CN207039476U - Power circuit and television set - Google Patents
Power circuit and television set Download PDFInfo
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- CN207039476U CN207039476U CN201721078975.1U CN201721078975U CN207039476U CN 207039476 U CN207039476 U CN 207039476U CN 201721078975 U CN201721078975 U CN 201721078975U CN 207039476 U CN207039476 U CN 207039476U
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Abstract
The utility model discloses a kind of power circuit and television set, wherein, power circuit includes EMI circuits, pfc circuit, the first AC DC converters, at least one 2nd AC DC converters and constant-current circuit, the input of EMI circuits is used to connect AC power, and the output end of EMI circuits and the input of pfc circuit connect；First output end of pfc circuit is connected with the input of the first AC DC converters, and the first output end of the first AC DC converters is used for the power supply for exporting mainboard, and the second output end of the first AC DC converters is used for the power supply for exporting power amplifier；Second output end of pfc circuit connects at least one 2nd AC DC converters, output end one constant-current circuit of corresponding connection of every one second AC DC converters, and constant-current circuit is used for the power supply for exporting backlight.This power circuit has the characteristics of efficiency high.
Description
Technical field
Technical field of television sets is the utility model is related to, more particularly to a kind of power circuit and television set.
Background technology
Existing television power circuit framework is as shown in Figure 1.The AC power of input successively EMI circuits, pfc circuit and
AC-DC converter, export three road DC voltages.Wherein, first via DC voltage is used for main board power supply, the second road DC voltage
For being powered to power amplifier, the 3rd road DC voltage passes through DC-DC converter and constant-current circuit again, exports the power supply of backlight.
There is the defects of efficiency is low in the circuit, concrete reason is as follows：
(1) output to the power supply of backlight is needed by AC-DC converter and DC-DC converter voltage transformation twice,
And voltage transformation can all bring power attenuation each time, power-efficient is reduced.For example AC-DC efficiency is 90%, DC-DC's
Efficiency is 96%, then the overall efficiency of power supply just only has 86.4%.
(2) DC voltage of AC-DC converter output is needed to mainboard and power amplifier power supply, and mainboard and the confession needed for power amplifier
Piezoelectric voltage is all relatively low, it is meant that power supply has to pass through low-voltage, high-current link in transmitting procedure, so as to reduce power supply effect
Rate.So that backlight electric power power is 200W, rectification tube voltage drop is 0.5V as an example：When backlight electric power voltage is 100V, corresponding electricity
Stream is 2A, and corresponding power attenuation is 1W；When backlight electric power voltage is 12V, corresponding electric current is 16.67A, corresponding power
Loss is 8.33W.It can be seen that low-voltage, high-current link can increase power attenuation.
Utility model content
Main purpose of the present utility model is to provide a kind of power circuit, it is intended to improves the efficiency of the power circuit.
To achieve the above object, the utility model proposes power circuit include EMI circuits, pfc circuit, the first AC-DC
Converter, at least one second AC-DC converter and constant-current circuit, the input of the EMI circuits are used to connect AC power,
The output end of the EMI circuits is connected with the input of the pfc circuit；First output end of the pfc circuit and described the
The input connection of one AC-DC converter, the first output end of first AC-DC converter are used for the power supply electricity for exporting mainboard
Source, the second output end of first AC-DC converter are used for the power supply for exporting power amplifier；The second of the pfc circuit is defeated
Go out end and connect at least one second AC-DC converter, the corresponding connection of output end of each second AC-DC converter
One constant-current circuit, the constant-current circuit are used for the power supply for exporting backlight.
Preferably, second AC-DC converter includes voltage output unit and Overvoltage protecting unit, the voltage output
The input of unit is the input of second AC-DC converter, the output end of the voltage output unit and the overvoltage
Protection location input connection, its connecting node be second AC-DC converter output end, the Overvoltage protecting unit
Output end be connected with the controlled end of the voltage output unit, the voltage output unit also includes feedback end, for connecting
Control chip in the constant-current circuit.
Preferably, the voltage output unit includes first resistor, second resistance, 3rd resistor, the 4th resistance, the 5th electricity
Resistance, the 6th resistance, the 7th resistance, the first electric capacity, the second electric capacity and voltage stabilizing adjustment pipe；It is the first end of the first resistor, described
The first end of second resistance and the interconnection of the first end of the 4th resistance, its connecting node are the output of the voltage output unit
End；The first end interconnection at the second end of the first resistor, the second end of the second resistance and the 3rd resistor, it is connected
Node is the input of the voltage output unit；Second end of the 3rd resistor, the first end, described of first electric capacity
The negative electrode interconnection of the first end of second electric capacity and voltage stabilizing adjustment pipe, its connecting node are controlled for the voltage output unit
End；Second end of first electric capacity is connected with the first end of the 5th resistance, the second end of the 5th resistance, described
Second end of four resistance, the second end of second electric capacity, the reference pole of voltage stabilizing adjustment pipe, the first of the 6th resistance
The interconnection of the first end of end and the 7th resistance, the second end of the 7th resistance are the feedback end of the voltage output unit；
The positive pole of the voltage stabilizing adjustment pipe and the second end of the 6th resistance are grounded.
Preferably, the Overvoltage protecting unit includes the 8th resistance, the 9th resistance, the tenth resistance, the 11st resistance, the tenth
Two resistance, the 3rd electric capacity, the 4th electric capacity, the first diode, the first voltage-regulator diode, the first transistor and second transistor；Institute
The first end interconnection of the first end of the 8th resistance, the first end of the 3rd electric capacity and the 9th resistance is stated, its connecting node is institute
The output end of Overvoltage protecting unit is stated, the second end of the 9th resistance is connected with the input of the first transistor, described
The controlled end of the first transistor, the second end of the 3rd electric capacity, the second end of the 8th resistance and the second transistor
Input interconnection, the controlled end of the second transistor, the output end of the first transistor, the first of the 4th electric capacity
End, the first end interconnection of the first end of the tenth resistance and the 11st resistance, the second end of the 11st resistance with
The negative electrode connection of first diode, the anode of first diode are connected with the anode of first voltage-regulator diode,
The negative electrode of first voltage-regulator diode is connected with the first end of the 12nd resistance, and the second end of the 12nd resistance is
The input of the Overvoltage protecting unit.
Preferably, the first transistor is PNP type triode, and the base stage of the PNP type triode is brilliant for described first
The controlled end of body pipe, the input of the extremely described the first transistor of transmitting of the PNP type triode, the PNP type triode
The extremely described the first transistor of current collection output end.
Preferably, the second transistor is NPN type triode, and the base stage of the NPN type triode is brilliant for described second
The controlled end of body pipe, the input of the extremely described second transistor of current collection of the NPN type triode, the NPN type triode
The extremely described second transistor of transmitting output end.
Preferably, the constant-current circuit includes control chip, power supply subelement and current output unit, the supplied for electronic list
Member is used to provide power supply for the control chip, and the controlled pin of the control chip is used to receive Core of TV set output
Control signal, the driving pin of the control chip are connected with the controlled end of the current output unit, the current output unit
Input be the constant-current circuit input, the output end of the current output unit is used for the power supply for exporting the backlight
Power supply.
Preferably, the power supply subelement includes the 13rd resistance, the 5th electric capacity, the 6th electric capacity, the 7th electric capacity, the 8th electricity
Hold, the second voltage-regulator diode, the first end of the 13rd resistance is used to input accessory power supply, the second of the 13rd resistance
The control source pin interconnection at end, the first end of the 5th electric capacity, the first end of the 6th electric capacity and the control chip, institute
State the second end of the 5th electric capacity, the second end of the 6th electric capacity, anode, the 7th electric capacity of second voltage-regulator diode
First end, the first end of the 8th electric capacity, the benchmark electricity of the common ground pin of the control chip and the control chip
Presser feet interconnect, the negative electrode of second voltage-regulator diode, the second end of the 7th electric capacity, the 8th electric capacity the second end and
The digital power pin interconnection of the control chip.
The utility model also proposes a kind of television set, including power circuit as described above, wherein, the power circuit bag
Include EMI circuits, pfc circuit, the first AC-DC converter, at least one second AC-DC converter and constant-current circuit, the EMI electricity
The input on road is used to connect AC power, and the output end of the EMI circuits is connected with the input of the pfc circuit；It is described
First output end of pfc circuit is connected with the input of first AC-DC converter, and the of first AC-DC converter
One output end is used for the power supply for exporting mainboard, and the second output end of first AC-DC converter is used to export power amplifier
Power supply；At least one second AC-DC converter of the second output end connection of the pfc circuit, each described second
The output end of AC-DC converter one constant-current circuit of corresponding connection, the constant-current circuit are used for the power supply electricity for exporting backlight
Source.
The utility model proposes power circuit in：On the one hand, the input of the first AC-DC converter and pfc circuit
First output end connects, the power supply of the first output end output mainboard of the first AC-DC converter, the second output end output work
The power supply put.On the other hand, the second output end of the input of the second AC-DC converter and pfc circuit connects, and second
The output end of AC-DC converter is connected with constant-current circuit so that constant-current circuit exports the power supply of backlight.So, it is only necessary to
AC-DC converter, be achieved that and meanwhile for mainboard, power amplifier and backlight power supply function.The power supply of output to exposure only needs
Converted by AC-DC converter primary voltage, and need not move through the big current limit link of low pressure, efficiency high.
Brief description of the drawings
, below will be to embodiment in order to illustrate more clearly of the utility model embodiment or technical scheme of the prior art
Or the required accompanying drawing used is briefly described in description of the prior art, it should be apparent that, drawings in the following description are only
It is some embodiments of the utility model, for those of ordinary skill in the art, is not paying the premise of creative work
Under, other accompanying drawings can also be obtained according to the structure shown in these accompanying drawings.
Fig. 1 is the high-level schematic functional block diagram of existing power supply circuit；
Fig. 2 is the high-level schematic functional block diagram of the embodiment of the utility model power circuit one；
Fig. 3 is the electrical block diagram of the embodiment of the second AC-DC converter one in Fig. 2；
Fig. 4 is the electrical block diagram of the embodiment of constant-current circuit one in Fig. 2.
Drawing reference numeral explanation：
Realization, functional characteristics and the advantage of the utility model purpose will be described further referring to the drawings in conjunction with the embodiments.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describing, it is clear that described embodiment is only part of the embodiment of the present utility model, rather than all
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not making creative work premise
Lower obtained every other embodiment, belong to the scope of the utility model protection.
It is to be appreciated that the description for being related to " first ", " second " etc. in the utility model is only used for describing purpose, and can not
It is interpreted as indicating or implies its relative importance or imply the quantity of the technical characteristic indicated by indicating.Thus, define " the
One ", at least one this feature can be expressed or be implicitly included to the feature of " second ".In addition, the skill between each embodiment
Art scheme can be combined with each other, but must can be implemented as basis with those of ordinary skill in the art, when technical scheme
With reference to occurring conflicting or will be understood that the combination of this technical scheme is not present when can not realize, also not in the utility model
It is required that protection domain within.
The utility model proposes a kind of power circuit.The power circuit is used in television set, has the characteristics of efficiency high.
Referring to Fig. 1, in one embodiment, above-mentioned power circuit includes EMI circuits 10, pfc circuit 20, the first AC-DC
The converter 30, (AC-DC of the second AC-DC converter 1 to the 2nd conversion as shown in Figure 1 of at least one second AC-DC converter 40
Device N) and constant-current circuit 50, the input of EMI circuits 10 is for connecting AC power, the output end and pfc circuit of EMI circuits 10
20 input connection.
First output end of pfc circuit 20 is connected with the input of the first AC-DC converter 30, the first AC-DC converter
40 the first output end is used for the power supply for exporting mainboard (figure does not mark), the second output end of the first AC-DC converter 40
For exporting the power supply of power amplifier (not shown).
Second output end of pfc circuit 20 connects at least one second AC-DC converter 40, every one second AC-DC conversion
The output end of device 40 one constant-current circuit 50 of corresponding connection, constant-current circuit 50 are used for the power supply electricity for exporting backlight (figure does not mark)
Source.
Here, power circuit may include 1 the second AC-DC converter 40, multiple second AC-DC converters are may also comprise
40, the number of the second AC-DC converter 40 can be specifically chosen according to the specifications parameter of backlight of television, is not limited herein.
(scheme not in addition, the first AC-DC converter 30 can be reverse exciting topological circuit (not shown) or LLC
Show) or other topological structures circuit；Second AC-DC converter 40 can be single reverse exciting topological circuit, also may be used
To be single LLC topological circuits, or the combination of reverse exciting topological circuit and LLC topological circuits, it is not limited herein.
Specifically, in this power circuit course of work：
First, EMI circuits 10 are filtered processing to the AC power of input；
Then, the AC power after filtered processing is carried out Active PFC processing by pfc circuit 20, and is exported respectively
To the first AC-DC converter 30 and some second AC-DC converters 40；
Then, the AC power after filtered and PFC processing is carried out power by the first AC-DC converter 30
Conversion process, to export the power supply of the power supply of TV SKD and television power amplifier；
At the same time, the second AC-DC converter 40 carries out the AC power after filtered and PFC processing
Power conversion processing, and export constant-current circuit 50 corresponding to a DC voltage value；
Finally, constant-current circuit 50 exports the power supply of backlight, television set work.
It should be noted that in the present embodiment, under conditions of television set normal work is ensured, the second AC-DC converter
40 output voltage should be as big as possible, so as to reduce the power attenuation of power circuit.
The utility model proposes power circuit in：On the one hand, the input and pfc circuit of the first AC-DC converter 30
20 the first output end connection, the power supply of the first output end output mainboard of the first AC-DC converter 30, the second output end
Export the power supply of power amplifier.On the other hand, the second output end of the input of the second AC-DC converter 40 and pfc circuit connects
Connect, the output end of the second AC-DC converter 40 is connected with constant-current circuit 50 so that constant-current circuit 50 exports the power supply electricity of backlight
Source.So, it is only necessary to AC-DC converter, be achieved that at the same for mainboard, power amplifier and backlight power supply function.Export to backlight
Power supply need to only pass through the primary voltage of the second AC-DC converter 40 and convert, and need not move through the big current limit link of low pressure, efficiency
It is high.
In addition, the output of the first AC-DC converter 30 and the second AC-DC converter 40 is separate, complementation interference, may be used also
To improve the adaptability of power circuit.
Optionally, above-mentioned second AC-DC converter 40 includes voltage output unit 41 and Overvoltage protecting unit 42, and voltage is defeated
Go out unit 41 input be the second AC-DC converter 40 input, the output end and overvoltage protection of voltage output unit 41
Unit 42 input connection, its connecting node be the second AC-DC converter 40 output end, the output of Overvoltage protecting unit 42
End is connected with the controlled end of voltage output unit 41, and voltage output unit 41 also includes feedback end FB1, for connecting constant-current circuit
Control chip U1 in 50.
Specifically, voltage output unit 41 exports the AC power of filtered and PFC processing.In the 2nd AC-
In the course of work of DC converters 40, the output voltage of the collection voltages output unit 41 of Overvoltage protecting unit 42, if overvoltage protection list
The output voltage values that member 42 collects voltage output unit 41 are higher than preset high-pressure threshold value, then voltage output unit 41 are exported
Voltage is corrected processing, reaches the purpose of the output over-voltage protection of voltage output unit 41.
It is noted that in the present embodiment, the voltage that voltage output unit 41 exports is except by Overvoltage protecting unit
Outside 42 control, also controlled by control chip U1 in constant-current circuit 50.
Overvoltage protecting unit 42 is set in the second AC-DC converter 40, power circuit overvoltage output can be prevented, so as to
Improve the reliability of power circuit.
It is preferred that above-mentioned voltage output unit 41 includes the first to the 7th resistance R1-R7, the first electric capacity C1, the second electric capacity
C2 and voltage stabilizing adjustment pipe U2；The first end of first resistor R1 first end, second resistance R2 first end and the 4th resistance R4 is mutual
Even, its connecting node is the output end of voltage output unit 41；First resistor R1 the second end, second resistance R2 the second end and
3rd resistor R3 first end interconnection, its connecting node are the input of voltage output unit 41；3rd resistor R3 the second end,
The negative electrode interconnection of first electric capacity C1 first end, the second electric capacity C2 first end and voltage stabilizing adjustment pipe U2, its connecting node are electricity
Press the controlled end of output unit 41；First electric capacity C1 the second end is connected with the 5th resistance R5 first end, the 5th resistance R5's
Second end, the 4th resistance R4 the second end, the second electric capacity C2 the second end, voltage stabilizing adjustment pipe U2 reference pole, the 6th resistance R6
First end and the 7th resistance R7 first end interconnection, the 7th resistance R7 the second end is the feedback end of voltage output unit 41；
Voltage stabilizing adjustment pipe U2 positive pole and the 6th resistance R6 the second end are grounded.
It is noted that in the present embodiment, it is (not shown that the input of voltage output unit 41 is also connected with an isolation optocoupler
Go out) anode, the controlled end of voltage output unit 41 is also connected with the negative electrode of an isolation optocoupler, and the isolation optocoupler is used for insulating power supply
Transformer (not shown) primary and secondary in circuit, to improve the security of circuit.
Specifically, the AC power after filtered and PFC processing is exported single by isolation optocoupler input voltage
Member 41, and exported by first resistor R1 and second resistance R2 to constant-current circuit 50.
In whole process, it is assumed that the reference voltage between voltage stabilizing adjustment pipe U2 reference pole and negative electrode is VREF, and voltage is defeated
The output voltage for going out unit 41 is V1, and the voltage fallen in the feedback end FB1 of voltage output unit 41 is V2；Flow through the 4th resistance R4
Electric current be I4, the electric current for flowing through the 6th resistance R6 is I6, and the electric current for flowing through the 7th resistance R7 is I7；4th resistance R4 resistance
For R4, the 6th resistance R6 resistance is R6, and the 7th resistance R7 resistance is R7.
Then have：
I6=I4+I7； (1)
I6=VREF/R6； (2)
I4=(V1-VREF)/R4； (3)
I7=(V2-VREF)/R7； (4)
Because reference voltage provides, the 6th resistance R6 resistances are fixed, and the electric current for flowing through the 6th resistance R6 is fixed, because
This, the output voltage size of voltage output unit 41 is related to the size of current for flowing through the 4th resistance R4, and flows through the 4th resistance
R4 size of current is related to the size of current for flowing through the 7th resistance R7, flows through the 7th resistance R7 size of current and falls in voltage
The feedback end FB1 of output unit 41 voltage swing is related.
That is, the output voltage of voltage output unit 41 is with falling the voltage swing phase in the feedback end FB1 of voltage output unit 41
Close, and the voltage fallen in the feedback end FB1 of voltage output unit 41 is bigger, the output voltage of voltage output unit 41 is just smaller, falls
Smaller in the feedback end FB1 of voltage output unit 41 voltage, the output voltage of voltage output unit 41 is bigger.
Preferably, above-mentioned Overvoltage protecting unit 42 includes the 8th to the 12nd resistance R12, the 3rd electric capacity C3, the 4th electric capacity
C4, the first diode D1, the first voltage-regulator diode DZ1, the first transistor Q1 and second transistor Q2；The first of 8th resistance R8
The first end interconnection at end, the 3rd electric capacity C3 first end and the 9th resistance R9, its connecting node are defeated for Overvoltage protecting unit 42
Go out end, the 9th resistance R9 the second end is connected with the first transistor Q1 input, the first transistor Q1 controlled end, the 3rd electricity
Hold the input interconnection at C3 the second end, the 8th resistance R8 the second end and second transistor Q2, second transistor Q2's is controlled
End, the first transistor Q1 output end, the 4th electric capacity C4 first end, the tenth resistance R10 first end and the 11st resistance R11
First end interconnection, the 11st resistance R11 the second end is connected with the first diode D1 negative electrode, the first diode D1 anode
It is connected with the first voltage-regulator diode DZ1 anode, the first voltage-regulator diode DZ1 negative electrode and the 12nd resistance R12 first end
Connection, the 12nd resistance R12 the second end are the input of Overvoltage protecting unit 42.
Here, the first transistor Q1 is chosen as PNP type triode, the base stage of PNP type triode is the first transistor Q1's
Controlled end, the transmitting extremely the first transistor Q1 input of PNP type triode, the current collection extremely first of PNP type triode are brilliant
Body pipe Q1 output end.
Second transistor Q2 is chosen as NPN type triode, and the base stage of NPN type triode is the controlled of second transistor Q2
End, the current collection extremely second transistor Q2 input of NPN type triode, the transmitting extremely second transistor of NPN type triode
Q2 output end.
Specifically, when the magnitude of voltage that voltage output unit 41 exports is more than default HVT high voltage threshold, fall in the second crystal
The voltage increase of pipe Q2 controlled ends, the pressure drop increase at the 8th resistance R8 both ends, the output voltage of voltage follower circuit are reduced, realized
Over-voltage protecting function.
Optionally, constant-current circuit 50 includes control chip U1, power supply subelement 51 and current output unit (not shown),
Power supply subelement 51 is used to provide power supply for control chip U1, and control chip U1 controlled pin is used to receive Core of TV set
The control signal of output, control chip U1 driving pin and current output unit controlled end connect, current output unit it is defeated
Enter input of the end for constant-current circuit 50, the output end of current output unit is used for the power supply for exporting backlight.
Here, it should be noted that the number of the control chip U1 selected driving pin is needed according to constant-current circuit 50
Way determines.Wherein, control chip U1 driving pin includes G1 as shown in Figure 4 to G16 and S1 to S16.When constant-current circuit 50
Driving pin of the way more than control chip U1 number when, multiple control chip U1 can be arranged in parallel, be driven with extending
The number of dynamic pin, adapt to the way of constant-current circuit 50.
In addition, the control chip U1 selected controlled pin include it is multiple, such as, controlled pin FAULTB as shown in Figure 4, use
In reception FAULT signals；Controlled pin CSB, for receiving IW-CS signals；Controlled pin MOSI, for receiving IW-MOSI signals；By
Pin SCK is controlled, for receiving IW-SCK signals；Controlled pin MISO, for receiving IW-MISO signals；Pin VSYNC/PWMIN is controlled to use
In reception VSYNC signals.
It is preferred that power supply subelement 51 includes the 13rd resistance R13, the 5th to the 8th electric capacity C5-C8, the pole of the second voltage stabilizing two
Pipe DZ2, the 13rd resistance R13 first end are used to input accessory power supply (3.3V power supplys as shown in Figure 4), the 13rd resistance
R13 the second end, the 5th electric capacity C5 first end, the 6th electric capacity C6 first end, the 7th electric capacity C7 first end and control core
Piece U1 control source pin VIN interconnection, the 6th electric capacity C6 the second end, the 7th electric capacity C7 the second end, the second voltage-regulator diode
DZ2 anode, the 8th electric capacity C8 first end, control chip U1 common ground pin VSS and control chip U1 reference voltage
Pin EPAD is interconnected, the second voltage-regulator diode DZ2 negative electrode, the 8th electric capacity C8 the second end and control chip U1 digital power pin
VDD is interconnected.
Hereinafter, with reference to Fig. 1 to Fig. 4, the operation principle of the utility model power circuit is illustrated：
First, EMI circuits 10 are filtered processing to the AC power of input；
Then, the AC power after filtered processing is carried out Active PFC processing by pfc circuit 20, and is exported respectively
To the first AC-DC converter 30 and some second AC-DC converters 40；
Then, the AC power after filtered and PFC processing is carried out power by the first AC-DC converter 30
Conversion process, to export the power supply of the power supply of TV SKD and television power amplifier；
At the same time, the second AC-DC converter 40 carries out the AC power after filtered and PFC processing
Power conversion processing, and export constant-current circuit 50 corresponding to a DC voltage value；
Finally, constant-current circuit 50 exports the power supply of backlight, television set work.
In whole process, if the voltage output unit output overvoltage in the second AC-DC converter 40, Overvoltage protecting unit
42 output control signals to the controlled end of voltage output unit 41, to reduce the output voltage of voltage output unit 41, reach
Press the purpose of protection.In addition, the control chip U1 controls in constant-current circuit 50 fall the electricity in the feedback end FB1 of voltage output unit 41
Pressure, so as to the size of the output voltage of control voltage output unit 41.
The utility model also proposes a kind of television set, and the television set includes power circuit as described above, the power circuit
Concrete structure with reference to above-described embodiment, because this television set employs whole technical schemes of above-mentioned all embodiments, therefore
All beneficial effects at least caused by the technical scheme with above-described embodiment, this is no longer going to repeat them.
Preferred embodiment of the present utility model is the foregoing is only, not thereby limits the scope of the claims of the present utility model,
Every equivalent structure change under inventive concept of the present utility model, made using the utility model specification and accompanying drawing content
Change, or directly/be used in other related technical areas indirectly and be included in scope of patent protection of the present utility model.
Claims (9)
1. a kind of power circuit, it is characterised in that including EMI circuits, pfc circuit, the first AC-DC converter, at least one
Two AC-DC converters and constant-current circuit, the input of the EMI circuits are used to connect AC power, the output of the EMI circuits
End is connected with the input of the pfc circuit；
First output end of the pfc circuit is connected with the input of first AC-DC converter, and the first AC-DC becomes
First output end of parallel operation is used for the power supply for exporting mainboard, and the second output end of first AC-DC converter is for defeated
Go out the power supply of power amplifier；
Second output end of the pfc circuit connects at least one second AC-DC converter, each 2nd AC-DC
The output end of converter one constant-current circuit of corresponding connection, the constant-current circuit are used for the power supply for exporting backlight.
2. power circuit as claimed in claim 1, it is characterised in that second AC-DC converter includes voltage output list
Member and Overvoltage protecting unit, the input of the voltage output unit are the input of second AC-DC converter, the electricity
The output end of pressure output unit is connected with the input of the Overvoltage protecting unit, and its connecting node becomes for the 2nd AC-DC
The output end of parallel operation, the output end of the Overvoltage protecting unit are connected with the controlled end of the voltage output unit, the voltage
Output unit also includes feedback end, for connecting the control chip in the constant-current circuit.
3. power circuit as claimed in claim 2, it is characterised in that the voltage output unit includes first resistor, second
Resistance, 3rd resistor, the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the first electric capacity, the second electric capacity and voltage stabilizing adjustment
Pipe；
The first end interconnection of the first end of the first resistor, the first end of the second resistance and the 4th resistance, it connects
Connect the output end that node is the voltage output unit；
The first end interconnection at the second end of the first resistor, the second end of the second resistance and the 3rd resistor, it connects
Connect the input that node is the voltage output unit；
Second end of the 3rd resistor, the first end of first electric capacity, the first end of second electric capacity and the voltage stabilizing
The negative electrode interconnection of pipe is adjusted, its connecting node is the controlled end of the voltage output unit；
Second end of first electric capacity is connected with the first end of the 5th resistance, the second end of the 5th resistance, described
Second end of the 4th resistance, the second end of second electric capacity, the voltage stabilizing adjustment reference pole of pipe, the of the 6th resistance
The first end of one end and the 7th resistance interconnects, and the second end of the 7th resistance is the feedback of the voltage output unit
End；
The positive pole of the voltage stabilizing adjustment pipe and the second end of the 6th resistance are grounded.
4. power circuit as claimed in claim 2, it is characterised in that the Overvoltage protecting unit includes the 8th resistance, the 9th
Resistance, the tenth resistance, the 11st resistance, the 12nd resistance, the 3rd electric capacity, the 4th electric capacity, the first diode, the pole of the first voltage stabilizing two
Pipe, the first transistor and second transistor；
The first end interconnection of the first end of 8th resistance, the first end of the 3rd electric capacity and the 9th resistance, it connects section
Point is the output end of the Overvoltage protecting unit, and the second end of the 9th resistance connects with the input of the first transistor
Connect, the controlled end of the first transistor, the second end of the 3rd electric capacity, the second end and described second of the 8th resistance
The input interconnection of transistor, the controlled end of the second transistor, the output end of the first transistor, the 4th electric capacity
First end, the interconnection of the first end of the first end of the tenth resistance and the 11st resistance, the of the 11st resistance
Two ends are connected with the negative electrode of first diode, the anode of the anode of first diode and first voltage-regulator diode
Connection, the negative electrode of first voltage-regulator diode is connected with the first end of the 12nd resistance, and the of the 12nd resistance
Two ends are the input of the Overvoltage protecting unit.
5. power circuit as claimed in claim 4, it is characterised in that the first transistor is PNP type triode, described
The base stage of PNP type triode is the controlled end of the first transistor, and the transmitting extremely described first of the PNP type triode is brilliant
The input of body pipe, the output end of the extremely described the first transistor of current collection of the PNP type triode.
6. power circuit as claimed in claim 4, it is characterised in that the second transistor is NPN type triode, described
The base stage of NPN type triode is the controlled end of the second transistor, and the current collection extremely described second of the NPN type triode is brilliant
The input of body pipe, the output end of the extremely described second transistor of transmitting of the NPN type triode.
7. power circuit as claimed in claim 1, it is characterised in that the constant-current circuit includes control chip, supplied for electronic list
Member and current output unit, the power supply subelement are used to provide power supply for the control chip, the control chip
Controlled pin is used for the control signal for receiving Core of TV set output, driving pin and the current output unit of the control chip
Controlled end connection, the input of the current output unit is the input of the constant-current circuit, the current output unit
Output end be used to export the power supply of the backlight.
8. power circuit as claimed in claim 7, it is characterised in that the power supply subelement includes the 13rd resistance, the 5th
Electric capacity, the 6th electric capacity, the 7th electric capacity, the 8th electric capacity, the second voltage-regulator diode, the first end of the 13rd resistance are used to input
Accessory power supply, the second end of the 13rd resistance, the first end of the 5th electric capacity, the first end of the 6th electric capacity and institute
State the control source pin interconnection of control chip, the second end of the 5th electric capacity, the second end of the 6th electric capacity, described second
The anode of voltage-regulator diode, the first end of the 7th electric capacity, the first end of the 8th electric capacity, the control chip it is public
The reference voltage pin of grounding leg and the control chip interconnects, the negative electrode of second voltage-regulator diode, the 7th electric capacity
The digital power pin interconnection at the second end, the second end of the 8th electric capacity and the control chip.
9. a kind of television set, it is characterised in that including the power circuit as described in claim 1-8 any one.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721078975.1U CN207039476U (en) | 2017-08-25 | 2017-08-25 | Power circuit and television set |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721078975.1U CN207039476U (en) | 2017-08-25 | 2017-08-25 | Power circuit and television set |
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| Publication Number | Publication Date |
|---|---|
| CN207039476U true CN207039476U (en) | 2018-02-23 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721078975.1U Active CN207039476U (en) | 2017-08-25 | 2017-08-25 | Power circuit and television set |
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| Country | Link |
|---|---|
| CN (1) | CN207039476U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039025A (en) * | 2018-08-31 | 2018-12-18 | 北京比特大陆科技有限公司 | Data processing circuit, method and calculating equipment |
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2017
- 2017-08-25 CN CN201721078975.1U patent/CN207039476U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039025A (en) * | 2018-08-31 | 2018-12-18 | 北京比特大陆科技有限公司 | Data processing circuit, method and calculating equipment |
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