The content of the invention
In view of this, it is an object of the invention to provide a kind of leadage circuit and leakage current control method and LED to controlCircuit processed, to solve the technical problem that the stability of controlled silicon conducting existing in the prior art is poor, efficiency is low and power consumption is big.
The technical solution of the present invention is to provide a kind of leadage circuit with lower structure, including：
Leakage current adjusts circuit, including the current source or/resistance that adjustment is managed and connected with the adjustment pipe；Exchange inputInput voltage is obtained through controllable silicon dimmer and rectifier bridge, and circuit is adjusted to load supplying, the leakage current through drive circuitBoth ends are connected with the high cold end of input voltage respectively；
Release control circuit, be connected with the control terminal of the adjustment pipe；In the preceding half cycle of half-sinusoid, electricity is inputted when describedForce down when threshold voltage, then adjust circuit generation leakage current by adjusting the control terminal leakage current of adjustment pipe, directlyInput current to the drive circuit is more than respective threshold electric current, then leakage current adjusts circuit and do not produce leakage current；The second half of half-sinusoid, when the input current of the drive circuit is less than respective threshold electric current, then by adjusting adjustment pipeControl terminal cause leakage current adjust circuit produce leakage current, until the input current of the drive circuit is down to Low thresholdWhen, then leakage current adjusts circuit and does not produce leakage current.
Preferably, the control circuit of releasing includes enable signal generation circuit and is connected to adjustment pipe control terminalDrive control circuit, the enable signal generation circuit produce table by detecting the input current of input voltage and drive circuitThe whether enabled signal of sign, the drive control circuit receive the characterization whether enabled signal, and control adjustment pipe accordinglyState.
Preferably, the enable signal generation circuit includes input voltage detection circuit, drive circuit input current is examinedSlowdown monitoring circuit and logic circuit, the input voltage detection circuit judge whether input voltage is less than threshold voltage, and result is defeatedGo out to the logic circuit, the input current of drive circuit input electric cur- rent measure electric circuit inspection to the drive circuit and reachDuring to the Low threshold, the enabled signal of the logic circuit output characterization to the drive control circuit.
Preferably, the input current of drive circuit input electric cur- rent measure electric circuit inspection to the drive circuit isRealize in the following way：Leakage current is sampled, obtains the sampled signal of characterization leakage current, the sampling of the leadage circuitWhen signal reaches corresponding reference value, judge that the drive circuit input current reaches the Low threshold.
Preferably, the drive control circuit receives the current sampling signal for characterizing total input current, and by itself and electricityFlow reference signal carries out Error processing, to obtain driving voltage, when leakage current adjusts circuit and enables, and the driving voltageAs adjustment management and control terminal voltage the leakage current for adjusting pipe is flowed through to adjust.
Preferably, the driving voltage can be used for the size of the input current of characterization drive circuit, by the drivingCompared with characterizing the reference voltage of threshold current, the input current that its comparative result then characterizes the drive circuit is voltageIt is no to reach threshold current.
Preferably, the drive control circuit includes error amplifier and first comparator, error amplificationThe first input end of device receives the current sampling signal of the total input current of characterization, its second input terminal receives the electric current ginsengSignal is examined, its output terminal outputting drive voltage, is connected, institute in the output terminal of error amplifier through switching with adjusting the control terminal of pipeThe control terminal for stating switch receives the whether enabled signal of characterization；Meanwhile the first input end of the first comparator receives the driveDynamic voltage, its second input terminal receive the reference voltage of the characterization threshold current, the output terminal output characterization of first comparatorWhether the input current of drive circuit reaches the signal of threshold current, and to obtain it is corresponding whether enabled signal.
Preferably, the drive circuit input electric cur- rent measure circuit includes add circuit and the second comparator, it is describedAdd circuit receive respectively characterize total input current current sampling signal and characterization leakage current current sampling signal, instituteTwo current sampling signal directions receiving on the contrary, therefore the signal of add circuit output characterization drive circuit input current,The first input end of second comparator receives the reference signal of characterization Low threshold, its second end receives the characterization drive circuitThe signal of input current, the output terminal of the second comparator are connected with the logic circuit.
Preferably, when the input voltage is less than the threshold voltage, after first time, then vent discharge is producedStream.
Another technical solution of the present invention is to provide a kind of leadage circuit with lower structure, including：
Leakage current adjusts circuit, including the current source or/resistance that adjustment is managed and connected with the adjustment pipe；Exchange inputInput voltage is obtained through controllable silicon dimmer and rectifier bridge, and circuit is adjusted to load supplying, the leakage current through on-off circuitBoth ends are connected with the high cold end of input voltage respectively；
Release control circuit, be connected with the control terminal of the adjustment pipe；In the preceding half cycle of half-sinusoid, electricity is inputted when describedForce down when threshold voltage, then adjust circuit generation leakage current by adjusting the control terminal leakage current of adjustment pipe, directlyInput current to the drive circuit is more than respective threshold electric current, then leakage current adjusts circuit and do not produce leakage current；The second half of half-sinusoid, when the input current of the drive circuit is less than respective threshold electric current, then controls the driving electricityRoad is not enabled or cuts off drive circuit circuit.
The another technical solution of the present invention is to provide a kind of leakage current control method of following steps, including：
Exchange input obtains input voltage to load supplying through controllable silicon dimmer and rectifier bridge, and leakage current is adjusted electricityThe both ends on road are connected with the high cold end of input voltage respectively, the leakage current adjust circuit include adjustment pipe and with it is describedAdjust the current source or/resistance of pipe series connection；
Control circuit of releasing is connected with the control terminal of the adjustment pipe；In the preceding half cycle of half-sinusoid, when the inputWhen voltage is less than threshold voltage, then circuit generation leakage current is adjusted by adjusting the control terminal leakage current of adjustment pipe,Until the input current of the drive circuit is more than respective threshold electric current, then leakage current adjusts circuit and does not produce leakage current；In the second half of half-sinusoid, when the input current of the drive circuit is less than respective threshold electric current, then adjusted by adjustingThe control terminal of pipe causes leakage current to adjust circuit and produce leakage current, until the input current of the drive circuit is down to low thresholdDuring value, then leakage current adjusts circuit and does not produce leakage current.
Preferably, in the preceding half cycle of half-sinusoid, first judge whether the input voltage is less than threshold voltage, if so,Then the leakage current adjusts circuit and enables, and produces leakage current；Judge whether the input current of the drive circuit is big againIn respective threshold electric current, if so, then the leakage current adjusting circuit does not enable；Judge whether into the later half of half-sinusoidWeek, if so, then determining whether the input current of the drive circuit is less than respective threshold electric current, if so, then described let outDischarge stream adjusts circuit and enables, if the input current of the drive circuit is further below Low threshold, the leakage current tuneEconomize on electricity road does not enable.
The another technical solution of the present invention is to provide a kind of leakage current control method of following steps, including：
Exchange input obtains input voltage to load supplying through controllable silicon dimmer and rectifier bridge, and leakage current is adjusted electricityThe both ends on road are connected with the high cold end of input voltage respectively, the leakage current adjust circuit include adjustment pipe and with it is describedAdjust the current source or/resistance of pipe series connection；
Control circuit of releasing is connected with the control terminal of the adjustment pipe；In the preceding half cycle of half-sinusoid, when the inputWhen voltage is less than threshold voltage, then circuit generation leakage current is adjusted by adjusting the control terminal leakage current of adjustment pipe,Until the input current of the drive circuit is more than respective threshold electric current, then leakage current adjusts circuit and does not produce leakage current；In the second half of half-sinusoid, when the input current of the drive circuit is less than respective threshold electric current, then the driving is controlledCircuit is not enabled or cuts off drive circuit circuit.
Another technical solution of the present invention is to provide a kind of LED control circuit with lower structure, and any of the above is a kind ofLeadage circuit and LED drive circuit, the LED drive circuit are on-off circuit or linear drive circuit.
Circuit structure using the present invention and method, compared with prior art, have the following advantages：The program of the present invention canApplied to switch drive scheme, the threshold voltage is zero-crossing values, when input voltage zero passage, produce leakage current so thatInput current is more than silicon-controlled maintenance electric current, according to the input of the wave characteristics of half cycle before and after sine wave and drive circuit electricityThe size of stream, control leakage current adjust whether circuit enables, and the present invention reduces vent discharge under the premise of dimming effect is ensuredStream, improves system effectiveness and system reliability, while is conducive to increase TRIAC maximum conduction angles, it is easier to meets maximum defeatedGo out the requirement of electric current.
Embodiment
The preferred embodiment of the present invention is described in detail below in conjunction with attached drawing, but the present invention is not restricted to theseEmbodiment.The present invention covers any replacement made in the spirit and scope of the present invention, modification, equivalent method and scheme.
Thoroughly understand to make the public have the present invention, be described in detail in present invention below preferred embodiment specificDetails, and description without these details can also understand the present invention completely for a person skilled in the art.
More specifically description is of the invention by way of example referring to the drawings in the following passage.It should be noted that attached drawing is adoptedNon-accurate ratio is used with more simplified form and, only to convenience, lucidly aid in illustrating the embodiment of the present inventionPurpose.
Refering to what is shown in Fig. 3, illustrating the circuit structure of the leadage circuit embodiment one of the present invention, driving electricity is applied to itExemplified by the LED control circuit of road driving, while it also can be suitably used for Linear Driving scheme.LED control circuit includes leadage circuitAnd LED drive circuit, the leadage circuit be used to solve the sudden strain of a muscle as caused by input current is too small under controllable silicon dimmerBright problem, and overcome the technological deficiency present in the prior art.Its input power inputs for exchange, and the exchange input is through controllableThe input voltage of the input voltage vrec, i.e. drive circuit of direct current are exported after silicon light modulator U02 and rectifier bridge U01.Exchange inputRectifier bridge U01 is connected to by controllable silicon dimmer U02, the positive output end of rectifier bridge is connected with the anode of diode D00, drivingCircuit anode is connected with the cathode of the diode D00.Since certain capacitive may be presented in LED drive circuit,Diode D00 is added between vrec and LED drive circuit；When the absolute value of exchange input reduces, LED drive circuit is due to toolThere is capacitive, its voltage can reduce relatively slow, and the sampling resistor for adding diode D00 and input voltage vrec detection circuits can willThe absolute value of vrec voltage follows exchange input, so as to ensure the accuracy to input voltage sampling.
The leadage circuit includes leakage current and adjusts circuit and control circuit of releasing, and the leakage current adjusts electricityRoad includes adjustment pipe M00 and the current source I 10 to connect with the adjustment pipe, can also use resistance and adjust the shape that pipe is connectedFormula.One end of current source I10 is connected to the positive output end of rectifier bridge, and the other end of adjustment pipe M00 is connected to the negative of rectifier bridge U01Output terminal.Release control circuit, be connected with the control terminal of the adjustment pipe.
In the preceding half cycle of half-sinusoid, when input voltage vrec is less than threshold voltage (may be configured as zero-crossing values), then through patrollingCollect circuit U 12 and circuit generation leakage current is adjusted by drive control circuit U18 control leakage currents, the leakage current isIblr, and leakage current is existed always, until the input current iin2 of drive circuit is more than respective threshold electric current, then releaseCurrent regulating circuit does not produce leakage current；In the second half of half-sinusoid, when the input current iin2 of the drive circuit is lowWhen respective threshold electric current, then circuit generation leakage current is adjusted by adjusting the control terminal leakage current of adjustment pipe M00,When the input current of the drive circuit is down to Low threshold (VREF6 characterizes high-low threshold value), then leakage current adjusts circuitDo not produce leakage current.
When input voltage vrec is less than threshold voltage, be delayed first time T1, then enabled leakage current adjust circuit withLeakage current, can reduce maximum conduction angle, so that the power consumption of releasing when reducing the big angle of flow.Threshold voltage in the present embodimentOrdinary circumstance refers to zero crossing, but according to the reality of circuit, then and zero point has certain deviation, for example, diode D00's drawsEnter, then zero crossing at this time is generally the pressure drop of diode D00 forward conductions.
The control circuit of releasing includes enable signal generation circuit and is connected to the drive control of adjustment pipe control terminalCircuit U 18, the enable signal generation circuit are produced by detecting the input current iin2 of input voltage vrec and drive circuitCharacterization whether enabled signal EN, the drive control circuit U18 receive the characterization whether enabled signal EN, and control accordinglyThe state of system adjustment pipe M00.I.e. when leakage current, which adjusts circuit, to be enabled, drive control circuit U18 control leakage currents are adjustedThe grid voltage of pipe M00 is adjusted in circuit, by the size for controlling leakage current iblr so that total input current iin3 is not less thanSetting value (the maintenance electric current of controllable silicon dimmer).Disconnect drive control circuit U18 and adjust circuit control terminal with leakage currentConnection may be such that leakage current adjusts circuit and do not enable, therefore, enabling and not enabled available adjustment pipe in the present embodimentWhether control terminal receives driving voltage to characterize, but is not limited to a kind of this mode.
The enable signal generation circuit includes several functional circuits, i.e., including input voltage detection circuit, drive circuitInput electric cur- rent measure circuit and logic circuit, in the present embodiment, the input voltage detection circuit judges input voltage vrecWhether it is less than threshold voltage (being characterized with VREF1), is compared by comparator U10, result is inputted to the logic circuit, whenInput voltage vrec is less than threshold voltage, then it is high level that comparator U10, which exports ZVD signals, and causes signal through logic circuitEN characterizations are enabled.In this attached drawing, it is input current iin2 detection circuits to be labelled with drive circuit input electric cur- rent measure circuit, canAccording to the input current iin2 of drive circuit, and compared with Low threshold (being characterized with VREF6), drive circuit input electricity is judgedWhether stream is less than threshold value；Judge whether drive circuit input current is higher than threshold value according to V8H in drive control circuit, it compares knotFruit is inputted to the logic circuit, by the whether enabled signal EN to the drive control circuit U18 of logic circuit output characterization.Sampling resistor and drive circuit series connection can be detected iin2 by drive circuit input electric cur- rent measure circuit, still, in order to reduceSystem power dissipation, in the present embodiment, to judge that drive circuit inputs indirectly by total input current iin3 and leakage current iblrElectric current iin2, resistance R60 sample total input current iin3, obtain sampled voltage RS3, resistance R50 sampling leakage current iblr, obtainTo sampled voltage RS2, RS3 is negative voltage, and RS2 is positive voltage.Therefore RS2 can be added with RS3 with add circuit U60, andIts absolute value is taken, when iin2 is close to 0, the output of add circuit U60 is also close to 0.The output terminal of add circuit U60 is connected to ratioCompared with the negative input end of device U61, the positive input terminal connection Low threshold reference signal VREF6 of the second comparator U61, works as input currentWhen iin2 is less than threshold value, then the output ZC of the second comparator U61 is height, then EN is low to control the leakage current to adjust circuitDo not enable.In the present embodiment, the Low threshold can be arranged to to level off to zero value, then, reference signal VREF6Level off to zero, when being less than Low threshold because of input current iin2, drive circuit input current is close to 0, so can be not required at this timeControllable silicon dimmer turns on, so being enabled without leadage circuit.
Refering to what is shown in Fig. 4, illustrate the concrete structure of drive control circuit in embodiment one.The drive control circuitU18 includes error amplifier U82 and the first input end of first comparator U83, the error amplifier U82 receive the tableThe current sampling signal RS3 of input current is levied, its second input terminal receives the current reference signal VREF81, its output terminal is defeatedGo out driving voltage V8, be connected in the output terminal of error amplifier U82 through switching K80 with adjusting the control terminal of pipe M00, the switchThe control terminal of K80 receive characterization whether enabled signal EN；Meanwhile described in the first input end reception of first comparator U83Driving voltage V8, its second input terminal receive the reference voltage VREF82 of the characterization threshold current, and first comparator U83's is defeatedThe signal of the input current iin2 sizes of outlet output characterization drive circuit, and to obtain it is corresponding whether enabled signalEN。
Because of driving voltages of the driving voltage V8 as adjustment pipe, its size determines the size of leakage current, therefore, can be withJudge the size of leakage current by detecting the driving voltage V8 in drive control circuit U18, when leakage current is 0, V8For 0；By directly detecting in leadage circuit, the voltage RS2 of leakage current can also be characterized to judge the size of leakage current.
The size of the upper voltage characterization input current iin3 of RS3, i.e. leakage current iblr add the input current of drive circuitIin2, when its enable signal EN is high, then amplifier U82 is by controlling its output terminal VG so that RS3 voltages are equal to reference voltageVREF81.The reference signal VREF82 of the output of amplifier U82 and characterization threshold current is compared by first comparator U83, is obtainedWhether it is higher than threshold current to voltage V8H, the input current iin2 that voltage V8H can characterize drive circuit.When iin2 is higher than thresholdWhen being worth electric current, then V8H is low；When iin2 is less than threshold current, then V8H is height.
Refering to what is shown in Fig. 5, illustrate the idiographic flow block diagram of embodiment one.In the preceding half cycle of half-sinusoid, institute is first judgedState whether input voltage vrec is less than threshold voltage, i.e., whether input voltage vrec detection circuits detection input voltage is less than settingValue, when it is less than setting value, then it exports ZVD as height, and otherwise ZVD is low.When ZVD is high, the output of logic circuit U12EN is height, enables drive control circuit U18, drive control circuit U18 control leadage circuit and enables, and produces leakage currentiblr.Judge whether the input current iin2 of the drive circuit is more than respective threshold electric current again, if so, then V8H=0, describedLeakage current adjusts circuit and does not enable, and EN is low.Judge whether the second half into half-sinusoid, if so, then determining whetherWhether the input current iin2 of the drive circuit is less than respective threshold electric current, if so, then V8H=1, then the leakage current tuneEconomize on electricity road enables, if the input current of the drive circuit further below Low threshold, i.e. leakage current iblr is higher than threshold value, drivesDynamic circuit input current is close to 0, so controllable silicon dimmer can be not required to turn at this time, then the leakage current adjusts circuitDo not enable.
Refering to what is shown in Fig. 6, illustrate the work wave of embodiment one.When controllable silicon dimmer turns off, input current iin is0, and VG is adjusted to ceiling voltage, the t31 moment in corresponding diagram 6, since input side has capacitive device, on the capacitive deviceCertain voltage can be remained, so leakage current iblr has current impulse, input current iin3 has current impulse., can at the t32 momentSilicon dimmer conduction is controlled, input voltage vin voltages are equal to AC-input voltage, when input current iin3 is less than setting value, then driveDynamic control circuit U18 adjusts the grid of pipe M00 by controlling so that leakage current iblr is not less than plus input current iin2 to be setDefinite value, i.e. iin3 are not less than setting value, which is slightly above controllable silicon dimmer as threshold current, the threshold currentMaintain electric current.When input current iin3 is low higher than threshold value, that is, V8H, i.e. the input current iin2 of drive circuit, which is more than or equal to, to be setDuring definite value, then the output EN of logic circuit is 0, that is, it is low to control the output VG of drive control circuit U18, leadage circuit is not madeEnergy.So as to reduce the power consumption of leadage circuit.It can judge the big of leakage current by detecting the V8 in drive control circuit U18It is small, when leakage current is 0, V8 0；Can also be by directly detecting in leadage circuit, the voltage RS2 for characterizing leakage current comesJudge the size of leakage current.In the later half cycle of half-sinusoid, in moment t33, when input current iin2 is less than setting value(judge or judged by RS2 by V8H), then the output EN of logic circuit is height, that is, controls drive control circuit U18'sK80 conductings are switched, enable leadage circuit.In moment t34, AC-input voltage is reduced to 0, input current 0, i.e. driving electricityThe input current iin2 on road is equal to iblr for 0, iin3, then the output EN of logic circuit is 0, and drive control circuit VG is 0,Leadage circuit is not enabled.
Refering to what is shown in Fig. 7, illustrate the particular circuit configurations of leadage circuit embodiment two of the present invention.Embodiment two is with implementingThe difference of example one is：In the second half of half-sinusoid, when the input current iin2 of drive circuit is less than threshold current,Leakage current adjusts circuit and does not enable, and the confession that logic circuit control drive circuit is not enabled or disconnection is to drive circuitElectricity, the present embodiment are the input terminal addition switch K10 in drive circuit, turn off switch K10.The embodiment is according to driveThe characteristic design of dynamic circuit, further reduce power consumption, improve system effectiveness.
Refering to what is shown in Fig. 8, illustrate the particular circuit configurations of leadage circuit embodiment three of the present invention.Embodiment three is with implementingExample two is similar, i.e. the second half in half-sinusoid, when the input current iin2 of drive circuit is less than threshold current, leakage currentCircuit is adjusted not enable, and logic circuit control drive circuit does not enable, and not enabled control drive circuit is by logic electricityThe whether enabled signal EN2 of another characterization of road direction drive circuit transmission, in these cases, EN2 is height, then drive circuit does not makeEnergy.
Refering to what is shown in Fig. 9, illustrate the FB(flow block) of leadage circuit embodiment two, three of the present invention.With embodiment one and his likeThe difference of journey (i.e. Fig. 5) is：In the preceding half cycle of half-sinusoid, when input voltage vrec is less than threshold voltage, first makeSignal EN2 is high or switch K10 conductings, so that drive circuit enables；In the second half of half-sinusoid, the drive circuitInput current iin2 is less than respective threshold electric current, then V8H=1, and at this time, enable signal EN2 is low or switch K10 shut-offs.
Refering to what is shown in Fig. 10, illustrate the work wave of leadage circuit embodiment two, three of the present invention.Its work wave and realityThe difference for applying the waveform of example one is：In embodiment one, at the t33 moment, when the input current iin2 of drive circuit is less thanDuring predetermined value, leadage circuit is enabled；And in embodiment two, three, at the t43 moment corresponding with one t33 of embodiment, work as drive circuitInput current iin2 when being less than predetermined value, do not enable leadage circuit, i.e., do not produce leakage current.
With reference to shown in figure 11, the circuit structure of leadage circuit example IV of the present invention is illustrated, the present embodiment is to implementThe improvement carried out in example one, the main distinction are drive circuit input electric cur- rent measure circuit.The drive circuit input electricityCurrent detection circuit detects that the input current of the drive circuit is realized in the following way：Leakage current is sampled, is obtainedThe sampled signal of leakage current is characterized, when the sampled signal of the leadage circuit reaches corresponding reference value, judges the driveDynamic circuit input current reaches the Low threshold.I.e. the present embodiment is compared by sampling leakage current indirectly with high thresholdCompared with it is achieved thereby that the comparison of drive circuit input current and Low threshold.The positive input terminal connection high threshold reference of comparator U61Signal VREF7, when leakage current iblr is higher than threshold value, then the output ZC of comparator U61 is height, then EN is low, described in controlLeakage current adjusts circuit and does not enable.In the present embodiment, the high threshold can be arranged to level off to maintain electric currentValue, then, reference signal VREF7 also levels off to reference voltage V REF81 in drive control circuit U18, because of leakage current iblr highWhen threshold value, drive circuit input current is close to 0, so controllable silicon dimmer can be not required to turn at this time, so need not let outElectric discharge road enables.
In addition, although embodiment is separately illustrated and is illustrated above, it is related to the common technology in part, in this areaThose of ordinary skill apparently, can be replaced and integrate between the embodiments, be related to one of embodiment and record is not knownContent, then refer to another embodiment on the books.It should be noted simultaneously that the error amplifier in the present invention can be withRealized using operational amplifier.
Embodiments described above, does not form the restriction to the technical solution protection domain.It is any in above-mentioned implementationModifications, equivalent substitutions and improvements made within the spirit and principle of mode etc., should be included in the protection model of the technical solutionWithin enclosing.