CN205491291U - Light -emitting diode (LED) driving circuit - Google Patents
Light -emitting diode (LED) driving circuit Download PDFInfo
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- CN205491291U CN205491291U CN201620031073.1U CN201620031073U CN205491291U CN 205491291 U CN205491291 U CN 205491291U CN 201620031073 U CN201620031073 U CN 201620031073U CN 205491291 U CN205491291 U CN 205491291U
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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 utility model provides a light -emitting diode (LED) driving circuit, including the control circuit constantly that switches on constantly that switches on of control power switch tube, the control power switch tube by constantly by control circuit constantly, switching on constantly, control circuit includes: the biggest cut off time control circuit for when switching power supply is in first state, with the cut off time that very first time T1 regards as the power switch pipe, work as when switching power supply is in the second state to the cut off time that second time T2 managed as the power switch, very first time T1 is less than second time T2. Control circuit includes by the moment: the biggest turn -on time control circuit provides the T3 conduct of third time the turn -on time of power switch pipe, through the control of power switch drive circuit ending constantly of power switch pipe. Thereby light -emitting diode (LED) driving circuit's control performance has been improved.
Description
Technical field
This utility model relates to switch power technology field, is specifically related to a kind of LED drive circuit.
Background technology
In Switching Power Supply, dimmer, when regulating on-Line Voltage, needs to carry out unnecessary on-Line Voltage
Excision, the portion voltage that on-Line Voltage modulated light device cuts away is 0, if now, the driving electricity of Switching Power Supply
Power tube in road is opened, and does not the most now have energy storage in the energy-storage units of Switching Power Supply；When in drive circuit
Power tube when closing because described energy-storage units is not transferred to outfan energy, so described driving
Electric circuit inspection, less than the moment of energy-storage units electric current to zero, i.e. can't detect the moment that power tube should turn on,
Therefore, generally at T1 of described control circuit indoor design one the longest power tube shut-in time.But T1's
Arranging when can cause some steamed bread ripple on-Line Voltage just over 0, power tube is switched on；And adjacent steamed bread ripple
After on-Line Voltage is more than 0, waiting the time of T1, described power tube is just opened.Therefore, if T1 is long,
Then can cause adjacent two steamed bread ripples, output energy is asymmetric, and then causes LED flicker occur；Work as LED
During load short circuits, because the output voltage of described Switching Power Supply is too low, described drive circuit detects not equally
In the moment that should turn on to power tube, now, just power tube is opened after still passing through the T1 time.If
T1 is too short, then operating frequency during LED load short circuit is higher, causes short-circuit dissipation the biggest.How to improve
The performance of LED drive circuit, preferably to power as those skilled in the art's skill urgently to be resolved hurrily to load
One of art problem.
Utility model content
In view of this, this utility model embodiment provides a kind of LED drive circuit, to improve LED driving electricity
The performance on road, it is achieved power supply more preferable to LED load.
For achieving the above object, the following technical scheme of this utility model embodiment offer:
A kind of LED drive circuit, is applied in Switching Power Supply, including:
The power switch pipe that outfan is connected with the energy-storage units in described Switching Power Supply；
Outfan controls, with described power switch pipe, the power switch driver circuit that end is connected；
Outfan is connected with the input of described power switch driver circuit, is used for controlling described power switch
The turn-on instant control circuit of the turn-on instant of pipe；
Wherein, described turn-on instant control circuit, including:
Maximum control circuit deadline, for when when being in the first state of described Switching Power Supply, it is provided that
Very first time T1 is as the deadline of described power switch pipe, when described Switching Power Supply is in the second state
Time, it is provided that the second time T2 is as the deadline of described power switch pipe, and described very first time T1 is little
In the second time T2.
Preferably, in above-mentioned LED drive circuit, described first state is the online electricity of described Switching Power Supply
When pressure is 0；Described second state is the load short circuits of described Switching Power Supply.
Preferably, in above-mentioned LED drive circuit, described turn-on instant control circuit, also include:
Zero cross detection circuit, for when current over-zero in the outlet side diode of Switching Power Supply, by institute
State power switch driver circuit and control the turn-on instant of described power switch pipe.
Preferably, in above-mentioned LED drive circuit, described maximum control circuit deadline, specifically for:
When the on-Line Voltage of described Switching Power Supply is 0, drive to described power switch every very first time T1
Circuit output once triggers signal, otherwise, with every the second time T2 to described power switch driver circuit
Output once triggers signal, and described triggering signal is described for being controlled by described power switch driver circuit
Power switch pipe turns on.
Preferably, in above-mentioned LED drive circuit, described maximum control circuit deadline is by electricity
Hold charge/discharge and described very first time T1 and the second time T2 is provided.
Preferably, in above-mentioned LED drive circuit, described maximum control circuit deadline, including:
First electric capacity of minus earth；
The first control switch in parallel with described first electric capacity, the described first control end controlling switch is used for
Obtain the output signal of described power switch driver circuit；
The DC source being connected with the positive pole of described first electric capacity, when the on-Line Voltage of described Switching Power Supply is 0
Time, described DC source, otherwise, is preset with second described first electric capacity charging with the first predetermined current
Electric current is to described first electric capacity charging, and described first predetermined current is more than the second predetermined current；
The first comparator that first input end is connected with the positive pole of described first electric capacity, described first comparator
The second input for obtaining the first reference voltage, the outfan of described first comparator as described
The outfan of big turn-on instant control circuit.
Preferably, in above-mentioned LED drive circuit, described DC source, including:
The first DC source that outfan is connected with the positive pole of described first electric capacity；
Second DC source and second controls switch, and described second controls first end and described second of switch
The outfan of DC source is connected, the second end is connected with the positive pole of described first electric capacity；
Outfan controls the state control circuit that the control end of switch is connected with described second, for when described
When the on-Line Voltage of Switching Power Supply is 0, turns on described second and control switch；Otherwise, described second is ended
Control switch.
Preferably, in above-mentioned LED drive circuit, outfan and the input of described power switch driver circuit
End is connected, for controlling the cut-off time control circuit of described power switch pipe cut-off time.
Preferably, in above-mentioned LED drive circuit, described cut-off time control circuit includes:
Energy-storage units current detection circuit, is used for when in the energy-storage units of Switching Power Supply, electric current reaches setting value
Time, the cut-off time of described power switch pipe is controlled by described power switch driver circuit；
Maximum ON time control circuit, for providing the 3rd time T3 leading as described power switch pipe
The logical time, controlled the cut-off time of described power switch pipe by described power switch driver circuit；
Regulation circuit, for regulating the size of described 3rd time T3 according to user's request.
Preferably, in above-mentioned LED drive circuit, described maximum ON time control circuit is for by electricity
The charge/discharge time held provides described 3rd time T3；
Described regulation circuit is used for according to user's request by the described maximum ON time control circuit of regulation
Electric capacity charge/discharge regulate described 3rd time T3.
A kind of LED drive circuit, is applied in Switching Power Supply, including:
The power switch pipe that outfan is connected with the energy-storage units in described Switching Power Supply；
Outfan controls, with described power switch pipe, the power switch driver circuit that end is connected；
Outfan is connected with the input of described power switch driver circuit, is used for controlling described power switch
The cut-off time control circuit of the cut-off time of pipe；
Described cut-off time control circuit, including:
Energy-storage units current detection circuit, is used for when in the energy-storage units of Switching Power Supply, electric current reaches setting value
Time, the cut-off time of described power switch pipe is controlled by described power switch driver circuit；
Maximum ON time control circuit, for providing the 3rd time T3 leading as described power switch pipe
The logical time, controlled the cut-off time of described power switch pipe by described power switch driver circuit；
Regulation circuit, for regulating the size of described 3rd time T3 according to user's request.
Preferably, in above-mentioned LED drive circuit, described maximum ON time control circuit is for by electricity
The charge/discharge time held provides described 3rd time T3；
Described regulation circuit is used for according to user's request by the described maximum ON time control circuit of regulation
Electric capacity charge/discharge regulate described 3rd time T3.
Preferably, in above-mentioned LED drive circuit, described energy-storage units current detection circuit includes:
Second comparator, the first input end of described second comparator is used for obtaining described Switching Power Supply energy storage
The sampled signal of cell current, the second input is for obtaining the second reference signal, according to described sampling letter
Number and the second reference signal comparative result output to described power switch driver circuit output be used for controlling institute
State the control signal of the cut-off time of power switch pipe；
Described maximum cut-off time control circuit, including:
Second electric capacity of minus earth；
The threeth control switch in parallel with described second electric capacity, the described 3rd control end controlling switch is used for
Obtain the inverted signal of the output signal of described power switch driver circuit；
The adjustable DC power supply being connected with the positive pole of described second electric capacity, with active user preset the 3rd pre-
If electric current is to described second electric capacity charging.
Preferably, in above-mentioned LED drive circuit, described adjustable DC source, including:
The 3rd DC source that outfan is connected with described second capacitance cathode；
The adjustable resistance being connected with described 3rd DC source, described adjustable resistance is used for regulating described 3rd straight
The size of current of stream source output.
When using the described LED drive circuit work shape to Switching Power Supply disclosed in the above embodiments of the present application
When state is controlled, when described maximum deadline control circuit 11 detect that described Switching Power Supply is in the
During one state, control described power according to the very first time T1 preset by described power switch driver circuit
The deadline of switching tube, i.e. within the T1 time period, described power switch pipe is in the conduction state, works as institute
State and detect when described Switching Power Supply is in the second state, control described merit according to the second time T2 preset
The deadline of rate switching tube, i.e. within the T2 time period, described power switch pipe is in the conduction state, can
See that the application is directed to the different conditions residing for described Switching Power Supply, to setting respectively of described power switch pipe
Having put different maximum ON times, and made, described very first time T1 is less than the second time T2,
Therefore, when described Switching Power Supply is in the second state, the ON time of described power switch pipe is long, enters
And the operating frequency that may result in now LED load is relatively low compared to for normal condition, thus reduce negative
Carry power consumption in this condition.Therefore improve the power supply performance of described LED drive circuit.
Accompanying drawing explanation
In order to be illustrated more clearly that this utility model embodiment or technical scheme of the prior art, below will
The accompanying drawing used required in embodiment or description of the prior art is briefly described, it should be apparent that,
Accompanying drawing in describing below is only embodiment of the present utility model, comes for those of ordinary skill in the art
Say, on the premise of not paying creative work, it is also possible to obtain other accompanying drawing according to the accompanying drawing provided.
Fig. 1 is the structural representation of a kind of LED drive circuit disclosed in the embodiment of the present application；
Fig. 2 is the structural representation of a kind of LED drive circuit disclosed in another embodiment of the application；
Fig. 3 is the structural representation of a kind of LED drive circuit disclosed in another embodiment of the application；
Fig. 4 is the structural representation of a kind of LED drive circuit disclosed in another embodiment of the application；
Fig. 5 is the structural representation of a kind 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 bread ripple；
Fig. 7 is the structural representation of a kind of LED drive circuit disclosed in another embodiment of the application；
Fig. 8 is the structural representation of a kind of LED drive circuit disclosed in another embodiment of the application；
Fig. 9 is the structural representation of a kind of Switching Power Supply disclosed in the embodiment of the present application.
Detailed description of the invention
Below in conjunction with the accompanying drawing in this utility model embodiment, to the technology in this utility model embodiment
Scheme is clearly and completely described, it is clear that described embodiment is only this utility model one
Divide embodiment rather than whole embodiments.Based on the embodiment in this utility model, this area is common
The every other embodiment that technical staff is obtained under not making creative work premise, broadly falls into this
The scope of utility model protection.
It is directed to the problems referred to above of the prior art, this application discloses a kind of LED drive circuit.
Seeing Fig. 1, this application discloses a kind of LED drive circuit, this LED drive circuit is applied to out
Close in power supply, including:
The power switch pipe M that outfan is connected with the energy-storage units 00 in described Switching Power Supply；
The power switch driver circuit 20 that outfan is connected with the control end of described power switch pipe 30, described
Power switch driver circuit 20 for controlling the conducting of described power switch pipe 30 according to the signal got
State；
The turn-on instant control circuit that outfan is connected with the input of described power switch driver circuit 20
10, described turn-on instant control circuit 10 is described for being controlled by described power switch driver circuit 20
The turn-on instant of power switch pipe 30；
Maximum control circuit deadline 11, described maximum it is provided with in described turn-on instant control circuit 10
Deadline, control circuit 11 was for when described Switching Power Supply is in the first state, it is provided that very first time T1
As the deadline of described power switch pipe 30, when when being in the second state of described Switching Power Supply, carry
For the second time T2 as deadline of described power switch pipe 30, described very first time T1 is less than the
Two time T2.
When using the described LED drive circuit work shape to Switching Power Supply disclosed in the above embodiments of the present application
When state is controlled, when described maximum deadline control circuit 11 detect that described Switching Power Supply is in the
During one state, controlled described by described power switch driver circuit 20 according to the very first time T1 preset
The deadline of power switch pipe 30, i.e. within the T1 time period, described power switch pipe 30 is in cut-off
State, when described Switching Power Supply is in the second state, controls described merit according to the second time T2 preset
The deadline of rate switching tube 30, i.e. within the T2 time period, described power switch pipe is in cut-off state,
Visible the application is directed to the different conditions residing for described Switching Power Supply, dividing described power switch pipe 30
Not being provided with different maximum deadlines, and make, described very first time T1 was less than for the second time
T2, therefore, when described Switching Power Supply is in the second state, the deadline of described power switch pipe is long,
And then the operating frequency that may result in now LED load is relatively low compared to for normal condition, thus reduce
Load power consumption in this condition.
Wherein, in concrete above-described embodiment, described first state is the on-Line Voltage of described Switching Power Supply
It it is state when 0；Described second state is the state of the load short circuits of described Switching Power Supply.
It is understood that in order to realize the described turn-on instant control circuit 10 electricity in described Switching Power Supply
When pressure is more than 0, the control to the conducting state of described power switch pipe 30, see Fig. 2, in the application
Stating in technical scheme disclosed in embodiment, described turn-on instant control circuit 10 can also include:
Zero cross detection circuit 12, described zero cross detection circuit 12 is for when the outlet side diode of Switching Power Supply
During middle current over-zero, control leading of described power switch pipe 30 by described power switch driver circuit 20
The logical moment.Certainly, it should be noted that defeated about the Switching Power Supply when Switching Power Supply in prior art
Circuit when going out current over-zero in the diode of side, the conducting state of described power switch pipe 30 being controlled and
Method has tended to ripe, and therefore, those skilled in the art directly use in prior art for described
The control circuit that the conducting state of power switch pipe 30 is controlled is as disclosed in the above embodiments of the present application
Described zero cross detection circuit 12.
It is understood that in order to optimize described maximum cut-off disclosed in the above embodiments of the present application further
The control process of time control circuit 11, the specific works mistake of described maximum control circuit deadline 11
Journey can be:
When the on-Line Voltage of described Switching Power Supply is 0, described zero cross detection circuit is not detected by outlet side
In diode during current over-zero, export one every very first time T1 to described power switch driver circuit 20
Secondary triggering signal, (the bearing of the most described Switching Power Supply when the on-Line Voltage of described Switching Power Supply is more than 0
When carrying short circuit), once trigger to export to described power switch driver circuit 20 every the second time T2
Signal, the triggering signal that described maximum control circuit deadline 11 is sent is for for by described power
Switch driving circuit 20 controls the triggering signal of described power switch pipe 30 conducting.
It is understood that in circuit, described very first time T1 and the generating mode of the second time T2
Varied, such as it can have control chip to generate, and the most described control chip is for when described switch
When the on-Line Voltage of power supply is 0, described zero cross detection circuit is not detected by electric current mistake in outlet side diode
When zero, generate very first time T1, when the on-Line Voltage of described Switching Power Supply is more than 0, when generating second
Between T2.Certainly, those skilled in the art can also use other generating modes to generate described very first time T1
With the second time T2, it is preferred that cut maximum described in technical scheme disclosed in the above embodiments of the present application
Only time control circuit 11 can be by electric capacity charge/discharge provides described very first time T1 and second
Time T2's, now, electric capacity can be charged by it by DC source, varying in size of charging current
Electric capacity can be caused to be charged to time of predeterminated voltage different, electric capacity be raised to time of predeterminated voltage i.e. it is believed that
It is very first time T1 and the second time T2.
When described maximum deadline, control circuit 11 was by providing described first to electric capacity charge/discharge
Between T1 and the second time T2 time, see Fig. 3, described maximum deadline, control circuit 11, can wrap
Include:
First electric capacity C1 of minus earth；
With described first first control switch K1 in parallel for electric capacity C1, described first controls the control of switch K1
End processed is for obtaining the output signal of described power switch driver circuit 30；
The DC source i being connected with the positive pole of described first electric capacity C1, when power tube ON time is by maximum
When ON time control circuit controls (when the on-Line Voltage of the most described Switching Power Supply is 0), described
Described first electric capacity C1 is charged, when power tube ON time is not by DC source i with the first predetermined current
When being controlled by maximum ON time control circuit (such as during load short circuits), with the second predetermined current pair
Described first electric capacity C1 charging, wherein, described first predetermined current is more than the second predetermined current；
The first comparator U1 that first input end is connected with the positive pole of described first electric capacity C1, described first
Second input of comparator U1 is used for obtaining the first reference voltage Vref, described first comparator U1's
Outfan is as the outfan of described maximum turn-on instant control circuit 11.
In foregoing circuit, if use the first predetermined current and the second predetermined current respectively to two simultaneously
The first different electric capacity C1 is charged, and uses the first predetermined current to fill described first electric capacity C1
During electricity, the time of the boost in voltage at described first electric capacity C1 two ends to the first reference voltage Vref can be designated as
Very first time T1, when using the second predetermined current that described first electric capacity C1 is charged, described first
The boost in voltage at electric capacity C1 two ends can be designated as the second time T2 to the time of the first reference voltage Vref, by
It is less than institute more than described second predetermined current, the very first time T1 therefore obtained in described first predetermined current
Stating the second time T2, user can be according to self-demand, and the first predetermined current and second needed for setting is preset
The i.e. available required very first time T1 and the second time T2 of electric current.
It is understood that control current source to export different size of first predetermined current and the second default electricity
The mode of stream can have multiple, and such as it can arrange required shunting electricity at the outfan of described current source
Road, can obtain different size of first predetermined current and second by the break-make controlling described shunt circuit
Predetermined current, naturally it is also possible to adopt first controlled in other ways needed for described DC source i generation user
Predetermined current and the second predetermined current, it is preferred that see Fig. 3, in skill disclosed in the above embodiments of the present application
In art scheme, described DC source i may include that
The first DC source i1 that outfan is connected with the positive pole of described first electric capacity C1；
Second DC source i2 and second control switch K2, described second control switch K2 the first end with
The outfan of described second DC source i2 is connected, the described second the second end and described the controlling switch K2
The positive pole of one electric capacity C1 is connected；
Outfan controls the state control circuit 111 that end is connected that controls of switch K2 with described second, described
State control circuit 111 is (ratio when power tube ON time is controlled by maximum ON time control circuit
When being 0 such as the on-Line Voltage of described Switching Power Supply), output is used for controlling described second control switch K2 and leads
Logical control signal；When power tube ON time be not by maximum ON time control circuit to control time (ratio
During such as load short circuits), output is for controlling the described second control signal controlling switch K2 cut-off.
That is, foregoing circuit is when described second switch pipe K2 closes, described first DC source i1 and second
DC source i2, collectively as described DC source i, exports the first predetermined current, when described second switch pipe
During K2 cut-off, described first DC source i1, as described DC source i, exports the second predetermined current.
It is understood that in technical scheme disclosed in the above embodiments of the present application the most described mistake
The control signal of zero testing circuit 12 and described maximum control circuit deadline 11 is transferred to described power
Switch driving circuit, sees Fig. 3, is additionally provided with a logic sum gate in described turn-on instant control circuit 10
OR, the first input end of described logic sum gate OR is connected with the outfan of described zero cross detection circuit 12,
Second input is connected with the outfan of described maximum control circuit deadline 11, is used for exporting described mistake
What zero testing circuit 12 and described maximum control circuit deadline 11 matched controls signal to described merit
Rate switch driving circuit 20.
It is understood that except above-mentioned for controlling described merit by described power switch driver circuit 20
Outside the turn-on instant control circuit 10 of the turn-on instant of rate switching tube 30, see Fig. 4, described LED and drive
Circuit also has for controlling cutting of described power switch pipe 30 by described power switch driver circuit 20
The only cut-off time control circuit 40 in moment, described cut-off time control circuit 40 outfan and described power
The input of switch driving circuit 20 is connected, described for being controlled by described power switch driver circuit 20
The cut-off time of power switch pipe.Wherein, traditional LED drive circuit has existed for described
The relevant control electricity of the cut-off time of described power switch pipe is controlled by described power switch driver circuit 20
Road, can directly use these circuit as cut-off time control circuit 40 described disclosed in the embodiment of the present application.
It is understood that applicant it has been investigated that, see Fig. 5, on-Line Voltage modulated light device cuts away
Part, because now on-Line Voltage is 0, when power switch pipe is opened, does not has in the energy-storage units of Switching Power Supply
There is energy storage；When described power switch pipe is closed, because being not transferred to outfan energy, so the most just
Can't detect the electric current of energy-storage units to the moment of zero, i.e. can't detect the moment that power tube should turn on.
Being directed to this, see Fig. 6, described cut-off time control circuit 40 may include that
Energy-storage units current detection circuit 41, for when the on-Line Voltage of Switching Power Supply is more than 0, passing through
Described power switch driver circuit 20 controls the cut-off time of described power switch pipe 30.
Maximum ON time control circuit 42, for when the on-Line Voltage of Switching Power Supply is 0, with the 3rd
Time T3 is as the ON time of described power switch pipe 30, by described power switch driver circuit 20
Control the cut-off time of described power switch pipe 30；
Regulation circuit 43, for regulating the size of described 3rd time T3 according to user's request.
Owing to, in the Switching Power Supply of different size, the size of the 3rd required time T3 can be different, therefore,
Technical scheme disclosed in the above embodiments of the present application can be by be set to by described 3rd time T3 can timing
Between, user can adjust the size of described 3rd time T3 according to the specification of Switching Power Supply.With above-described embodiment
Disclosed technical scheme is similar, and described 3rd time T3 can also be by the charge/discharge generation to electric capacity
, i.e. described maximum ON time control circuit 42 is for providing by the charge/discharge time of electric capacity
Described 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
During more than 0, when being controlled the cut-off of described power switch pipe 30 by described power switch driver circuit 20
Interlock circuit and the method carved have leveled off to maturation, and it can directly use of the prior art mutually powered-down
Road is as energy-storage units current detection circuit 41 described disclosed in the above embodiments of the present application, certainly, described
The structure of energy-storage units current detection circuit 41 can also see Fig. 7:
Described energy-storage units current detection circuit 41, including:
Second comparator U2, the first input end of described second comparator U2 is used for obtaining sampling inductance electricity
The ohmically magnitude of voltage of stream, the second input is for obtaining the second reference signal Vcsref, according to described
The ohmically magnitude of voltage of sampling inductive current and the comparative result of the second reference signal Vcsref export to institute
State power switch driver circuit 20 and export the control of the cut-off time for controlling described power switch pipe 30
Signal；
See Fig. 7, described maximum cut-off time control circuit 42, may include that
Second electric capacity C2 of minus earth；
With described second the 3rd control switch K3 in parallel for electric capacity C2, the described 3rd controls the control of switch K3
End processed is for obtaining the inverted signal of the output signal of described power switch driver circuit 20；
The adjustable DC power supply IRT being connected with the positive pole of described second electric capacity C2, according to required power
The value of factor and optimized dimming effect, described adjustable DC power supply IRT preset with active user
Three predetermined current are to described second electric capacity C3 charging, and certain user can be set by described regulation circuit 43
The size of described 3rd predetermined current thus obtain the 3rd required time T3；
First input end is connected with described second electric capacity C2 positive pole, the second input input has the 3rd benchmark letter
The 3rd comparator U3 of number VRTref, the outfan of described 3rd comparator U3 is as described maximum cut-off
The outfan of moment control circuit 42.
It is understood that user can regulate described with crossing the mode arranging adjustable resistance in above-described embodiment
The output electric current of adjustable DC source IRT, now, sees Fig. 5, described adjustable DC source IRT, including:
The 3rd DC source i3 that outfan is connected with described second electric capacity C2 positive pole；
The adjustable resistance RT being connected with described 3rd DC source i3, described adjustable resistance RT are used for regulating institute
State the size of current of the 3rd DC source i3 output.
It is understood that lead at described energy-storage units current detection circuit 41 and described maximum for convenience
The control signal of logical time control circuit 42 is transferred to described power switch driver circuit 20, sees Fig. 7,
A logic sum gate OR, described logic sum gate has been may also set up equally in described cut-off time control circuit 40
The first input end of OR is connected with the outfan of described energy-storage units current detection circuit 41, the second input
Hold the outfan with described maximum ON time control circuit 42 to be connected, be used for exporting described energy-storage units electricity
What current detection circuit 41 and described maximum ON time control circuit 42 matched controls signal to described merit
Rate switch driving circuit 20.
Preferably, in technical scheme disclosed in the above embodiments of the present application, described LED scheme can use figure
Set-up mode in 8, wherein, has introduced in partial content above-described embodiment and had illustrated, to these contents
The application is not illustrating.
Seeing Fig. 8, described regulation circuit preferably employs rest-set flip-flop, and the most described trigger obtains
Characterize the outfan of the short-circuit signal of load short circuits, the S end of described trigger and described 3rd comparator U3
Be connected, the R input of described rest-set flip-flop with by phase inverter X and described power switch driver circuit
The outfan of 20 is connected；
The input of described phase inverter X is connected with the outfan of described power switch driver circuit 20, output
End is connected with the control end of described 3rd switching tube K3 respectively at the R end of described rest-set flip-flop；
The outfan of described power switch driver circuit 20 is connected with the control end of described first switching tube；
The input of described zero cross detection circuit 12 is for obtaining the zero-acrross ing moment detection letter of described energy-storage units
Number Source for judging the outlet side of described Switching Power Supply according to described zero-acrross ing moment detection signal Source
Whether diode there is current over-zero.
It is understood that disclosed herein as well is another LED drive circuit, it is applied to switch electricity
In source, seeing Fig. 5, this LED drive circuit includes:
The power switch pipe 30 that outfan is connected with the energy-storage units 00 in described Switching Power Supply；
Outfan controls, with described power switch pipe 30, the power switch driver circuit 20 that end is connected；
The cut-off time control circuit that outfan is connected with the input of described power switch driver circuit 20
40, described cut-off time control circuit 40 is described for being controlled by described power switch driver circuit 20
The cut-off time of power switch pipe 30；
Described cut-off time control circuit 40, including:
Energy-storage units current detection circuit, is used for when in the energy-storage units of Switching Power Supply, electric current reaches setting value
Time, the cut-off time of described power switch pipe is controlled by described power switch driver circuit；
Maximum ON time control circuit 42, for providing the 3rd time T3 as described power switch pipe
The ON time of 30, controls cutting of described power switch pipe 30 by described power switch driver circuit 20
The only moment；
Regulation circuit 43, for regulating the size of described 3rd time T3 according to user's request.
With above-described embodiment disclosed in LED drive circuit corresponding, described maximum ON time control circuit
42, specifically for:
When the on-Line Voltage of Switching Power Supply is 0, drive electricity every the 3rd time T3 to described power switch
Road 20 exports once for controlling the triggering signal of described power switch pipe 30 cut-off.
With above-described embodiment disclosed in LED drive circuit corresponding, described maximum ON time control circuit
42 for providing described 3rd time T3 by the charge/discharge time of electric capacity；
Described regulation circuit 43 is used for according to user's request by the described maximum ON time control circuit of regulation
The charge/discharge of the electric capacity in 20 regulates described 3rd time T3.
With above-described embodiment disclosed in LED drive circuit corresponding, see Fig. 7, described energy-storage units electricity
Current detection circuit 41 includes:
Second comparator U2, the first input end of described second comparator U2 is for sampling inductive current
Ohmically magnitude of voltage, the second input is for obtaining the second reference signal Vcsref, according to described energy storage
Sampled signal CS of cell current and the comparative result output of the second reference signal Vcsref are opened to described power
Close drive circuit 20 output for controlling the control signal of the cut-off time of described power switch pipe 30；
With above-described embodiment disclosed in LED drive circuit corresponding, see Fig. 7, during described maximum cut-off
Carve control circuit 42, including:
Second electric capacity C2 of minus earth；
With described second the 3rd control switch K3 in parallel for electric capacity C2, the described 3rd controls the control of switch K3
End processed is for obtaining the inverted signal of the output signal of described power switch driver circuit 20；
The adjustable DC power supply IRT being connected with the positive pole of described second electric capacity C2, described Switching Power Supply is in
During the first state, the 3rd predetermined current that described adjustable DC power supply IRT presets with active user is to described
Second electric capacity C2 charging.
With above-described embodiment disclosed in LED drive circuit corresponding, see Fig. 7, described adjustable DC source
IRT, may include that
The 3rd DC source i3 that outfan is connected with described second electric capacity C2 positive pole；
The adjustable resistance RT being connected with described 3rd DC source i3, described adjustable resistance RT are used for regulating institute
State the size of current of the 3rd DC source i3 output.
It is understood that be directed to above-mentioned LED drive circuit, disclosed herein as well is a kind of LED and drive
The control method on galvanic electricity road, is applied in Switching Power Supply, including:
Obtain the sampled signal characterizing described Switching Power Supply energy-storage units electric current, arrive in described sampled signal
During setting value, control the cut-off of described Switching Power Supply power switch；
Judge the state that described Switching Power Supply is presently in, if described Switching Power Supply is in the first state,
Using very first time T1 as the deadline of the power switch pipe of described Switching Power Supply；If described switch electricity
Source is in the second state, then using the second time T2 as the deadline of described power switch pipe, and described
One time T1 is less than the second time T2.
Corresponding with said apparatus, said method can also include: when described Switching Power Supply is in the first shape
When state or the second state, provide the 3rd time T3 as the conducting of described power switch pipe according to user's request
Time.
Corresponding with said apparatus, said method can also include: detects described Switching Power Supply outlet side two
Electric current whether zero crossing in the pipe of pole, if then controlling power switch conducting.
Described Switching Power Supply is in the second state particularly as follows: the load of described Switching Power Supply is in short-circuit condition.
Corresponding with said apparatus, described using very first time T1 as described LED drive circuit in merit
The deadline of rate switching tube, including:
Export once every very first time T1 power switch driver circuit in described LED drive circuit
Trigger signal；
The described deadline using the second time T2 as described power switch pipe, including:
Once to trigger signal every the second time T2 to the output of described power switch driver circuit；
Wherein, described triggering signal is for controlling described power switch by described power switch driver circuit
Pipe turns on.
Concrete, corresponding with said apparatus, described using very first time T1 as described LED driving electricity
The deadline of the power switch pipe in road, including:
Described very first time T1 is provided by the way of to electric capacity charge/discharge, using very first time T1 as
The deadline of power switch pipe in described LED drive circuit；
The described deadline using the second time T2 as described power switch pipe, including:
Described second time T2 is provided by the way of to electric capacity charge/discharge, using the second time T2 as
The deadline of described power switch pipe.
It is understood that corresponding to above-mentioned LED drive circuit, disclosed herein as well is a kind of switch electricity
Source, it can apply LED drive circuit disclosed in above-mentioned any one.
Wherein, described Switching Power Supply is can be Buck power supply or Buck-Boost power supply.
When described Switching Power Supply is Buck power supply and described LED drive circuit is to have adjustable resistance RT's
During drive circuit, seeing Fig. 9, described Switching Power Supply includes:
Dimmer 60；
The inductance L that first end is connected with the outfan of described dimmer 60；
Negative pole is connected with first end of described inductance L, positive pole by diode D and described inductance L the
The 3rd electric capacity C3 that two ends are connected, the positive pole phase of the negative electrode of described diode D and described 3rd electric capacity C3
Even, anode is connected with second end of described inductance L；
Described LED drive circuit 100 also includes:
The zero passage detection switching tube 70 that first end is connected with second end of described inductance L；
First end of described power switch pipe 30 is by described zero-acrross ing moment testing circuit 70 and described inductance L
The second end be connected, described zero passage detection switching tube 70 is used for the common port of described power switch pipe 30
Thering is provided zero-acrross ing moment detection signal Source, the second end of described power switch pipe 30 passes through the first resistance
R1 ground connection；
One end of described adjustable resistance RT is connected with described 3rd DC source i3, other end ground connection；
The negative pole of described sustained diode is by the power supply of the second resistance R2 with described LED drive circuit
End VCC is connected；
The feeder ear VCC of described LED drive circuit passes through the 4th electric capacity C4 ground connection.
In this specification, each embodiment uses the mode gone forward one by one to describe, and each embodiment stresses
Being the difference with other embodiments, between each embodiment, identical similar portion sees mutually.
For method disclosed in embodiment, due to its with embodiment disclosed in circuit corresponding, so describing
Fairly simple, relevant part sees method part and illustrates.
Described above to the disclosed embodiments, makes professional and technical personnel in the field be capable of or uses
This utility model.Multiple amendment to these embodiments will be aobvious for those skilled in the art
And be clear to, generic principles defined herein can be without departing from spirit or scope of the present utility model
In the case of, realize in other embodiments.Therefore, this utility model is not intended to be limited to institute herein
These embodiments shown, and it is to fit to consistent with principles disclosed herein and features of novelty the widest
Scope.
Claims (14)
1. a LED drive circuit, is applied in Switching Power Supply, it is characterised in that including:
The power switch pipe that outfan is connected with the energy-storage units in described Switching Power Supply；
Outfan controls, with described power switch pipe, the power switch driver circuit that end is connected；
Outfan is connected with the input of described power switch driver circuit, is used for controlling described power switch
The turn-on instant control circuit of the turn-on instant of pipe；
Wherein, described turn-on instant control circuit, including:
Maximum control circuit deadline, for when when being in the first state of described Switching Power Supply, it is provided that
Very first time T1 is as the deadline of described power switch pipe, when described Switching Power Supply is in the second state
Time, it is provided that the second time T2 is as the deadline of described power switch pipe, and described very first time T1 is little
In the second time T2.
LED drive circuit the most according to claim 1, it is characterised in that described first state
When being 0 for the on-Line Voltage of described Switching Power Supply；Described second state is that the load of described Switching Power Supply is short
Road.
LED drive circuit the most according to claim 1, it is characterised in that described turn-on instant
Control circuit, also includes:
Zero cross detection circuit, for when current over-zero in the outlet side diode of Switching Power Supply, by institute
State power switch driver circuit and control the turn-on instant of described power switch pipe.
LED drive circuit the most according to claim 3, it is characterised in that described maximum cut-off
Time control circuit, specifically for:
When the on-Line Voltage of described Switching Power Supply is 0, drive to described power switch every very first time T1
Circuit output once triggers signal, otherwise, with every the second time T2 to described power switch driver circuit
Output once triggers signal, and described triggering signal is described for being controlled by described power switch driver circuit
Power switch pipe turns on.
LED drive circuit the most according to claim 1, it is characterised in that described maximum cut-off
Time control circuit is by electric capacity charge/discharge provides described very first time T1 and the second time T2.
LED drive circuit the most according to claim 1 or 5, it is characterised in that described maximum
Deadline control circuit, including:
First electric capacity of minus earth；
The first control switch in parallel with described first electric capacity, the described first control end controlling switch is used for
Obtain the output signal of described power switch driver circuit；
The DC source being connected with the positive pole of described first electric capacity, when the on-Line Voltage of described Switching Power Supply is 0
Time, described DC source, otherwise, is preset with second described first electric capacity charging with the first predetermined current
Electric current is to described first electric capacity charging, and described first predetermined current is more than the second predetermined current；
The first comparator that first input end is connected with the positive pole of described first electric capacity, described first comparator
The second input for obtaining the first reference voltage, the outfan of described first comparator as described
The outfan of big turn-on instant control circuit.
LED drive circuit the most according to claim 6, it is characterised in that described DC source,
Including:
The first DC source that outfan is connected with the positive pole of described first electric capacity；
Second DC source and second controls switch, and described second controls first end and described second of switch
The outfan of DC source is connected, the second end is connected with the positive pole of described first electric capacity；
Outfan controls the state control circuit that the control end of switch is connected with described second, for when described
When the on-Line Voltage of Switching Power Supply is 0, turns on described second and control switch；Otherwise, described second is ended
Control switch.
LED drive circuit the most according to claim 1, it is characterised in that also include, outfan
It is connected with the input of described power switch driver circuit, is used for controlling described power switch pipe cut-off time
Cut-off time control circuit.
LED drive circuit the most according to claim 8, it is characterised in that described cut-off time
Control circuit includes:
Energy-storage units current detection circuit, is used for when in the energy-storage units of Switching Power Supply, electric current reaches setting value
Time, the cut-off time of described power switch pipe is controlled by described power switch driver circuit；
Maximum ON time control circuit, for providing the 3rd time T3 leading as described power switch pipe
The logical time, controlled the cut-off time of described power switch pipe by described power switch driver circuit；
Regulation circuit, for regulating the size of described 3rd time T3 according to user's request.
LED drive circuit the most according to claim 9, it is characterised in that described maximum conducting
Time control circuit is for providing described 3rd time T3 by the charge/discharge time of electric capacity；
Described regulation circuit is used for according to user's request by the described maximum ON time control circuit of regulation
Electric capacity charge/discharge regulate described 3rd time T3.
11. 1 kinds of LED drive circuits, are applied in Switching Power Supply, it is characterised in that including:
The power switch pipe that outfan is connected with the energy-storage units in described Switching Power Supply；
Outfan controls, with described power switch pipe, the power switch driver circuit that end is connected；
Outfan is connected with the input of described power switch driver circuit, is used for controlling described power switch
The cut-off time control circuit of the cut-off time of pipe；
Described cut-off time control circuit, including:
Energy-storage units current detection circuit, is used for when in the energy-storage units of Switching Power Supply, electric current reaches setting value
Time, the cut-off time of described power switch pipe is controlled by described power switch driver circuit；
Maximum ON time control circuit, for providing the 3rd time T3 leading as described power switch pipe
The logical time, controlled the cut-off time of described power switch pipe by described power switch driver circuit；
Regulation circuit, for regulating the size of described 3rd time T3 according to user's request.
12. LED drive circuits according to claim 11, it is characterised in that described maximum is led
Logical time control circuit is for providing described 3rd time T3 by the charge/discharge time of electric capacity；
Described regulation circuit is used for according to user's request by the described maximum ON time control circuit of regulation
Electric capacity charge/discharge regulate described 3rd time T3.
13. according to the LED drive circuit described in claim 11 or 12, it is characterised in that described storage
Can include by cell current testing circuit:
Second comparator, the first input end of described second comparator is used for obtaining described Switching Power Supply energy storage
The sampled signal of cell current, the second input is for obtaining the second reference signal, according to described sampling letter
Number and the second reference signal comparative result output to described power switch driver circuit output be used for controlling institute
State the control signal of the cut-off time of power switch pipe；
Described maximum cut-off time control circuit, including:
Second electric capacity of minus earth；
The threeth control switch in parallel with described second electric capacity, the described 3rd control end controlling switch is used for
Obtain the inverted signal of the output signal of described power switch driver circuit；
The adjustable DC power supply being connected with the positive pole of described second electric capacity, with active user preset the 3rd pre-
If electric current is to described second electric capacity charging.
14. LED drive circuits according to claim 13, it is characterised in that described straight-adjustable
Stream source, including:
The 3rd DC source that outfan is connected with described second capacitance cathode；
The adjustable resistance being connected with described 3rd DC source, described adjustable resistance is used for regulating described 3rd straight
The size of current of stream source output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620031073.1U CN205491291U (en) | 2016-01-13 | 2016-01-13 | Light -emitting diode (LED) driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620031073.1U CN205491291U (en) | 2016-01-13 | 2016-01-13 | Light -emitting diode (LED) driving circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205491291U true CN205491291U (en) | 2016-08-17 |
Family
ID=56668490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620031073.1U Withdrawn - After Issue CN205491291U (en) | 2016-01-13 | 2016-01-13 | Light -emitting diode (LED) driving circuit |
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| Country | Link |
|---|---|
| CN (1) | CN205491291U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105517244A (en) * | 2016-01-13 | 2016-04-20 | 上海新进芯微电子有限公司 | LED (light-emitting diode) driving circuit and method for controlling conduction/cut-off time of switching power supply |
-
2016
- 2016-01-13 CN CN201620031073.1U patent/CN205491291U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105517244A (en) * | 2016-01-13 | 2016-04-20 | 上海新进芯微电子有限公司 | LED (light-emitting diode) driving circuit and method for controlling conduction/cut-off time of switching power supply |
| CN105517244B (en) * | 2016-01-13 | 2018-04-06 | 上海新进芯微电子有限公司 | LED drive circuit and the method at controlling switch power supply conduction and cut-off moment |
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