CN107529254A - Switching device and the LED drive system being applicable, driving method - Google Patents
Switching device and the LED drive system being applicable, driving method Download PDFInfo
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- CN107529254A CN107529254A CN201710922929.3A CN201710922929A CN107529254A CN 107529254 A CN107529254 A CN 107529254A CN 201710922929 A CN201710922929 A CN 201710922929A CN 107529254 A CN107529254 A CN 107529254A
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- 230000005347 demagnetization Effects 0.000 claims description 51
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/40—Details of LED load circuits
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The application provides a kind of switching device and the LED drive system being applicable, driving method, wherein, the switching device includes switch element and controller；Controller connecting valve unit, wherein the switch element is used to be connected between input source and resonance device, including：Detection unit is used to obtain the first electric signal for reflecting curent change in resonance device from the switch element and obtained for reflecting that input source provides the second electric signal of voltage change, first detection signal is exported when detecting the disconnection moment of the switch element set based on first electric signal, and the second detection signal is exported when detecting the change based on second electric signal and set the turn-on instant of the switch element；Control unit connects the detection unit, for controlling connected switching means conductive or disconnection based on the first detection signal received and the second detection signal.The application effectively increases the power output efficiency of drive system.
Description
Technical field
The application is related to field of LED drive, more particularly to a kind of switching device and be applicable LED drive system, driving
Method.
Background technology
LED (light emitting diode) due to operating voltage is very low, operating current very little, shock resistance and anti-seismic performance it is good,
The reliability high life is long, is easy to the multifrequency natures such as light modulation, in the multiple fields extensive use such as illumination, device, display, instruction.So
And LED component has almost harsh requirement to driving power, such as in order to ensure LED reflects corresponding spy in the application
Property, LED drive power need to have very in efficiency conversion, effective power, constant current accuracy, power source life, electromagnetic compatibility etc.
High requirement.
In order to provide the constant current-supplying with High Power Factor to LED load, LED drive power is used by resonance device
Vibration and the type of drive of output constant current electric current.Common LED drive power is according to the different operating mould of resonance device at present
Formula includes：Switching device based on BCM (critical continuous mode current working mode) or opening based on DCM (interrupted current mode of operation)
Close device etc..These switching devices by peripheral circuit connect resonance device, and be directed to by the detection to resonance device and
The constant current output for meeting High Power Factor index is effectively provided using resonance.
In fact, improving power factor can be realized by improving switching device, while technical staff is desirable with partly leading
Body integrated technology, which is tried one's best, reduces loss and the size of switching device.So the research for switching device is increasingly deep.Such as Fig. 1
It is shown, which depict a kind of circuit reduction schematic diagram of LED drive system, wherein between switching device 911 and resonance device 912
Electric signal in resonance device is gathered by sampling resistor RFBL and RFBH, and the valley control by detecting the electric signal is based on
The conducting and disconnection of the switching device 911 of raster data model.In above-mentioned a kind of switching device, due to the vibration week of resonance device
Phase is not necessarily associated with the supply variation cycle, causes the power output of whole drive system inefficient.
The content of the invention
The application provides a kind of switching device and the LED drive system being applicable, driving method, for solving drive system
The inefficient problem of power output.
To achieve the above object and other purposes, the application provides a kind of controller in first aspect, for connecting valve
Unit, wherein the switch element is used to be connected between input source and resonance device, including：Detection unit, for described in
Switch element obtains the first electric signal for reflecting curent change in resonance device and obtained for reflecting that input source is provided
Second electric signal of voltage change, it is defeated when detecting the disconnection moment of the switch element set based on first electric signal
Go out first detection signal, and when detecting the change based on second electric signal and set the conducting of the switch element
The second detection signal is exported during quarter；Control unit, connect the detection unit, for based on the first detection signal that is received and
Second detection signal controls connected switching means conductive or disconnection.
In some embodiments of the first aspect, the detection unit includes：Demagnetization starts detection module, connection
Between the sampling end of switch element and control unit, for when detecting the switching means conductive, based on being adopted described in
First electric signal of sample end collection proceeds by timing of magnetizing, and exports first detection signal at the end of timing of magnetizing.
In some embodiments of the first aspect, the demagnetization, which starts detection module, to be included：Reference voltage generates
Circuit, for determining voltage corresponding to the average output current of the resonance device by detecting first electric signal, and
One reference voltage is determined based on identified voltage；Signal generating circuit, it is connected with described control unit, institute is detected for working as
When stating switching means conductive, a ramp-electrical signal is generated；Comparison circuit, with the reference voltage generating circuit and signal generation electricity
Road is connected, voltage and the reference voltage for the ramp-electrical signal, and is reached in the voltage of the ramp-electrical signal
First detection signal is exported during to reference voltage.
In some embodiments of the first aspect, the reference voltage generating circuit includes mutual conductance integrator, tool
There are first input end, the second input and output end, the first input end connects the sampling end, and second input connects
A reference voltage source is connect, the output end is used to connect an outside low-pass filter unit.
In some embodiments of the first aspect, the signal generating circuit includes ramp signal generator, tool
There are control terminal and output end, the control terminal connects described control unit, and the output end connects the comparison circuit.
In some embodiments of the first aspect, the detection unit includes：Demagnetization detection of end module, with connecting
Be connected between drive end and the control unit of the switch element, for compare from the drive end collection the second electric signal with
Default valley point voltage threshold value, and the detection of output second letter when the voltage of second electric signal reaches the valley point voltage threshold value
Number.
In some embodiments of the first aspect, the valley point voltage threshold value is based on being posted in the switch element
The set threshold voltage of raw electric capacity release.
In some embodiments of the first aspect, described control unit includes：Control module, for based on being connect
The first detection signal output of receipts makes the switch controlling signal of the switching means conductive and based on the second detection received
Signal output makes the switch controlling signal that the switch element disconnects；Drive module, it is connected with the control module, for by institute
The switch controlling signal of reception is converted into corresponding switching drive signal to drive connected switch element.
In some embodiments of the first aspect, the controller also includes：Delay cell, detected for working as
The switch element maintains off-state when disconnecting in a delay duration.
In some embodiments of the first aspect, the detection unit obtains the from the source electrode of the switch element
One electric signal and grid the second electric signal of acquisition from the switch element.
The application provides a kind of switching device in second aspect, including：Switch element, for being connected to input source and resonance
Between device；And as above any described controller, it is connected with the switch element, for flowing through the switch by detection
The first electric signal and the second electric signal of unit carry out the control that is turned on or off to switch element.
In some embodiments of the second aspect, the switch element includes the power tube based on raster data model；
The controller obtains the first electric signal from the source electrode of the power tube, and obtains the second telecommunications from the grid of the power tube
Number.
The application provides a kind of LED drive system in the third aspect, including：DC-AC conversion device, for by alternating current
It is converted into direct current and exports；Resonance device, for providing constant current-supplying to LED load based on controlled vibration；As described above
Switching device, it is connected on the path between the DC-AC conversion device and resonance device, for based on acquired first
Electric signal and the second electric signal control the path to be turned on or off；Wherein, first electric signal is used to reflect resonance device
Interior curent change, second electric signal are used to reflect that input source provides voltage change.
In some embodiments of the third aspect, in addition in low-pass filter unit, with the switching device
Detection unit is connected.
The application provides a kind of method of controlling switch in fourth aspect, including：Obtain the first telecommunications for flowing through switch element
Number and the second electric signal；Wherein buckling；The disconnection moment of switch element is set based on first electric signal, and reaching
State and disconnect the switch element when disconnecting the moment；And the change based on second electric signal sets leading for the switch element
The logical moment, and the switch element is turned on when reaching the turn-on instant.
In some embodiments of the fourth aspect, it is described based on the first electric signal set switch element disconnection when
The mode at quarter includes：When starting the ramp voltage of timing one when detecting the switching means conductive and reaching a reference voltage
The switch element is controlled to disconnect at the time of growing, and the ramp voltage is reached into the reference voltage；Wherein, it is described with reference to electricity
Press as first electric signal obtains after testing voltage.
In some embodiments of the fourth aspect, the change based on the second electric signal sets the switch single
The mode of the turn-on instant of member includes：Compare second electric signal and default valley point voltage threshold value, and work as second telecommunications
Number voltage be defined as the turn-on instant of the switch element when reaching the valley point voltage threshold value.
In some embodiments of the fourth aspect, the valley point voltage threshold value is based on being posted in the switch element
The set threshold voltage of raw electric capacity release.
In some embodiments of the fourth aspect, methods described, which also includes working as, detects that the switch element disconnects
The step of off-state of the switch element is maintained in Shi Yi delay durations.
The application provides a kind of LED driving methods at the 5th aspect, including：Utilize method of controlling switch institute as described above
The conducting and disconnection of each step controlling switch device provided；And the conducting based on the switching device and disconnection control resonance
The oscillatory process of device, to drive LED load to work.
The application provides a kind of LED control chips at the 6th aspect, including：As above any described controller, for leading to
Cross detection flow through connected switch element the first electric signal and the second electric signal the switch element is carried out to lead on-off
Open control.
In some embodiments of the described 6th aspect, LED control chips also include the switch element.
Switching device provided herein and the LED drive system being applicable, driving method, from the sampling of switch element
End collection is used for the first electric signal for reflecting curent change in resonance device, and is gathered from the drive end of switch element for anti-
The second electric signal that input source provides voltage change is reflected, then controls resonance to fill by detecting the first electric signal and the second electric signal
The oscillatory process put, the waveform change of input source can be maximally utilized, realizes to provide high power load that there is High Power Factor
Drive circuit.
Brief description of the drawings
Fig. 1 is the circuit reduction schematic diagram of LED drive system in one embodiment in correlation technique.
Fig. 2 is the simplification electrical block diagram of switch element in one embodiment in the application switching device.
Fig. 3 is the structural representation of controller in one embodiment in the application switching device.
Fig. 4 is that the simplification circuit structure of demagnetization starting detection module in one embodiment shows in the application switching device
It is intended to.
Fig. 5 is the oscillogram that RAMP, COMP and Off_pulse are respectively held in Fig. 4.
Fig. 6 is the ripple that switching device respectively holds electric signal under the Vin signal intensities that input source provides in the application in circuit
Shape figure.
Fig. 7 is that the simplification circuit structure of demagnetization detection of end module in one embodiment shows in the application switching device
It is intended to.
Fig. 8 is structural representation of the application switching device in another embodiment.
Fig. 9 is the structural representation of the application switching device in another embodiment.
Figure 10 is each end oscillogram for including delay control signal in Fig. 9 structures.
Figure 11 is the chip package schematic diagram of the application LED control chips in one embodiment.
Figure 12 is chip package schematic diagram of the application LED control chips in another embodiment.
Figure 13 is the simplification circuit diagram of the application LED information display system in one embodiment.
Figure 14 is the flow chart of the application method of controlling switch in one embodiment.
It should be noted that in Fig. 6 and 10 Vin for input source institute output voltage signal envelope waveform figure.
Embodiment
Illustrate presently filed embodiment below by way of specific instantiation, those skilled in the art can be by this specification
Disclosed content understands other advantages and effect of the application easily.The application can also pass through specific realities different in addition
The mode of applying is embodied or practiced, the various details in this specification can also be based on different viewpoints with application, without departing from
Various modifications or alterations are carried out under spirit herein.
It should be noted that structure, ratio, size depicted in this specification institute accompanying drawings etc., only coordinating
Content disclosed in bright book, so that those skilled in the art understands and reads, it is not limited to the enforceable limit of the application
Fixed condition, therefore do not have technical essential meaning, the modification of any structure, the change of proportionate relationship or the adjustment of size, not
Influence under the effect of the application can be generated and the purpose that can reach, all should still fall and be obtained in techniques disclosed in this application content
In the range of covering.It is meanwhile cited such as " on ", " under ", "left", "right", " centre " and " one " etc. in this specification
Term, understanding for narration is merely convenient to, and is not used to limit the enforceable scope of the application, the change of its relativeness or tune
It is whole, in the case where changing technology contents without essence, when being also considered as the enforceable category of the application.
Although the oscillatory process of resonance device can be adjusted using Fig. 1 controller, due to its not necessarily with input
The current fluctuation cycle is related, and the constant current voltage stability for causing resonance device to be exported is poor.Therefore, the application provides a kind of switch
Device, method of controlling switch and applicable LED drivings.
It should be noted that switching device technical scheme provided herein is applied not only in LED drive system, may be used also
To include the circuit system of switching device applied to other, it is medium to be such as used for instrument and meter, Medical Devices, air cleaning facility.
Wherein, the switching device can be integrated into a kind of chip or by electron device package on the carrier of such as pcb board.
Switching device described herein can control its oscillatory process by power supply of the control to resonance device, wherein,
Controller and switch element are included in switching device.The switch element need to access the supply line of resonance device with controlled conducting
Or disconnect the circuit.Controller is then used for the break-make of controlling switch unit.
Wherein, the switch element includes controlled switching devices.The quantity of the controlled switching devices can be one or
It is multiple.The controlled switching devices can be a power tube based on raster data model, or be made up of the cascade of multiple power tubes.
For example, referring to Fig. 2, it is shown as a kind of simplified electrical block diagram of switch element.Power tube Q1 is raster data model, its
Grid connects the output end of controller 11, and source electrode is used to connect resonance device 3, drained for connecting input source 2.Wherein, it is described
Input source 2 includes civil power and DC-AC conversion device.
In order to more effectively utilize the power supply of input source with driving load, referring to Fig. 3, it is shown as the control of the application offer
The structural framing schematic diagram of device processed in one embodiment.The controller includes detection unit 111 and control unit 112.
The detection unit 111 is used to obtain for reflecting curent change in resonance device 3 from the switch element 12
First electric signal and obtain for reflecting that input source 2 provides the second electric signal of curent change, described the is based on when detecting
One electric signal and first detection signal is exported during the disconnection moment of the switch element 12 that sets, and when detecting based on described the
The change of two electric signals and export the second detection signal when the turn-on instant of the switch element 12 is set.
Here, the detection unit 111 can by gather respectively switch element 12 and resonance device 3, switch element 12 with
The connecting node of input source 2 obtains first electric signal and the second electric signal.In some embodiments, the detection unit
The drive end of power tube in the sampling end and switch element 12 of 111 connecting valve units 12, to obtain the first electric signal respectively
With the second electric signal.For example, as shown in Fig. 2 power tube Q1 source electrode is to obtain first in the connecting valve unit 12 of controller 11
Electric signal, power tube Q1 grid is to obtain the second electric signal in the connecting valve unit 12 of controller 11.
Wherein, because first electric signal picks up from the sampling end being connected with resonance device of switch element, so first
Electric signal reflects that curtage changes in resonance device.Institute's controller can be broken based on the first electric signal controlling switch unit
Open.Wherein, it is connected between the controller and resonance device by sample circuit, the sample circuit includes sampling resistor.
In some embodiments, the controller is built-in with one end connection sampling end of sampling resistor and sampling resistor, or resonance device
In be built-in with the sampling end of sampling resistor and controller and connect the sampling resistor, then or controller sampling end pass through it is external
Sampling resistor connects resonance device.
Further, since switch element accesses input source, so can also be obtained from switch element for reflecting input source institute
Second electric signal of the voltage change of offer.By taking the switch element for including power tube as an example, due to power tube drain-gate pole it
Between there is parasitic capacitance, therefore, the voltage change of input source is reflected on the grid for being used as drive end by parasitic capacitance.So
The second electric signal on collection grid can also reflect voltage or curent change that input source is provided.
The detection unit can be separately provided the testing conditions for detection switch disconnection and turn-on instant, corresponding when meeting
Switching means conductive or disconnection are controlled during condition.The detection unit is also based on the current conducting state of switch element or disconnected
Open state only detects to one of electric signal.Such as switch element period in the conduction state, the detection unit is only
The first electric signal is detected in order to export first detection signal.Such as during switch element is off, the detection is single
Member only detects the second electric signal in order to export the second detection signal.
In some embodiments, the detection unit both individually detected acquired each electric signal also cooperate with each other with
It is easy to exactly be controlled switch element.
Wherein, turned on for controlling switch unit, the detection unit includes demagnetization and starts detection module, and it is single to be connected to switch
Between the sampling end and control unit of member, for when detecting the switching means conductive, based on being gathered from the sampling end
The first electric signal proceed by timing of magnetizing, and export first detection signal at the end of timing of magnetizing.
Referring to Fig. 4, it is shown as the simplification circuit diagram of the demagnetization starting detection module in one embodiment,
The demagnetization starting detection module includes：Reference voltage generating circuit 412.
The reference voltage generating circuit 412 is connected with the sampling end CS, for determining a reference voltage by detecting.
Wherein, the reference voltage generating circuit 412 includes mutual conductance integrator.The mutual conductance integrator is by by first electric signal
Error between a reference voltage threshold is amplified and Integral Processing obtains the reference voltage.
For example, the mutual conductance integrator in the reference voltage generating circuit 412, has first input end, the second input
And output end, the first input end connect the sampling end CS, second input connects a reference voltage source, institute
State output end COMP and export the reference voltage.Wherein, because first electric signal is in substantially linear change, the ginseng exported
It is basicly stable to examine voltage.The output end is additionally operable to connect an outside low-pass filter unit so that the reference voltage exported
Vcomp is relatively stable.
For example, as shown in figure 4, mutual conductance integrator Gm negative input (i.e. first input end) connection power tube Q2 source
Pole (i.e. sampling end CS), Gm positive input (i.e. the second input) are connected with receiving voltage all the time with a reference voltage source
VREF, output end COMP export the reference voltage Vcomp.Wherein described reference voltage source can be integrated in the switching device
It is connected together or by chip pin.
As shown in figure 4, the demagnetization starting detection module also includes signal generating circuit 411 and comparison circuit 415.
Wherein, the signal generating circuit 411 is connected with described control unit 413, detects that the switch is single for working as
When member 42 turns on, a ramp-electrical signal is generated.Here, the control terminal of the signal generating circuit 411 is attached to the control
Between unit 412 and switch element 42, the drive end (GATE ends) of power tube is such as connected to, turns on switch element 42 to receive
Control signal.For example, power tube A1 (being unillustrated), power tube A1 drive end are included in the signal generating circuit 411
Power tube Q1 drive end is connected, when power tube A1 is receiving the control signal of conducting, controls the signal generating circuit
Ramp signal generator generation ramp signal in 411.Wherein described ramp signal generator can be the circuit for including electric capacity,
Using electric capacity charging required for duration since switch element 42 turn on when timing, the capacitance voltage linear rise during charging
And capacitance voltage is exported to comparison circuit.The output end of the ramp signal generator exports RAMP signals to comparison circuit.
The comparison circuit 415 is connected with the reference voltage generating circuit 412 and signal generating circuit 411, for than
The voltage of the ramp-electrical signal and the reference voltage, and it is defeated when the voltage of the ramp-electrical signal reaches reference voltage
Go out first detection signal.
By taking Fig. 4 as an example, and referring to Fig. 5, it is shown as RAMP, COMP and Off_pulse (output letter of comparison circuit
Number) oscillogram respectively held.Ramp signal (RAMP signals) in signal generating circuit is transported to the positive input of comparison circuit
End, while Vcomp or the branch pressure voltage based on Vcomp are transported to the negative input of comparison circuit, comparison circuit is in RAMP
When signal voltage is less than Vcomp voltages (or Vcomp partial pressure), low level is exported, when RAMP signal voltages reach even above
During Vcomp voltages (or Vcomp partial pressure), high level is exported.Wherein, in Fig. 4 examples, the Off_ of the comparison circuit 415
The high level that pulse ends are exported is first detection signal, and it illustrates that Vramp voltages have reached Vcomp voltages (or Vcomp
Partial pressure).The control signal that described control unit 413 disconnects switch element based on the first detection signal output received.
The signal generating circuit also includes leadage circuit (being unillustrated).The control terminal of the leadage circuit can be with slope
The output end of signal generator shares.For example, leadage circuit includes the controlled switch (such as power tube A2) of ground connection and believed with slope
Electric capacity in number generator is in parallel, wherein power tube A2 and the reverse break-makes of power tube A1.Described control unit is based on being received
The control signal that first detection signal output disconnects switch element is also outputted to the control terminal of the signal generating circuit.Such as work(
Rate pipe A2 grid.When receiving the control signal of disconnection, power tube A2 is turned on and electricity in ramp signal generator of releasing
Hold charged lotus so that Vramp voltages that ramp signal generator is exported reduce, when Vramp be less than Vcomp voltages (or
Vcomp partial pressure), the Off_pulse signal voltages that the comparison circuit is exported switch to low level, control unit from high level
Due to not receiving the second detection signal, so still controlling switch unit remains off.
Turned on for controlling switch unit, the detection unit includes：Demagnetization detection of end module, with being connected to the switch
Between the drive end and control unit of unit, for comparing the second electric signal and default valley point voltage from drive end collection
Threshold value, and export the second detection signal when the voltage of second electric signal reaches the valley point voltage threshold value.Wherein, valley
Voltage threshold can be slightly higher than or slightly below ground voltage.For the switch element comprising semiconductor devices, such as include work(
The switch element of rate pipe, when voltage change in switch element, parasitic capacitance charge or discharge therewith.The demagnetization detection of end
Module can determine leading for switch element by detecting in the second electric signal because of test spike caused by the electric discharge of parasitic capacitance
The logical moment.Corresponding, the valley point voltage threshold value is based on the set threshold value electricity of parasitic capacitance release in the switch element
Pressure.
Referring to Fig. 6, which show switch element as input source voltage is put from the of short duration period of high step-down, parasitic capacitance
Electricity and in the second electric signal GATE caused test spike oscillogram.The demagnetization detection of end module is received by comparing
The second electric signal whether reach valley point voltage threshold value, it is on the contrary then not export if so, then export the second detection signal.For example,
Referring to Fig. 7, it is shown as the simplified electrical circuit diagram of demagnetization detection of end module in switching device.The demagnetization detection of end module
Comprising comparator 512, the negative input of comparator 512 connection power tube Q1 GATE ends to receive second electric signal,
Its positive input connects a reference voltage source to maintain valley point voltage threshold value zcd_ref.Referring to Fig. 6 and 7, in switch element 52
During conducting, power tube Q1 grid voltage is height, then the voltage of the second electric signal is consistently higher than valley point voltage threshold value zcd_
Ref, comparator export low level all the time.When the Vin voltages that input source 2 provides are by high step-down, between power tube grid leak pole
Parasitic capacitance discharge so that grid voltage is being reduced to low level initial instantaneous period continuation test with Vin, with described in generation
Test spike, now, the voltage that the comparator 512 compares the second electric signal are less than or equal to valley point voltage threshold value zcd_ref, and
Output ZCD is second detection signal of pulse signal (or being high level).Control unit 513 controls according to the second detection signal
Switch element 52 turns on.
Described control unit is used to drive to described second based on the first detection signal received and the second detection signal
End output is used for the control signal for driving the switch element.
When control unit receives the first detection signal for representing demagnetization start time, to the to be connected with switch element
The control signal that the output of two drive ends disconnects, and when control unit receives the second detection signal of expression demagnetization finish time
When, the control signal turned on is exported to the switch element.Wherein, turn on and disconnect control signal can be pulse signal or
Enable signal.For example, with reference to shown in Fig. 2 and 3, the switch element 12 includes power tube Q1, and the control signal is enabled letter
Number, i.e., lasting level signal, and inputted from the drive end (Gate ends) of the power tube Q1.When control signal is low level
When, pressure difference is unsatisfactory for conducting voltage between power tube Q1 grid source, and power tube Q1 hourglass source electrode disconnects, then the switch element 12
Unpowered exports.When control signal is high level, power tube Q1 hourglass source electrode conducting, the then electric current that input source 2 is provided leads to
Cross the switch element and be delivered to resonance device 3.
Here, described control unit can be made up of the circuit comprising logical device, wherein, the logical device is included but not
It is limited to：Analog logic devices and digital logic device.Wherein, the analog logic devices are used for the device for handling analog electrical signal
Part, it includes but is not limited to：Comparator and door, OR gate etc.；The digital logic device is used to handle represents number by pulse signal
The device of word signal, it includes but is not limited to：Trigger, gate circuit, latch, selector etc..Described control unit passes through two
Individual port receives first detection signal and the second detection signal respectively, and received signal is patrolled using logic allocation list
Collect processing, then the control signal being turned on or off based on result output.
In some embodiments, described control unit includes control module and drive module.
The control module connecting detection unit, for making the switch single based on the first detection signal output received
The switch controlling signal that member disconnects, and the switch for making the switching means conductive is exported based on the second detection signal received
Control signal.
Wherein, Fig. 8 is referred to, it is shown as structural representation of the switching device in another embodiment.The control
Molding block 613 includes two inputs, one of input connection demagnetization starting detection module 611, for receiving the first inspection
Survey signal；Another input connection demagnetization detection of end module 612, for receiving the second detection signal.Control module 613 is
The logic circuit that waveform based on the first detection signal and the second detection signal, signal are combined and configured.For example, such as Fig. 8,
Control module 613 includes trigger, and the reset terminal (R ends) of trigger can connect demagnetization directly or by the peripheral circuit of trigger
Detection module 611 and demagnetization detection of end module 612 are originated, to receive first detection signal；The set end (S ends) of trigger
Can be directly or by the peripheral circuit connecting detection unit of trigger, to receive the second detection signal.The first detection letter
Number and the second detection signal be exemplified as pulse signal.When it is low level signal that R terminations, which receive pulse signal and S ends, based on tactile
Send out the logical combination inside device, the switch controlling signal that trigger output disconnects；It is low when S terminations receive pulse signal and R ends
During level signal, based on the logical combination inside trigger, the switch controlling signal of trigger output conducting.For including power
For the switch element 62 of pipe, the switch controlling signal need to be exported to switch element 62 via the drive module 614.
The drive module 614 connects the control module 613, as shown in figure 8, it is used to control on the switch received
Signal is converted into corresponding switching drive signal to drive connected switch element 62.Here, the drive module 614 can be used
Switch controlling signal is amplified, and output possesses the electric current of certain driving force with the power tube in driving switch unit 62.
Power tube Q1 grid in the output end connecting valve unit 62 of the drive module 614 so that power tube Q1 is defeated after being switched on
Enter source and provide energy to resonance device.
In some embodiments, it is also easy to produce in during due to input source at a flash after being changed into high level from low level
Voltage pulsation, this causes corresponding second electric signal also to fluctuate output voltage, the electricity of parasitic capacitance in the voltage superposition of fluctuation
Bucklingization may cause detection of end module the second detection signal of generation by mistake of demagnetizing.To prevent the false touch of demagnetization detection of end module
Hair, the controller also include：Delay unit.
The delay unit is used to maintain off-state in a delay duration when detecting that the switch element disconnects.
The first detection signal therefore, delay unit can be connected or receive with the output end of detection module, to determine
The switch element disconnects, and when detecting that switch element disconnects, starts with the timing that is delayed, during the timing that is delayed, control
Unit not exports conductivity control signal all the time, and after the timing that is delayed terminates, control unit is based on the second detection letter received
Number conducting switch element.Wherein, the delay unit is delayed to grow and provided less than controller disconnection switch element to input source
Voltage from the high duration reduced.
In some embodiments, the disconnection control signal that the delay cell can be to switch element is effective, and it is disconnected to latch this
Open the delay duration of control signal one and export corresponding delay control signal to the detection unit.Accordingly, the demagnetization knot
Beam detection module the delay control signal duration no matter the voltage of the second electric signal whether to be down to valley point voltage threshold value equal
The second detection signal is not exported, until the delay control signal disappears.
In other embodiment, referring to Fig. 9, it is shown as the structural representation of the switching device comprising delay unit
Figure.The delay cell 714 is attached between control module 713 and drive module 715, and exported with control module 713
It is effective to disconnect control signal, the delay duration of signal one, the delays time to control letter of the latch are latched when receiving and disconnecting control signal
Number output to drive module, in the drive module 715 comprising logic circuit to the delay control signal duration without
The conducting of driving switch unit is refused by whether control module exports conductivity control signal, until the delay control signal disappears
Lose.
By taking Fig. 9 as an example, the internal circuit of switching device provided herein include CS sampling ends, COMP ends, ZCD ends,
OFF_PULSE ends and GATE ends, wherein, demagnetization starting detection module 711 and demagnetization detection of end module 712 are adopted with CS respectively
Sample end connects to receive the first electric signal and the second electric signal with GATE ends, and defeated by OFF_PULSE ends and ZCD ends respectively
Go out first detection signal and the second detection signal；Control module 713 receives the first detection signal and the second detection letter respectively
Number and output switch control signal；Drive module 715 is connected with the control module 713 for amplifying switch controlling signal to drive
Dynamic late-class circuit.It is connected with the controller and is included by the citing of switch element 72 of controller control and is based on grid
The on-off circuit of (GATE ends) driving.
By taking Fig. 9 as an example, and Figure 10 is referred to, wherein, Figure 10 is shown as each comprising delay control signal Strong_pd waveforms
Hold waveform diagram.The course of work of switching device now is described by taking T1 to T2 periods as an example.When controller turns on switch list
During member 72 (corresponding T1 moment), CS ends are magnetized by resonance device 3 influences the generation elevated electric signal of voltage, the demagnetization in controller
The first electric signal CS that starting detection module 711 gathers CS ends is inputted to reference voltage generating circuit, wherein reference voltage generation
Mutual conductance integrator in circuit, the first electric signal CS and voltage Vref error voltage is amplified and integrated by mutual conductance integrator
It is big after reason, export Vcomp voltages from COMP ends；At the same time, the signal generating circuit in demagnetization starting detection module 711 is being controlled
Start to produce a ramp signal during device conducting switch element processed, the voltage Vramp and voltage Vcomp of the ramp signal are exported respectively
To the positive input and negative input of comparison circuit, when Vramp voltages reach Vcomp voltages, the output of comparison circuit
Hold (OFF_PULSE ends) output high level (i.e. first detection signal).Due to turning on switch element, detection of end module of demagnetizing
712 the second electric signal GATE received voltage is consistently higher than valley point voltage threshold value Vzcd_ref, so demagnetization detection of end
The output end of module 712 (ZCD ends) exports low level all the time during switch element 72 turns on, the control module in control unit
713 switches disconnected when reset terminal (such as R ends) receives high level and set end receives low level from output end (such as Q ends) output
Control signal (GATE_ON signals), drive module 715 in control unit export the GATE_ON signals to opening from high to low
Close the grid of the power tube Q1 in unit 72 so that power tube Q2 grid (GATE ends) voltage reduces, so as to cause power tube
Q1 disconnects.First electric signal CS produces the ripple of voltage reduction with the release process (process of demagnetizing) of resonance device electric energy accordingly
Shape.
In the initial instantaneous period of demagnetization, to prevent input source Vin from producing shake, delay unit 714 between high period
Conducting power pipe Q1 is refused based on control signal positive drive modular is disconnected, until delay timing terminates.
During demagnetization, on the one hand, the disconnection that power tube Q2 grids are received when demagnetization starting detection module 711 controls letter
Number when, wherein signal generating circuit reset ramp signal cause the Vramp voltages at RAMP ends to be less than Vcomp voltages, OFF_PULSE
Hold to the reset terminal of control unit and export low level.On the other hand, influenceed by power tube Q1 grid leaks pole parasitic capacitance discharge, second
A transient delays of the electric signal GATE after the disconnection of switch element 72 produces the voltage change of test, the module inspection of demagnetization detection of end
Survey the second electric signal GATE and be less than valley point voltage threshold value Vzcd_ref, so as to export high level (i.e. the second detection signal).Control
Control module 713 in unit is when reset terminal (such as R ends) receives low level and set end receives high level from output end (such as Q
End) output conducting switch controlling signal (GATE_ON signals are from low to high), drive module in control unit is by the GATE_
ON signals are amplified to the grid (GATE ends) of the power tube Q2 in actuable switch unit 72 and by power tube Q2 conducting powers
Pipe Q1, input source 2 is so turned on to the supply path between resonance device 3, the first electric signal CS is accordingly with the electric energy of resonance device 3
Storing process (i.e. magnetization process) and produce the elevated waveform of voltage.The controller repeats to magnetize and process of demagnetizing, so as to
In resonance device 3 constant current-supplying is provided to load.
So that the controller is configured in LED drive system as an example, the application can provide one kind and include the controller
LED control chips.The LED control chips include the pin being connected with external circuit.Wherein, the controller can be independent
Encapsulation is encapsulated in a LED control chips and the external switch element with other circuits (such as reference voltage source).It please join
Figure 11 is read, it is shown as the encapsulation schematic diagram of LED control chips in one embodiment.The LED control chips include
COMP pins, CS pins, GATE pins, VCC pin and GND pin.Wherein, COMP pins are used to connect low-pass filter unit,
Facilitate ensuring that the Vcomp in controller is basicly stable.CS pins are connected with resonance device and switch element joining place to obtain
One electric signal.Power tube Q1 grid in GATE pin connecting valve units, for control to be turned on and disconnected to switch element
System；GATE pins also provide the second electric signal.VCC pin connects externally fed power supply or external capacitive, for controlling core for LED
Piece is powered and reference voltage source provides burning voltage.GND pin is used to be grounded.
In some embodiments, the power tube Q1 in switch element can be incorporated in LED control chips.Refer to figure
12, it is shown as the encapsulation schematic diagram of LED control chips in yet another embodiment.The LED control chips draw comprising COMP
Pin, CS pins, VCC pin, DRAIN pins and GND pin.Wherein, COMP pins are used to connect low-pass filter unit, are easy to really
The Vcomp protected in controller is basicly stable.CS pins are connected with resonance device and switch element joining place to obtain the first telecommunications
Number.VCC pin connects externally fed power supply or external capacitive, for being provided surely for the power supply of LED control chips and reference voltage source
Determine voltage；VCC pin can be with the grid of power tube Q1 in connecting valve unit to provide burning voltage.GND pin is used to connect
Ground.DRAIN pins are used to connect input source.Second electric signal is gathered by INTRA-CHIP POWER pipe Q1 GATE ends.
A kind of LED drive system designed using above-mentioned switching device that the application also provides.Figure 13 is refer to, it is aobvious
It is shown as the structural representation of the LED drive system in one embodiment.The LED drive system includes：AC-DC conversion
Device 81, switching device 82 and resonance device 83.
The DC-AC conversion device 81 is used to convert alternating current to direct current.Wherein, the DC-AC conversion device 81
It can access civil power.The LED drive system can be according to the ginseng of each device in the voltage and work frequency selection control of input source
Number.The DC-AC conversion device 81 includes：The rectifier circuit and low-pass filter circuit to connect with input source.For example, as schemed
Shown in 13, diode D2, D3, D4 and D5 form rectifier circuit, and bag is provided between the output end and ground terminal of rectifier circuit
The low-pass filter circuit of the C1 containing electric capacity.
The resonance device 83 is used to provide constant current-supplying to LED load based on controlled energy variation.Wherein, it is described humorous
Vibrating device 83 includes LC oscillators and its peripheral circuit, and the peripheral circuit includes the sampling electricity being connected with switching device sampling end
Resistance.Wherein, the parameter of the inductance of the LC oscillators and electric capacity can be based on civil power work frequency, line voltage, output voltage and
Current specification, the duration that magnetizes, demagnetization duration and determine.For example, resonance device 83 is under critical continuous mode current working mode, it is humorous
The time of magnetizing of vibrating device 83 keeps not substantially under the line voltage virtual value of a certain fixation and fixed output voltage specification
Become, with this so that whole LED drive system has High Power Factor under critical continuous mode current working mode.
The switching device 82 is connected with the DC-AC conversion device 81 and resonance device 83, for based on detection from institute
Sampling end the first electric signal gathered and the second electric signal gathered from first drive end are stated to control the path to turn on
Or disconnect.For example, the simplified electrical circuit diagram of the switching device can be found in Fig. 4,5,6,7,9,11 and its corresponding description.
By taking Figure 13 as an example, the course of work of the LED drive system driving LED load is as follows：DC-AC conversion device 81
By civil power conversion be defined rectangular wave and export to switching device 82, switching device 82 is turned on and filled to resonance device 83 when initial
Magnetic, switching device 82 gather first electric signal at power tube Q1 CS ends, and second electric signal at GATE ends.Wherein, switch
Demagnetization starting detection module in device 82 produces a ramp-electrical signal according to the conductivity control signal of switching device, and according to the
The reference voltage Vcomp of the corresponding ramp-electrical signal of one electric signal generation, the demagnetization starting detection module are based on ramp-electrical signal
The duration that reference voltage Vcomp spent, which is risen to, from initial voltage carries out timing of magnetizing.Demagnetization detection of end in switching device
Module is consistently greater than valley point voltage threshold value Vzcd_ref according to the second electric signal and not exports the second detection signal.When demagnetizing
The timing of magnetizing of beginning detection module terminates, i.e. when Vramp is more than or equal to Vcomp, output first detection signal is into switching device
Control unit, by control unit controlling switch device 82 switch element disconnect so that resonance device 82 start demagnetization behaviour
Make.When demagnetization operation starts, the disconnection control signal instruction in by switching device 82, ramp signal resets cause demagnetization to originate
Detection module does not export first detection signal；At the same time, GATE terminal voltages explore downward to Vzcd_ref, when demagnetization detection of end mould
When block judges that GATE terminal voltages are less than Vzcd_ref, demagnetization detection of end module exports the second detection signal, institute to control unit
Switching means conductive of the control unit accordingly in controlling switch device is stated, resonance device enters operation of magnetizing.
The LED drive system also includes low-pass filter unit, is connected with the detection unit in the switching device.
Wherein, the low-pass filter unit is the circuit comprising electric capacity, wherein, the electric capacity and the demagnetization in detection unit
Starting detection module is connected.For example, as shown in figure 13, electric capacity Ccomp connection controllers in the low-pass filter unit
COMP ends.The low-pass filter unit is used for the variation for reducing Vcomp voltages so that RAMP signals are raised to Vcomp from initial value
The duration that voltage is spent is remained unchanged substantially, that is, the duration that magnetizes is basically unchanged, so under critical continuous mode current working mode
Obtain High Power Factor.
The application also provides a kind of method of controlling switch.The method of controlling switch can be held by the switching device
OK, or the device by can perform each step in the method for controlling switch performs.
Figure 14 is referred to, it is shown as the flow chart of the method for controlling switch in one embodiment.The switch control
Method processed includes：Step S110, S120.
In step s 110, the first electric signal and the second electric signal are obtained from switch element；Wherein, first electric signal
For reflecting curent change in resonance device, second electric signal is used to reflect that input source provides voltage change.
Here, the electric current of the resonance device can be flowed through from the either end detection for the switch element being connected with resonance device,
To obtain first electric signal.In some embodiments, the mode of acquisition first electric signal can gather opens described in
Pass unit is put the sampling end being connected with resonance device and obtained.For example, the sampling end of switch element is connect by sampling resistor
Enter at the circuit node between resonance device and switch element, to obtain first electric signal.Wherein, resonance device and switch
Sample circuit can be set between unit, curtage change can be by the of the sampling resistor side in the resonance device
One reflection of electrical signals comes out.Wherein, the sample circuit includes sampling resistor.The sampling resistor can be built in moving back for controller
In Magnetic testi unit, or it is built in resonance device, then or on the path to demagnetize between detection unit and resonance device.
Second electrical signal collection is from inside switch element.The drive end is the driving of switching device in switch element
End, for example, shown in Fig. 2, first drive end is power tube Q1 grid.Posted due to existing between power tube Q1 grid leak pole
Raw electric capacity, cause to drain received voltage change when, the second electrical signal voltage that grid is received also changes and is superimposed therewith
The voltage change of parasitic capacitance.So when the voltage change that input source is provided, by the second electric signal energy for gathering grid
It is enough more easily to obtain changing the voltage change more highlighted, and then more accurately controlling switch unit can turn on, realize resonance
The purpose that the description process of device matches with the voltage change of input source.
In the step s 120, the disconnection moment of switch element is set based on first electric signal, and it is described disconnected reaching
The switch element is disconnected when opening the moment；And the change based on second electric signal is when setting the conducting of the switch element
Carve, and the switch element is turned on when reaching the turn-on instant.
Here, mean resonance device described in current direction when detecting switching means into conduction, the electricity in resonance device
Sense start to magnetize, i.e., at the time of switching device is transferred to conducting state by off-state for the resonance device magnetize starting when
Carve.The switching device disconnects can be by the switch controlling signal in detection switch device or the voltage of detection first detection signal
And determine.
Wherein, it is described following steps to be used to hold based on the step of disconnection moment of the first electric signal setting switch element
OK：Start the duration that the ramp voltage of timing one reaches a reference voltage when detecting the switching means conductive, and by described in
Ramp voltage controls the switch element to disconnect at the time of reaching the reference voltage；Wherein, the reference voltage is after testing
The voltage that first electric signal obtains.
Here, the ramp signal is transported to comparison circuit compared with a reference voltage Vcomp, ramp signal
Voltage Vramp rises to the duration that magnetizes that the duration that reference voltage Vcomp spent is resonance device from initial value.When
When Vramp rises to Vcomp, setting resonance device magnetize end can enter demagnetization operation, so, control the switching device to break
Open.For example, comparing Vramp and Vcomp using comparison circuit, the switching device is controlled to break when Vramp is more than or equal to Vcomp
Open.
Here, Vcomp voltages are caused voltage based on first electric signal, one mutual conductance integrator of input.For example,
Acquired the first electric signal (CS electric signals) for flowing through resonance device is transported to reference voltage generating circuit to export Vcomp
Voltage.For example, the reference voltage generating circuit includes mutual conductance integrator, its positive input receives a reference voltage Vref,
Negative input receives first electric signal, then the mutual conductance integrator exports Vcomp voltages as the reference voltage.Wherein,
Voltage source is provided on the basis of reference voltage Vref, and the reference voltage source can specially provide the reference voltage Vref, or be based on
Chip power supply voltage VCC partial pressures and obtain.
The step of change based on second electric signal sets the turn-on instant of the switch element can use following step
It is rapid to perform：Compare second electric signal and default valley point voltage threshold value, and when the voltage of second electric signal reaches institute
It is defined as the turn-on instant of the switch element when stating valley point voltage threshold value.
Here, as shown in Figures 9 and 10, drive end in switching device (the i.e. switching device during being magnetized to resonance device
During conducting), influenceed by power tube Q1 conductings, the second electric signal maintains low high level.(switched during resonance device demagnetizes
During device disconnects), shaped input power Vin voltage waveform change is detected, when there is lower saltus step in Vin, power tube
Q1 grid G ATE ends output is lower when jumping along and exploring downward to valley point voltage threshold value Vzcd_ref, and the voltage of the second electric signal is less than etc.
In the valley point voltage threshold value, then setting demagnetization finish time and the conducting of controlling switch device.
For the switching device comprising semiconductor devices, as shown in Figures 9 and 10 be used as switching device by the use of power tube Q1
Switching device for, when switching device disconnect zero-time during, the voltage pulsation of input source can influence power tube Q1 grid
Pole tension is fluctuated, and so as to cause the second electric signal test change occur, the voltage triggered to prevent test change corresponding is opened
Close device to mislead, methods described is during detection demagnetization terminates, in addition to the delay detection institute when disconnecting the switching device
The step of stating the second electric signal.
When switching device disconnects, the corresponding disconnection delay duration of control signal one is latched.In the delay duration survival phase
Between no matter whether the voltage of the second electric signal is down to valley point voltage threshold value not the second detection signal of output, until the delay
Timing terminates.Wherein, the delay timing duration is less than the high level duration of input source.
The method of controlling switch is filled by setting the demagnetization process of external resonant device to be used for realization pair with the resonance
Put connected switching device and carry out break-make control, so realize the lasting or interrupted oscillation of resonance device, it is permanent to be provided to load
Stream power supply.
When the load that resonance device is connect is LED load, the application provides a kind of LED driving methods again, to realize LED
The constant current-supplying of load.The LED driving methods are used for the drivetrain for carrying out constant current-supplying to LED load using resonance device
System.
The LED driving methods by performing each step of method of controlling switch, when it is determined that demagnetization start time when, control with
The switching device of resonance device connection disconnects so that the inductance in resonance device enters demagnetization and operated, and resonance device is to LED
Load output constant current power supply.When it is determined that demagnetization finish time when, controllable switch device conducting so that the inductance in resonance device
Into operation of magnetizing.It is thus based on the conducting of the switching device and disconnects to drive LED load to the vibrational control of resonance device
Work.
Although the application is disclosed as above with preferred embodiment, it is not for limiting the application, any this area
Technical staff is not being departed from spirit and scope, may be by the methods and technical content of the disclosure above to this Shen
Please technical scheme make possible variation and modification, therefore, every content without departing from technical scheme, according to the application
Any simple modifications, equivalents, and modifications made to above example of technical spirit, belong to technical scheme
Protection domain.
Claims (22)
- A kind of 1. controller, for connecting valve unit, wherein the switch element is used to be connected to input source and resonance device Between, it is characterised in that including：Detection unit, for obtaining the first electric signal for reflecting curent change in resonance device from the switch element and obtaining Take and provide the second electric signal of voltage change in reflection input source, set when detecting based on first electric signal First detection signal is exported during the disconnection moment of switch element, and is worked as and is detected the change based on second electric signal and set The second detection signal is exported during the turn-on instant for putting the switch element；Control unit, the detection unit is connected, for based on the first detection signal received and the control of the second detection signal The switching means conductive connected or disconnection.
- 2. controller according to claim 1, it is characterised in that the detection unit includes：Demagnetization starts detection module, is connected between the sampling end of switch element and control unit, and described open is detected for working as When closing unit conducting, timing of magnetizing is proceeded by based on the first electric signal gathered from the sampling end, and in the timing knot that magnetizes First detection signal is exported during beam.
- 3. controller according to claim 2, it is characterised in that the demagnetization, which starts detection module, to be included：Reference voltage generating circuit, for determining a reference voltage by detecting first electric signal；Signal generating circuit, it is connected with described control unit, for when detecting the switching means conductive, generating a slope Electric signal；Comparison circuit, it is connected with the reference voltage generating circuit and signal generating circuit, for the ramp-electrical signal Voltage and the reference voltage, and export first detection signal when the voltage of the ramp-electrical signal reaches reference voltage.
- 4. controller according to claim 3, it is characterised in that the reference voltage generating circuit integrates including mutual conductance Device, there is first input end, the second input and output end, the first input end connects the sampling end, and described second is defeated Enter one reference voltage source of end connection, the output end exports the reference voltage；Wherein, the output end is additionally operable to connect One outside low-pass filter unit.
- 5. controller according to claim 3, it is characterised in that the signal generating circuit includes ramp signal Device, there is control terminal and output end, the control terminal connects described control unit, and the output end connects the comparison circuit.
- 6. controller according to claim 1, it is characterised in that the detection unit includes：Demagnetization detection of end module, With being connected between drive end and the control unit of the switch element, for comparing the second telecommunications from drive end collection Number with default valley point voltage threshold value, and when the voltage of second electric signal reaches the valley point voltage threshold value output second inspection Survey signal.
- 7. controller according to claim 6, it is characterised in that the valley point voltage threshold value is based on the switch element The set threshold voltage of middle parasitic capacitance release.
- 8. controller according to claim 1, it is characterised in that described control unit includes：Control module, for making the switch controlling signal of the switching means conductive based on the first detection signal output received And make the switch controlling signal of the switch element disconnection based on the second detection signal output received；Drive module, it is connected with the control module, is driven for the switch controlling signal received to be converted into corresponding switch Signal is moved to drive connected switch element.
- 9. controller according to claim 1, it is characterised in that also include：Delay cell, described open is detected for working as Close when unit disconnects and maintain off-state in a delay duration.
- 10. controller according to claim 1, it is characterised in that source electrode of the detection unit from the switch element Obtain the first electric signal and obtain the second electric signal from the grid of the switch element.
- A kind of 11. switching device, it is characterised in that including：Switch element, for being connected between input source and resonance device；AndController as described in any in claim 1-10, is connected with the switch element, described for being flowed through by detection The first electric signal and the second electric signal of switch element carry out the control that is turned on or off to switch element.
- 12. switching device according to claim 11, it is characterised in that the switch element is included based on raster data model Power tube；The controller obtains the first electric signal from the source electrode of the power tube, and is obtained from the grid of the power tube Second electric signal.
- A kind of 13. LED drive system, it is characterised in that including：DC-AC conversion device, for converting alternating current to direct current and exporting；Resonance device, for providing constant current-supplying to LED load based on controlled vibration；Switching device as described in any in claim 11-12, be connected to the DC-AC conversion device and resonance device it Between path on, for controlling the path to be turned on or off based on the first acquired electric signal and the second electric signal；Wherein, Buckling.
- 14. LED drive system according to claim 13, it is characterised in that also including low-pass filter unit, opened with described The detection unit closed in device is connected.
- A kind of 15. method of controlling switch, it is characterised in that including：The first electric signal and the second electric signal are obtained from switch element；Wherein, first electric signal is used to reflect resonance device Interior curent change, second electric signal are used to reflect that input source provides voltage change；The disconnection moment of switch element is set based on first electric signal, and opened when reaching the disconnection moment described in disconnection Close unit；And the change based on second electric signal sets the turn-on instant of the switch element, and led reaching described The switch element is turned on during the logical moment.
- 16. method of controlling switch according to claim 15, it is characterised in that first electric signal that is based on sets switch The mode at the disconnection moment of unit includes：Start the duration that the ramp voltage of timing one reaches a reference voltage when detecting the switching means conductive, and by described in Ramp voltage controls the switch element to disconnect at the time of reaching the reference voltage；Wherein, the reference voltage is after testing The voltage that first electric signal obtains.
- 17. method of controlling switch according to claim 15, it is characterised in that the change based on the second electric signal is set Putting the mode of the turn-on instant of the switch element includes：Compare second electric signal and default valley point voltage threshold value, and work as The voltage of second electric signal is defined as the turn-on instant of the switch element when reaching the valley point voltage threshold value.
- 18. method of controlling switch according to claim 17, it is characterised in that the valley point voltage threshold value is based on described The set threshold voltage of parasitic capacitance release in switch element.
- 19. method of controlling switch according to claim 15, it is characterised in that also include working as detecting the switch element The step of off-state of the switch element is maintained during disconnection in a delay duration.
- A kind of 20. LED driving methods, it is characterised in that including：Each step controlling switch device provided using the method for controlling switch as described in any in claim 15-19 is led Logical and disconnection；AndThe oscillatory process of conducting and disconnection control resonance device based on the switching device, to drive LED load to work.
- A kind of 21. LED control chips, it is characterised in that including：Controller as described in any in claim 1-10, for flowing through the first electricity of connected switch element by detection Signal and the second electric signal carry out the control that is turned on or off to the switch element.
- 22. LED control chips according to claim 21, it is characterised in that also including the switch element.
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| CN201710922929.3A CN107529254B (en) | 2017-09-30 | 2017-09-30 | Switching device, and applicable LED driving system and driving method |
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| CN201710922929.3A CN107529254B (en) | 2017-09-30 | 2017-09-30 | Switching device, and applicable LED driving system and driving method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107529254B (en) | 2024-01-26 |
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