CN107635323A - Led drive circuit - Google Patents
Led drive circuit Download PDFInfo
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- CN107635323A CN107635323A CN201711083767.5A CN201711083767A CN107635323A CN 107635323 A CN107635323 A CN 107635323A CN 201711083767 A CN201711083767 A CN 201711083767A CN 107635323 A CN107635323 A CN 107635323A
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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]
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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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Abstract
The application provides a kind of LED drive circuit.LED drive circuit includes the power switch pipe that output end is connected with the energy-storage units in Switching Power Supply；The power switch driver circuit that output end is connected with the control terminal of power switch pipe；Output end is connected with the input of power switch driver circuit, the cut-off time control circuit of the cut-off time for controlling power switch pipe；Cut-off time control circuit, including：Energy-storage units current detection circuit, for when electric current reaches setting value in the energy-storage units of Switching Power Supply, the cut-off time of power switch pipe to be controlled by power switch driver circuit；Maximum ON time control circuit, for providing ON times of the 3rd time T3 as power switch pipe, the cut-off time of power switch pipe is controlled by power switch driver circuit；Circuit is adjusted, for adjusting the 3rd time T3 size according to user's request.So as to improve the control performance of LED drive circuit.
Description
It is on 01 13rd, 2016 the applying date that the application, which is, Application No.：It is 201610020741.5 entitled：LED
The divisional application of the method at drive circuit and controlling switch power supply conduction and cut-off moment.
Technical field
The present invention relates to switch power technology field, and in particular to a kind of LED drive circuit.
Background technology
In Switching Power Supply, light modulator is when adjusting on-Line Voltage, it is necessary to be cut off to unnecessary on-Line Voltage, online
The portion voltage that voltage modulated light device is cut away is 0, if now, power tube in the drive circuit of Switching Power Supply is opened, then this
When Switching Power Supply energy-storage units in there is no energy storage；When the power tube in drive circuit is closed, because the energy-storage units do not have
Output end energy is delivered to, so at the time of the drive circuit can't detect energy-storage units electric current to zero, that is, can't detect
At the time of power tube should turn on, therefore, generally in the control circuit indoor design one most long power tube shut-in time T1.
But T1 setting, when can cause some steamed bun ripple on-Line Voltages just over 0, power tube is switched on；And adjacent steamed bun ripple is online
After voltage is more than 0, T1 time is waited, the power tube is just opened.Therefore, if T1 is long, two neighboring steamed bun can be caused
Bow wave, output energy is asymmetric, and then causes LED to flash；When LED load short circuit, because the Switching Power Supply is defeated
Go out brownout, at the time of the drive circuit equally can't detect power tube and should turn on, now, after still passing through the T1 times
Just power tube is opened.If T1 is too short, working frequency during LED load short circuit is higher, causes short-circuit dissipation very big.How
Improve the performance of LED drive circuit, with to load preferably power supply for those skilled in the art's technical problem urgently to be resolved hurrily it
One.
The content of the invention
In view of this, the embodiment of the present invention provides a kind of LED drive circuit and controlling switch power supply conduction and cut-off moment
Method, to improve the performance of LED drive circuit, realize to the more preferable power supply of LED load.
To achieve the above object, the embodiment of the present invention provides following technical scheme：
A kind of LED drive circuit, applied in Switching Power Supply, including：
The power switch pipe that output end is connected with the energy-storage units in the Switching Power Supply；
The power switch driver circuit that output end is connected with the control terminal of the power switch pipe；
Output end is connected with the input of the power switch driver circuit, for controlling the conducting of the power switch pipe
The turn-on instant control circuit at moment；
Wherein, the turn-on instant control circuit, including：
Maximum deadline control circuit, for when the Switching Power Supply is when being in first state, there is provided the very first time
Deadlines of the T1 as the power switch pipe, when the Switching Power Supply is in the second state, there is provided the second time T2 makees
For the deadline of the power switch pipe, the very first time T1 is less than the second time T2.
Preferably, in above-mentioned LED drive circuit, the first state is the on-Line Voltage of the Switching Power Supply when being 0；Institute
State the load short circuits that the second state is the Switching Power Supply.
Preferably, in above-mentioned LED drive circuit, the turn-on instant control circuit, in addition to：
Zero cross detection circuit, for when current over-zero in the outlet side diode of Switching Power Supply, being opened by the power
Close the turn-on instant that drive circuit controls the power switch pipe.
Preferably, in above-mentioned LED drive circuit, the maximum deadline control circuit, it is specifically used for：
When the Switching Power Supply on-Line Voltage be 0, exported every very first time T1 to the power switch driver circuit
Trigger signal, it is otherwise, described to export a trigger signal to the power switch driver circuit every the second time T2
Trigger signal is used to control the power switch pipe to turn on by the power switch driver circuit.
Preferably, in above-mentioned LED drive circuit, the maximum deadline control circuit is by electric capacity charge/discharge
To provide the very first time T1 and the second time T2.
Preferably, in above-mentioned LED drive circuit, the maximum deadline control circuit, including：
First electric capacity of negative pole ground connection；
First controlling switch in parallel with first electric capacity, the control terminal of first controlling switch are described for obtaining
The output signal of power switch driver circuit；
The dc source being connected with the positive pole of first electric capacity, it is described when the on-Line Voltage of the Switching Power Supply is 0
Dc source is charged with the first predetermined current to first electric capacity, and otherwise, first electric capacity is filled with the second predetermined current
Electricity, first predetermined current are more than the second predetermined current；
The first comparator that first input end is connected with the positive pole of first electric capacity, the second of the first comparator are defeated
Enter end to be used to obtain the first reference voltage, the output of the output end of the first comparator as the turn-on instant control circuit
End.
Preferably, in above-mentioned LED drive circuit, the dc source, including：
The first dc source that output end is connected with the positive pole of first electric capacity；
Second dc source and the second controlling switch, the first end of second controlling switch and second DC source
Output end is connected, the second end is connected with the positive pole of first electric capacity；
The state control circuit that output end is connected with the control terminal of second controlling switch, for when the Switching Power Supply
On-Line Voltage when being 0, turn on second controlling switch；Otherwise, second controlling switch is ended.
Preferably, in above-mentioned LED drive circuit, output end is connected with the input of the power switch driver circuit, uses
In the cut-off time control circuit for controlling the power switch pipe cut-off time.
Preferably, in above-mentioned LED drive circuit, the cut-off time control circuit includes：
Energy-storage units current detection circuit, for when electric current reaches setting value in the energy-storage units of Switching Power Supply, passing through
The power switch driver circuit controls the cut-off time of the power switch pipe；
Maximum ON time control circuit, for providing ON times of the 3rd time T3 as the power switch pipe,
The cut-off time of the power switch pipe is controlled by the power switch driver circuit；
Circuit is adjusted, for adjusting the size of the 3rd time T3 according to user's request.
Preferably, in above-mentioned LED drive circuit, the maximum ON time control circuit be used for by the charging of electric capacity/
Discharge time provides the 3rd time T3；
The regulation circuit is used for according to electric capacity of the user's request by adjusting in the maximum ON time control circuit
Charge/discharge adjust the 3rd time T3.
A kind of LED drive circuit, applied in Switching Power Supply, including：
The power switch pipe that output end is connected with the energy-storage units in the Switching Power Supply；
The power switch driver circuit that output end is connected with the control terminal of the power switch pipe；
Output end is connected with the input of the power switch driver circuit, for controlling the cut-off of the power switch pipe
The cut-off time control circuit at moment；
The cut-off time control circuit, including：
Energy-storage units current detection circuit, for when electric current reaches setting value in the energy-storage units of Switching Power Supply, passing through
The power switch driver circuit controls the cut-off time of the power switch pipe；
Maximum ON time control circuit, for providing ON times of the 3rd time T3 as the power switch pipe,
The cut-off time of the power switch pipe is controlled by the power switch driver circuit；
Circuit is adjusted, for adjusting the size of the 3rd time T3 according to user's request.
Preferably, in above-mentioned LED drive circuit, the maximum ON time control circuit be used for by the charging of electric capacity/
Discharge time provides the 3rd time T3；
The regulation circuit is used for according to electric capacity of the user's request by adjusting in the maximum ON time control circuit
Charge/discharge adjust the 3rd time T3.
Preferably, in above-mentioned LED drive circuit, the energy-storage units current detection circuit includes：
Second comparator, the first input end of second comparator are used to obtain the Switching Power Supply energy-storage units electric current
Sampled signal, the second input be used for obtain the second reference signal, the ratio according to the sampled signal and the second reference signal
Relatively result exports the control letter that the cut-off time for controlling the power switch pipe is exported to the power switch driver circuit
Number；
The maximum cut-off time control circuit, including：
Second electric capacity of negative pole ground connection；
Threeth controlling switch in parallel with second electric capacity, the control terminal of the 3rd controlling switch are described for obtaining
The inverted signal of the output signal of power switch driver circuit；
The adjustable DC power supply being connected with the positive pole of second electric capacity, with default 3rd predetermined current pair of active user
The second electric capacity charging.
Preferably, in above-mentioned LED drive circuit, the adjustable DC source, including：
The 3rd DC source that output end is connected with second capacitance cathode；
The adjustable resistance being connected with the 3rd DC source, the adjustable resistance are used to adjust the 3rd DC source output
Size of current.
A kind of method at controlling switch power supply conduction and cut-off moment, including：
The sampled signal for characterizing the Switching Power Supply energy-storage units electric current is obtained, setting value is reached in the sampled signal
When, control the Switching Power Supply power switch to end；
The state that the Switching Power Supply is presently in is judged, if the Switching Power Supply is in first state, during with first
Between deadlines of the T1 as the power switch pipe of the Switching Power Supply；If the Switching Power Supply is in the second state, with
Deadlines of the second time T2 as the power switch pipe, the very first time T1 are less than the second time T2.
Preferably, in the method at above-mentioned controlling switch power supply conduction and cut-off moment, in addition to：
ON times of the 3rd time T3 as the power switch pipe is provided according to user's request.
Preferably, in the method at above-mentioned controlling switch power supply conduction and cut-off moment, in addition to：
Detect in the Switching Power Supply outlet side diode electric current whether zero crossing, if then controlling power switch conducting.
Preferably, in the method at above-mentioned controlling switch power supply conduction and cut-off moment, the Switching Power Supply is in first state
Specially：The on-Line Voltage of the Switching Power Supply is 0, and the Switching Power Supply is in the second state and is specially：The Switching Power Supply
Load be in short-circuit condition.
Preferably, in the method at above-mentioned controlling switch power supply conduction and cut-off moment, it is described using very first time T1 described in
The deadline of the power switch pipe of Switching Power Supply, including：
A trigger signal is exported every power switch driver circuits of the very first time T1 into LED drive circuit；
The deadline using the second time T2 as the power switch pipe, including：
To export a trigger signal to the power switch driver circuit every the second time T2；
Wherein, the trigger signal is used to control the power switch pipe to turn on by the power switch driver circuit.
Preferably, in the method at above-mentioned controlling switch power supply conduction and cut-off moment, it is described using very first time T1 described in
The deadline of the power switch pipe of Switching Power Supply, including：
The very first time T1 is provided by way of to electric capacity charge/discharge, electricity is driven using very first time T1 as LED
The deadline of power switch pipe in road；
The deadline using the second time T2 as the power switch pipe, including：
The second time T2 is provided by way of to electric capacity charge/discharge, the power is used as using the second time T2
The deadline of switching tube.
The working condition of Switching Power Supply is controlled when using the LED drive circuit disclosed in the above embodiments of the present application
When processed, when the maximum deadline control circuit 11 detects that the Switching Power Supply is in first state, according to default
Very first time T1 controls the deadline of the power switch pipe by the power switch driver circuit, i.e., in the T1 periods
Interior, the power switch pipe is in the conduction state, when it is described detect that the Switching Power Supply is in the second state when, according to default
The second time T2 control deadline of the power switch pipe, i.e., within the T2 periods, the power switch pipe is in and led
Logical state, it is seen that the application is directed to the different conditions residing for the Switching Power Supply, the setting respectively to the power switch pipe
Different maximum ON times, and cause, the very first time T1 is less than the second time T2, therefore, when the switch is electric
When source is in the second state, the ON time length of the power switch pipe, and then the working frequency phase of now LED load can be caused
It is relatively low compared with for normal condition, so as to reduce the power consumption of load in this condition.Therefore the LED drive circuit is improved
Power supply performance.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the required accompanying drawing used in technology description to be briefly described, it should be apparent that, drawings in the following description are only this
The embodiment of invention, for those of ordinary skill in the art, on the premise of not paying creative work, can also basis
The accompanying drawing of offer obtains other accompanying drawings.
Fig. 1 is a kind of structural representation of LED drive circuit disclosed in the embodiment of the present application；
Fig. 2 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 3 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 4 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 5 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 6 is when the very first time, T1 was long, causes the asymmetric schematic diagram of steamed bun ripple；
Fig. 7 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 8 is a kind of structural representation of LED drive circuit disclosed in another embodiment of the application；
Fig. 9 is a kind of structural representation of Switching Power Supply disclosed in the embodiment of the present application.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained every other under the premise of creative work is not made
Embodiment, belong to the scope of protection of the invention.
Above mentioned problem of the prior art is directed to, this application discloses a kind of LED drive circuit and controlling switch power supply
The method at conduction and cut-off moment.
Referring to Fig. 1, this application discloses a kind of LED drive circuit, the LED drive circuit is applied in Switching Power Supply, bag
Include：
The power switch pipe M that output end is connected with the energy-storage units 00 in the Switching Power Supply；
The power switch driver circuit 20 that output end is connected with the control terminal of the power switch pipe 30, the power switch
Drive circuit 20 is used for the conducting state that the power switch pipe 30 is controlled according to the signal got；
The turn-on instant control circuit 10 that output end is connected with the input of the power switch driver circuit 20, it is described to lead
Logical moment control circuit 10 is used for the turn-on instant that the power switch pipe 30 is controlled by the power switch driver circuit 20；
Maximum deadline control circuit 11, the maximum deadline are provided with the turn-on instant control circuit 10
Control circuit 11 is used for when the Switching Power Supply is in first state, there is provided very first time T1 is as the power switch pipe 30
Deadline, when the Switching Power Supply is when being in the second state, there is provided the second time T2 is as the power switch pipe 30
Deadline, the very first time T1 is less than the second time T2.
The working condition of Switching Power Supply is controlled when using the LED drive circuit disclosed in the above embodiments of the present application
When processed, when the maximum deadline control circuit 11 detects that the Switching Power Supply is in first state, according to default
Very first time T1 controls the deadline of the power switch pipe 30 by the power switch driver circuit 20, i.e., in the T1 times
In section, the power switch pipe 30 is in cut-off state, when the Switching Power Supply is in the second state, according to default second
Time T2 controls the deadline of the power switch pipe 30, i.e., within the T2 periods, the power switch pipe is in cut-off shape
State, it is seen that the application is directed to the different conditions residing for the Switching Power Supply, to being respectively provided with for the power switch pipe 30
Different maximum deadlines, and cause, the very first time T1 is less than the second time T2, therefore, when the Switching Power Supply
During in the second state, the deadline length of the power switch pipe, and then the working frequency of now LED load can be caused to compare
It is relatively low for normal condition, so as to reduce the power consumption of load in this condition.
Wherein, in specific above-described embodiment, the first state is the shape when on-Line Voltage of the Switching Power Supply is 0
State；Second state is the state of the load short circuits of the Switching Power Supply.
It is understood that in order to realize that the turn-on instant control circuit 10 is more than 0 in the voltage of the Switching Power Supply
When, the control to the conducting state of the power switch pipe 30, referring to Fig. 2, technical scheme disclosed in the above embodiments of the present application
In, the turn-on instant control circuit 10 can also include：
Zero cross detection circuit 12, the zero cross detection circuit 12 are used for when electric current mistake in the outlet side diode of Switching Power Supply
When zero, the turn-on instant of the power switch pipe 30 is controlled by the power switch driver circuit 20.Certainly, it is necessary to explanation
Be, in the prior art in the outlet side diode of the Switching Power Supply when Switching Power Supply during current over-zero to the power switch
The circuit and method that the conducting state of pipe 30 is controlled have tended to be ripe, and therefore, those skilled in the art are directly using existing
There is the control circuit for being used for being controlled in technology to the conducting state of the power switch pipe 30 as the above-mentioned implementation of the application
The zero cross detection circuit 12 disclosed in example.
It is understood that in order to further optimize the maximum deadline control disclosed in the above embodiments of the present application
The control process of circuit 11, the specific work process of the maximum deadline control circuit 11 can be：
When the on-Line Voltage of the Switching Power Supply is 0, the zero cross detection circuit is not detected by outlet side diode
During current over-zero, a trigger signal is exported to the power switch driver circuit 20 every very first time T1, when the switch
When the on-Line Voltage of power supply is more than 0 (such as during load short circuits of the Switching Power Supply), with every the second time T2 to the work(
Rate switch driving circuit 20 exports a trigger signal, and the trigger signal transmitted by the maximum deadline control circuit 11 is
For controlling the trigger signal of the conducting of power switch pipe 30 by the power switch driver circuit 20.
It is understood that in circuit, the very first time T1 and the second time T2 generating mode are varied, example
As it can have control chip generation, now the control chip is used for when the on-Line Voltage of the Switching Power Supply is 0, described
When zero cross detection circuit is not detected by current over-zero in outlet side diode, very first time T1 is generated, when the Switching Power Supply
When on-Line Voltage is more than 0, the second time T2 is generated.Certainly, those skilled in the art can also use other generating modes to generate
The very first time T1 and the second time T2, it is preferred that maximum described in technical scheme disclosed in the above embodiments of the present application
Deadline control circuit 11 can be by providing electric capacity charge/discharge the very first time T1 and the second time T2,
Now, it can be charged by dc source to electric capacity, and the of different sizes of charging current can cause electric capacity to be charged to default electricity
The time of pressure is different, and the time that electric capacity is raised to predeterminated voltage is regarded as very first time T1 and the second time T2.
When the maximum deadline control circuit 11 is by providing electric capacity charge/discharge the very first time T1 and
During two time T2, referring to Fig. 3, the maximum deadline control circuit 11, it can include：
First electric capacity C1 of negative pole ground connection；
The first controlling switch K1, the first controlling switch K1 in parallel with the first electric capacity C1 control terminal is used to obtain
Take the output signal of the power switch driver circuit 30；
The dc source i being connected with the positive pole of the first electric capacity C1, when power tube ON time is by maximum ON time
When control circuit is to control (such as the on-Line Voltage of the Switching Power Supply be 0 when), the dc source i is with the first predetermined current
To the first electric capacity C1 charge, when power tube ON time be not by maximum ON time control circuit to control when (such as
During load short circuits), the first electric capacity C1 is charged with the second predetermined current, wherein, first predetermined current is more than second
Predetermined current；
The first comparator U1 that first input end is connected with the positive pole of the first electric capacity C1, the first comparator U1's
Second input is used to obtain the first reference voltage Vref, when the output end of the first comparator U1 is as the maximum conducting
Carve the output end of control circuit 11.
In foregoing circuit, if simultaneously using the first predetermined current and the second predetermined current respectively different to two the
One electric capacity C1 is charged, when being charged using the first predetermined current to the first electric capacity C1, the first electric capacity C1 two
The time of the boost in voltage at end to the first reference voltage Vref can be designated as very first time T1, using the second predetermined current to described
When one electric capacity C1 is charged, the time of boost in voltage to first reference voltage Vref at the first electric capacity C1 both ends can be designated as
Second time T2, because first predetermined current is more than second predetermined current, therefore obtained very first time T1 is less than
The second time T2, user can be according to self-demands, and setting the first required predetermined current and the second predetermined current can obtain
To required very first time T1 and the second time T2.
It is understood that control electric current source exports the mode of different size of first predetermined current and the second predetermined current
Can have it is a variety of, such as its can the current source output end set needed for shunt circuit, by controlling the shunting
The break-make of circuit can obtain different size of first predetermined current and the second predetermined current, naturally it is also possible to using other modes
Control the first predetermined current and the second predetermined current needed for the dc source i generations user, it is preferred that referring to Fig. 3, at this
Apply in technical scheme disclosed in above-described embodiment, the dc source i can include：
The first dc source i1 that output end is connected with the positive pole of the first electric capacity C1；
Second dc source i2 and the second controlling switch K2, the first end of the second controlling switch K2 and described second straight
Stream source i2 output end is connected, the second end of the second controlling switch K2 is connected with the positive pole of the first electric capacity C1；
The state control circuit 111 that output end is connected with the control terminal of the second controlling switch K2, the state control
Circuit 111 when power tube ON time by maximum ON time control circuit to control when (for example the Switching Power Supply is online
When voltage is 0), export the control signal for controlling the second controlling switch K2 conductings；When power tube ON time is not
During by maximum ON time control circuit to control (such as during load short circuits), export for controlling the second controlling switch K2
The control signal of cut-off.
That is, when the second switch pipe K2 is closed, the first DC source i1 and the second DC source i2 are total to foregoing circuit
With the dc source i is used as, the first predetermined current, when the second switch pipe K2 ends, first DC source are exported
I1 exports the second predetermined current as the dc source i.
It is understood that the zero passage detection is electric for convenience in technical scheme disclosed in the above embodiments of the present application
The control signal of road 12 and the maximum deadline control circuit 11 is transferred to the power switch driver circuit, referring to Fig. 3,
Be additionally provided with a logic sum gate OR in the turn-on instant control circuit 10, the first input end of the logic sum gate OR with it is described
The output end of zero cross detection circuit 12 is connected, the second input and the output end phase of the maximum deadline control circuit 11
Even, for exporting the zero cross detection circuit 12 and control signal that the maximum deadline control circuit 11 matches is to institute
State power switch driver circuit 20.
It is understood that it is used to control the power switch pipe by the power switch driver circuit 20 except above-mentioned
Outside the turn-on instant control circuit 10 of 30 turn-on instant, also have referring to Fig. 4, in the LED drive circuit and be used to pass through
The power switch driver circuit 20 controls the cut-off time control circuit 40 of the cut-off time of the power switch pipe 30, described
The output end of cut-off time control circuit 40 is connected with the input of the power switch driver circuit 20, for passing through the power
Switch driving circuit 20 controls the cut-off time of the power switch pipe.Wherein, exist in traditional LED drive circuit and use
In the relevant control circuit to the cut-off time for controlling the power switch pipe by the power switch driver circuit 20,
Can be directly using these circuits as the cut-off time control circuit 40 disclosed in the embodiment of the present application.
It is understood that applicant it has been investigated that, referring to Fig. 5, part that on-Line Voltage modulated light device is cut away because
Now on-Line Voltage is 0, when power switch pipe is opened, does not have energy storage in the energy-storage units of Switching Power Supply；When the power switch
When pipe is closed, because being not transferred to output end energy, at the time of also just can't detect the electric current of energy-storage units to zero, i.e.,
At the time of can't detect power tube should turn on.
This is directed to, referring to Fig. 6, the cut-off time control circuit 40 can include：
Energy-storage units current detection circuit 41, for when the on-Line Voltage of Switching Power Supply is more than 0, being opened by the power
Close the cut-off time that drive circuit 20 controls the power switch pipe 30.
Maximum ON time control circuit 42, for when Switching Power Supply on-Line Voltage be 0 when, using the 3rd time T3 as
The ON time of the power switch pipe 30, cutting for the power switch pipe 30 is controlled by the power switch driver circuit 20
The only moment；
Circuit 43 is adjusted, for adjusting the size of the 3rd time T3 according to user's request.
Because in the Switching Power Supply of different size, the size of the 3rd required time T3 can be different, therefore, in the application
State technical scheme disclosed in embodiment can be by being arranged to time regulatable by the 3rd time T3, and user can be according to Switching Power Supply
Specification adjust the size of the 3rd time T3.To above-described embodiment disclosed in technical scheme it is similar, the 3rd time T3
Can also be by being generated to the charge/discharge of electric capacity, i.e. the maximum ON time control circuit 42 is used for by electric capacity
Charge/discharge time provides the 3rd time T3.
Wherein, in technical scheme disclosed in the above embodiments of the present application, when the on-Line Voltage of Switching Power Supply is more than 0,
Controlled by the power switch driver circuit 20 cut-off time of the power switch pipe 30 interlock circuit and method
Level off to maturation, it can be directly using interlock circuit of the prior art as the storage disclosed in the above embodiments of the present application
Energy cell current detection circuit 41, certainly, the structure of the energy-storage units current detection circuit 41 can also be referring to Fig. 7：
The energy-storage units current detection circuit 41, including：
Second comparator U2, the second comparator U2 first input end is used for the resistance for obtaining sampling inductive current
Magnitude of voltage, the second input be used for obtain the second reference signal Vcsref, according to it is described sampling inductive current it is ohmically
Magnitude of voltage and the second reference signal Vcsref comparative result export to be exported for controlling to the power switch driver circuit 20
The control signal of the cut-off time of the power switch pipe 30；
Referring to Fig. 7, the maximum cut-off time control circuit 42, can include：
Second electric capacity C2 of negative pole ground connection；
The threeth controlling switch K3 in parallel with the second electric capacity C2, the 3rd controlling switch K3 control terminal are used to obtain
Take the inverted signal of the output signal of the power switch driver circuit 20；
The adjustable DC power supply IRT being connected with the positive pole of the second electric capacity C2, according to the value of required power factor
With the dimming effect of optimization, the adjustable DC power supply IRT is with default 3rd predetermined current of active user to described second
Electric capacity C3 charges, and the size that certain user can set the 3rd predetermined current by the regulation circuit 43 is required so as to obtain
The 3rd time T3；
First input end is connected with the second electric capacity C2 positive poles, the input of the second input has the 3rd reference signal VRTref
The 3rd comparator U3, the output of the output end of the 3rd comparator U3 as the maximum cut-off time control circuit 42
End.
It is understood that in above-described embodiment user can it is used set adjustable resistance mode adjust the adjustable DC
Source IRT output current, now, referring to Fig. 5, the adjustable DC source IRT, including：
The 3rd DC source i3 that output end is connected with the second electric capacity C2 positive poles；
The adjustable resistance RT being connected with the 3rd DC source i3, the adjustable resistance RT are used to adjust the 3rd direct current
The size of current of source i3 outputs.
It is understood that for convenience in the energy-storage units current detection circuit 41 and the maximum ON time control
The control signal of circuit 42 processed is transferred to the power switch driver circuit 20, referring to Fig. 7, the cut-off time control circuit 40
A logic sum gate OR, the first input end of the logic sum gate OR and the energy-storage units current detecting are inside equally may also set up
The output end of circuit 41 is connected, and the second input is connected with the output end of the maximum ON time control circuit 42, for defeated
Go out the energy-storage units current detection circuit 41 and control signal that the maximum ON time control circuit 42 matches is to institute
State power switch driver circuit 20.
Preferably, in technical scheme disclosed in the above embodiments of the present application, the LED schemes can use the setting in Fig. 8
Mode, wherein, introduce and illustrated in partial content above-described embodiment, these contents the application is not being illustrated.
Referring to Fig. 8, the regulation circuit preferably uses rest-set flip-flop, and it is short to obtain sign load for the trigger for convenience
The short-circuit signal on road, the S ends of the trigger are connected with the output end of the 3rd comparator U3, and the R of the rest-set flip-flop is defeated
Enter end with by phase inverter X with the output end of the power switch driver circuit 20 to be connected；
The input of the phase inverter X is connected with the output end of the power switch driver circuit 20, output end respectively at
The R ends of the rest-set flip-flop are connected with the control terminal of the 3rd switching tube K3；
The output end of the power switch driver circuit 20 is connected with the control terminal of the first switch pipe；
The input of the zero cross detection circuit 12 is used for the zero-acrross ing moment detection signal for obtaining the energy-storage units
Source be used to judge according to the zero-acrross ing moment detection signal Source in the outlet side diode of the Switching Power Supply whether
There is current over-zero.
It is understood that disclosed herein as well is another LED drive circuit, applied in Switching Power Supply, referring to
Fig. 5, the LED drive circuit include：
The power switch pipe 30 that output end is connected with the energy-storage units 00 in the Switching Power Supply；
The power switch driver circuit 20 that output end is connected with the control terminal of the power switch pipe 30；
The cut-off time control circuit 40 that output end is connected with the input of the power switch driver circuit 20, described section
Only moment control circuit 40 is used for the cut-off time that the power switch pipe 30 is controlled by the power switch driver circuit 20；
The cut-off time control circuit 40, including：
Energy-storage units current detection circuit, for when electric current reaches setting value in the energy-storage units of Switching Power Supply, passing through
The power switch driver circuit controls the cut-off time of the power switch pipe；
Maximum ON time control circuit 42, during for providing conductings of the 3rd time T3 as the power switch pipe 30
Between, cut-off time of the power switch pipe 30 is controlled by the power switch driver circuit 20；
Circuit 43 is adjusted, for adjusting the size of the 3rd time T3 according to user's request.
With above-described embodiment disclosed in LED drive circuit it is corresponding, the maximum ON time control circuit 42 is specific to use
In：
When the on-Line Voltage of Switching Power Supply is 0, exported every the 3rd time T3 to the power switch driver circuit 20
Once it is used for the trigger signal for controlling the power switch pipe 30 to end.
With above-described embodiment disclosed in LED drive circuit it is corresponding, the maximum ON time control circuit 42 be used for lead to
The charge/discharge time of electric capacity is crossed to provide the 3rd time T3；
The regulation circuit 43 is used for according to user's request by adjusting in the maximum ON time control circuit 20
The charge/discharge of electric capacity adjusts the 3rd time T3.
With above-described embodiment disclosed in LED drive circuit it is corresponding, referring to Fig. 7, the energy-storage units current detection circuit
41 include：
Second comparator U2, the second comparator U2 first input end is used for the ohmically electricity for sampling inductive current
Pressure value, the second input be used for obtain the second reference signal Vcsref, according to the energy-storage units electric current sampled signal CS and
Second reference signal Vcsref comparative result exports to be exported for controlling the power to the power switch driver circuit 20
The control signal of the cut-off time of switching tube 30；
With above-described embodiment disclosed in LED drive circuit it is corresponding, referring to Fig. 7, the maximum cut-off time control circuit
42, including：
Second electric capacity C2 of negative pole ground connection；
The threeth controlling switch K3 in parallel with the second electric capacity C2, the 3rd controlling switch K3 control terminal are used to obtain
Take the inverted signal of the output signal of the power switch driver circuit 20；
The adjustable DC power supply IRT being connected with the positive pole of the second electric capacity C2, the Switching Power Supply are in first state
When, the adjustable DC power supply IRT is charged with default 3rd predetermined current of active user to the second electric capacity C2.
With above-described embodiment disclosed in LED drive circuit it is corresponding, referring to Fig. 7, the adjustable DC source IRT, can wrap
Include：
The 3rd DC source i3 that output end is connected with the second electric capacity C2 positive poles；
The adjustable resistance RT being connected with the 3rd DC source i3, the adjustable resistance RT are used to adjust the 3rd direct current
The size of current of source i3 outputs.
It is understood that being directed to above-mentioned LED drive circuit, disclosed herein as well is a kind of control of LED drive circuit
Method processed, applied in Switching Power Supply, including：
The sampled signal for characterizing the Switching Power Supply energy-storage units electric current is obtained, setting value is reached in the sampled signal
When, control the Switching Power Supply power switch to end；
The state that the Switching Power Supply is presently in is judged, if the Switching Power Supply is in first state, during with first
Between deadlines of the T1 as the power switch pipe of the Switching Power Supply；If the Switching Power Supply is in the second state, with
Deadlines of the second time T2 as the power switch pipe, the very first time T1 are less than the second time T2.
Corresponding with said apparatus, the above method can also include：When the Switching Power Supply is in first state or second
During state, ON times of the 3rd time T3 as the power switch pipe is provided according to user's request.
Corresponding with said apparatus, the above method can also include：Detect electric in the Switching Power Supply outlet side diode
Stream whether zero crossing, if then control power switch conducting.
The Switching Power Supply is in the second state：The load of the Switching Power Supply is in short-circuit condition.
It is corresponding with said apparatus, it is described using very first time T1 as the LED drive circuit in power switch pipe
Deadline, including：
A trigger signal is exported every power switch driver circuits of the very first time T1 into the LED drive circuit；
The deadline using the second time T2 as the power switch pipe, including：
To export a trigger signal to the power switch driver circuit every the second time T2；
Wherein, the trigger signal is used to control the power switch pipe to turn on by the power switch driver circuit.
Specifically, the power switch pipe using very first time T1 as the Switching Power Supply corresponding with said apparatus
Deadline, including：
The very first time T1 is provided by way of to electric capacity charge/discharge, the switch is used as using very first time T1
The deadline of the power switch pipe of power supply；
The deadline using the second time T2 as the power switch pipe, including：
The second time T2 is provided by way of to electric capacity charge/discharge, the power is used as using the second time T2
The deadline of switching tube.
It is understood that correspond to above-mentioned LED drive circuit, disclosed herein as well is a kind of Switching Power Supply, it can be with
Using there is LED drive circuit disclosed in above-mentioned any one.
Wherein, it can be Buck power supplys or Buck-Boost power supplys that the Switching Power Supply, which is,.
When the Switching Power Supply is Buck power supplys and the LED drive circuit is the drive circuit with adjustable resistance RT
When, referring to Fig. 9, the Switching Power Supply includes：
Light modulator 60；
The inductance L that first end is connected with the output end of the light modulator 60；
Negative pole is connected with the first end of the inductance L, and positive pole is connected by diode D with the second end of the inductance L
3rd electric capacity C3, the negative electrode of the diode D are connected with the positive pole of the 3rd electric capacity C3, anode and the second of the inductance L
End is connected；
The LED drive circuit 100 also includes：
The zero passage detection switching tube 70 that first end is connected with the second end of the inductance L；
The first end of the power switch pipe 30 detects the circuit 70 and inductance L the second end by the zero-acrross ing moment
It is connected, the common port of the zero passage detection switching tube 70 and the power switch pipe 30 is used to provide zero-acrross ing moment detection signal
Source, the second end of the power switch pipe 30 are grounded by first resistor R1；
One end of the adjustable resistance RT is connected with the 3rd dc source i3, other end ground connection；
The negative pole of the sustained diode is connected by second resistance R2 with the feeder ear VCC of the LED drive circuit；
The feeder ear VCC of the LED drive circuit is grounded by the 4th electric capacity C4.
Each embodiment is described by the way of progressive in this specification, what each embodiment stressed be and other
The difference of embodiment, between each embodiment identical similar portion mutually referring to.For method disclosed in embodiment
For, due to its with embodiment disclosed in circuit it is corresponding, so description is fairly simple, related part is said referring to method part
It is bright.
The foregoing description of the disclosed embodiments, professional and technical personnel in the field are enable to realize or using the present invention.
A variety of modifications to these embodiments will be apparent for those skilled in the art, as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, it is of the invention
The embodiments shown herein is not intended to be limited to, and is to fit to and principles disclosed herein and features of novelty phase one
The most wide scope caused.
Claims (4)
- A kind of 1. LED drive circuit, applied in Switching Power Supply, it is characterised in that including：The power switch pipe that output end is connected with the energy-storage units in the Switching Power Supply；The power switch driver circuit that output end is connected with the control terminal of the power switch pipe；Output end is connected with the input of the power switch driver circuit, for controlling the cut-off time of the power switch pipe Cut-off time control circuit；The cut-off time control circuit, including：Energy-storage units current detection circuit, for when electric current reaches setting value in the energy-storage units of Switching Power Supply, by described Power switch driver circuit controls the cut-off time of the power switch pipe；Maximum ON time control circuit, for providing ON times of the 3rd time T3 as the power switch pipe, pass through The power switch driver circuit controls the cut-off time of the power switch pipe；Circuit is adjusted, for adjusting the size of the 3rd time T3 according to user's request.
- 2. LED drive circuit according to claim 1, it is characterised in that the maximum ON time control circuit is used for The 3rd time T3 is provided by the charge/discharge time of electric capacity；The regulation circuit be used for according to user's request by adjust the filling of the electric capacity in the maximum ON time control circuit/ Electric discharge adjusts the 3rd time T3.
- 3. LED drive circuit according to claim 1 or 2, it is characterised in that the energy-storage units current detection circuit bag Include：Second comparator, the first input end of second comparator are used to obtain adopting for the Switching Power Supply energy-storage units electric current Sample signal, the second input are used to obtain the second reference signal, the comparison knot according to the sampled signal and the second reference signal Fruit exports the control signal that the cut-off time for controlling the power switch pipe is exported to the power switch driver circuit；The cut-off time control circuit, including：Second electric capacity of negative pole ground connection；Threeth controlling switch in parallel with second electric capacity, the control terminal of the 3rd controlling switch are used to obtain the power The inverted signal of the output signal of switch driving circuit；The adjustable DC power supply being connected with the positive pole of second electric capacity, with default 3rd predetermined current of active user to described Second electric capacity charges.
- 4. LED drive circuit according to claim 3, it is characterised in that the adjustable DC source, including：The 3rd DC source that output end is connected with second capacitance cathode；The adjustable resistance being connected with the 3rd DC source, the adjustable resistance are used for the electricity for adjusting the 3rd DC source output Flow size.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711083767.5A CN107635323B (en) | 2016-01-13 | 2016-01-13 | LED drive circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610020741.5A CN105517244B (en) | 2016-01-13 | 2016-01-13 | LED drive circuit and the method at controlling switch power supply conduction and cut-off moment |
| CN201711083767.5A CN107635323B (en) | 2016-01-13 | 2016-01-13 | LED drive circuit |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201610020741.5A Division CN105517244B (en) | 2016-01-13 | 2016-01-13 | LED drive circuit and the method at controlling switch power supply conduction and cut-off moment |
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| CN107635323A true CN107635323A (en) | 2018-01-26 |
| CN107635323B CN107635323B (en) | 2019-10-08 |
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| CN201711083767.5A Active CN107635323B (en) | 2016-01-13 | 2016-01-13 | LED drive circuit |
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| CN107071964B (en) * | 2017-02-10 | 2019-04-30 | 深圳欧创芯半导体有限公司 | Low voltage difference output current overshoot suppression circuit |
| CN107690213B (en) * | 2017-10-17 | 2024-05-24 | 无锡恒芯微科技有限公司 | Non-isolated low-voltage non-flicker LED driving circuit |
| CN108347168A (en) * | 2018-03-15 | 2018-07-31 | 广州金升阳科技有限公司 | A kind of time width detection circuit and its control method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102316627A (en) * | 2010-06-29 | 2012-01-11 | 日立空调·家用电器株式会社 | Led lighting device |
| CN104869686A (en) * | 2014-02-26 | 2015-08-26 | 欧司朗有限公司 | Driving circuit and illuminating device comprising same |
| CN204836696U (en) * | 2015-08-05 | 2015-12-02 | 肖志军 | Constant -current drive circuit that LED lamp can be adjusted luminance |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3829532B2 (en) * | 1999-05-26 | 2006-10-04 | 松下電工株式会社 | Discharge lamp lighting device |
| CN101951177B (en) * | 2010-09-06 | 2014-05-07 | Bcd半导体制造有限公司 | Switching power supply system and switching power supply control circuit |
| CN102412727B (en) * | 2011-11-25 | 2014-02-19 | 成都芯源系统有限公司 | Switching power supply, control circuit thereof and dimming method |
| CN205491291U (en) * | 2016-01-13 | 2016-08-17 | 上海新进芯微电子有限公司 | Light -emitting diode (LED) driving circuit |
-
2016
- 2016-01-13 CN CN201610020741.5A patent/CN105517244B/en active Active
- 2016-01-13 CN CN201711083767.5A patent/CN107635323B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102316627A (en) * | 2010-06-29 | 2012-01-11 | 日立空调·家用电器株式会社 | Led lighting device |
| CN104869686A (en) * | 2014-02-26 | 2015-08-26 | 欧司朗有限公司 | Driving circuit and illuminating device comprising same |
| CN204836696U (en) * | 2015-08-05 | 2015-12-02 | 肖志军 | Constant -current drive circuit that LED lamp can be adjusted luminance |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105517244B (en) | 2018-04-06 |
| CN105517244A (en) | 2016-04-20 |
| CN107635323B (en) | 2019-10-08 |
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