CN203748048U - Constant-power combined driver for LED lamp filament - Google Patents

Abstract

The utility model discloses a constant-power combined driver for an LED lamp filament, and irons out the intrinsic defects of one-dimensional LED lamp filament drive scheme that the lighting number of LEDs increases with the rising of a voltage, and decreases with the falling of the voltage. According to a transient value of a direct-current voltage of the rectification pulsation of a supply network, the series and parallel combination of an LED lamp filament circuit is timely adjusted, so as to guarantee the constant number of the lighting LEDs. During a low voltage, the LED lamp filament segments are adjusted in a mode that fewer segments are connected in series and more segments are connected in parallel. During a high voltage, the LED lamp filament segments are adjusted in a mode that more segment are connected in series and less segments are connected in parallel. And the combination of the LED lamp filament segments is switched dynamically, thereby adapting to the change of a pulsating voltage in a self-adaptive manner, enabling the number of the lighting LEDs to be constant, and reducing the power frequency flickering of LED illumination. Moreover, the luminance of the LEDs is not affected by the voltage fluctuation of the supply network, thereby enabling an LED lamp based on a high-voltage drive technology of a commercial power grid to obtain and maintain a good and stable illumination effect. The superiority of the utility model lies in that the driver is suitable for the commercial power grid to supply power to various types of environments, especially the severe environments of remote areas far from a central area. The driver supplies a high-efficiency, safe and stable effect of illumination based the impeccable technology and very low cost.

Description

LED filament power stabilize combination drive

[technical field]

The present invention relates to a kind of LED lighting circuit driver, be specifically related to a kind of LED filament power stabilize combination drive.The invention belongs to energy-conserving and environment-protective field of semiconductor illumination, also belong to microelectric technique and integrated circuit (IC) design application.

[background technology]

LED is as lighting source, has the features such as energy-efficient, safety long-life, is used widely gradually.For obtaining high-quality illuminating effect, electronic circuit aspect has many ripe designs.The Switching Power Supply low-voltage direct-current driver series of products of main flow based on PWM pulse modulation technology, have wide input voltage, stable output characteristic and the useful life substantially meeting the demands, and integrated multiple protection measure, comparatively safe reliable; Shortcoming is that electronic circuit is complicated, peripheral component is many, volume be difficult to do little, high expensive, if technical processing is bad, EMI electromagnetic radiation in addition.

In the direct powered LED lighting light source of utility grid and light fixture, gradually adopt high voltage direct driving more, from the complete LED lighting circuit without driver: as two string reverse parallel connection LED filaments, to the single-string LED filament that connects rectifier bridge, even useful 4 sections of LED filament strings form the AC LED scheme that ' luminous rectifier bridge ' adds single-string LED filament etc., and general lighting function can be provided.Described LED filament, as shown in Figure 1, refers to that its voltage-current characteristic is the linear superposition of all LED voltage-current characteristics in filament by two above end to end single components in series of identical parameters LED.1-1 symbology ' direct-current LED filament ' in Fig. 1,1-2 is its represented >=2 LED series circuit, 1-3 symbology ' AC LED filament ', 1-4 is its represented circuit, is to be formed by two sections of identical direct-current LED filament reverse parallel connections.Succinct without driver LED lighting circuit, but be difficult for coordinating various unstable state factors, oversimplification causes light efficiency low, fragile, processes the bad power frequency flicker that has.

The straight crystal drive circuit of commercial LED filament of line voltage is dynamically chased in development in recent years, all based on a paths of LEDs filament or some sections of LED filaments, form a road series circuit and implement to control, all belong to one-dimensional linear and control category, its principle and feature are: [1] rectification pulse dc high voltage is directly loaded on LED filament (part paragraph); The LED filament that [2] one tunnels are in series, the total forward drop of its turning part LED and pulsating dc voltage value linear matched, remaining LED is in cut-off state; [3] conducting LED quantity and real-time pulsating dc voltage values match, that is: the pulsating dc voltage conducting LED total quantity that rises increases, and the pulsating voltage conducting LED total quantity that declines reduces; [4] relation of pulsating dc voltage numerical value V and conducting LED number n is roughly n=V/V _fm, V here _fmall LED forward voltage V in LED filament _fstatistical expectation.Control circuit also can, according to pulsating voltage lifting trend, with suitable lead, be adjusted n numerical value, in the hope of optimum efficiency in advance.

Through limited retrieval, learn, adopt the partial monopoly of utility grid high pressure direct driving technologies scheme to have: [1] U.S. < < Reduced flicker AC LED lamp with separately shortable sections of an LED string > >, number of patent application: US20110227489A1; [2] Chinese < < has the photo engine > > of light switching array, number of patent application: 201120343284.6; [3] Chinese < < ac high-voltage multistage light source drive device > >, number of patent application: 201320021625.7, etc.; It is reported that there is similar patent application countries and regions such as also having Taiwan, Korea S.

Discussion herein, is all limited to the whole string of single lamp list LED filamentray structure, and how whole single lamp string LED filament principle be identical, slightly.

The form that described one-dimensional linear is dynamically chased voltage LED filament direct driving circuit has multiple, to connect one group of electronic switch for each the LED light-emitting diode in LED filament the most intuitively, have how many LED just with how many group electronic switches, in one line control one by one absolutely clear.If obviously so done, wiring is crowded, and the high fault of cost is many, can only have a talk about, real inadvisable.Practical solution has: whole piece LED filament is divided into some sections, and each section of series LED quantity optimization is definite, then each section of LED filament section optimized the arrangement of to combination, is connected to switch, dynamically controls series connection conducting LED total quantity; Drive circuit IC internal circuit is optimized, and outside lead is simplified, and doing like this cost poor efficiency really well can be practical.

In drive circuit control unit, some schemes arrange suitable figure place up/down binary counter as control routine ROM address generator, this counter OPADD code points to ROM discrete cell in real time, ROM exports each way switch control signal level, through buffer stage, drive respective electronic switch, switch in real time corresponding LED filament section and carry out tandem compound and control its conducting state, realize and dynamically chase pulsating dc voltage and change, the LED quantity of the conducting that makes to connect is able to match with voltage.

With electronic switch array, switch each LED filament section tandem compound and break-make, by the LED filament section of suitable length, adapt to change in voltage, realize that the high conducting LED of voltage is many, low conducting LED is few for voltage, this is the essence of one dimension control program.For example AC220V application, if 100 of whole cluster of lamps, ornamental silk LED sums, can divide 7 sections, each section of LED quantity is respectively: 1,2,4,8,16,32,37, need special-purpose 7 electronic switches, its final stage LED quantity is determined by formula 100-(1+2+4+8+16+32)=37, is with all the other each section of LED quantity sums of binary combination in bracket.But side circuit inaccuracy controls to single led V _fchange, the arrangement of each section of LED quantity is 1m, 2m, 4m, 8m, 16m, 32m, R etc., the integer that m is>=1, and R is the difference that whole cluster of lamps, ornamental silk LED sum deducts binary combination section LED quantity.As m=1 and AC220V, just as described in above-listed; If change m=2, LED hop count is 6 sections, and each section of LED series connection quantity is respectively 2,4,8,16,32,38, needs 6 electronic switches; Change 5 sections of m=4, LED number is respectively 4,8,16,32,40, needs 5 electronic switches; If change 4 sections of m=8, LED is 8,16,32,44, only needs 4 electronic switches.Obviously m value increases, and LED hop count reduces, and circuit becomes simple, but Current Control effect becomes coarse: stepped-up voltage span becomes large, the electric current I of the LED filament of flowing through _frate of change is larger, and these are as shown in middle Fig. 4-2 waveform of Fig. 4.The technological improvement of compromise is to increase current regulator part as current regulator diode, or makes electric current adjust diode CRD, its cut-off current I _fwaveform, as shown in the 4-3 figure of Fig. 4, is constant value in conduction period substantially.Increase CRD and can sacrifice some power consumption efficiencies, to exchange simple circuit for and to control steadily.

As practical circuit, Fig. 2 provides the circuit theory diagrams of m=8, symbol V _hfor rectification pulse dc high voltage, Vdd is the power supply that IC circuit internal electric source offers control circuit, Gnd is ground wire, ADin is control circuit signal sampling input point, Fig. 3 is carried in voltage waveform view on LED filament, DCV ordinate side numerical value is pulsating dc voltage scale, and left side AC220V is normal voltage waveform, and the right AC220V-30% is voltage waveform on the low side; Fig. 4 is electrical waveform apportion schematic diagram, and 4-1 shows LED filament voltage waveform, and 4-2 is the LED current waveform of circuit while not taking constant current measure, and 4-3 is constant current waveform, and 4-4 is LED power waveform.In conjunction with lower list 1, can find out the voltage control process of dynamically chasing of Fig. 2 circuit: be along with rectified pulsatory voltage declines from peak value from the top down, till address 1100 reaches zero passage change point; Otherwise with voltage, rise until peak value from bottom to top.Different voltage section LED filament sections have various combination, and the LED filament section of flowing through current circuit is different, only lists the electric current route of several combinations in right ' the electric current route code name ' hurdle of table, and current path shown in Fig. 2 right part dotted line helps to analyze.

Table 1:

This scheme power consumption efficiency and power factor specification are fine, and also almost without peripheral components, simple circuit, takies PCB area little.Though very practical, this type of scheme still has it obviously not enough: when pulsating dc voltage is lower, obviously very little, LED lamp brightness of illumination is obviously on the low side for conducting LED quantity, and illuminating effect has power frequency scintillation.On the other hand, larger at voltage ripple of power network, particularly remote districts or power transmission and transformation far-end are grown the power utilization environment of distance, and line voltage is sometimes far below supply standard lower limit.Because this type of Center for architecture feature is that in LED filament, conducting LED quantity and pulsating dc voltage numerical value match according to one-dimensional linear positive correlation rule, when line voltage is on the low side, the LED quantity that participates in work conducting is on the low side, as Fig. 3 the right waveform 3 _-shown in 2, cause obviously reducing and dimmed in LED lamp brightness ratio normal voltage situation, illuminating effect is also with regard to variation.

In order to overcome this technological deficiency, make the LED lamp also can normal illumination when line voltage is on the low side, and eliminate illumination flicker, the invention discloses ' LED filament power stabilize combination drive ' technical scheme.LED lamp driver based on the technical program, and the LED lamp driver integrated circuit (IC) based on the technical program, to LED filament, provide stable driving power, guarantee the LED lamp stable luminescence that utility grid directly drives, brightness is neither fluctuateed with voltage fluctuation, overcome power frequency flicker problem, also with power network fluctuation, light and shade does not occur changes simultaneously, significantly improved illuminating effect, thereby can adapt to very severe power grid environment not up to standard, contribute to accelerate to promote LED green energy conservation illumination cause at all utility grid power supply areas.

The technical program is based oneself upon novel concept, provides various reasonable and succinct drive circuit design, so that according to different application, selects optimal circuit arrangement, has solved preferably the difficult problem that stroboscopic and power network fluctuation cause the brightness of LED lamp to change.

[summary of the invention]

The technical problem to be solved in the present invention is: the deficiency that overcomes the combination of AC network high-voltage LED lamp one-dimensional linear before this drive scheme: when when voltage is high, in LED lamp, many, the voltage of conducting LED quantity is low, conducting LED quantity is few, causes the defect that power frequency is glimmered and lamp does not work during low pressure; The invention provides two dimension combination Driving technique scheme: LED filament power stabilize combination drive.This driver can just change by dynamic following pulsating dc voltage, and Rational Arrangement Combined Led Light Up silk section keeps LED lamp conducting LED quantity stable, thereby the lightness stabilized equilibrium of LED lamp power consumption based on LED filamentray structure is glimmered without power frequency; Again can be in wider utility grid alternating voltage fluctuation range, to the LED illuminating lamp based on LED filamentray structure, provide constant lighting power, guarantee that it is not subject to utility grid voltage influence of fluctuations, export relatively constant luminous flux, keep the good illumination effect of brightness stability.

The invention discloses LED filament power stabilize combination drive, ' voltage rises the bright number of LED and increases to have overcome one dimension LED filament drive scheme, the bright number of voltage drop LED subtracts ' inherent shortcoming, according to power supply network rectification pulsating dc voltage instantaneous value, adjust the connection in series-parallel of LED heater chain in good time and combine to guarantee that the shinny LED quantity of conducting is stable: when voltage is low, LED filament section is adjusted to few series connection multi-parallel, voltage height many strings is few also, dynamically switch the combination of LED filament section, self adaptation pulsating voltage changes, make the shinny LED quantity of conducting stable, both reduced LED lamp gaffer stroboscopic bright, be not subject to again the impact of power supply network voltage fluctuation on LED lamp luminosity, make the LED lamp based on utility grid high drive technology, can obtain and keep good stable illuminating effect.

The present invention is superior, and part is: adapt to the utility grid various environment of powering, particularly away from the outlying district adverse circumstances of center, with perfect technology and extremely low cost, provide safely and reliably highly effective and safe stable illuminating effect again.

The present invention is superior, and part is: the technical program surmounts one-dimensional linear control technology category, thoroughly abolish the one dimension of the dependence adjustment LED filament ' length ' of ' voltage rises the bright number increasing of LED, the bright number of voltage drop LED subtracts ' before this and controlled natural mode, at two-dimensional space, adjust ' width ' variation of LED filament off the beaten trackly, repartitioned and each LED filament section of dynamic combined, make utility grid voltage no matter on the low side or normal, the LED quantity of conducting in LED filament can keep stable.The LED lamp that use is manufactured based on this technical scheme driver, adapt to the utility grid various environment of powering, particularly away from the outlying district adverse circumstances of center, with perfect technology and extremely low cost, provide safely and reliably highly effective and safe stable illuminating effect again.

The technical program improvements are, AC network LED high-voltage drive is existed to three shortcomings that become, and are improved to three constant:

[1] the shinny LED quantity of conducting in one dimensional driving device institute driving LED filament, raises and increases with pulsating dc voltage, with Rectified alternating current drops, reduces; This LED filament power stabilize combination drive, when power supply network voltage just changes, in driving LED filament, the shinny LED quantity of conducting is constant or substantially constant, and the shinny LED quantitative proportion of conducting keeps relative stability;

[2] one dimensional driving device provides the power of LED filament illumination, along with pulsating dc voltage raises and increases, along with Rectified alternating current drops, reduces; When voltage ripple of power network, along with voltage raises and power consumption increase, along with voltage drop, power consumption reduces.This LED filament power stabilize combination drive provides the lighting power of LED lamp with voltage ripple of power network, not change;

[3] the LED lamp that one dimensional driving device drives, along with utility grid voltage fluctuation, light and shade can occur its brightness of illumination changes: voltage its brightness that raises increases, and its brightness of voltage drop declines.The LED lamp that this LED filament power stabilize combination drive drives, can keep constant illuminating effect, and its brightness of illumination does not change light and shade variation occurs with voltage ripple of power network.

Realize three and change to three constant upgradings, rely on rational technical scheme, be now described as follows.

First, by electrical network standard, form the required LED total quantity of the whole string of list LED filament of LED lamp lighting circuit.China AC220V electrical network of take is example, national power supply quality standard GB12325-90 regulation, and utility grid voltage fluctuation range lower limit-10% is to the upper limit+7%, and the actual situation that surpasses above-mentioned standard that has.Consider circuit load, the pulsating dc voltage measured value upper limit is approximately decided to be 300V for the time being, can arrange like this LED quantity N:N=300V/V of single whole string LED filament _fm, get V _fm=3V, N=100, that is: forming the whole LED quantity of whole string LED filament is 100.For ease of the equal whole string of Equal LED filament, to facilitate LED filament section to switch permutation and combination, get 96 LED and form whole cluster of lamps, ornamental silk.

Again according to perfect condition analysis.Surmounted with pulsating voltage and just changed and increase and decrease the one dimensional driving scheme of emitting led quantity, the technical program ' LED filament power stabilize combination drive ' is in whole pulsating dc voltage excursion, arrange in the whole filament of LED all LED all to participate in as much as possible work: normally together, luminous shinny.Want to reach this technical goal, the technological means that this programme adopts is: LED filament two dimension segmentation the change in formation combined method.

As military camp 96 soldier queue the change in formation: along with magnificent and mighty rhythmical " become ' ' battle array password sound; Indian file; become column of twos, column of threes, the column of fours; ..., then become square formation, then broaden gradually; ... gradually becoming four row ranks, three row ranks, double rank, finally become a row rank, is so far half the change in formation cycle; Continue again conversion and get back to again Indian file, complete a whole array transformation cycle; Go round and begin again, innumerable, then in array, soldier's sum remains unchanged.

Principle accordingly, let us first rises and constantly starts to analyze from pulsating dc voltage zero crossing: when voltage approaches 3.6V, i.e. suitable V _f1.2 times before, Drive and Control Circuit splits into 96 sections by whole string LED filament: 1 LED is exactly 1 section, then makes all LED all in parallel, namely 96 LED are all in parallel, are equivalent to a row rank of soldier's array, even if Rectified alternating current is pressed in less than 3.6V like this _dCso, under low voltage condition, also can guarantee that 100% LED normally is luminous; Then pulsating voltage continues to rise, and surpasses 3.6V _dCbut less than 7.2V _dCbefore, rearrange immediately Combined Led Light Up silk section and make it become ' narrow ': 48 LED filament sections of every section of 2 LED series connection are in parallel, 2 strings 48 also, are equivalent to soldier's array two row ranks, remain 100% LED conducting luminous; Pulsating dc voltage continues to raise again, LED filament again becomes ' narrow ' change ' length ' and reconfigures, become 3 strings 32 also, then have 4 strings 24 also, 6 strings 16 also, 8 strings 12 also, 12 strings 8 also, 16 strings 6 also, 24 strings 4 also, 32 strings 3 also, 48 strings 2 also, when pulsating dc voltage approaches peak value, the complete filament of ' length ' single string that finally becomes a string 96 LED series connection, as the soldier of Indian file array, has completed LED filament section array and by ' wide ', has been become the combined cycle that converts for half of ' length '; The pulsating dc voltage that immediately gets off declines from peak value, just starts the another combined transformation cycle that is become ' wide ' for half by ' length ' ..., in this way etc., its principle same procedure is similar, repeats no more.

In above-mentioned all the change in formation permutation and combination, LED is 100% participation normally, normal luminous shinny, therefore, the brightness of the LED lamp that the technical program ' LED filament power stabilize combination drive ' drives, in whole grid voltage change in the cycle, all will can not change, therefore, the technical program has fundamentally solved a difficult problem for power frequency flicker in the past dexterously.The integral body fluctuation of reply power supply network voltage, the principle of the technical program firm power is just the same, without repeating.

The above is the idealized discussion based on the technical program basic principle, what side circuit can not be as idealized analysis above, LED filament cutting details is haggled over every penny.In fact, at any node of LED filament segmentation, the realization of its partition and combination function, all needs to rely on electronic switch array to carry out precisely operation according to harsh sequential.Obviously, circuit engineering design in practical application, need to distribute in LED filament division paragraph quantity and position, each paragraph LED quantity, take into account in addition LED lamp illuminating effect, and easy to use, reduce supplies consumption, reduce integrated cost, be convenient in enormous quantities manufacture and logistics, and be beneficial to the whole balance such as the many factors of scrapping recycle, through in many ways deeply weighing to meet each other half way, reach relative best solution.

A kind of LED filament power stabilize combination drive, it is characterized in that: utility grid ac high-voltage directly drives LED lamp, the whole string of the list LED filament of its cascaded structure is divided into N section LED filament section, wherein have one section or be equivalent to one section of LED filament section and be only connected to drive circuit IC pin at least, and do not connect other LED filament section; The LED filament section that has at least a period of time fragment to be to provide 2 roads or multiple series series in the driving control cycle of drive circuit IC doubles or is increased to many times with parallel way work, total On current; Along with pulsating dc voltage just changes, control circuit carries out series and parallel by these LED filament sections at any time and rearranges combination, make the shinny LED total quantity of conducting in LED lamp, neither with pulsating dc voltage, rise and significantly increase, also with voltage drop, significantly do not reduce (except zero passage translate phase voltage), remain that the shinny LED quantity of conducting is higher than 70% stable state of LED sum; Described LED filament hop count N is the integer between 2 and 9.

Fig. 5 provides side circuit schematic diagram, rectification pulsating dc voltage V _hdeliver to IC and LED filament section, adopt the electrical quantity whole string LED filament that identical LED is in series to be substantially divided into four sections: LED _sUa, LED _sUb, LED _sUc and LED _sUd, is called for short A, B, C, D, and every section of N LEDs quantity is identical, and in AC220V electric power system, N is between 20 and 26, and in AC110V electrical network, N reduces by half, and is 10 to 13, and all the other power supply network situations can be analogized and suitably increase and decrease accordingly.

As shown in Fig. 5 circuit: dashed rectangle is IC encapsulation boundary, is based on drive integrated circult IC of the present invention (as follows) in it; Its outer each LED filament section is not directly connected, and compound mode therebetween depends on the On/Off assembled state of integrated circuit (IC) internal electron switch arrays.Associative list 2, illustrates its principle and the course of work.Left the first hurdle of table 2 ' pulsating voltage section ', ' V _p=nominal peak ', in AC220V system, can be by V _pbe set as 300V _dC, it moves each column voltage scope and analogizes.

Table 2

In conjunction with the three amplitude wave shape schematic diagrames of Fig. 6, can observe the variation along with pulsating dc voltage, the variation of the voltage that carries and each conducting LED filament section total current ∑ I that flows through on conducting LED filament _fvariation waveform.

Visible in table 2, electronic switch K0 to K9 has 10, and wherein K0 is master switch, once close all end-∑ of LED filament I _f=0, LED lamp extinguishes.So K0 switch is the patron saint of whole circuit, when system generation overcurrent, overvoltage or the unusual condition such as overheated, closing K0 switch is one of safety measure.In addition, at LED paragraph, switch the unsteady state of moment, in some situations, also need K0 switch moment to close cooperation, avoid unexpected generation when guaranteeing that unstable state is switched.In fact, the switch control time sequence of above-mentioned switch arrays is quite accurate, entirely true errorless in the situation that in switching manipulation, is perfectly safe, also without K0 switch motion frequently.K0 provides system insurance to have two states: [1] is closed condition Off thoroughly, and LED filament no longer includes electric current by quitting work; [2] limited current state Limit: be not thoroughly to close, but limit the size of total On current, make within circuit power consumption drops to lsafety level, to alleviate fault and maintain again circuit working state.

K1, K4, K7 switch are responsible for respectively the anodal directly power supply lines in upper end of LED paragraph B, C, D, and corresponding LED paragraph will be directly from rectification pulsating dc voltage V in conducting _hobtain power supply, do not consider that A section is because A directly hangs over V here _hon; And K3, K6, K9 switch are responsible for respectively A, B, C section lower end negative pole through the Grounding of K0 switch, to form electric current I _floop, same, the direct K0 switch in D section lower end is without consideration; K2, K5, K8 switch are the interface channels of controlling each adjacent LED paragraph, and On is connected to string, and Off disconnects can be also.These 10 switches are most important in the high speed of LED filament section is switched the change in formation, and all have the excellent specific property of tolerating high voltage, utmost point low on-resistance, high-frequency switching response.

From top to bottom, voltage rises gradually and is divided into 4 stages on table 2 left hand the first hurdle, and the compound mode of LED filament section A, B, C, D also and then changes: at first paragraph 0～V _p/ 4 is 0V _mto 75V _dCvoltage section, four LED paragraph ABCD are in parallel, and in fact LED is 24 strings 4 combination, and the LED of conducting accounts for sum 100%, at second segment V _p/ 4～V _p/ 2 is 75V _dCto 150V _dC, LED paragraph two string two also, in fact LED be 48 strings 2 also, the LED of conducting still accounts for sum 100%, at the 3rd section of V _p/ 2～3V _p/ 4 is 150V _dCto 225V _dC, only have three LED paragraphs to be connected into a string, LED is single string combination of 72 strings, conducting LED also accounts for 75%; The 4th section of 3V _p/ 4～V _pbe 225V _dCto 300V _dC, all four LED paragraphs are connected into a whole string, and LED is whole single string combination of 96 strings, and conducting LED accounts for again 100%.Lower half period is analogized in this way.

It should be noted that the 3rd section of V _p/ 2～3V _p/ 4 is 150V _dCto 225V _dC, have two kinds three LED filament section tandem compounds of ABC and BCD.Owing to being LED in circuit _sUd has arranged constant current tube CRD, so enable BCD combination.If also seal in constant current tube CRD in K3, the K6 at oval dotted line place, K9 loop in figure, ABC is the same with BCD, and two select one.

CRD current regulator diode can absorb the variable part higher than required voltage, to LED branch current I _fplay stabilization, but will consume part additional energy, this part energy changes into heat at CRD, causes IC chip temperature to rise.In figure, CRD is constant current link, also be control unit monitoring LED filament load state real-time sampling point, sampling also can alternate manner, sampled signal is delivered to AD converter or voltage comparator input ADin, its numerical representation method LED filament section is born voltage loads real time status, most important to the control decision of switch arrays action.During application design, consider the impact of CRD voltage drop on LED filament section, can be by LED _sUd section LED reasonable quantity reduces, for example, subtract 2 to 3 LEDs, becomes N-2 or N-3.For making the impedance of four sections of LED filaments consistent, control procedure is simply smooth-going, dotted ellipse ring position below K3, K6, K9 in Fig. 5 if desired, for each LED filament section loop all increases a CRD, although multiplex 3 CRD of circuit like this, the energy conversion efficiency of driver is lost, but LED light source and the user of light fixture manufacturing enterprise are more convenient in the use procedure of driver, contribute to LED Lighting Industry production capacity to improve, failure rate declines, and integrated cost can reduce.

The setting of sensing circuit ADin, can perception LED filament in current loading information, control unit accordingly can decision-making connection in series-parallel assembled scheme, switch rhythm and is carried out constantly.Therefore, the drive circuit IC based on the technical program, adapts to various voltage electrical networks, and Application Engineer only need, by particular mains voltages standard, adjust series LED quantity in whole string LED filament and each LED filament section.As with reference to figure 5, the LED filament that LED is in series divides tetra-sections of A, B, C, D, every section of series LED quantity N is identical, at AC220V power supply network, N is the integer between 20 and 26, and in AC110V electrical network, LED quantity reduces by half, be 10 to 13, the situation of all the other power supply networks can be analogized accordingly, and the drive IC of using is constant, very convenient.

In Fig. 5 circuit diagram, also have three place's dotted portions to be illustrated:

[1] LED _sUe, accesses section as selecting of LED filament, and for guarding against too high crest voltage harm etc., the LED quantity basis electrical network situation that it forms is determined.Upper end positive pole meets L _d-be LED _sUd lower end, if negative pole choosing in lower end meets L _ek0 can break its electric current and protect, but because of in parallel with CRD, effectiveness is little; If lower end directly connects ground wire V _sS/ Gnd end, bypass K0 make whole piece LED filament no longer be subject to K0 protection, therefore must conscientiously calculate careful employing, suggestion need not.

[2] SEL end, selects in order to miscellaneous function, for example, select power or size of current: have ground connection and unsettled two options.

[3] Adj end, accessible power semifixed resistor R _adj, LED lamp power consumption is finely tuned.

Circuit shown in Fig. 5, can be packaged in 12 pins and above integrated circuit (IC), such as SOP12 or other encapsulation etc.

A kind of LED filament power stabilize combination drive, it is characterized in that: the driver IC IC making based on this driver principles has 12 or 14 pins, wherein there are 8 pins for connecting and composing four sections of LED filament sections of LED lamp illuminating circuit, the series LED quantity of each LED filament section equates, and every section of LED filament section two ends are only connected with 2 pins of driver IC, between each LED filament section, be not mutually directly connected.

Fig. 5 circuit is slightly done to change as Fig. 7: according to series LED, count 1:2 at LED filament section LED _sUin D ' tap ' be divided into two sections of D1, D2, tapping point is connected to the new pin L who arranges of driver IC _d12upper, meanwhile, switch control program increases a link: by the 3V of table 2 _p/ 4～V _pstage is divided into two sections: 3V _p/ 4～11V _p/ 12 and 11V _p/ 12～V _p; The electric state of its control is as listed in table 3; The variation of Fig. 7 circuit waveform figure is only that waveform approaches the region at top, the many small stairs of voltage and power waveform, and it is fine and smooth that waveform transition becomes, and improved slightly some efficiency.Internal circuit has only increased a high-pressure electronic switch, and control program code has increased by one, again layout control program.The oscillogram coordinating with Fig. 7 circuit is omitted.

Table 3

A kind of LED filament power stabilize combination drive, it is characterized in that: the driver IC IC making based on this driver principles has 12 or 14 pins, wherein there are 9 pins for connecting and composing five sections of LED filament sections of LED lamp illuminating circuit, the series LED quantity of three sections of LED filament sections in these five sections of LED filament sections equates, and each section of LED filament section two ends are only connected with 2 pins of driver IC, between each LED filament section, be not mutually directly connected, be not connected with two sections of remaining LED filament sections yet; Remaining two sections of end to end being cascaded of LED filament section, the LED quantity sum of these two sections of LED filament sections equates with the quantity of LED in any one section of LED filament section in first three section, and LED quantitative proportion is roughly 1:2 in these two sections of LED filament sections that are composed in series, its three contacts are connected with 3 pins of drive IC, and are not connected with any a section of first three section of LED filament section; In implementing circuit, the principle that first, second, third each section of LED filament section series LED quantity equals other two sections of series LED quantity sums is constant, and each section of actual series LED quantity details can suitably be adjusted.

Fig. 5 circuit is suitably simplified and designed, option is placed on to the nude film Dies operation stage before encapsulation, particularly by ground wire V _sS/ Gnd is connected on the metal fin that is placed on paster IC belly, and available 8 pin package are made more the less and lower integrated circuit (IC) of price of compact volume as SOP8 etc.Fig. 8 provides the circuit theory diagrams after Reduced Design.Compare with Fig. 5, the change of slightly doing is: by Adi, SEL changes SL1, SL0 into, forms 2 binary system selecting sides, provides 2 ²four kinds of selections, for example the power of optional LED lamp is ' lacking ' ' in ' ' on ' ' greatly ' fourth gear, respectively corresponding I _f=15mA, 30mA, 50mA, 100mA apply in AC220V system, and the power consumption of the LED lamp of making is corresponding approximately 4.5W, 9W, 15W and 30W respectively, substantially can cover staple market demand.Consider and take into account other electrity market, on chip DieS, also can increase again a selecting side SL2, process so option and double, reach 2 ³=8 kinds of options, only increase by one section of fuse again.

A LED filament power stabilize combination drive, is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, and LED lamp illuminating circuit is four sections of LED filament sections, and every section of series LED quantity equates; 8 pins of IC are divided into 4 pairs, and every pair connects respectively one section of LED filament section two ends, and each section of LED filament section is only connected with two IC pins and is not mutually directly connected; Drive circuit ground wire V _sS/ Gnd and pulsation high-voltage ground wire share IC belly metal fin, high voltage V _hinput and certain section of anodal IC mono-pin that shares of LED filament section.

Upper, middle and lower three amplitude wave shape schematic diagrames for Fig. 6, while clearly having analyzed 4 sections of LED filament power stabilize combination drive work of above-mentioned Fig. 5 and Fig. 8 two packing forms IC, voltage, electric current and the power consumption situation of LED filament section circuit.Three width figure are corresponding up and down, there is the different pulsating direct current envelope curve of three of left, center, right height (the sinusoidal dotted line of half-wave), ' normal voltage ' ' extra-high pressure ' ' extra low voltage ' represents respectively three kinds of phenomenons of power supply network voltage, both can show relatively constant power supply network state of long period, even so also can be reflected as the state of somewhere power supply network in short time to moment.

From 6-11,6-12,6-13 voltage waveform: have CRD to LED heater current I _frestriction, LED voltage that filament carries is stepped, forms the area that is close to Delta Region between waveform step shoulder and pulsating dc voltage curve (half-wave sinusoidal dotted line), is exactly current regulator diode load that CRD bears.Obviously introduce CRD and consumed considerable energy.

The figure that is positioned at centre of three width figure is the extreme case of ' extra-high pressure ', and when voltage surpasses safety line, the protection switch K0 in circuit is cut-off current I immediately _f, cause waveform to occur breach: no current inactivity, obviously, some exaggeration of the width of breach in figure, processes gimmick just in order to give prominence to the effect of explanation K0 open-circuit-protection; Once it is normal that voltage recovers, and again enters immediately normal operating conditions: K0 opens, and allows electric current I _fthe LED filament of flowing through, all recover normal.

Driving the difference place of scheme essence with other high voltage direct, is also the technical program innovative point place, finds expression in the current waveform of middle figure: map of current ordinate is not with ' electric current I ' or ' On current I _f' indicate, and adopt ∑ I _f' total On current ' concept, take pains in to characterize this be collection four paths of LEDs filament sections, from source V _hto home to return to V _sSge road I _fthe total current ∑ I of parallel-current sum _f.As seen from the figure, the Changing Pattern of total current and pulsating dc voltage: be not that voltage rises electric current liter, voltage drop electric current falls, but act in a diametrically opposite way: when voltage is low, electric current is large on the contrary, and when voltage is high, electric current is on the contrary little.So, the technical program ' LED filament power stabilize combination drive ', looks like a load impedance converter, and load is LED heater chain, when pulsating voltage is low, the impedance of LED filament is become to low-resistance, and voltage becomes high resistant while raising, so P=V ²in/R, there are two variablees: voltage V and resistance R change each other in the same way, and finally reaching P is steady state value, so just there is light stable.

Well-known: electrical power is the product of electric current and voltage.The target of the technical program is: the LED lamp of doing brightness stability.No matter how power supply network voltage changes, and even significantly exceeds national power supply quality standard, and stabilized illumination is unaffected in the same old way for the LED lamp based on this technology.This point can be known and see from figure below of Fig. 6, 6-31, two little gap are arranged at 6-32 waveform top, crenel on picture city wall in ancient times, this is because the combination of LED filament section changes to ' three sections of LED filament section series connection ' period, its power consumption is 75%, except 6-32 has the wide and dark gap of overvoltage protection, 4 sections of parallel connections during low pressure, during middle pressure, 2 sections of string 2 tunnels also, it is all 100% full power, this is in 6-33 ' extra low voltage ' see the most obviously in situation: except pulsating dc voltage waveform pass zero point conversion moment by, whole section occurs with square wave: the illuminating circuit power stability of LED lamp, mean that illuminating effect is stable.

Fig. 9 circuit is one of this programme ' LED filament power stabilize combination drive ' integrated circuit Pin8 package application.Similar with Fig. 5 Fig. 8, Fig. 9 also drives four sections of LED filament sections, difference is to simplify internal circuit and abandoned for four tunnel Parallel Control stages, LED filament section combination control procedure also significantly changes: whole string LED filament is divided in half into two sections, one section is inserted 2 taps, is equivalent to and is divided into four sections of LED filament section A, B, C, D, and each section of LED quantity is: A=48, B=24, C=16, D=8, sum or 96.A is only connected with 2 IC pins, B, C, tri-sections of head and the tail series connection of D, and its two ends and two taps are connected with 4 IC pins.Below in conjunction with table 4 and Fig. 9 circuit and waveform Figure 10 thereof, be illustrated.

Table 4

At pulsating dc voltage zero crossing, start the first stage of rising, i.e. 0～V _p/ 2 hurdles are greatly about 150V _dCwhen following, electronic switch array forms the combining form of A//(B+C+D) by LED filament section, in parallel with A after B, C, tri-sections of series connection of D, its effect be 48 strings 2 also, the whole LED conductings in LED lamp are luminous; Second stage V _p/ 2～3V _p/ 4, LED circuit becomes a road by 2 tunnel parallel connections and connects: have the LED filament section A of 48 LEDs series connection to be connected from beginning to end with the LED filament section B of 24 LEDs series connection, form 72 LEDs series circuits, now conducting LED quantity accounts for sum 75%; To entering phase III 3V _p/ 4～11V _pthe combination of/12, LED filament series circuit becomes A, B, tri-sections of series connection of C, forms 88 LEDs series circuits, and conducting LED quantity accounts for sum 91.67%; To entering fourth stage 11V _p/ 12～V _p, the combination of LED heater chain becomes the complete LED filament of the whole series connection of 96 LEDs of A, B, C, tetra-sections of series connection of D, conducting LED quantity or 100%.

From Figure 10 oscillogram, Fig. 9 circuit turn-on duty ratio is a little less than Fig. 5 Fig. 8 circuit, and when low pressure, duty ratio declines more obviously especially, and reason is that Fig. 9 subscheme abandons 4 paths of LEDs filament section Parallel Control processes, make LED filament section conducting lowest threshold voltage promote one times, the angle of flow diminishes; But Fig. 9 actuator electrical source efficiency is a little more than Fig. 5 Fig. 8 driver, and particularly IC internal circuit is obviously simplified, only with 6 electronic switches, simplified 40%, external LED line is also simplified.

A kind of LED filament power stabilize combination drive, it is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, the illuminating circuit that forms LED lamp has four sections of LED filament sections, each section of LED quantity differs: first paragraph LED filament section is in series by half the LED of LED sum that accounts for the complete LED filament of single string, its head and the tail two ends are connected to two pins of IC, are no longer connected with other LED filament section; The LED quantity of second segment LED filament section series connection is half of first paragraph, and the LED of the 3rd section of series connection is 2/3rds of second segment, remaining LED the 4th section of LED filament section in series; Second, third, the 4th section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and two middle contacts are connected to other 4 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other three sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

Circuit shown in Figure 11, has similarity with Fig. 9: abandoning four periods of Parallel Control stages, simplify internal circuit, be also packaged into 8 pin 8-pin IC, is also one of the technical program ' LED filament power stabilize combination drive ' application circuit; Difference is that Figure 11 circuit can use binary digit logical combination control technology, makes to drive electric energy efficiency to improve.Its four sections of LED filament sections are still called for short A, B, C, D, and LED quantity is distributed: A=7N, B=4N, C=2N, D=IN, and LED sum is 14N, N numerical associations power supply network environment, the optional N=7 of AC220V or 6; 7N LEDs LED filament in series section A, equals the summation of B, C, tri-sections of series LED quantity of D.LED filament section A is only connected with two pins of IC, does not connect other LED filament section; Tri-sections of B, C, D are end to end to be connected into a stringly, for high voltage stage adopts binary combination switch to control, prepares.Semifixed resistor R in Figure 11 _adjthe power that is selection and adjustment LED lamp with IC pin Adj facilitates.

Figure 11 circuit control procedure is in two stages: when pulsating dc voltage is lower than V _pduring/2 threshold value, it is in parallel that LED filament section is combined as 7N 2 tunnels of connecting, and 100%LED conducting is luminous; The limit once voltage rose, the combination of LED filament section becomes a road series connection immediately; So can be divided into: last stages 2 tunnel is in parallel, after-stage one tunnel series connection.But the series connection stage also will be subdivided into two little stages:

At pulsating dc voltage in V _p/ 2 to 11V _pin the time of between/14, LED filament section is combined as simple stack series connection, that is: A+B, realized the series LED filament of 7N+4N=11N, its LED conducting quantity accounts for total quantity 11/14=78.6%, and it is stable that luminous flux still can keep, and stable without meticulous binary combination control effect illumination; When voltage continues to rise, surpass 11V _pafter/14, start binary system and switch K1 and K2, only need three actions to realize 12N string, 13N string, 14N string, with regard to completing this stage switch to control, reach pulsating voltage peak value.Due to its oscillogram and Figure 10 very approaching, just the many small stairs in waveform top, therefore slightly do figure, directly with circuit Figure 11 and switch control procedure table 5, are illustrated.Certainly, second stage can omnidistancely be controlled by binary combination, and waveform increases by 3 small stairs again, and power-efficient slightly improves, but illumination meeting slightly becomes flicker, slightly.

Table 5

The definition of the IC pin that Figure 11 circuit is packaged with Fig. 9 circuit and distribution and with LED filament section be connected definition can be just the same, control concept and circuit design scheme are slightly distinguished, yet slightly better on power supply conversion efficiency.

A LED filament power stabilize combination drive, is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, and the illuminating circuit that forms LED lamp has four sections of LED filament sections, LED total quantity is 14N, when AC220V power grid application, N=6 or 7, all the other electrical networks are with this analogy; The LED quantity of each LED filament section series connection differs: first paragraph LED filament section is in series by half the 7N LEDs of LED sum 14N that accounts for the complete LED filament of single string, and its head and the tail two ends are connected to two pins of IC, are no longer connected with other LED filament section; Second segment LED filament section series connection 4N LEDs, the 3rd section of series connection 2N LEDs, remaining 1N LEDs is connected into the 4th section of LED filament section; Second, third, the 4th section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and two middle contacts are connected to other 4 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other three sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

Fig. 9 circuit is further simplified, obtain Figure 12 circuit, there are 5 electronic switches its inside, and all drive circuit integration packagings are in 6 pin IC, if this encapsulation belly has heat dissipation metal plate best, can increase a functional pin.Drive IC is carried out unit switch control to forming three sections of LED filament sections of LED lamp lighting circuit; Forming the LED total quantity that these three sections of LED filament sections connect is 6N, in AC220V electrical network, and N=16, all the other electrical network analogies are calculated.Three sections of LED filament section series LED quantity differ, and first paragraph LED filament section takies half LED, by 3N LEDs, be in series, and second segment series connection 2N LEDs, the 3rd section of series connection 1N LEDs; Distribute the key of these three sections of LED filament section institute series LED quantity to be: first paragraph series LED quantity equals all the other two sections of series LED quantity sums, as for the concrete quantity of a certain section of series LED and mutually ratio is overcritical therebetween, such as these three sections can be 46,30,16 LEDs etc., only pursue actual motion optimum efficiency.6 pin arrangements of drive IC are: two pins of first paragraph LED filament section two termination, do not connect all the other LED filament sections, two ends and the contact of another two sections of series LED filament sections, be connected to three pins of IC, IC also has a pin for power selection, or as the power semifixed resistor incoming end of LED lamp; Electrical network pulse dc high voltage only shares with one section of LED filament section is anodal, and the negative pole of electrical network pulsating direct current is connected by IC belly heat dissipation metal plate with the ground wire of drive circuit, if encapsulation IC belly is without heat dissipation metal plate, power adjustment end is become to ground wire incoming end.

Figure 12 circuit also can be encapsulated in the IC encapsulation of belly with 5 pin 5-Pin of heat dissipation metal plate, circuit ground is connected to IC belly metal fin, IC power selection Dies stage before encapsulation completes, 5 pins provide LED filament section to connect completely, wherein the anodal shared IC pin of the positive pole of one section of LED filament section and electrical network pulsating direct current.To forming the requirement of each LED filament section series LED quantity, with above-mentioned in full accord.

As shown in figure 13, the function of its stable output light flux is obviously visible for the electrical waveform schematic diagram of foregoing circuit.

A LED filament power stabilize combination drive, is characterized in that: the integrated circuit (IC) of making based on this driver principles has 6 pins, or 5 pin IC of belly band metal fin; Forming LED lamp illuminating circuit has three sections of LED filament sections, and LED sum is 6N, when AC220V power grid application, and N=16, all the other electrical networks are analogized; The LED quantity of each LED filament section series connection differs: first paragraph LED filament section is in series by accounting for half 3N LEDs of the complete LED filament LED sum of single string 6N, and its head and the tail two ends are connected to two pins of IC, are not connected with other LED filament section; Second segment LED filament section series connection 2N LEDs, remaining 1N LEDs is connected into the 3rd section of LED filament section; Second, third section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and middle contact are connected to other 3 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other two sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

Figure 12 is further simplified again: two sections of LED filaments that only drive quantity to equate, as shown in figure 14.Its circuit is simplified IC inside and is only had 4 for controlling the electronic switch of LED filament section fractionation combination, for connecting the pin of LED filament section, only need 4, be packaged in belly most suitable with the SMD SMD packing forms of 4Pin of metal fin, both reduce volume, simplified technique, reduce costs again, ideal for the ultra-large application of unification specification.

Practical effect after Figure 14 circuit simplification like this once to be described especially: LED volt-ampere characteristic shows that it starts conducting voltage at its V _fabout 2/3 place of nominal value, once conducting, its electric current I _fto rise rapidly over voltage climbing speed; Figure 14 circuit is that two sections of LED filament paths have arranged constant current tube CRD, unlikely out of control for guaranteeing electric current; Figure 15 is voltage waveform view, provides the voltage waveform of LED filament in Figure 14 circuit: curve is at V _pthe step at/2 places is that drive IC becomes two sections of LED filament section parallel combinations in the line of demarcation of tandem compound; The thick dashed line of voltage waveform is the waveform that mechanical type is drawn, and heavy line is true waveform, and the efficiency of visible true waveform is far above the waveform of mechanics comprehension.

Select the encapsulation IC form that number of pins is many convenient, as select the encapsulation IC of 5 pin, 6 pin or 8 pin.

A kind of LED filament power stabilize combination drive, it is characterized in that: the integrated antenna package of making based on this driver principles becomes 4 pin IC of belly band metal fin, or 5,6,8 pin IC, drive 2 sections of series LED quantity that form LED lamp illuminating circuit to equate and discrete LED filament section, electrical network pulsating dc voltage positive pole and wherein one section of anodal shared IC pin of LED filament section, in 4 pin IC, circuit ground and pulsating dc voltage negative pole are connected to belly metal fin; In implementing circuit, the principle that two sections of LED filament sections do not connect mutually and series LED quantity is equal is constant, the actual series LED quantity of each LED filament section details capable of regulating.

Figure 16 is by looseization of encapsulation appropriateness of Figure 14 drives integrated circuit (IC), be placed in SOP8, its pin connecting for LED filament section only has 4, for the pin that function is selected and power is finely tuned, 3 are provided, it is quite convenient to use, simplified drive IC kind model, be suitable for producing in enormous quantities, buying and reduce stock, can increase economic efficiency.

A kind of LED filament power stabilize combination drive, it is characterized in that: the integrated antenna package of making based on this driver principles is in the IC of 8 pins encapsulation, packing forms is SOP8, DIP-8, PSDIP-8, its 4 pins connect 2 sections of LED filament sections that drive formation LED lamp illuminating circuit, these two sections of LED filament section series LED quantity equate, but directly do not connect between two sections of LED filament sections; In implementing circuit, the principle that two sections of LED filament section series LED quantity is equal is constant, the actual series LED quantity of each LED filament section details capable of regulating; Other 3 pins of this drive IC, can provide power grade option, and access power fine setting device.

Figure 17 circuit, is one of application circuit based on this LED filament power stabilize combination drive principle, can make Pin8 encapsulated integrated circuit IC.Slightly deposit difference part with aforementioned each circuit and be, Figure 17 circuit segments implementing the 2 tunnel Parallel Control stages of control procedure, has reduced on state threshold voltage, has expanded the circuit working cycle angle of flow, and efficiency increases; For this reason, Figure 17 circuit has been done corresponding adjustment by LED filament section: whole string LED filament is therefrom divided into and is not connected but quantity equal two parts mutually, and every part is again the same structure being in series by several sections of LED filament sections; In the Parallel Control period, increased the flexibility of fine setting.Associative list 6 and Figure 18 can further analyze the control procedure of Figure 17 circuit.

Table 6

A kind of LED filament power stabilize combination drive, it is characterized in that: the drive IC of making based on this driver principles, driving the whole string LED filament of formation LED lamp lighting circuit is to be divided into N section LED filament identical by the hop count of connecting, that series LED quantitative proportion is identical piecemeal tandem compound section, between this N section LED filament tandem compound section, do not connect mutually, its two ends and intermediate contact are directly linked on drive circuit IC pin; In AC network, in the cycle, have the stage of this N section LED filament tandem compound section conducting work in parallel, also have the stage of its tandem compound conducting work, these two stages all can also be subdivided into some little stages to raise the efficiency, to improve control effect; N is the integer between 2 to 4.

Described LED filament tandem compound section is exactly the longer LED filament section being composed in series by some sections of LED filament sections.

The LED lamp directly driving based on electrical network high pressure, there are various Driving technique schemes, and a kind of LED filament power stabilize combination drive based on the technical program, it is characterized in that: utility grid ac high-voltage directly drives LED lamp, the whole string of the list LED filament of its cascaded structure is divided into N section LED filament section, wherein have one section or be equivalent to one section of LED filament section and be only connected to drive circuit IC pin at least, and do not connect other LED filament section; The LED filament section that has at least a period of time fragment to be to provide 2 roads or multiple series series in the driving control cycle of drive circuit IC doubles or is increased to many times with parallel way work, total On current; Along with pulsating dc voltage just changes, control circuit carries out series and parallel by these LED filament sections at any time and rearranges combination, make the shinny LED total quantity of conducting in LED lamp, neither with pulsating dc voltage, rise and significantly increase, also with voltage drop, significantly do not reduce (except zero passage translate phase voltage), remain that the shinny LED quantity of conducting is higher than 70% stable state of LED sum; Described LED filament hop count N is the integer between 2 and 9.

While showing grid voltage change, must occur to the stage of rare 2 sections of LED filament section parallel operations, the LED filament section of certain moment parallel connection can be combined into series connection form again afterwards, there is the LED filament series connection stage, this variation is along with line voltage periodically changes the constantly circulation that goes round and begins again, conducting LED quantity in LED lamp is not is not increased and decreased with pulsating dc voltage lifting, keep conducting LED quantity relatively stable, illuminating effect is relatively stable.

Along with high V _femerging in large numbers of LED chip and thick-film packaged LED device, the LED filament section application meeting that many LED are composed in series is further extensive, also constantly updates with the connected mode of drive IC.Figure 19～Figure 21 is exactly several connection examples, and in figure, each LED filament symbology quantity equates the LED filament section that LED is in series, and says: Figure 19 and Fig. 9 and Figure 11 are the same from circuit theory, and Figure 20 Figure 21 is identical with Fig. 7 essence.Connect and change a lot, principle is similar, repeats no more.

Key point of the present invention and superior point are: using the LED lamp series LED filament forming as electrical network load, with splitting, carried out impedance transformation with combination technique and just changed to adapt to line voltage: voltage height no matter, in LED lamp, conducting LED quantity keeps stable, LED lamp brightness preservation is stable, this is one of key point of the present invention, is also one of superior point.

[accompanying drawing explanation]

Fig. 1: 1-1 is direct-current LED filament universal circuit symbol, and 1-2 is the series LED circuit of its represented serial number >=2; 1-3 is AC LED filament universal circuit symbol, and 1-4 connects and the LED circuit of reverse parallel connection for its represented two-way.

Fig. 2: one dimension LED filament combination drive schematic diagram, control circuit drives respective electronic switch, and LED filament section series connection quantity is controlled in combination, to adapt to utility grid voltage, changes.

Fig. 3: LED filament carrying voltage waveform view in Fig. 2, the left side is normal electrical network AC220V, the right is voltage pattern on the low side.

Fig. 4: LED filament electrical characteristic picture group in Fig. 2, comprise 4-1 voltage, electric current and 4-4 power, map of current has two width: 4-2 sawtooth waveforms is non-constant current I _fcurrent waveform schematic diagram, increases after current regulator diode CRD, and electric current becomes constant current I _ffig. 4-3.

Fig. 5 is based on LED filament power stabilize combination drive circuit theory schematic diagram of the present invention, dashed rectangle is drive circuit IC encapsulation boundary, its inside is drive circuit simplified schematic diagram, the equal LED filament section of its outer 4 sections of LED series connection quantity is connected respectively on 8 pins of IC, there is no each other line; IC inside circuit has 10 high-pressure electronic switches, and it changes this 4 sections of LED filament section connection in series-parallel combining forms to control power drives, guarantees the stable of conducting LED total quantity.

Fig. 6: the electrical characteristic picture group that is LED filament in Fig. 5,6-11 is the oscillogram of LED filament when normal line voltage, 6-12 and 6-13 are respectively overvoltage and under-voltage oscillogram, in figure, each step is the result of LED filament section combined transformation: first step is the waveform of 4 sections of LED filament sections parallel connection from bottom to top, second step is 2 sections of string 2 tunnels waveforms also, the 3rd step is the waveform that 3 sections of LED filament sections are connected into a road, and the 4th step is the waveform that 4 sections of LED filaments are all connected into a road; Wherein the fracture at 6-12 middle part be due to IC overvoltage protection, by K switch 0, close due to, if not close but current limliting, waveform is not like this, 6-13 is because line voltage is too low, LED can only circulation conversion between four sections of parallel connections and the 2 tunnel parallel connections of 2 sections of strings; 6-21,6-22 and 6-23 are the situations of LED electric current of flowing through under three kinds of states of power supply network: 4 sections have 4 tunnel electric current I when in parallel _f, electric current=4I _f, 2 road electric current=2I during 2 and 2 string _f, a road string all only has 1 road I no matter be 3 sections or 4 sections _f, electric current is minimum; 6-31,6-32 and 6-33 are the power consumptions in LED filament section, also indirectly reflect the luminous power of LED lamp, are stable as seen at LED conducting phase power.

Fig. 7: be that Fig. 5 circuit is out of shape a little, by the 4th section of LED filament section LED _sUd is divided into two as LED _sUd1 and LED _sUd2, controls the three phases of going forward still according to deconsolidation process not, and process is identical, just in the end in the 4th step process, adds at twice series connection: first seal in LED _sUd2 generates a lower step, then seals in LED _sUd1 step fills up, and processes like this, has reduced the trigonum area between LED voltage and line voltage envelope curve, can improve drive efficiency.

Fig. 8: be the distortion that Fig. 5 circuit encapsulates in compression, can be encapsulated in the 8Pin integrated circuit (IC) of belly with metal fin.

Fig. 9: be that Fig. 5 circuit is further simplified distortion, only with 6 electronic switches, reduced by 4 sections of Parallel Control processes, repartitioned the series LED quantitative proportion of LED filament section, in the Yi road series connection stage, the increase and decrease of LED filament section divides three sections of realizations, has optimized LED load waveform, also reduced IC number of pins, encapsulation can be done littlely.

Figure 10: be Fig. 9 circuit waveform schematic diagram.

Figure 11: the combined deformation that is Fig. 9 circuit: change control logic and sequential, further optimized drive efficiency.

Figure 12: be the further simplification of Fig. 9, be convenient to less IC encapsulation, for example the IC of 5Pin or 6Pin packing forms; Control circuit has only been used 5 electronic switches, only three sections of LED filament section combinations that form the whole illuminating circuits of LED lamp is controlled, and wiring and manufacture craft are simplified, and controls effect and becomes slightly aobvious coarse.

Figure 13: be Figure 12 circuit waveform schematic diagram.

Figure 14: be to Figure 12 circuit Rational Simplification further, except 6Pin, 5Pin, likely make belly with the IC of the 4Pin packing forms of metal fin; Control circuit is only used 4 electronic switches, and the LED filament section only two sections of LED quantity being equated, form the whole illuminating circuits of LED lamp is carried out the Infinite Cyclic conversion of 2 sections of parallel connections and 2 sections of series connection and controlled; Wiring and manufacture craft are simplified more, and the actual driving effect of circuit is higher than the data of calculating, and effect is pretty good.

Figure 15: the voltage waveform view that is LED in Figure 14 circuit, the thick dashed line waveform that has step is to simplify the waveform of analyzing, and heavy line waveform is the waveform in conjunction with LED I-V Characteristic Analysis and actual measurement, though visible circuit is greatly simplified, but drive effect still to meet application request

Figure 16: be the version that Figure 14 drives integrated circuit (IC) is loosely changed encapsulation, can be placed in SOP8 encapsulation, its pin connecting for LED filament section only has 4, for the pin that function is selected and power is finely tuned, 3 are provided, it is quite convenient to use, simplified the kind model of drive IC, stock's extruding of having optimized buying and having sold, increased economic efficiency.

Figure 17: two parts LED that forms LED lamp lighting circuit is the Combined Led Light Up silk section that version is identical, LED quantity is equal, at line voltage lower than stage of 50%, driver forms 2 road parallel forms by these two sections of LED filament combined segment, carry out first 3N//3N Precise control of 4N//4N again, make to be improved than the control effect of aforementioned several schemes: widened the angle of flow, improved power supply conversion efficiency, and circuit complexity increases seldom.

Figure 18: be the waveform schematic diagram of Figure 17 circuit working, can see the step that 2 tunnel Parallel Control stage 3N//3N occur to 4N//4N changing moment waveform.

Figure 19: ' the 6 unit LEDs filaments based on drive IC application of the present invention ' connection layout, each section of LED filament is integrated LED device or the thick-film packaged LED device that series LED quantity is equal, similar with Fig. 9 and Figure 11 circuit.

Figure 20: ' the unit 8 LED filament ' connection layout based on drive IC application of the present invention, each section of LED filament is integrated LED device or the thick-film packaged LED device that series LED quantity is equal, or slightly changes, identical with Fig. 7 circuit essence.

Figure 21: ' the 12 unit LEDs filaments based on drive IC application of the present invention ' connection layout, each section of LED filament is integrated LED device or the thick-film packaged LED device that series LED quantity is equal, identical with Fig. 7 circuit essence.

[embodiment]

Embodiment mono-, 30W outdoor lighting LED light source modular assembly

The present embodiment, as shown in Fig. 7 circuit, has omitted PCB layout engineering drawing and structural design drawing; This IC is 5 sections of LED filament power stabilize combination drive, contained for 4 tunnels parallel connection and 2 tunnel Parallel Control stages, on state threshold voltage is only DC50V, conducting angular width to 141.6 ° duty ratio nearly 80%, the illuminating effect of quite stable can be provided at the power utilization environment of line voltage shakiness, very practical; Its drive efficiency is higher than Fig. 5 Fig. 8 circuit arrangement, and internal drive circuits has only increased by 1 high-pressure electronic switch, and cost benefit is very high, and this circuit can be encapsulated in 8 hem facing sheet IC, takies not enough 1cm ²area, again almost without peripheral components; The peripheral LED circuit of light sources that it drives, is divided into 4 paragraphs that series LED quantity is equal, three sections of corresponding A, B and C, the 4th section is divided into two sections, corresponding D1 and D2, IC draws 9 lines to these LED filament sections, and this concentrates the LED light source module of arranging very convenient to LED light source consisting relatively.Concrete application is: 30W outdoor lighting LED light source modular assembly is provided, for combining various outdoor large lighting devices, comprises major trunk roads LED street lamp, Square Lamp etc., also can be used for the indoor occasions such as bulkhead lamp capable.

Embodiment bis-, LED bulb

The present embodiment as shown in Figure 9, has omitted PCB layout figure and structural design drawing; This drive circuit IC is packaged into SOP8 form, though only had for 2 tunnel Parallel Control stages, its low pressure stabilized illumination and still very good without stroboscopic illuminating effect; Because this IC volume is small, almost without peripheral components, with it, coordinate the bulb of manufacturing below 10W, cost is low, the life-span is long, easy to use, and light efficiency is stablized.

Embodiment tri-, LED straight lamp

The present embodiment as shown in figure 14, has omitted PCB layout figure and structural design drawing; This drive circuit IC is packaged into SOP8 form, though only had for 2 tunnel Parallel Control stages, its low pressure stabilized illumination and still very good without stroboscopic illuminating effect; Because this IC only takies 0.3cm ²pCB area, again without peripheral components, and only drives two sections of LED filaments, only have 4 circuit connections, and LED arranges not taboo: every LEDs brightness is moderate identical, so be applicable to drive very much narrow and long LED light source array, with it, coordinates the LED straight lamp of manufacturing below 15W very practical.

Embodiment tetra-, LED bulb

The present embodiment as shown in figure 17, has omitted PCB layout figure and structural design drawing; This drive circuit IC is packaged into SOP8 form, and its 2 tunnel Parallel Control substage becomes two little stages, has reduced threshold voltage, has widened the angle of flow, but its low pressure stabilized illumination and still very good without stroboscopic illuminating effect; IC only takies 0.3cm ²pCB area, again without peripheral components, and only drives two sections of LED filaments, though 6 circuit connections can drive four sections of LED filaments, so be applicable to drive very much relatively concentrated LED light source array, with it, coordinates the LED bulb of manufacturing below 10W very practical.

Claims (10)

1. a LED filament power stabilize combination drive, it is characterized in that: utility grid ac high-voltage directly drives LED lamp, the whole string of the list LED filament of its cascaded structure is divided into N section LED filament section, wherein have one section or be equivalent to one section of LED filament section and be only connected to drive circuit IC pin at least, and do not connect other LED filament section; The LED filament section that has at least a period of time fragment to be to provide 2 roads or multiple series series in the driving control cycle of drive circuit IC doubles or is increased to many times with parallel way work, total On current; Along with pulsating dc voltage just changes, control circuit carries out series and parallel by these LED filament sections at any time and rearranges combination, make the shinny LED total quantity of conducting in LED lamp, neither with pulsating dc voltage, rise and significantly increase, also with voltage drop, significantly do not reduce, remain that the shinny LED quantity of conducting is higher than 70% stable state of LED sum; Described LED filament hop count N is the integer between 2 and 9.

2. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the driver IC IC making based on this driver principles has 12 or 14 pins, wherein there are 8 pins for connecting and composing four sections of LED filament sections of LED lamp illuminating circuit, the series LED quantity of each LED filament section equates, and every section of LED filament section two ends are only connected with 2 pins of driver IC, between each LED filament section, be not mutually directly connected.

3. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the driver IC IC making based on this driver principles has 12 or 14 pins, wherein there are 9 pins for connecting and composing five sections of LED filament sections of LED lamp illuminating circuit, the series LED quantity of three sections of LED filament sections in these five sections of LED filament sections equates, and each section of LED filament section two ends are only connected with 2 pins of driver IC, between each LED filament section, be not mutually directly connected, be not connected with two sections of remaining LED filament sections yet; Remaining two sections of end to end being cascaded of LED filament section, the LED quantity sum of these two sections of LED filament sections equates with the quantity of LED in any one section of LED filament section in first three section, and LED quantitative proportion is roughly 1: 2 in these two sections of LED filament sections that are composed in series, its three contacts are connected with 3 pins of drive IC, and are not connected with any a section of first three section of LED filament section; In implementing circuit, the principle that first, second, third each section of LED filament section series LED quantity equals other two sections of series LED quantity sums is constant, and each section of actual series LED quantity details can suitably be adjusted.

4. a kind of LED filament power stabilize combination drive according to claim 1, is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, and LED lamp illuminating circuit is four sections of LED filament sections, and every section of series LED quantity equates; 8 pins of IC are divided into 4 pairs, and every pair connects respectively one section of LED filament section two ends, and each section of LED filament section is only connected with two IC pins and is not mutually directly connected; Drive circuit ground wire V _sS/ Gnd and pulsation high-voltage ground wire share IC belly metal fin, high voltage V _hinput and certain section of anodal IC mono-pin that shares of LED filament section.

5. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, the illuminating circuit that forms LED lamp has four sections of LED filament sections, each section of LED quantity differs: first paragraph LED filament section is in series by half the LED of LED sum that accounts for the complete LED filament of single string, its head and the tail two ends are connected to two pins of IC, are no longer connected with other LED filament section; The LED quantity of second segment LED filament section series connection is half of first paragraph, and the LED of the 3rd section of series connection is 2/3rds of second segment, remaining LED the 4th section of LED filament section in series; Second, third, the 4th section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and two middle contacts are connected to other 4 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other three sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

6. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the integrated circuit (IC) of making based on this driver principles has 8 pins, the illuminating circuit that forms LED lamp has four sections of LED filament sections, and LED total quantity is 14N, when AC220V power grid application, N=6 or 7; The LED quantity of each LED filament section series connection differs: first paragraph LED filament section is in series by half the 7N LEDs of LED sum 14N that accounts for the complete LED filament of single string, and its head and the tail two ends are connected to two pins of IC, are no longer connected with other LED filament section; Second segment LED filament section series connection 4N LEDs, the 3rd section of series connection 2N LEDs, remaining 1N LEDs is connected into the 4th section of LED filament section; Second, third, the 4th section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and two middle contacts are connected to other 4 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other three sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

7. a kind of LED filament power stabilize combination drive according to claim 1, is characterized in that: the integrated circuit (IC) of making based on this driver principles has 6 pins, or 5 pin IC of belly band metal fin; Forming LED lamp illuminating circuit has three sections of LED filament sections, and LED sum is 6N, when AC220V power grid application, and N=16; The LED quantity of each LED filament section series connection differs: first paragraph LED filament section is in series by accounting for half 3N LEDs of the complete LED filament LED sum of single string 6N, and its head and the tail two ends are connected to two pins of IC, are not connected with other LED filament section; Second segment LED filament section series connection 2N LEDs, remaining 1N LEDs is connected into the 3rd section of LED filament section; Second, third section of end to end LED filament section equating with first paragraph LED quantity that is connected into of LED filament section, its two ends and middle contact are connected to other 3 pins of IC; In implementing circuit, it is constant that first paragraph LED filament section series LED quantity equals the principle of other two sections of series LED quantity sums, and each section of actual series LED quantity details can suitably be adjusted.

8. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the integrated antenna package of making based on this driver principles becomes 4 pin IC of belly band metal fin, or 5,6,8 pin IC, drive 2 sections of series LED quantity that form LED lamp illuminating circuit to equate and discrete LED filament section, electrical network pulsating dc voltage positive pole and wherein one section of anodal shared IC pin of LED filament section, in 4 pin IC, circuit ground and pulsating dc voltage negative pole are connected to belly metal fin; In implementing circuit, the principle that two sections of LED filament sections do not connect mutually and series LED quantity is equal is constant, the actual series LED quantity of each LED filament section details capable of regulating.

9. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the integrated antenna package of making based on this driver principles is in the IC of 8 pins encapsulation, packing forms is SOP8, DIP-8, PSDIP-8, its 4 pins connect 2 sections of LED filament sections that drive formation LED lamp illuminating circuit, these two sections of LED filament section series LED quantity equate, but directly do not connect between two sections of LED filament sections; In implementing circuit, the principle that two sections of LED filament section series LED quantity is equal is constant, the actual series LED quantity of each LED filament section details capable of regulating; Other 3 pins of this drive IC, can provide power grade option, and access power fine setting device.

10. a kind of LED filament power stabilize combination drive according to claim 1, it is characterized in that: the drive IC of making based on this driver principles, driving the whole string LED filament of formation LED lamp lighting circuit is to be divided into N section LED filament identical by the hop count of connecting, that series LED quantitative proportion is identical piecemeal tandem compound section, between this N section LED filament tandem compound section, do not connect mutually, its two ends and intermediate contact are directly linked on drive circuit IC pin; In AC network, in the cycle, have the stage of this N section LED filament tandem compound section conducting work in parallel, also have the stage of its tandem compound conducting work, these two stages all can also be subdivided into some little stages to raise the efficiency, to improve control effect; N is the integer between 2 to 4.