CN104953849B - A kind of self-excited push-pull type transducer class Switching Power Supply - Google Patents

Abstract

The invention discloses a kind of self-excited push-pull type transducer class Switching Power Supply；Including a transformer, the transformer includes an at least magnetic core, and described magnetic core includes a magnet ring, it is characterised in that：A segment length is provided with the magnet ring and is less than total length of magnetic path half, and sectional area is more than the projection of the sectional area more than 100% of main magnetic circuit；No less than one gap is provided among the projection, projection is divided into Shang Qiaobi and Xia Qiaobi.The self-excited push-pull type transducer class Switching Power Supply of the present invention, using Royer circuits, by the magnet ring or magnetic core of the present invention, the advantages of realizing Jensen circuits；The working frequency of autonomous inverter can be improved；Improve efficiency；Solve transformer saturation three-level tip cutting edge of a knife or a sword current problems；Reduce output ripple；While frequency is improved, primary electrical sensibility reciprocal, same volume magnet ring are not changed, bearing power grade is effectively lifted, and power density is further lifted.

Description

A kind of self-excited push-pull type transducer class Switching Power Supply

Technical field

The present invention relates to a kind of power supply, more particularly to a kind of self-excited push-pull type transducer class Switching Power Supply, belong to power supply skill Art field.

Background technology

Existing self-excited push-pull type transducer, circuit structure was from U.S. Luo Ye (G.H.Royer) invention in 1955 Self-oscillation push-pull transistor single phase transformer DC converter, also makees Royer circuits, and this is also to realize high frequency conversion control electricity The beginning on road；Partial circuit looks into the auto-excitation type of match (Jen Sen, some places translations " well is gloomy ") invention from the U.S. in 1957 Recommend dual transformer circuit, after be referred to as self-oscillation Jensen circuits or Jensen circuits；Both circuits, descendant are referred to as Self-excited push-pull type transducer.The related work principle of self-excited push-pull type transducer is in Electronic Industry Press《Switching Power Supply Principle and design》Page 67 to page 70 are described, book number ISBN7-121-00211-6；The principal mode of circuit is above-mentioned famous Royer circuits and self-oscillation Jensen circuits；Shown in accompanying drawing 1 for the common application scheme of self-excited push-pull type transducer, circuit Structure is Royer circuits；The circuit of accompanying drawing 3 is self-oscillation Jensen circuits, and in fig. 1, circuit will utilize transformer B1 magnetic Heart saturated characteristic is vibrated, in the Jensen circuits of accompanying drawing 2, the self-oscillating frequency and driving function of circuit, by magnetic saturation Transformer B1 realize that therefore, main power transformer B2 is operated in undersaturated condition；Royer circuits and Jensen circuits are all Use such as Fig. 2 magnet rings.Royer circuits as shown in Figure 1, its operation principle are:After power on, triode TR1, TR2 It may be simultaneously turned on beginning with, electric current Ic1 and Ic2 pass through armature winding N2 and N3 in a reverse direction；Due to two pipes The parameter of son can not possibly be just the same, thus always will not be equal in two collector currents that the coil midstream of winding N2 and N3 two is crossed , work as IC1>During IC2, the induced voltage of main flux and coil in iron core is mainly determined by IC1 change；It is assumed that transformer As shown in figure 1, when IC1 is increased by figure direction, the feedback voltage on coil N4 makes for T primary coils and feedback coil corresponding end TR2 base stages are just, to increase Ib2, Ib2 increase makes Ic2 continue to increase again, and such positive feedback effect rapidly makes TR2 over the ground Into saturation state；Feedback voltage on opposite coil N1 makes TR1 base stages be negative over the ground；So that Ib1 reduces, IC1 subtracts therewith Small, this positive feedback promptly makes TR1 enter cut-off state；So after power on, triode TR1 cut-offs, TR2 saturations are led Logical, subsequent TR1 is conductive and enters saturation, TR2 cut-offs, such two pipes alternate conduction and cut-off, constantly, so as to form vibration Working condition.Its work characteristics is：Push-pull oscillator is carried out using transformer B1 magnetic cores saturated characteristic, and is ensured in triode TR1, TR2 saturations advance into saturation state (if triode elder generation saturation, can burn out)；Transformer output waveform is approximate square waves, because of it Circuit structure is simple, so production cost is low, and stability is high；But main magnetic core B1 is operated in alternately saturation state, Fig. 2 magnet ring works Such as Fig. 4 between the magnetic region of work, because work magnet ring is all operated in saturation state, efficiency can be relatively low, in addition because magnetic saturation can cause electricity Spike is flowed, this current spike can cause larger loss, so the conversion efficiency of circuit is relatively low, and electromagnetic interference EMI characteristic phases To poor.With the development of power technology, the continuous lifting of power density, the appearance of modular power, present power supply is proposed New requirement, modular power source are a kind of power supplys of the totally-enclosed of brick.His main advantage is small volume, and weight is gently, high Frequencyization, also it is exactly anti-interference, low noise heat exchange is highly reliable, that is, miniaturization, slimming, lightweight and high frequency, switch The volume and weight of power supply is mainly by energy-storage travelling wave tube（Magnetic element and electric capacity）Determine, therefore the miniaturization of Switching Power Supply is real It is exactly the volume for reducing wherein energy-storage travelling wave tube as far as possible in matter；Within the specific limits, the raising of switching frequency, can not only be effectively Reduce the size of electric capacity, inductance and transformer, but also can suppress to disturb, improve the dynamic property of system；Therefore, high frequency Change is the main direction of development of Switching Power Supply；In order to realize that module high frequency will have to the selection of magnetic core, such as magnetic conductivity and AE values High requirement；The frequency of oscillation of Royer circuits is the function of supply voltage, in Electronic Industry Press《The original of Switching Power Supply Reason and design》The 18th row of page 68 is described, book ISBN 7-121-00211-6；It is incorporated herein as follows：In formula：F is Frequency of oscillation；Bw is work magnetic induction intensity (T), typically takes 50%~70% saturation point Bm values；N is coil turn；S For magnetic core net sectional area；Vs is working power voltage；Input voltage can not change, and N is the number of turns, with power output size phase Close, it is impossible to change；S is magnetic core net sectional area, in the case of module, existing process volume requirement, it is not possible to change；Bw is Worked magnetic induction intensity (T), and the magnetic conductivity that can increase magnetic material is reduced；μ= B/H；Wherein H is magnetic field intensity B magnetic Induction (T)；Such as Fig. 4, magnetic core is operated in curve ranges, and we are to core material slowly impressed current, magnetic flux density (magnetic Induction) also can and then it increase, when electric current adds to a certain degree, we can have found that magnetic flux density can increase very slowly, Er Qiehui The asymptote of convergence one, when this asymptote of convergence this when magnetic flux density our saturation flux density Bm for being known as. Reach that the time of this value is directly related to H, because H is the magnetic field added to outside electric current, in the case that input current is constant, you wish By changing the quick magnetic saturation of H, magnetic conductivity is big, then same big impressed current I make it that H value changes are also bigger；Magnetic conductivity is such as Fruit is zero, then great input current will not also produce H values, be unable to reach magnetic saturation, if magnetic conductivity is almost limitless big, only Add a low current, H is also just rapidly saturated reaching very much close to infinity, B.B = μ0*μ*H；As described above, increase μ values can The working frequency of effective increase autonomous convertor, when autonomous inverter magnetic core also has following benefit from the larger magnetic core of μ values； According to formula E=L*I*I；The μ * IPK*N/l of L=0.4, wherein, E is unit interval energy, and L is primary electrical sensibility reciprocal, and P is output work Rate, t are the time, and l is effective magnetic circuit length；It can be released according to above formula, low μ values and the contrast of high μ values magnet ring, in circle ratio, AE Value, in the case that shape size keeps constant, while high μ values magnet ring frequency provides, under equal load effect, the electricity of product Flow valuve is effectively declined, so as to improve product power density；In the case of Same Efficieney is ensured, reduction magnet ring that can be appropriate, Further increase frequency and power density；Its shortcoming is that technology is limited, and common high μ values magnet ring in the market is relative permeability 5000-7000, limiting value accomplishes 15000, but application and temperature coefficient are limited, it is impossible to produces in enormous quantities；Relative cost It is higher.

Jensen circuit operation principles and Royer circuits are closely similar, and its self-oscillatory upset is by driving magnet ring B1 is completed, and main magnet ring tightly plays energy transmission, is not operate at saturation state, because of the specificity of its operation principle, it is perfectly kept away All shortcomings of Royer circuits are opened；Because its self-oscillatory upset is by driving magnet ring B1 to complete, B1 only serves driving three The effect of level pipe, required electric current is very small during its work, it is possible to reduces magnet ring B1 volume as far as possible；Because magnet ring B1 small volumes, operating current is small, and magnetic core B2 is operated in unsaturated state, so its EMI characteristic is very good；Because its is self-oscillatory Upset is by driving magnet ring B1 to complete, and B1 magnetic saturation characteristic does sufficiently fast, can be easily accomplished the lifting of frequency； But it is double magnet rings design, and double magnet rings will coiling, and be the saturation requirement for meeting B1, coiling quantity is a lot, cost of labor It is all higher with material cost；Solder joint is more, and solder joint, welding cost are high too much in limited space；Complex process, production Defective products can not meet；Dual transformer, magnet ring volume are limited, and are unfavorable for product miniaturization, can not be improved power density.

The content of the invention

（One）Technical problems to be solved

To solve the above problems, the present invention proposes a kind of self-excited push-pull type transducer class Switching Power Supply, Royer electricity is utilized Road, realize the function of Jensen circuits.

（Two）Technical scheme

The self-excited push-pull type transducer class Switching Power Supply of the present invention, including a transformer, the transformer include at least one Magnetic core, described magnetic core include a magnet ring, it is characterised in that：A segment length is provided with the magnet ring and is less than total length of magnetic path Half, and sectional area is more than the projection of the sectional area more than 100% of main magnetic circuit；It is provided among the projection no less than one Individual gap, projection is divided into Shang Qiaobi and Xia Qiaobi.

Further, the lower bridge wall is arranged at most between the gap of inner side and magnet ring inner ring；The lower bridge wall is arranged at Most on the outside of the gap of inner side.

Further, the Shang Qiaobi is added with the sectional area of lower bridge wall cuts more than or equal to the magnet ring beyond projection The 80% ~ 100% of area.

As preferred embodiment, the gap internal diameter is not less than enamel-covered wire external diameter.

As preferred embodiment, the high spot offers a circular or strip hole.

As preferred embodiment, the high spot offers two circular or strip holes side by side.

The present invention operation principle be the self-excited push-pull type transducer of above-mentioned technical proposal, using Fig. 1 Royer circuits as , the transformer B1 in Fig. 1 self-excited push-pull type transducers uses the technical scheme of the invention described above, the symmetrical operation original of circuit Reason does not change, and when triode TR2 saturation conductions, correspondingly, triode TR1 is completely switched off, corresponding to triode TR2 Electric current in coil NP2 windings, and magnetic induction intensity caused by this electric current are linearly increasing with the time, but magnetic induction is strong When degree increases to the saturation point Bm of transformer B1 magnetic cores, the inductance value of coil reduces rapidly, so that triode TR2 collection Electrode current sharply increases, and increased speed is much larger than the increase of base current, and triode TR2 departs from saturation, triode TR2 Colelctor electrode to emitter stage pressure drop UCE increase, correspondingly, the voltage on transformer NP2 windings is reduced by same numerical value, line The voltage for enclosing the sensing of NB2 windings reduces, and triode TR2 base voltages is also reduced, causes triode TR2 to cut-off side To change, now, the voltage on transformer B1 coils will be reverse, turn on another triode TR1, hereafter, repeat This process, form push-pull oscillator.

As described above, bridge wall parameter above and below rational configuration, as shown in figure 4, can makel _CDDotted line marked area magnetic flux density carries Height, reach saturation value in advance, in the application of Royer circuits, driving winding technique can be driven into triode in advance in this region Driving stage is overturn, and other region magnetic flux densities are unsaturated during because of lower bridge wall saturation, will not go out in triode current collection level current spike The current spike that existing magnetic saturation is brought, EMI characteristics, the stability of triode can be all improved.Frequency significantly rises, Royer The frequency of oscillation of circuit is the function of supply voltage, in Electronic Industry Press《The principle and design of Switching Power Supply》68th The 18th row of page is described, book ISBN 7-121-00211-6.It is incorporated herein as follows：

... ... ... formula (1)

In formula：F is frequency of oscillation；Bw is work magnetic induction intensity (T), typically takes 50%~70% saturation point Bm Value；N is coil turn；S is magnetic core net sectional area；Vs is working power voltage.Because S is that magnetic core is effective during portion of area saturation Sectional area drops to half and following.Because H from 0 to speed during saturation point is also significantly faster than that other regions during saturation.Because local full Unsaturated with, other regions, whole core loss declines, and upper figure is that major loop magnetization curve efficiency is obviously improved.On even During figure sectional area A1+A2=A, because driving winding technique is in Xia Qiaobi, frequency upgrading is obvious, and energy is transmitted in the unit interval with frequency The increase of rate and bring bigger power, can substantially increase the power density of unit of product.Frequency rises, and AE values do not change Become, same number of turns outputting inductance is bigger, output filter effect it is more readily apparent, output ripple effectively decline energy loss mainly by Increase in magnetic induction intensity caused by the saturation point Bm of transformer B1 magnetic cores, prior art uses sectional area identical magnetic The heart, substantially to allow whole magnetic core to reach saturation point Bm, and want more energy to can be only achieved saturation.As shown in figure 5, transformer The route of the operating point motion of B1 magnetic cores is ABCDE, and moving line is EFGHA within each and every one cycle of lower half, i.e., complete at one In cycle, for whole region and in the self-excited push-pull type transducer of the present invention, transformer is deposited for the working region of prior art magnetic core First reach magnetically saturated part than principal part at one section, i.e., it is local first to reach than principal part under the ascending magnetic field excitation of identical Magnetic saturation, but its length is very short, allows this bit of local magnetic core to reach the saturation point Bm of itself, can equally cause circuit Push-pull oscillator, the working region of this local a part of magnetic core be whole region, and but part length it is very short, the energy of consumption Amount is greatly reduced；Simultaneously therefore there is current spike also in triode ON and shut-off in the self-excited push-pull type transducer of the present invention And reduce, have the advantage that：Also therefore the ripple that is superimposed on the output DC voltage of the self-excited push-pull type transducer of the present invention Decline；Because principal part is not operated in saturation state, its corresponding magnetic core working region work area is obviously reduced, institute Very low with the energy that principal part consumes, the energy overall reduction of magnetic core consumption of the invention is very big.The solution of the present invention is used, can To reduce energy expenditure when recommending conversion every time, under same working frequency, the consumption of self-excited push-pull type transducer circuit It can reduce, can equally realize that working frequency is lifted and loss rises and little, realize that change at high frequencies is changed efficiency and risen.

Beneficial effect

Compared with prior art, self-excited push-pull type transducer class Switching Power Supply of the invention, using Royer circuits, passes through The magnet ring or magnetic core of the present invention, the advantages of realizing Jensen circuits；The working frequency of autonomous inverter can be improved；Improve effect Rate；Solve transformer saturation three-level tip cutting edge of a knife or a sword current problems；Reduce output ripple；While frequency is improved, do not change just Level inductance value, same volume magnet ring, bearing power grade are effectively lifted, and power density is further lifted.

Brief description of the drawings

Fig. 1 is self-excited push-pull type transducer Royer circuit diagrams in the prior art；

Fig. 2 is self-excited push-pull type transducer Royer magnet rings in the prior art；

Fig. 3 is self-excited push-pull type transducer Jensen circuit diagrams in the prior art；

Fig. 4 is magnetic core front view of the present invention；

Fig. 5 is magnetic circuit schematic diagram of the present invention；

Fig. 6 is the transformer magnetic core comparative bid parameter of the same number of turns of the invention made with conventional magnet ring；

Fig. 7 is the transformer magnetic core curve comparison figure of the same number of turns of the invention made with conventional magnet ring；

Fig. 8 is the transformer magnetic core comparative bid parameter of the same number of turns of the invention made with conventional magnet ring；

Fig. 9 is the transformer magnetic core curve comparison figure of the same number of turns of the invention made with conventional magnet ring；

Figure 10 is the transformer magnetic core schematic diagram of embodiment 3；

Figure 11 is the transformer magnetic core schematic diagram of embodiment 3.

Embodiment

Embodiment one：

Using such as Fig. 4 magnetic cores, self-excited push-pull type transducer Switch power supply, as shown in figure 1, magnetic core is using the milli of overall diameter 5 1 millimeter opening, 2.3 squares of millis of principal part cross-sectional area are made a call in rice, 6 millimeters of jut external diameter, 2.7 millimeters of internal diameter, jut centre Rice, and the local product of bridge wall equal cross-sections up and down is 1.35 square millimeters, local lower bridge wall is circle, and length is much smaller than 1 Millimeter；On lower bridge wall around driving winding NB1=NB2 coils 3 enclose, the turn coil of main winding NP1=NP2 coilings 17, NS1=NS2 windings around The circle of system 19, R1 values 1.2K, C1 value 104K, TR1, TR2 use 200 method multiple 30V triode, with using conventional magnetic Circuit in the transformer load map one for the same number of turns that ring such as Fig. 2 make, in 200mA under the premise of fully loaded, fully loaded 5% ~ 100% carries out test comparison, as shown in Figure 6：

Using the conversion efficiency of self-excited push-pull type transducer of the invention from underloading to fully loaded whole section, have and substantially carry Rise, make contrast chart with software, curve 1 as shown in Figure 7 therein is the self-excited push-pull type transducer using the present invention The comparison diagram of conversion efficiency curve and existing product, ripple parameter of the invention is especially good, effectively reduces product and rear class is produced The interference of product；Frequency upgrading is obvious.

Embodiment two：

Using such as Fig. 4 magnetic cores, circuit such as Fig. 1 of self-excited push-pull type transducer, magnetic core uses 5 millimeters of overall diameter, jut Exceptionally 6 millimeters of footpath, 2.7 millimeters of internal diameter make a call to 11 millimeter opening among jut, 2.3 square millimeters of principal part cross-sectional area, and office Portion divide into bridge wall up and down, and sectional area sum is 2.3 square millimeters, and local lower bridge wall is circle, and length is much smaller than 1 milli Rice.Enclosed on lower bridge wall around driving winding NB1=NB2 coils 3, the turn coil of main winding NP1=NP2 coilings 13, NS1=NS2 winding techniques 15 circles, 104K is taken with R1 values 2K, C1, TR1, TR2 use 200 method multiple 30V triode.

Conventional magnetic core such as Fig. 2, magnetic core use overall diameter millimeters, 3 millimeters of internal diameter, are highly 2.5 millimeters, cross-sectional area 3.75 square millimeters, around driving winding NB1=NB2 coils 3 enclose, the turn coil of main winding NP1=NP2 coilings 20, NS1=NS2 windings around The circle of system 24,104K is taken with R1 values 0.68K, C1, TR1, TR2 use 200 method multiple 30V triode；It is full in 400mA Under the premise of load, test comparison is carried out fully loaded 5% ~ 100%, as shown in Figure 8；

Using the conversion efficiency of self-excited push-pull type transducer of the invention from underloading to fully loaded whole section, have obvious excellent In existing product, ripple parameter of the invention is also an advantage over existing product, and frequency rises more obvious, and output ripple is small with 10 mV；Use the feature of embodiment two for, frequency substantially rises, and in the case where magnet ring size is constant, load is increased into 400mA, Delivery efficiency is that impacted is as shown in figure 11.

Using the conversion efficiency of self-excited push-pull type transducer of the invention from underloading to fully loaded whole section, have and substantially carry Rise, as shown in figure 9, in contrast with it is made of software, wherein the conversion efficiency curve of the self-excited push-pull type transducer using the present invention With the comparison diagram of existing product；The ripple parameter of the present invention is especially good, is enclosed in input than reducing, starts the situation of resistance increase Under, the startup of 2W full loads is out of question, and frequency improves, and output ripple is in below 30mV；Now in external 33 microfarads of output end Electric capacity, ripple can be less than 10Mv, effectively reduce interference of the product to rear class product.

According to above example, in the case of core volume is unchanged, the magnetic core of same volume can band using the present invention Play bigger load, and whole parameters of efficiency ripple can all rise.

Embodiment three：

The transformer magnetic core that Figure 10 to Figure 11 uses for third embodiment of the invention self-excited push-pull type transducer, their work Make principle and embodiment one, embodiment two is identical, repeats no more here.

The above-described embodiments are merely illustrative of preferred embodiments of the present invention, not to the structure of the present invention Think and scope is defined.On the premise of design concept of the present invention is not departed from, technology of the ordinary people in the field to the present invention The all variations and modifications that scheme is made, all should drop into protection scope of the present invention, the claimed technology contents of the present invention, All record in detail in the claims.

Claims (5)

1. A kind of 1. self-excited push-pull type transducer class Switching Power Supply, it is characterised in that：Including a transformer, the transformer includes An at least magnetic core, described magnetic core include a magnet ring, it is characterised in that：A segment length is provided with the magnet ring and is less than total magnetic Road length half, and sectional area is at least above the projection of the sectional area 100% of main magnetic circuit；It is provided with not among the projection Less than one gap, Shang Qiaobi and Xia Qiaobi are divided into by projection；The lower bridge wall is arranged at most in the gap and magnet ring of inner side Between ring；Winding technique is driven in the lower bridge wall.
2. 2. the self-excited push-pull type transducer class Switching Power Supply according to claim 1, it is characterised in that：The Shang Qiaobi is with The sectional area sum of bridge wall is between 80% ~ 100% of the magnet ring sectional area beyond projection.
3. 3. the self-excited push-pull type transducer class Switching Power Supply according to claim 1, it is characterised in that：The gap internal diameter is not Less than enamel-covered wire external diameter.
4. 4. the self-excited push-pull type transducer class Switching Power Supply according to claim 1, it is characterised in that：The high spot opens up There is a circular or strip hole.
5. 5. the self-excited push-pull type transducer class Switching Power Supply according to claim 1, it is characterised in that：The high spot is side by side Offer two circular or strip holes.