CN110112925A - Primary side feedback reverse exciting switching voltage regulator - Google Patents
Primary side feedback reverse exciting switching voltage regulator Download PDFInfo
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- CN110112925A CN110112925A CN201910475130.3A CN201910475130A CN110112925A CN 110112925 A CN110112925 A CN 110112925A CN 201910475130 A CN201910475130 A CN 201910475130A CN 110112925 A CN110112925 A CN 110112925A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
-
- H—ELECTRICITY
- 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
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
-
- 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
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a kind of primary side feedback reverse exciting switching voltage regulators.The present invention receives ac signal by voltage input module, generates after carrying out rectifying and wave-filtering to ac signal and exports first voltage；Primary side sampling module carries out voltage detecting to the auxiliary winding of transformer, to export sampled voltage to controlling chip；Chip starting when receiving first voltage is controlled, and adjusts the waveform of first voltage according to sampled voltage, so that armature winding receives first voltage；Transformer to first voltage carry out reduction regulation after by voltage output module be terminal power；The secondary side feed circuit of optocoupler and three end adjustable shunt reference sources composition is eliminated by primary side feedback circuit framework, secondary common mode inductance is eliminated by the parameter designing of optimization, reduce circuit complexity and cost, reduce loss and volume by the transformer sandwich winding of optimization, transformer production technique is simplified, high energy efficiency, the small in size and high reliability of Switching Power Supply are realized.
Description
Technical field
The present invention relates to switch power technology field more particularly to a kind of primary side feedback reverse exciting switching voltage regulators.
Background technique
With the aggravation of global energy shortage and climate warming phenomenon, national governments propose and have formulated various environmental protection instructions
And Energy Efficiency Standard has greatly pushed a new generation more using U.S. DoE and European Union COC V5 as newest six grades of Energy Efficiency Standards of representative
The appearance of efficient more energy efficient product and universal, allows the extremely low loss of high energy efficiency to become the basic framework and criterion of product design.Switch
" heart " and power resources of the power supply as electronic product are to improve product efficiency to reduce power consumption, design more excellent energy conservation and produce
The source of product.New standard and the market demand require the design circuit framework in high standard lower switch power supply unit simpler, electricity
Source design voltage range is wider, and design parameter, which is more simplified, to be easier to produce.
Primary side feedback circuit is widely used in the Switching Power Supply of small-power such as 12W power stage (containing 12W or less), is
This power section Switching Power Supply provides excellent solution.But since primary side feedback circuit is not direct sampled output
The voltage of (after secondary windings rectification), but by will be sampled when end in auxiliary winding voltage in each degaussing phase
To carry out control loop feedback, when terminal system output power is larger, and load current is changed greatly, the output voltage of power supply
Precision and regulation are deteriorated, and output voltage range changes greatly, and output ripple becomes larger, and influences normal work and the part of terminal system
Performance indicator.And when terminal system output power is larger, Switching Power Supply loss can be increased dramatically, high-voltage capacitance, power supply chip
And the Primary Components such as transformer bear larger current, and device loss is caused to increase, device specification increases.These make primary side feedback
Circuit is difficult to be applied well in the more high-power section of Switching Power Supply such as 18W power stage (or bigger output power), more
Hardly possible realizes the high energy efficiency and small size of high-power section of Switching Power Supply.
Summary of the invention
The main purpose of the present invention is to provide a kind of primary side feedback reverse exciting switching voltage regulators, it is intended to solve big in the prior art
The technical problem that power section primary side feedback reverse exciting switching voltage regulator volume is big and efficiency is low.
To achieve the above object, the present invention provides a kind of primary side feedback reverse exciting switching voltage regulator, and the primary side feedback flyback is opened
Powered-down source includes voltage input module, control chip, transformer, voltage output module and primary side sampling module；The transformer
Including armature winding, auxiliary winding and secondary windings, and the armature winding, auxiliary winding and secondary windings using sandwich around
Method coiling；Wherein,
The voltage input module, for receiving ac signal, and after carrying out rectifying and wave-filtering to the ac signal
It generates and exports first voltage；
The primary side sampling module, for carrying out voltage detecting to the auxiliary winding, to export sampled voltage to described
Control chip；
The control chip adjusts institute for the starting when receiving the first voltage, and according to the sampled voltage
The waveform of first voltage is stated, so that the armature winding receives the first voltage；
The transformer obtains for carrying out reduction regulation to the first voltage and exports second voltage to the electricity
Press output module；
The voltage output module, for carrying out rectifying and wave-filtering to the second voltage to export DC voltage.
Preferably, the transformer further includes shield winding and skeleton, the armature winding include the first armature winding and
Second armature winding；It is wound with the first armature winding on the skeleton, is covered with the first insulation outside first armature winding
Adhesive tape is wound with shield winding and auxiliary winding, the shield winding and the auxiliary winding outside first insulating tape
Same layer setting, is covered with the second insulating tape outside the shield winding and the auxiliary winding, outside second insulating tape
Portion is wound with secondary windings, and third insulating tape, coiling outside the third insulating tape are covered with outside the secondary windings
There is the second armature winding, the 4th insulating tape is covered with outside second armature winding, first armature winding is around first
Direction coiling, the auxiliary winding, the shield winding, the secondary windings and second armature winding are along second party
To coiling, the first direction and the second direction are opposite.
Preferably, the ripple current rate value range of the transformer is 0.6~0.9；
When the DC voltage is 12V, the turn ratio value range of the transformer is 7~9.2, in the DC voltage
When for 5V, the turn ratio value range of the transformer is 12~16.
It preferably, further include RCD absorption module, the control built-in chip type switching tube, the RCD absorption module is for inhaling
The first peaking voltage that leakage inductance generates on the armature winding when receiving switching tube cut-off；The voltage output mould
Block, the second peaking voltage that the secondary windings generates when being also used to absorb switching tube conducting.
Preferably, the voltage input module includes protection circuit, rectification circuit, EMI filter circuit and start-up circuit；Institute
Protection circuit is stated connect with firewire and zero curve, the rectification circuit be arranged the protection circuit and the EMI filter circuit it
Between, the start-up circuit and the EMI filter circuit with connect, the start-up circuit and the control chip and RCD suction
Module is received to be separately connected.
Preferably, the primary side sampling module is connect with the supply pin of the control chip, for being the control chip
Power supply.
Preferably, the protection circuit includes fuse, varistor and thermistor, and the rectification circuit includes bridge-type
Rectify diode, the EMI filter circuit includes first capacitor, the second capacitor and common mode inductance, the first capacitor with it is described
Second capacitor is high-voltage electrolytic capacitor；The start-up circuit includes first resistor, second resistance and third capacitor；Wherein,
The first end of the fuse is connect with the firewire, and the of the second end of the fuse and the varistor
The first end of one end and the bridge rectifier diode is separately connected；
The second end of the varistor is separately connected with the first end of the thermistor and the zero curve；
The second end of the thermistor is connect with the second end of the bridge rectifier diode；
The third end of the bridge rectifier diode is connect with the first end of the first capacitor, two pole of bridge rectifier
4th end of pipe is connect with the second end of the first capacitor；
The first end of the first capacitor is also connect with the first end of the common mode inductance, the second end of the first capacitor
Also it is connect with the second end of the common mode inductance；
The third end of the common mode inductance is connect with the first end of second capacitor, the 4th termination of the common mode inductance
Primary ground；
The first end of second capacitor is also connect with the first end of the first resistor, the second end of second capacitor
Connect primary ground；
The first end of the first resistor is also connect with the RCD absorption module, the second end of the first resistor and institute
State the first end connection of second resistance；
The second end of the second resistance and the control supply pin of chip, the first end of the third capacitor and described
Primary side sampling module is separately connected；
The primary ground of the second termination of the third capacitor.
Preferably, the RCD absorption module includes 3rd resistor, the 4th resistance, the 5th resistance, the 4th capacitor and the one or two
Pole pipe；Wherein,
The first end of the 3rd resistor is connect with the first end of the first resistor, the second end of the 3rd resistor with
The first end of 5th resistance connects；
The first end of 4th resistance is connect with the first end of the 3rd resistor, the second end of the 4th resistance with
The first end of 5th resistance connects；
The first end of 4th capacitor and the first end of the 4th resistance and the first end of the armature winding are distinguished
Connection, the second end of the 4th resistance are connect with the first end of the 5th resistance；
The second end of 5th resistance is connect with the cathode of the first diode；
The anode of the first diode connects respectively with the drain electrode foot of the switching tube and the second end of the armature winding
It connects.
Preferably, the primary side sampling module includes the 6th resistance, the 7th resistance, the 8th resistance, the second diode and the
Five capacitors；Wherein,
The first end of 6th resistance is connect with the first end of the auxiliary winding, the second end of the 6th resistance with
The anode of second diode connects；
The cathode of second diode is connect with the supply pin of the second end of the second resistance and the control chip；
The first end of the first end of 7th resistance and the first end of the 6th resistance and the auxiliary winding is distinguished
Connection, the second end of the 7th resistance connect respectively with the sampling foot of the control chip and the first end of the 5th capacitor
It connects, the second end of the 7th resistance also connects primary ground through the 8th resistance；
The primary ground of the second termination of 5th capacitor.
Preferably, the voltage output module includes the 9th resistance, third diode, the 6th capacitor, the 7th capacitor, the 8th
Capacitor, output cathode and output negative pole；The third diode is low pressure drop Schottky barrier diodes；Wherein,
The first end of 9th resistance is connect with the anode of the third diode, the second end of the 9th resistance with
The first end of 6th capacitor connects；
The first end, described of the cathode of the second end of 6th capacitor and the third diode, the 7th capacitor
The first end and output cathode of 8th capacitor are separately connected；
The anode of the third diode is also connect with the first end of the secondary windings, the cathode of the third diode
Also it is separately connected with the first end, the first end of the 8th capacitor and the output cathode of the 7th capacitor；
The second of 7th capacitor terminates time polar region；
The second of 8th capacitor terminates time polar region；
The output negative pole is connect with the second end of the secondary windings.
The present invention receives ac signal by voltage input module, and generates after carrying out rectifying and wave-filtering to ac signal
And export first voltage；Primary side sampling module carries out voltage detecting to the auxiliary winding of transformer, to export sampled voltage to control
Coremaking piece；Chip starting when receiving first voltage is controlled, and adjusts the waveform of first voltage according to sampled voltage, so that just
Grade winding receives first voltage；Transformer to first voltage carry out reduction regulation after by voltage output module be terminal power；It is logical
The secondary side feed circuit that primary side feedback circuit framework eliminates optocoupler and three end adjustable shunt reference sources composition is crossed, optimization is passed through
Parameter designing eliminates secondary common mode inductance, reduces circuit complexity and cost, passes through the transformer sandwich winding of optimization
Reduce loss and volume, simplify transformer production technique, realizes the high energy efficiency, small in size and highly reliable of Switching Power Supply
Property.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
The structure shown according to these attached drawings obtains other attached drawings.
Fig. 1 is a kind of functional schematic of one embodiment of primary side feedback reverse exciting switching voltage regulator of the present invention；
Fig. 2 is the structural schematic diagram of transformer in an embodiment；
Fig. 3 is the schematic illustration of transformer in an embodiment；
Fig. 4 is a kind of structural schematic diagram of one embodiment of primary side feedback reverse exciting switching voltage regulator of the present invention.
Drawing reference numeral explanation:
The embodiments will be further described with reference to the accompanying drawings for the realization, the function and the advantages of the object of the present invention.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiment is only a part of the embodiments of the present invention, instead of all the embodiments.Base
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts it is all its
His embodiment, shall fall within the protection scope of the present invention.
It is to be appreciated that if relating to directionality instruction (such as up, down, left, right, before and after ...) in the embodiment of the present invention,
Then directionality instruction be only used for explain under a certain particular pose (as shown in the picture) between each component relative positional relationship,
Motion conditions etc., if the particular pose changes, directionality instruction is also correspondingly changed correspondingly.
In addition, being somebody's turn to do " first ", " second " etc. if relating to the description of " first ", " second " etc. in the embodiment of the present invention
Description be used for description purposes only, be not understood to indicate or imply its relative importance or implicitly indicate indicated skill
The quantity of art feature." first " is defined as a result, the feature of " second " can explicitly or implicitly include at least one spy
Sign.It in addition, the technical solution between each embodiment can be combined with each other, but must be with those of ordinary skill in the art's energy
It is enough realize based on, will be understood that the knot of this technical solution when conflicting or cannot achieve when occurs in the combination of technical solution
Conjunction is not present, also not the present invention claims protection scope within.
The present invention provides a kind of primary side feedback reverse exciting switching voltage regulator.
Please with reference to Fig. 1 and Fig. 4, in one embodiment, the circuit includes voltage input module 100, control chip
300, transformer 400, voltage output module 500 and primary side sampling module 200；The transformer 400 includes armature winding 20, auxiliary
Help winding 24 and secondary windings 25, and the armature winding 20, auxiliary winding 24 and secondary windings 25 using sandwich winding around
System；Wherein, the voltage input module 100 carries out rectifying and wave-filtering for receiving ac signal, and to the ac signal
After generate and export first voltage；The primary side sampling module 200, for carrying out voltage detecting to the auxiliary winding 24, with
Sampled voltage is exported to the control chip 300；The control chip 300, for the starting when receiving the first voltage,
And the waveform of the first voltage is adjusted according to the sampled voltage, so that the armature winding 20 receives the first voltage；
The transformer 400 obtains for carrying out reduction regulation to the first voltage and exports second voltage to the voltage output
Module 500；The voltage output module 500, for carrying out rectifying and wave-filtering to the second voltage to export DC voltage.
It should be noted that setting is arranged between auxiliary winding 24 and control chip 300 after control chip 300 starts
Primary side sampling module 200 voltage of auxiliary winding 24 can be sampled when each degaussing phase will terminate, and will sampling
Voltage is sent to control chip 300, and control chip 300 carries out the reference voltage of sampled voltage and chip interior error amplifier
Compare, adjusting duty ratio according to error voltage receives it by transformer to adjust the waveform of first voltage.By controlling core
Stable output DC voltage may be implemented in the control of piece 300.
It should be understood that primary side feedback reverse exciting switching voltage regulator described in the present embodiment can be for output relatively high power such as
The power supply of 18W power stage, in the prior art, usually using secondary side feed circuit in the Switching Power Supply of 18W power stage, primary side is anti-
Current feed circuit is typically employed in the Switching Power Supply of small-power such as 12W power stage (containing 12W or less).
This is because primary side feedback circuit carries out voltage sample, estimation output voltage and feedback control by armature winding,
To there is static difference control；The direct sampling and outputting voltage of secondary side feed circuit is zero steady state error control.This rings primary side feedback in feedback
It answers in speed compared with secondary side feedback compared to weaker.Primary side feedback circuit is not direct sampled output (after secondary windings rectification)
Voltage, but it is anti-by being sampled to carry out control loop when each degaussing phase will terminate in auxiliary winding voltage
Feedback, when output line is longer or line footpath is thinner, there can be larger pressure drop on load line.Although primary side feedback driving chip
There is the function to cable voltage-drop compensation, but when terminal system output power is larger, and load current is changed greatly, dynamic response
Performance may be difficult to meet the requirements, and the output voltage precision and regulation of power supply are deteriorated, and output voltage range changes greatly, export line
Wave becomes larger, and influences the normal work and partial properties index of terminal system.In the case where the output power of Switching Power Supply increases,
Switching Power Supply primary current increases, if Switching Power Supply work cannot be made to reduce primary current in continuous mode, and still works
In the biggish discontinuous mode of primary current, then Switching Power Supply loss can increased dramatically, high-voltage capacitance, power supply chip, transformer
Equal Primary Components bear larger current, and device temperature rise is caused to increase, and loss increases, and efficiency reduces, and device specification increases.These make
Primary side feedback circuit is obtained to be currently mainly used in the Switching Power Supply of 12W power stage (containing 12W or less).
Six grades of efficiency Switching Power Supplies of existing market 18W power stage mainly use secondary side feed circuit, have common mode in secondary
It is designed in the case where inductance, and design voltage range is relatively narrow, usually AC90-264V, is unable to satisfy market segment and special
Client is for the demand under the conditions of high voltage AC 300V.Such as India Market since its grid conditions is bad, voltage ripple of power network compared with
Greatly.Significantling change for network voltage generates big voltage high-current, and the design of super wide voltage AC81-300V has effectively ensured this
Safe handling under abnormal power supply environment, provides high reliability.If making up primary side feedback by increasing device specification mode
Circuit part performance is insufficient and to realize six grades of Energy designs reluctantly be not a difficult design.But the increase of Primary Component specification
(such as transformer specification or high-voltage capacitance specification) can directly result in the increase of Switching Power Supply volume, and cost increases, and it is anti-to lose secondary side
The advantages of current feed circuit itself should possess circuit reduction, small size, high power density, without the place really solved the problems, such as.
The present embodiment is by transformer and the design of each functional circuit so that in ultra-wide design voltage range
Under AC81-300V, primary side feedback circuit framework is successfully used, secondary common mode inductance is removed, realizes a kind of ultra-wide electricity
Range is pressed, succinctly, without secondary common mode inductance, high average efficiency, extremely low no-load loss, the relatively high power of high power density corpusculum
Grade (such as 18W) primary side feedback Switching Power Supply design.
Further, primary side feedback reverse exciting switching voltage regulator further includes RCD absorption module 600, and control chip 300 is built-in with out
Pipe (not shown) is closed, leakage inductance generates on the armature winding 20 when RCD absorption module 600 is for absorbing switching tube cut-off
The first peaking voltage；The voltage output module 500 is also used to absorb secondary windings when switching tube conducting
25 the second peaking voltages generated.
It should be noted that controlling chip when the supply pin VCC for controlling chip 300 does not receive the first voltage
300 do not work, and switching tube is in an off state, when the supply pin VCC of control chip 300 receives the first voltage and starts
Afterwards, switching tube is closed.In the moment that switching tube disconnects, transformer leakage inductance can generate peaking voltage on switching tube, excessive
Peaking voltage be easy to puncture switching tube, therefore in Switching Power Supply increase RCD absorption module 600, can be effective
Protective switch pipe trouble free service.
It should be noted that include the secondary RC absorbing circuit being made of resistance and capacitor in voltage output module 500,
Effect is that secondary Schottky diode reverse spike voltage is absorbed during switching tube shutdown, makes the reversed point of Schottky diode
Peak voltage power supply is in its specification value hereinafter, to guarantee Schottky diode trouble free service.
Either the first peak voltage to be absorbed of RCD absorption module 600 or secondary RC absorbing circuit to be absorbed the
Two peak voltages, peak voltage size are determined that the former is due to primary winding leakage inductance by design of transformer parameter
It causes, the latter is since transformer secondary output winding leakage inductance causes.Excessive peak voltage not only influences power supply normal work, and
It also will cause power-fail.And absorbing high peak voltage then reduces power-efficient, increases loss, so that power source temperature liter
It is high.The loss that RCD absorption module 600 generates is one of Switching Power Supply dominant loss source, reasonable transformer device structure and parameter
Design can make transformer leakage inductance substantially reduce, so that leakage inductance control is reduced from source in a reasonable and optimal value
Peak voltage improves power-efficient, reduces loss, reduces device temperature.
It should be noted that the loss of reverse exciting switching voltage regulator mainly comprises the following steps: switching tube, transformer 400,
Voltage output module 500 and RCD absorption module 600.Wherein transformer 400 and switching tube are then the maximum loss of entire power supply
Source.The transformer winding structure of the sandwich winding of optimization is to realize six grades of efficiency switches of relatively high power (such as 18W) primary side feedback
The most important ring of power transformer frame.
As shown in figure 3, N1 is the first armature winding 21, N2 is auxiliary winding 24, and E1 is line shield winding 23, N4 second
Armature winding 22, NC indicate floating, and N3 is secondary windings 25.
Please together referring to Fig. 2 and Fig. 3, transformer includes skeleton 1000, magnetic core (not shown) and line packet 2000, magnetic core installation
In skeleton 1000, line packet 2000 includes the first armature winding 21, the second armature winding 22, line shield winding 23, auxiliary winding 24
And secondary windings 25, the first armature winding 21 is wound on skeleton 1000, and first is covered with outside the first armature winding 21 absolutely
Edge adhesive tape 3000, the wired shield winding 23 of 3000 outside coiling of the first insulating tape and auxiliary winding 24,23 He of line shield winding
24 same layer of auxiliary winding is arranged, and the second insulating tape 4000 is covered with outside line shield winding 23 and auxiliary winding 24, second absolutely
It is wound with secondary windings 25 outside edge adhesive tape 4000, third insulating tape 5000, third insulation are covered with outside secondary windings 25
It is wound with the second armature winding 22 outside adhesive tape 5000, the 4th insulating tape 6000, institute are covered with outside the second armature winding 22
The first armature winding 21 is stated along first direction coiling, the auxiliary winding 23, the shield winding 24, the secondary windings 25 with
And second armature winding 22 coiling in a second direction, the first direction and the second direction are opposite.
It should be understood that transformer uses sandwich winding coiling in the present embodiment, realized by line shielding to radiation
Effective inhibition of interference and Conduction Interference.Also, auxiliary winding 24 and 23 same layer of line shield winding and interval setting, can be reduced
For the coiling number of plies of transformer to reduce layer capacitance, auxiliary winding 24 can also play the role of equivalent shield, reduce transformer leakage
Feel and couple insufficient caused voltage fluctuation.
It should be noted that traditional general leakage inductance of sequence layer winding is the 5%-15% or so of inductance, sandwich
The general leakage inductance of winding is the 3%-5% or so of inductance, when the more big then leakage inductance of output power is bigger, to influence Switching Power Supply
Energy.The sandwich winding transformer optimized in the present embodiment reduces transformer temperature, increases the effective of transformer primary and secondary
Coupling area is significantly reduced the leakage inductance of transformer；Armature winding is sufficiently coupled so that switch power source output voltage adjusts
Rate and precision effectively improve, and it is dynamic when power increases (being promoted to 18W power stage by 12W) to improve primary side feedback
State response.Simultaneously as leakage inductance is reduced, the voltage stress of switching tube is reduced, and switching loss reduces, and RCD absorption module 600 is lost
Reduce, reduces the temperature and loss of Primary Component and circuit, also dropped as switching tube and common-mode interference current caused by cooling fin
It is low, so as to improve EMI.
Further, the ripple current rate value range of the transformer is 0.6~0.9；It is 12V in the DC voltage
When, the turn ratio value range of the transformer is 7~9.2, when the DC voltage is 5V, the turn ratio value of the transformer
Range is 12~16.
It can be readily appreciated that Switching Power Supply is there are three types of operating mode: continuous conduction mode, discontinuous conduction mode and critical
Conduction mode.Switching Power Supply is generally operational in continuous conduction mode and discontinuous conduction mode, in continuous conduction mode lower switch
The peak point current of pipe and diode is about the half to work in discontinuous conduction mode.Peak primary when due to switching tube conducting
Electric current and the rms current value for generating thermal losses are greatly reduced, so that power supply switch tube conduction loss, transformer loss and electricity
The secondary diode conduction loss in output module 500 is pressed to reduce, output ripple also substantially reduces, and power supply average efficiency obtains greatly
Width is promoted, and no-load loss reduces.At the same time since 100 mesohigh capacitor ripple current of voltage input module is equal to primary electrical
Virtual value is flowed, secondary filter capacitor ripple current reduces with primary current and reduced, then high-voltage capacitance under continuous conduction mode
It is lost and reduces with secondary filter capacitor, capacitor and size can also substantially reduce in type selecting, simultaneously because primary current subtracts
It is small make due to primary side feedback in the case that power increase the big problem of output ripple must lead abundant solution.
In the concrete realization, the operating mode of control switch power supply is that continuous conduction mode or discontinuous conduction mode can be with
By to ripple current rate KRPThe design of parameter is realized.Ripple current rate KRPIt determines the mode of Switching Power Supply work, calculates
Formula is as follows:
Wherein IRFor primary ripple current, IPFor peak primary currents.
Work as KRP≤ 1.0, Switching Power Supply works in continuous conduction mode；Work as KRP>=1.0, Switching Power Supply work is continuously being led
Logical mode；Work as KRP=1, Switching Power Supply works in critical conduction mode.
Therefore, ripple current rate KRPSetting will directly determine Switching Power Supply operating mode, influence the magnetic core of transformer
Loss, power device size and primary and secondary capacitance current stress etc. select rationally and preferably ripple current rate KRPIt is to design most
The key point of excellent transformer.In the present embodiment, the ripple current rate K of transformerRPPreferably 0.6~0.9.
In the concrete realization, the turn ratio of transformer directly affects the switching frequency and transformer sensibility reciprocal of power supply, by reasonable
Transformer turn ratio selection so that transformer sensibility reciprocal and Switching Power Supply working frequency are best, leakage inductance is minimum.In the present embodiment,
For the power supply of 12V output, the turn ratio of transformer can be in 7~9.2 values；For the power supply of 5V output, the turn ratio of transformer can
In 12~16 values；The switching frequency of power work under full load conditions is in 55~80KHz.
Since the small loss of the switching frequency of power work under full load conditions causes to have to using large-sized transformation greatly
Device；The primary side feedback power supply that can only operate in non-continuous mode causes transformer to exist since primary current is big, switching frequency is low
Interior critical power ratio device size specification must increase with balancing loss, these are not obvious when Switching Power Supply power is small
It influences (such as 12W and following power power-supply), but when power reaches 18W or higher, then becomes the bottleneck of design.Due to opening
It closes tube voltage and secondary diode voltage increases, significantly limit power supply design voltage range.Sandwich winding structure, low pressure
It is operable with continuous conduction mode and the reasonable turn ratio, three's combination can greatly optimize the loss of power, improve switching frequency,
It improves average efficiency and reduces no-load loss, reduce transformer size, be possibly realized but also design voltage range is wider.
By the design of above-mentioned transformer and the optimization of combination relevant parameter, high-power primary side feedback electricity can effectively solve
Bottleneck is designed in source, so that six grades of efficiency primary side feedback reverse exciting switching voltage regulators of 18W power stage are implemented as possibility.Hereinafter, in conjunction with
Transformer winding, shielded layer adjust transformer parasitic capacitance, in the case where removing secondary common mode inductance, realize and effectively inhibit
While the interference of EMI, it can further reduce the cost.
Continuing with reference to shown in Fig. 2 and Fig. 3, skeleton 1000 includes primary side 10 and primary side 26, is covered outside primary side 10
It is stamped insulation rubber band (not shown), primary side 10 is provided with the first pin 1, the second pin 2, third pin 3,4 and of the 4th pin
5th pin 5, primary side 26 are provided with extension block (not shown), and extension block prolongs from primary side 26 along the direction far from primary side 10
It stretches, extension block is provided with the 6th pin 6 and the 7th pin 7.In one embodiment, by covering the isolation of " L " type in primary side 10
Adhesive tape reaches insulation effect, eliminates the first armature winding 21 in the prior art, auxiliary winding 24, line shield winding 23 and
Teflon casing at the disengaging pin of two armature windings 22.In another embodiment, auxiliary winding 24 and line shield winding 23
After complete second insulating tape 4000 of same layer coiling, second insulating tape, 4000 reflexed is covered into the first pin 1, the in primary side 10
Two pins 2, third pin 3, the 4th pin 4 and the 5th pin 5, achieve the effect that insulation rubber band.The insulation rubber band of primary side 10
Replace Teflon casing, the production efficiency for improving sandwich winding transformer can not only be brought around insulation rubber by automation machine,
And reduce production cost.
By the way that extension block is arranged in primary side 26, to increase the creepage distance between the 6th pin 6 and line packet 2000
And the 7th creepage distance between pin 7 and line packet 2000, it eliminates secondary windings 25 and passes in and out Teflon casing at pin.
Specifically, the creepage distance of the solder joint of the 6th pin 6 and line packet 2000, the solder joint of the 7th pin 7 and line packet 2000 climb electricity away from
From being 6.5mm-6.7mm.The present embodiment by the extension block width of control primary side 26 by the 6th pin 6 and line packet 2000 it
Between creepage distance and the 7th pin 7 and line packet 2000 between creepage distance control in 6.5mm-6.7mm, meet most stringent
High aititude safety required distance.
In the present embodiment sandwich winding transformer, the starting point of the first armature winding 21 is connect with third pin 3, third
Pin 3 is the tap foot of the first armature winding 21, and the end of the first armature winding 21 is connect with the 4th pin 4, the 4th pin 4
It is connect with the drain electrode of power supply, the power supply drain electrode of the present embodiment is MOSFET (metal-oxide half field effect transistor) or the control of built-in MOSFET
The drain electrode of coremaking piece, the starting point of the second armature winding 22 are connect with third pin 3, the end and first of the second armature winding 22
Pin 1 connects, and the first pin 1 is connected with 10 anode of primary side.The starting point of auxiliary winding 24 is connect with the 5th pin 5, and the 5th
Pin 5 is connected with positive pole, and the 5th pin 5 of the present embodiment is connected with the anode of the power supply of control chip.Auxiliary around
Group 24 end connect with the second pin 2, the second pin 2 is connected with 10 ground of primary side, the starting point of line shield winding 23 and
The connection of second pin 2, the end floating of line shield winding 23.The starting point of secondary windings 25 is connect with the 7th pin 7, and the 7th
Pin 7 is connected with 26 anode of primary side, and the end of secondary windings 25 is connect with the 6th pin 6, the 6th pin 6 and primary side 26
Ground is connected.First armature winding 21 of the present embodiment, the second armature winding 22, line shield winding 23 and auxiliary winding 24 line
Diameter is identical.
In one embodiment, the first armature winding 21 is made of an enameled wire coiling 59 circle that diameter is 0.25mm；It is auxiliary
Winding 24 is helped to be made of an enameled wire coiling 11 circle that diameter is 0.25mm；Line shield winding 23 is by one of diameter 0.25mm
The circle of enameled wire coiling 11 is constituted.The 23 same layer coiling of auxiliary winding 24 and line shield winding, first coiling auxiliary winding 24, around complete auxiliary
Further around line shield winding 23 processed after winding 24, secondary windings 25 encloses structure by the three layer insulation wire coiling 9 that diameter is 0.65mm
At；Second armature winding 22 is made of an enameled wire coiling 24 circle that diameter is 0.25mm；Pass through each winding disengaging of transformer
The design optimization of foot, so that each winding disengaging foot does not generate intersection, the first armature winding 21, the second armature winding 22, line shielding
The line footpath of winding 23 and auxiliary winding 24 is identical to use the same automatic winding machine, reduce sandwich winding transformer
Automatic winding machine quantity in winding process, significantly reduces production cost, and greatly improve production efficiency.
In the present embodiment, sandwich winding transformer further includes magnetic core shielding line (not shown), the starting of magnetic core shielding line
End is connect with the second pin 2, and the end of magnetic core shielding line is tin plating and connect with magnetic core.Second pin of the present embodiment is grounded,
Magnetic core shielding line one end connects magnetic core, and other end ground connection can prevent electromagnetic interference, prevent sandwich winding transformer to other yuan
Part is interfered.In the present embodiment, the first insulating tape 3000, the second insulating tape 4000, the 4th insulating tape 6000 are
Two layers, third insulating tape 5000 is three layers.First insulating tape 3000, the second insulating tape 4000, the 4th insulating tape
6000 be not increase parasitic capacitance while can guarantee insulation two layers, and set between the second armature winding 22 and secondary windings 25
Three-layer insulated adhesive tape is set as adjustment parasitic capacitance, improves and optimize EMI.
The present embodiment receives ac signal by voltage input module, and to raw after ac signal progress rectifying and wave-filtering
At and export first voltage；Primary side sampling module carries out voltage detecting to the auxiliary winding of transformer, to export sampled voltage extremely
Control chip；Chip starting when receiving first voltage is controlled, and adjusts the waveform of first voltage according to sampled voltage, so that
Armature winding receives first voltage；Transformer to first voltage carry out reduction regulation after by voltage output module be terminal power；
The secondary side feed circuit that optocoupler and three end adjustable shunt reference sources composition are eliminated by primary side feedback circuit framework, passes through optimization
Parameter designing eliminate secondary common mode inductance, reduce circuit complexity and cost, by the transformer sandwich of optimization around
Method reduces loss and volume, simplifies transformer production technique, realizes the high energy efficiency, small in size and highly reliable of Switching Power Supply
Property.
It is a kind of structural schematic diagram of one embodiment of primary side feedback reverse exciting switching voltage regulator of the present invention referring to Fig. 4, Fig. 4.
In the present embodiment, the voltage input module 100 includes protection circuit 110, rectification circuit 120, EMI filter circuit
130 and start-up circuit 140；The protection circuit 110 is connect with firewire L and zero curve N, and the rectification circuit 120 is arranged described
It protects between circuit 110 and the EMI filter circuit 130, the start-up circuit 140 is with the EMI filter circuit 130 and even
It connects, the start-up circuit 140 is separately connected with the control chip 300 and the RCD absorption module 600.
Further, the primary side sampling module 200 also electricity through the start-up circuit 140 with the control chip 300
Source foot connection, for powering for the control chip 300.
Further, the protection circuit 110 includes fuse F1, varistor MOV1 and thermistor NTC, described whole
Current circuit 120 include bridge rectifier diode DP1, the EMI filter circuit 130 include first capacitor C1, the second capacitor C2 and
Common mode inductance LF1, the first capacitor C1 and the second capacitor C2 are high-voltage electrolytic capacitor；The start-up circuit 140 wraps
Include first resistor R1, second resistance R2 and third capacitor C3；Wherein, the first end of the fuse F1 is connect with the firewire L,
The second end of the fuse F1 and the first end of the varistor MOV1 and the first end of the bridge rectifier diode DP1
It is separately connected；The second end of the varistor MOV1 connects respectively with the first end of the thermistor NTC and the zero curve N
It connects；The second end of the thermistor NTC is connect with the second end of the bridge rectifier diode DP1；The bridge rectifier two
The third end of pole pipe DP1 is connect with the first end of the first capacitor C1, the 4th end of the bridge rectifier diode DP1 and institute
State the second end connection of first capacitor C1；The first end of the first capacitor C1 also connects with the first end of the common mode inductance LF1
It connects, the second end of the first capacitor C1 is also connect with the second end of the common mode inductance LF1；The of the common mode inductance LF1
Three ends are connect with the first end of the second capacitor C2, the primary ground of the 4th termination of the common mode inductance LF1；Second capacitor
The first end of C2 is also connect with the first end of the first resistor R1, the primary ground of the second termination of the second capacitor C2；It is described
The first end of first resistor R1 is also connect with the RCD absorption module 600, the second end of the first resistor R1 and described second
The first end of resistance R2 connects；The supply pin VCC of the second end of the second resistance R2 and the control chip 300, described the
The first end of three capacitor C3 and the primary side sampling module 200 are separately connected；The primary ground of the second termination of the third capacitor C3.
It should be understood that fuse F1, varistor MOV1 and the thermistor NTC1 in protection circuit 110 are constituted
It is able to achieve the protection circuit of anti-lightning, alternating voltage is rectified into pulsating direct current, EMI after bridge rectifier diode DP1
Pulsating dc voltage is obtained the DC voltage of smooth steady, the DC voltage by filter circuit 130 after high-voltage filtering capacitor
By the start-up resistor (i.e. first resistor R1 and second resistance R2) in start-up circuit 140 to the supply pin VCC of control chip 300
Start-up capacitance (i.e. third capacitor C3) charging, until the end VCC, voltage reaches the starting voltage of control chip 300, controls chip 300
Start and entire switch power supply system is driven to work.
It should be noted that EMI filter circuit 130 is using two high-voltage electrolytic capacitors (i.e. electricity of first capacitor C1 and second
Hold C2) intermediate plus common mode inductance (LF1) ∏ type EMI filter circuit, it can preferably inhibit primary terminal of switch power supply EMI to interfere,
Reduce the loss of EMI filter circuit 130.
It, all can be in the input terminal of power supply due to Switching Power Supply itself at work and when electronic equipment is in running order
There is noise, generate radiation and Conduction Interference, can also enter AC network and interfere other electronic equipments, so must take effectively
Braking measure.It is effectively method using EMI filter circuit in terms of the Conduction Interference for inhibiting noise.Using high-voltage electricity
The electromagnetic interface filter circuit of solution capacitor substitution tradition X capacitor can remove bleeder resistance, greatly reduce power supply no-load loss, so that
The design of six grades of efficiency no-load loss becomes simple.Wherein, the total capacity value range of first capacitor C1 and the second capacitor C2 are 2
~3UF/W, it is therefore preferable to 2UF/W.
High-voltage electrolytic capacitor is power supply Primary Component, and influences one of the main devices of power-supply system size, due to height
It presses the amount of capacity of electrolytic capacitor directly related with design of transformer parameter, flows through primary winding when switching tube conducting
Electric current is equal to the ripple current value for flowing through high-voltage electrolytic capacitor.By the design optimization of transformer parameter, armature winding electricity is reduced
Flow valuve can both greatly improve the average efficiency of power supply, reduce loss, also can reduce the capacity and ruler of high-voltage electrolytic capacitor
It is very little.In the case where meeting performance indicator, substantially reduces high-voltage capacitance size, be one of efficient six level power supply of efficiency of small size
Important indicator.
In addition, in the concrete realization, start-up resistor R in start-up circuit 140inLoss calculation formula are as follows:
Wherein, RinFor the resistance value of start-up resistor, VdcFor the input voltage of start-up circuit 140, VCC-ONTo start voltage.By
Above formula is it is found that the resistance value for increasing start-up resistor can reduce the loss of start-up circuit 140, to increase the average effect of Switching Power Supply
Rate reduces the no-load loss of power supply.
Therefore, control chip 300 can use the control chip of low starting current, in the feelings for not influencing the power supply rise time
Under condition, appropriateness reduces the capacitance of third capacitor C3, increases the resistance value of start-up resistor, can reduce the loss of start-up circuit 140,
To reduce no-load loss, the average efficiency of Switching Power Supply is improved.Wherein, the value range of third capacitor C3 be 4.7uF~
10uF, it is therefore preferable to 6.8uF.
Further, the voltage input module 100 further includes by the tenth resistance, eleventh resistor, twelfth resistor,
The function compensation circuit of nine capacitors and the tenth capacitor composition can when not integrating the function compensation circuit in control chip 300
Operating point and performance is caused to generate drift with the variation of temperature environment to increase this circuit to avoid device.
Further, the RCD absorption module 600 includes 3rd resistor R3, the 4th resistance R4, the 5th resistance R5, the 4th
Capacitor C4 and first diode D1；Wherein, the first end of the 3rd resistor R3 is connect with the first end of the first resistor R1,
The second end of the 3rd resistor R3 is connect with the first end of the 5th resistance R5；The first end of the 4th resistance R4 and institute
The first end connection of 3rd resistor R3 is stated, the second end of the 4th resistance R4 is connect with the first end of the 5th resistance R5；
The first end of the 4th capacitor C4 connects respectively with the first end of the 4th resistance R4 and the first end of the armature winding 20
It connects, the second end of the 4th resistance R4 is connect with the first end of the 5th resistance R5；The second end of the 5th resistance R5
It is connect with the cathode of the first diode D1；The switching tube of the anode of the first diode D1 and the control chip 300
Drain electrode foot and the second end of the armature winding 20 be separately connected.In the concrete realization, the first end of the armature winding 20
Also secondary ground is connect through Y capacitance CY1.
It can be readily appreciated that the energy stored in magnetic core of transformer can pass through armature winding in the moment of switching tube shutdown
Leakage inductance generate very high peak voltage；This peak voltage pulse and input voltage and secondary winding are reflected into armature winding
Back-emf voltage superposition after, be added between the hourglass source electrode D foot and S foot of chip 300 (control) of switching tube, hold together very much
Easily switching tube is punctured；Therefore, it is necessary to increase a RCD peaking voltage absorbing circuit in the armature winding of transformer,
Protective switch pipe trouble free service.
Further, the primary side sampling module 200 includes the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, second
Diode D2 and the 5th capacitor C5；Wherein, the first end of the 6th resistance R6 is connect with the first end of the auxiliary winding 24,
The second end of the 6th resistance R6 is connect with the anode of the second diode D2；The cathode of the second diode D2 and institute
State the second end of second resistance R2 and the supply pin VCC connection of the control chip 300；The first end of the 7th resistance R7 with
The first end of the 6th resistance R6 connects, the sampling foot FB of the second end of the 7th resistance R7 and the control chip 300
And the first end of the 5th capacitor C5 is separately connected, the second end of the 7th resistance R7 also connects just through the 8th resistance R8
Grade ground；The primary ground of the second termination of the 5th capacitor C5.
It can be readily appreciated that being examined by the voltage of sampling resistor (the 7th resistance R7 and the 8th resistance R8) to auxiliary winding 24
It surveys, feeds back to control chip 300, so that control chip 300 adjusts duty ratio and operating switch frequency, realize to output voltage
Adjustment, to realize precise and stable output.In the present embodiment, the second diode D2 is rectifier diode, with the 6th resistance R6
Rectification circuit is formed, effect is control chip 300 after high voltage startup work, provides subsequent hold for control chip 300
Continuous power supply.
Further, the voltage output module 500 includes the 9th resistance R9, third diode D3, the 6th capacitor C6, the
Seven capacitor C7, the 8th capacitor C8, output cathode V+ and output negative pole V-；The third diode D3 is low pressure drop Schottky rectification
Diode；Wherein, the first end of the 9th resistance R9 is connect with the anode of the third diode D3, the 9th resistance R9
Second end connect with the first end of the 6th capacitor C6；The second end of the 6th capacitor C6 and the third diode D3
Cathode, the first end of the 7th capacitor C7, the first end of the 8th capacitor C8 and output cathode V+ be separately connected；It is described
The anode of third diode D3 is connect with the first end of the secondary windings 25, the cathode of the third diode D3 also with it is described
The first end of 7th capacitor C7, the first end of the 8th capacitor C8 and the output cathode V+ are separately connected；The 7th capacitor C7
Second terminate time polar region；The second of the 8th capacitor C8 terminates time polar region；The output negative pole V- and the secondary windings
Second end connection.
It should be noted that the 9th resistance R9 and the 6th capacitor C6 forms secondary RC absorbing circuit, effect is to switch
Pipe absorbs secondary Schottky diode (i.e. third diode D3) backward voltage spike during turning off, make the anti-of Schottky diode
It works in its specification value to peak voltage hereinafter, to guarantee Schottky diode trouble free service.
In conjunction with the design of transformer, increase the resistance value of the 3rd resistor R3 and the 4th resistance R4 in RCD absorption module 600；
The capacitance for reducing the 4th capacitor C4 of Absorption Capacitance, can reduce RCD absorption module 600 in the case where meeting EMI index
Loss.The 5th resistance R5 of series resistance of first diode D1 is for reducing leakage inductance concussion；Reduce the 9th resistance R9 resistance value and
The capacitance of 6th capacitor C6 can reach the loss for reducing secondary RC absorbing circuit in the case where meeting EMI index.Its
In, the Standard resistance range of 3rd resistor R3 and the 4th resistance R4 are preferably 200K Ω~390K Ω, the capacitance model of the 4th capacitor C4
Enclose preferably 1nF~2.2nF.The Standard resistance range of 5th resistance R5 is preferably the Ω of 30 Ω~200；The Standard resistance range of 9th resistance R9
Preferred 220pF~the 1000pF of capacitance swing of the preferably Ω of 10 Ω~68, the 6th capacitor C6.
In addition, being also the loss source of power supply since the pole Xiao Te rectifier diode is as power device carrying high current
One of, in the concrete realization, it can choose the pole the Xiao Te rectifier diode of model band " L " low pressure drop type, to reduce voltage output
The loss of module 500.
The present embodiment by 18W power stage power supply unit use primary side feedback circuit, remove secondary common mode inductance,
Greatly simplify circuit framework, reduces the complexity of integrated circuit, increase power supply reliability, reduce costs simultaneously.Together
When, by the specific design of device each in circuit and the unique design of transformer, solve primary side feedback circuit in the prior art
Defect when applied to relatively high power Switching Power Supply, so that Switching Power Supply meets six grades of Energy Efficiency Standards of EU criteria.
The above is only a preferred embodiment of the present invention, is not intended to limit the scope of the invention, all to utilize this hair
Equivalent structure or equivalent flow shift made by bright specification and accompanying drawing content is applied directly or indirectly in other relevant skills
Art field, is included within the scope of the present invention.
Claims (10)
1. a kind of primary side feedback reverse exciting switching voltage regulator, which is characterized in that including voltage input module, control chip, transformer, electricity
Press output module and primary side sampling module；The transformer includes armature winding, auxiliary winding and secondary windings, and the primary
Winding, auxiliary winding and secondary windings use sandwich winding coiling；Wherein,
The voltage input module is generated for receiving ac signal, and after carrying out rectifying and wave-filtering to the ac signal
And export first voltage；
The primary side sampling module, for carrying out voltage detecting to the auxiliary winding, to export sampled voltage to the control
Chip；
The control chip, for the starting when receiving the first voltage, and according to sampled voltage adjustment described the
The waveform of one voltage, so that the armature winding receives the first voltage；
The transformer, it is defeated to the voltage for carrying out reduction regulation to the first voltage, obtaining and exporting second voltage
Module out；
The voltage output module, for carrying out rectifying and wave-filtering to the second voltage to export DC voltage.
2. primary side feedback reverse exciting switching voltage regulator as described in claim 1, which is characterized in that the transformer further includes line shielding
Winding and skeleton, the armature winding include the first armature winding and the second armature winding；It is wound at the beginning of first on the skeleton
Grade winding, is covered with the first insulating tape outside first armature winding, is wound with shielding outside first insulating tape
Winding and auxiliary winding, the shield winding and auxiliary winding same layer setting, the shield winding and the auxiliary winding
Outside is covered with the second insulating tape, and secondary windings is wound with outside second insulating tape, is covered outside the secondary windings
It is stamped third insulating tape, is wound with the second armature winding outside the third insulating tape, outside second armature winding
Be covered with the 4th insulating tape, first armature winding around first direction coiling, the auxiliary winding, the shield winding,
The secondary windings and second armature winding coiling in a second direction, the first direction and the second direction phase
Instead.
3. primary side feedback reverse exciting switching voltage regulator as claimed in claim 2, which is characterized in that the ripple current rate of the transformer
Value range is 0.6~0.9；
When the DC voltage is 12V, the turn ratio value range of the transformer is 7~9.2, is 5V in the DC voltage
When, the turn ratio value range of the transformer is 12~16.
4. primary side feedback reverse exciting switching voltage regulator as claimed in claim 3, which is characterized in that the primary side feedback flyback switch electricity
Source further includes RCD absorption module, the control built-in chip type switching tube, and the RCD absorption module is for absorbing the switching tube
The first peaking voltage that leakage inductance generates on the armature winding when cut-off；
The voltage output module, the second spike that the secondary windings generates when being also used to absorb switching tube conducting
Voltage.
5. primary side feedback reverse exciting switching voltage regulator as claimed in claim 4, which is characterized in that the voltage input module includes protecting
Protection circuit, rectification circuit, EMI filter circuit and start-up circuit；The protection circuit is connect with firewire and zero curve, the rectified current
Road is arranged between the protection circuit and the EMI filter circuit, and the start-up circuit is connect with the EMI filter circuit,
The start-up circuit is also separately connected with the control chip and the RCD absorption module.
6. primary side feedback reverse exciting switching voltage regulator as claimed in claim 5, which is characterized in that the primary side sampling module with it is described
The supply pin connection for controlling chip, for powering for the control chip.
7. such as primary side feedback reverse exciting switching voltage regulator described in claim 5 or 6, which is characterized in that the protection circuit includes protecting
Dangerous silk, varistor and thermistor, the rectification circuit include bridge rectifier diode, and the EMI filter circuit includes the
One capacitor, the second capacitor and common mode inductance, the first capacitor and second capacitor are high-voltage electrolytic capacitor；The starting
Circuit includes first resistor, second resistance and third capacitor；Wherein,
The first end of the fuse is connect with the firewire, the first end of the second end of the fuse and the varistor
And the first end of the bridge rectifier diode is separately connected；
The second end of the varistor is separately connected with the first end of the thermistor and the zero curve；
The second end of the thermistor is connect with the second end of the bridge rectifier diode；
The third end of the bridge rectifier diode is connect with the first end of the first capacitor, the bridge rectifier diode
4th end is connect with the second end of the first capacitor；
The first end of the first capacitor is also connect with the first end of the common mode inductance, the second end of the first capacitor also with
The second end of the common mode inductance connects；
The third end of the common mode inductance is connect with the first end of second capacitor, and the 4th termination of the common mode inductance is primary
Ground；
The first end of second capacitor is also connect with the first end of the first resistor, and the second termination of second capacitor is just
Grade ground；
The first end of the first resistor is also connect with the RCD absorption module, the second end of the first resistor and described the
The first end of two resistance connects；
The first end and the primary side of the supply pin of the second end of the second resistance and the control chip, the third capacitor
Sampling module is separately connected；
The primary ground of the second termination of the third capacitor.
8. primary side feedback reverse exciting switching voltage regulator as claimed in claim 7, which is characterized in that the RCD absorption module includes the
Three resistance, the 4th resistance, the 5th resistance, the 4th capacitor and first diode；Wherein,
The first end of the 3rd resistor is connect with the first end of the first resistor, the second end of the 3rd resistor with it is described
The first end of 5th resistance connects；
The first end of 4th resistance is connect with the first end of the 3rd resistor, the second end of the 4th resistance with it is described
The first end of 5th resistance connects；
The first end of 4th capacitor is separately connected with the first end of the 4th resistance and the first end of the armature winding,
The second end of 4th resistance is connect with the first end of the 5th resistance；
The second end of 5th resistance is connect with the cathode of the first diode；
The anode of the first diode is separately connected with the drain electrode foot of the switching tube and the second end of the armature winding.
9. primary side feedback reverse exciting switching voltage regulator as claimed in claim 8, which is characterized in that the primary side sampling module includes the
Six resistance, the 7th resistance, the 8th resistance, the second diode and the 5th capacitor；Wherein,
The first end of 6th resistance is connect with the first end of the auxiliary winding, the second end of the 6th resistance with it is described
The anode of second diode connects；
The cathode of second diode is connect with the supply pin of the second end of the second resistance and the control chip；
The first end of 7th resistance is separately connected with the first end of the 6th resistance and the first end of the auxiliary winding,
The second end of 7th resistance is separately connected with the sampling foot of the control chip and the first end of the 5th capacitor, described
The second end of 7th resistance also connects primary ground through the 8th resistance；
The primary ground of the second termination of 5th capacitor.
10. primary side feedback reverse exciting switching voltage regulator as claimed in claim 9, which is characterized in that the voltage output module includes
9th resistance, third diode, the 6th capacitor, the 7th capacitor, the 8th capacitor, output cathode and output negative pole；Described 3rd 2
Pole pipe is low pressure drop Schottky barrier diodes；Wherein,
The first end of 9th resistance is connect with the anode of the third diode, the second end of the 9th resistance with it is described
The first end of 6th capacitor connects；
The cathode of the second end of 6th capacitor and the third diode, the first end of the 7th capacitor, the described 8th
The first end and output cathode of capacitor are separately connected；
The anode of the third diode is also connect with the first end of the secondary windings, the cathode of the third diode also with
First end, the first end of the 8th capacitor and the output cathode of 7th capacitor are separately connected；
The second of 7th capacitor terminates time polar region；
The second of 8th capacitor terminates time polar region；
The output negative pole is connect with the second end of the secondary windings.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110808682A (en) * | 2019-11-26 | 2020-02-18 | 深圳创维－Rgb电子有限公司 | Switch power supply circuit without high-voltage large electrolytic capacitor and television |
| CN111740615A (en) * | 2020-06-13 | 2020-10-02 | 深圳市海洋王照明工程有限公司 | Temperature and humidity detection device and switching power supply circuit thereof |
| CN112201457A (en) * | 2020-08-26 | 2021-01-08 | 珠海格力电器股份有限公司 | High-frequency transformer winding structure, switching power supply circuit and power adapter |
| CN112822820A (en) * | 2021-02-01 | 2021-05-18 | 郑州地铁集团有限公司运营分公司 | LED down lamp drive controller |
| CN112821750A (en) * | 2021-01-04 | 2021-05-18 | 格力电器（武汉）有限公司 | Circuit board of power adapter, power adapter and electric equipment |
| CN113676066A (en) * | 2021-08-31 | 2021-11-19 | 深圳市雅晶源科技有限公司 | EMI shielding system of gallium nitride quick charging source |
| CN115603283A (en) * | 2022-11-21 | 2023-01-13 | 珠海智融科技股份有限公司（Cn） | Flyback protection circuit |
| EP4057303A4 (en) * | 2019-11-08 | 2024-01-03 | Shenzhen Huntkey Electric Co Ltd | Planar transformer, circuit board having same and power converter |
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| CN207938419U (en) * | 2018-04-10 | 2018-10-02 | 广东力王高新科技股份有限公司 | A kind of mobile phone Switch Power Transformer |
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| CN201590919U (en) * | 2009-11-30 | 2010-09-22 | Bcd半导体制造有限公司 | High-power factor high-performance LED driving circuit |
| CN202632965U (en) * | 2012-04-27 | 2012-12-26 | 昂宝电子（上海）有限公司 | Transformer structure |
| CN205666127U (en) * | 2016-06-16 | 2016-10-26 | 亚元科技（宜昌）电子有限公司 | Flyback switching power supply transformer |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4057303A4 (en) * | 2019-11-08 | 2024-01-03 | Shenzhen Huntkey Electric Co Ltd | Planar transformer, circuit board having same and power converter |
| CN110808682A (en) * | 2019-11-26 | 2020-02-18 | 深圳创维－Rgb电子有限公司 | Switch power supply circuit without high-voltage large electrolytic capacitor and television |
| CN111740615A (en) * | 2020-06-13 | 2020-10-02 | 深圳市海洋王照明工程有限公司 | Temperature and humidity detection device and switching power supply circuit thereof |
| CN112201457A (en) * | 2020-08-26 | 2021-01-08 | 珠海格力电器股份有限公司 | High-frequency transformer winding structure, switching power supply circuit and power adapter |
| CN112821750A (en) * | 2021-01-04 | 2021-05-18 | 格力电器（武汉）有限公司 | Circuit board of power adapter, power adapter and electric equipment |
| CN112822820A (en) * | 2021-02-01 | 2021-05-18 | 郑州地铁集团有限公司运营分公司 | LED down lamp drive controller |
| CN113676066A (en) * | 2021-08-31 | 2021-11-19 | 深圳市雅晶源科技有限公司 | EMI shielding system of gallium nitride quick charging source |
| CN115603283A (en) * | 2022-11-21 | 2023-01-13 | 珠海智融科技股份有限公司（Cn） | Flyback protection circuit |
| CN115603283B (en) * | 2022-11-21 | 2023-03-21 | 珠海智融科技股份有限公司 | Flyback protection circuit |
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Application publication date: 20190809 |