation type converter regulates it to export according to the feedback current received.
2. the flyback based on Voltage Feedback according to claim 1 directly drives LED power circuit, it is characterized in that: in described switching circuit, be provided with a N-channel MOS pipe, a NPN type triode and a PNP type triode, the control signal described in grid reception of described N-channel MOS pipe, drain electrode connects the negative pole of LED lamp bar, source electrode by shunt resistance ground connection, and connects the emitter of described PNP type triode; The collector electrode of described PNP type triode connects the reference pole of described three end adjustable shunt reference sources, and base stage connects the collector electrode of described NPN type triode; The control signal described in base stage reception of described NPN type triode, the grounded emitter of NPN type triode.
3. the flyback based on Voltage Feedback according to claim 1 directly drives LED power circuit, it is characterized in that: in described switching circuit, be provided with two NPN type triode and a PNP type triode, the control signal described in base stage reception of first NPN type triode, collector electrode connects the negative pole of LED lamp bar, emitter by shunt resistance ground connection, and connects the emitter of described PNP type triode; The collector electrode of described PNP type triode connects the reference pole of described three end adjustable shunt reference sources, and base stage connects the collector electrode of second NPN type triode; The control signal described in base stage reception of second NPN type triode, the grounded emitter of second NPN type triode.
4. the flyback based on Voltage Feedback according to any one of claim 1 to 3 directly drives LED power circuit, it is characterized in that: described control signal via after a shaping circuit process, then transfers to described switching circuit; An operational amplifier is provided with in described shaping circuit, the control signal described in in-phase input end reception of described operational amplifier, inverting input receives described power supply via the bias voltage formed after the second potential-divider network dividing potential drop, controls signal to described switching circuit after the output output Shaping of operational amplifier.
5. the flyback based on Voltage Feedback according to claim 4 directly drives LED power circuit, it is characterized in that: described control signal is pwm signal, and the amplitude of described bias voltage is less than 0.8V.
6. the flyback based on Voltage Feedback according to any one of claim 1 to 3 directly drives LED power circuit, it is characterized in that: the plus earth of described three end adjustable shunt reference sources, negative electrode connects the emission side of an optocoupler, the inverse excitation type converter described in sensitive side connection of optocoupler.
7. the flyback based on Voltage Feedback according to claim 6 directly drives LED power circuit, it is characterized in that: be parallel with a resistance at the two ends of the emission side of described optocoupler, one end of described resistance connects the negative electrode of three end adjustable shunt reference sources, the power supply described in the other end is connected by a current-limiting resistance.
8. the flyback based on Voltage Feedback according to claim 6 directly drives LED power circuit, it is characterized in that: in described inverse excitation type converter, be provided with flyback PWM controller and switch transformer, described flyback PWM controller receives the electric current of described opto-coupled feedback, and it exports the duty ratio of the pwm signal of switch transformer to according to described Current adjustment, to stablize the amplitude of power supply and the LED drive power exported by switch transformer.
9. a television set, be provided with system board and display screen, LED lamp bar is provided with in described display screen, it is characterized in that: the flyback based on Voltage Feedback be also provided with in described television set any one of claim 1 to 8 as described in claim directly drives LED power circuit, described power supply transfers to system board, for system board is powered.
10. television set according to claim 9, is characterized in that: described power supply is by the standby power needed for a DC-DC pressurizer conversion generation system mainboard.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420751218.6U CN204231217U (en) | 2014-12-04 | 2014-12-04 | A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420751218.6U CN204231217U (en) | 2014-12-04 | 2014-12-04 | A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204231217U true CN204231217U (en) | 2015-03-25 |
Family
ID=52929266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420751218.6U Withdrawn - After Issue CN204231217U (en) | 2014-12-04 | 2014-12-04 | A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204231217U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104377971A (en) * | 2014-12-04 | 2015-02-25 | 青岛歌尔声学科技有限公司 | Flyback direct-drive LED power circuit on basis of voltage feedback and television set |
| CN105245111A (en) * | 2015-11-13 | 2016-01-13 | 营口营成电子设备有限公司 | Control system of high direct voltage output voltage stabilization and constant current source |
| WO2017049815A1 (en) * | 2015-09-25 | 2017-03-30 | 深圳创维－Rgb电子有限公司 | Television backlight driving device and driving method thereof |
| CN113163538A (en) * | 2020-01-22 | 2021-07-23 | 海信视像科技股份有限公司 | Display device |
-
2014
- 2014-12-04 CN CN201420751218.6U patent/CN204231217U/en not_active Withdrawn - After Issue
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104377971A (en) * | 2014-12-04 | 2015-02-25 | 青岛歌尔声学科技有限公司 | Flyback direct-drive LED power circuit on basis of voltage feedback and television set |
| CN104377971B (en) * | 2014-12-04 | 2017-03-08 | 青岛歌尔声学科技有限公司 | A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set |
| WO2017049815A1 (en) * | 2015-09-25 | 2017-03-30 | 深圳创维－Rgb电子有限公司 | Television backlight driving device and driving method thereof |
| US9936554B2 (en) | 2015-09-25 | 2018-04-03 | Shenzhen Skyworth-Rgb Electronic Co., Ltd | Television backlight driving device and the driving method thereof |
| CN105245111A (en) * | 2015-11-13 | 2016-01-13 | 营口营成电子设备有限公司 | Control system of high direct voltage output voltage stabilization and constant current source |
| CN105245111B (en) * | 2015-11-13 | 2018-08-17 | 营口营成电子设备有限公司 | A kind of control system of high direct voltage output voltage stabilizing and constant-current supply |
| CN113163538A (en) * | 2020-01-22 | 2021-07-23 | 海信视像科技股份有限公司 | Display device |
| CN113163243A (en) * | 2020-01-22 | 2021-07-23 | 海信视像科技股份有限公司 | Display device |
| CN113163243B (en) * | 2020-01-22 | 2022-12-13 | 海信视像科技股份有限公司 | Display device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104377971A (en) | Flyback direct-drive LED power circuit on basis of voltage feedback and television set | |
| CN204244540U (en) | There is light-emitting component power supply circuit and the control circuit wherein of dimming function | |
| CN102244964B (en) | Hybrid multi-output power supply and regulating method thereof | |
| CN104363685B (en) | Flyback direct-drive LED (Light Emitting Diode) power supply circuit based on current feedback and television | |
| CN104935843A (en) | LED (Light-Emitting Diode) television two-in-one power supply circuit and LED television | |
| CN201718080U (en) | LED backlight source driving system | |
| CN107454712B (en) | Display device, lighting device and power supply circuit capable of simultaneously outputting constant current and constant voltage | |
| CN104902653A (en) | LED constant-voltage dimming power supply and LED lamp dimming system | |
| WO2018133136A1 (en) | Backlight control circuit and electronic device | |
| CN204231217U (en) | A kind of flyback based on Voltage Feedback directly drives LED power circuit and television set | |
| CN103037589A (en) | Light-emitting diode (LED) constant current drive circuit and liquid crystal display television (LCD TV) | |
| CN102421230A (en) | Color adjusting driver for LED (Light-Emitting Diode) lamp | |
| CN102711316B (en) | LED backlight source drive device and liquid crystal display device utilizing same | |
| CN209787523U (en) | LED drive circuit and LED lamp | |
| CN202404873U (en) | Constant voltage and constant current drive circuit of LED display screen | |
| CN102256418A (en) | PWM (pulse width modulation) dimming circuit | |
| CN104053275A (en) | Lighting apparatus | |
| CN203368849U (en) | LED driving circuit compatible with a variety of voltage outputs, and driving power source | |
| CN107079555A (en) | linear post regulator | |
| CN204217185U (en) | A kind of flyback based on current feedback directly drives LED power circuit and television set | |
| CN102779486A (en) | LED (Light-Emitting Diode) driving circuit capable of regulating current balance by negative voltage | |
| US9204515B2 (en) | Light source module, light source module driving circuit and driving method | |
| US11291092B2 (en) | PWM dimming circuit with low stand-by power | |
| CN104253955A (en) | Low-power-consumption constant current and stable voltage control circuit and television | |
| CN211406380U (en) | Power parallel driver |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20150325 Effective date of abandoning: 20171114 |