CN103648219B - Light-emitting diode (LED) switch constant-current driving circuit - Google Patents
Light-emitting diode (LED) switch constant-current driving circuit Download PDFInfo
- Publication number
- CN103648219B CN103648219B CN201310705124.5A CN201310705124A CN103648219B CN 103648219 B CN103648219 B CN 103648219B CN 201310705124 A CN201310705124 A CN 201310705124A CN 103648219 B CN103648219 B CN 103648219B
- Authority
- CN
- China
- Prior art keywords
- voltage
- led
- module
- output
- power tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 51
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 51
- 239000010703 silicon Substances 0.000 claims abstract description 51
- 239000003990 capacitor Substances 0.000 claims abstract description 39
- 238000001514 detection method Methods 0.000 claims abstract description 38
- 238000005070 sampling Methods 0.000 claims abstract description 12
- 238000004146 energy storage Methods 0.000 claims abstract description 4
- 230000000052 comparative effect Effects 0.000 claims description 21
- 238000012360 testing method Methods 0.000 claims description 21
- 230000001276 controlling effect Effects 0.000 claims description 18
- 238000012423 maintenance Methods 0.000 claims description 5
- 230000007704 transition Effects 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 9
- 230000008859 change Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention provides a light-emitting diode (LED) switch constant-current driving circuit. The LED switch constant-current driving circuit comprises a voltage input module, an energy storage inductor, a freewheel diode, an LED module serving a load, a power tube for draining current and constant current, a detection module for detecting an input voltage phase state, a dimming control module connected to the detection module, an error amplifier connected to the dimming control module, a valley bottom detection circuit for detecting power tube drain voltage, a pulse width modulation circuit connected to the error amplifier and the valley bottom detection circuit, a control circuit for controlling the power tube according to detection voltage and PWM signals and a driving circuit of the power tube, wherein according to the dimming control module, input reference voltage Vref2 of the error amplifier and dimming control signals Vdimo are generated jointly through the detection voltage and reference voltage Vref1; the error amplifier enables the Vref2 to be compared with sampling voltage; and the pulse width modulation circuit is used for generating the PWM signals. According to the LED switch constant-current driving circuit, an electrolytic capacitor is not needed, an electronic transformer and a silicon controlled dimmer are compatible, the unique power tube in multiplexing simultaneously gives consideration to the draining current and the constant current, and the cost is effectively reduced.
Description
Technical field
The present invention relates to LED Drive Control Technique field, particularly relate to a kind of LED switch constant-current drive circuit.
Background technology
LED is the semiconductor device worked under a kind of low-voltage direct condition, under the low-voltage alternating-current initial conditions of controllable silicon dimmer and electronic transformer, market demand LED being replaced to the application such as existing MR16 is very vigorous, and on this basis again the demand of compatible silicon controlled dimmer be also very considerable in the international market.But when replacing the traditional lighting light fixtures such as MR16 with LED, some problems can be run into:
First, the compatibility issue of LED and electronic transformer.The electric current flowing through electronic transformer must be more than or equal to its work keeping electric current guarantee electronic transformer reliable and stable, otherwise can make the desultory work of electronic transformer or not work, and occurs the phenomenon that LED glimmers.Electronic transformer in the application of the light fixtures such as MR16, because MR16 belongs to purely resistive load, and work time power ratio higher, can 50W be reached, therefore there is not compatibility issue with electronic transformer.But when MR16 is replaced to LED, the power of LED work greatly reduces, general is all at below 10W, and LED is not linear unit, input voltage must be greater than threshold voltage Vf just can have electric current to flow through LED, and this just causes when LED does not also have conducting, electric current is not had to flow through LED, also do not have electric current to flow through electronic transformer, electronic transformer just cannot normally work, Here it is LED application circuit and the incompatible reason of electronic transformer.Be illustrated in figure 1 the Buck type LED drive circuit 1 of alternative MR16 commonplace in prior art, what exported by electronic transformer 112 due to AC power 111 is the high frequency ac signal of 12vrms, therefore need to convert alternating voltage to direct voltage by rectification unit 113, the voltage that voltage input module 11 exports is the commutating voltage after sinusoidal voltage rectification.Because Buck circuit has requirement for minimum operating voltage, voltage after rectification must be greater than the threshold voltage Vf of LED string, therefore must carry out filtering and improve minimum voltage by the larger electrochemical capacitor C of parallel connection capacitance after voltage input module 11, exactly because the existence of this filter capacitor C, in a bit of time in twice power frequency period, this electrochemical capacitor C just can be filled, follow-up LED module 12 is powered by this electrochemical capacitor C or inductance L, other times voltage input module does not work, and does not also just have electric current to flow through from electronic transformer 112.And electronic transformer 112 must flow through certain electric current (namely keeping electric current) could keep normal operating conditions always, the existence of therefore larger filter capacitor C will cause electronic transformer 112 normally to work, there is intermittent output, practical manifestation out be exactly that LED module 12 is constantly glimmering.
Secondly, jumbo electrochemical capacitor is not used can to bring the stability problem of LED constant current.Solve the compatibility issue of electronic transformer, just must avoid using jumbo electrochemical capacitor, if but electrochemical capacitor that need not be large, the later input voltage of rectification just there will be the low pressure being low to moderate 0V, and due to the characteristic of electronic transformer, may there is the situation of less stable in its output voltage, and LED is a kind of current control device, needing the electric current of circuit to LED to regulate and control, is generally the control mode taking real-time constant current.When not adopting large electrochemical capacitor or at input voltage less stable, LED real-time current just likely less stable, also just can not realize reliable constant current.
Finally, application cost problem.Also need in some applications to support controllable silicon dimmer, and controllable silicon dimmer has the problem the same with electronic transformer, must ensure exactly to be greater than to keep the electric current of electric current to flow through the reliable and stable work of guarantee controllable silicon dimmer.In the scheme of more existing support controllable silicon dimmers, usually two kinds of solutions are had, one connects a part of bleeder circuit in chip exterior, the electric current ensureing to flow through controllable silicon dimmer and electronic transformer by bleeder circuit is greater than its maintenance electric current, make it normal work, but this bleeder circuit needs to increase many peripheral components, improves the cost of application system; Another kind inside chip, arranges a special power tube for leakage current, although this scheme greatly reduces the cost of system peripheral devices, needs to have more a special power tube for earial drainage, cause the cost increase of chip.
The development in existing LED Drive Control Technique field of these three problem extreme influence is this field urgent problem.
Summary of the invention
The shortcoming of prior art in view of the above, the object of the present invention is to provide a kind of LED switch constant-current drive circuit, for solving in prior art LED drive circuit and controllable silicon dimmer and the problem such as electronic transformer is incompatible, stability is not high, application cost is high.
For achieving the above object and other relevant objects, the invention provides a kind of LED switch constant-current drive circuit, described LED switch constant-current drive circuit at least comprises:
Voltage input module, described voltage input module comprises AC power, is connected to the controllable silicon dimmer of described AC power, is connected to the electronic transformer of described controllable silicon dimmer and is connected to the rectification unit of described electronic transformer output;
Inductance, is connected to the output of described voltage input module, for providing energy storage when input voltage is too low to load;
Diode, its anode is connected to described inductance, as fly-wheel diode;
LED module, is connected to the negative electrode of described diode, as load;
Power tube, its drain terminal is connected between described inductance and diode, source ground connection, size of current is adjusted by the switching frequency and/or duty ratio that regulate the gate voltage of described power tube, make the electric current flowing through described controllable silicon dimmer and electronic transformer be greater than its respective maintenance electric current, and realize the constant current of described LED module;
Detection module, is parallel to described Power Entry Module, is detected the phase state of input voltage by described detection module;
Dimming controlling module, be connected to the output of described detection module and be connected with a reference voltage, for detection voltage and described reference voltage are made comparisons and exported comparative result, described detection voltage be multiplied with described reference voltage simultaneously and export new reference voltage;
Error amplifier, is connected to described dimming controlling module and described LED module, and the sampled voltage that the reference voltage export described dimming controlling module and described LED module export is made comparisons, and exports comparative result;
The lowest point testing circuit, is connected to the drain terminal of described power tube, for detecting the source-drain voltage of described power tube, regulating pwm signal that described power tube is opened, reduce loss during described power tube conducting when this voltage is in the lowest point;
Pulse width modulation circuit, be connected to the output of described error amplifier and the lowest point testing circuit, pwm signal is produced by described error amplifier and the lowest point testing circuit acting in conjunction, the comparative result that described error amplifier exports controls described pwm signal and jumps to low level by high level, pwm signal described in the output voltage control of described the lowest point testing circuit by low transition to high level;
Control circuit, be connected to the output of described pulse width modulation circuit and described adjusting control circuit, output signal is selected according to the comparative result that described adjusting control circuit exports, directly export high level signal when the comparative result that described adjusting control circuit exports is low level, when the comparative result that described adjusting control circuit exports is high level, output signal follows the pwm signal that described pulse width modulation circuit exports;
Drive circuit, between the control end being connected to described control circuit and described power tube, drives the gate voltage of described power tube by the output signal of described control circuit.
Preferably, described controllable silicon dimmer be forward position controllable silicon or after along controllable silicon.
Preferably, described rectification unit comprises two groups of diode groups in parallel, and each diode group comprises two diodes of series connection, and the two poles of the earth of described electronic transformer are connected between two diodes of each diode group.
Preferably, the voltage that described voltage input module exports is the commutating voltage after sinusoidal voltage rectification.
Preferably, also comprise a filter capacitor, described filter capacitor one end is connected with the output of described voltage input module, other end ground connection.
Preferably, described detection module comprises at least 2 grades of divider resistances of series connection.
Preferably, described LED module comprises the LED string that multiple LED is composed in series, the sampling resistor of connecting with described LED string, the other end ground connection of described sampling resistor, the filter capacitor in parallel with described LED string and sampling resistor.
Preferably, also comprise a building-out capacitor, described building-out capacitor one end is connected with the output of described error amplifier, other end ground connection, for stablizing the output voltage of described error amplifier.
Preferably, also comprise a building-out capacitor, described building-out capacitor one end is connected with the output of described detection module, other end ground connection, for stablizing the output voltage of described detection module.
Preferably, the reference voltage being connected to described dimming controlling module input is default definite value or changing value.
As mentioned above, LED switch constant-current drive circuit of the present invention, has following beneficial effect:
1, the compatibility with controllable silicon dimmer and electronic transformer can just be realized without the need to jumbo electrochemical capacitor.
2, the current constant control stability of LED drive circuit is high.
3, without the need to external special current by pass, also without the need to built-in special earial drainage power tube, multiplexing high power valve uniquely,
Effectively reduce the cost of chip and system application.
Accompanying drawing explanation
Fig. 1 is shown as Buck type LED drive circuit schematic diagram of the prior art.
Fig. 2 is shown as LED switch constant-current drive circuit schematic diagram of the present invention.
The controllable silicon dimmer that Fig. 3 to Fig. 8 is shown as LED switch constant-current drive circuit of the present invention is operated in each point voltage waveform view when 100% duty ratio.
The controllable silicon dimmer that Fig. 9 to Figure 14 is shown as LED switch constant-current drive circuit of the present invention is operated in each point voltage waveform view when certain duty ratio.
Element numbers explanation
1 Buck type LED drive circuit
11 Power Entry Modules
111 AC power
112 electronic transformers
113 rectification units
12 LED modules
2 LED switch constant-current drive circuits
21 voltage input modules
211 AC power
212 controllable silicon dimmers
213 electronic transformers
214 rectification units
22 LED modules
221 LED strings
23 testing circuits
24 dimming controlling module
25 error amplifiers
26 the lowest point testing circuits
27 pulse width modulation circuits
28 control circuits
29 drive circuits
L inductance
D diode
M power tube
Embodiment
Below by way of specific instantiation, embodiments of the present invention are described, those skilled in the art the content disclosed by this specification can understand other advantages of the present invention and effect easily.The present invention can also be implemented or be applied by embodiments different in addition, and the every details in this specification also can based on different viewpoints and application, carries out various modification or change not deviating under spirit of the present invention.
Refer to Fig. 2 to Figure 14.It should be noted that, the diagram provided in the present embodiment only illustrates basic conception of the present invention in a schematic way, then only the assembly relevant with the present invention is shown in graphic but not component count, shape and size when implementing according to reality is drawn, it is actual when implementing, and the kenel of each assembly, quantity and ratio can be a kind of change arbitrarily, and its assembly layout kenel also may be more complicated.
As shown in Figure 2, the invention provides a kind of LED switch constant-current drive circuit 2, described LED switch constant-current drive circuit 2 comprises: voltage input module 21; Inductance L; Diode D; LED module 22; Power tube M; Testing circuit 23; Dimming controlling module 24; Error amplifier 25; The lowest point testing circuit 26; Pulse width modulation circuit 27; Control circuit 28; Drive circuit 29.
Voltage input module 21, for providing adjustable input voltage Vin.
As shown in Figure 2, described voltage input module 21 comprises AC power 211, is connected to the controllable silicon dimmer 212 of described AC power 211, is connected to the electronic transformer 213 of described controllable silicon dimmer 212 and is connected to the rectification unit 214 of described electronic transformer 213 output.
Described controllable silicon dimmer 212 can be forward position controllable silicon also can be rear along controllable silicon, in the present embodiment, is preferably forward position controllable silicon.
Described rectification unit 214 comprises two groups of diode groups in parallel, and each diode group comprises two diodes of series connection, and the two poles of the earth of described electronic transformer 213 are connected between two diodes of each diode group.
Can filter capacitor be connect after described voltage input module 21, also can not connect filter capacitor.In the present embodiment, be connected with filter capacitor C1 after described voltage input module 21, described filter capacitor C1 one end is connected with the output of described voltage input module 21, other end ground connection, carries out filtering for the voltage Vin exported described voltage input module 21.
The voltage Vin that described voltage input module 21 exports is the commutating voltage after sinusoidal voltage rectification.
As shown in Figure 2, described inductance L is connected to the output of described voltage input module 21, for providing energy storage when input voltage vin is too low to load LED lamp string 221, guarantees LED string 221 constant current operation.
As shown in Figure 2, the anode of described diode D is connected between described inductance L and described LED module 22, as fly-wheel diode.
As shown in Figure 2, described LED module 22 is connected to the negative electrode of described diode D, as load.
Described LED module 22 comprises the LED string 221 that multiple LED is composed in series, the other end ground connection of the sampling resistor Rfb connected with described LED string 221, described sampling resistor Rfb, the filter capacitor C2 in parallel with described LED string 221 and sampling resistor Rfb.In the present embodiment, described LED string 221 is the LED of 6 cascaded structures.
As shown in Figure 2, the drain terminal of described power tube M is connected between described inductance L and diode D, source ground connection, control by described drive circuit 29, size of current is adjusted by the switching frequency and/or duty ratio that regulate the gate voltage Vg of described power tube M, make the electric current flowing through described controllable silicon dimmer 212 and electronic transformer 213 be greater than its respective maintenance electric current, realize the constant current of described LED module 22 simultaneously.Play earial drainage effect when described controllable silicon dimmer 212 and electronic transformer 213 normally do not work, play constant current effect when described controllable silicon dimmer 212 and electronic transformer 213 normally work.
As shown in Figure 2, described detection module 23 is parallel to described Power Entry Module 21, is detected the phase state of input voltage vin by described detection module 21.
Described detection module 23 comprises at least two-stage divider resistance of series connection, and as shown in Figure 2, in the present embodiment, detection module is be parallel to described voltage input module 21 after two-stage divider resistance R1 and R2 be connected in series, R1 and R2 series connection.
The output of described detection module 23 is also connected with a building-out capacitor C3, and described building-out capacitor C3 other end ground connection, for stablizing the output voltage Vdim of described detection module 23.
As shown in Figure 2, described dimming controlling module 24 is connected to the output of described detection module 23 and is connected with a reference voltage Vref, described reference voltage Vref is default definite value or changing value, the detection voltage that described detection module 23 exports by described dimming controlling module 24 and described reference voltage Vref are made comparisons, export comparative result and be transferred to described control circuit 28, be multiplied with described reference voltage Vref by described detection voltage Vdim obtains new reference voltage Vref 2 simultaneously.
As shown in Figure 2, described error amplifier 25 is connected to described dimming controlling module 24 and described LED module 22, and the sampled voltage Vfb that the reference voltage Vref 2 described dimming controlling module 24 exported and described LED module 22 export makes comparisons, and export comparative result Vcomp.
The output of described error amplifier 25 is also connected with a building-out capacitor C4, and described building-out capacitor C4 one end is connected with the output of described error amplifier, other end ground connection, for stablizing the output voltage Vcomp of described error amplifier 25.
As shown in Figure 2, described the lowest point testing circuit 26 is connected to the drain terminal of described power tube M, for detecting the source-drain voltage of described power tube M, regulating pwm signal that described power tube M is opened, reduce loss during power tube M conducting when this voltage is in the lowest point.
As shown in Figure 2, described pulse width modulation circuit 27 is connected to the output of described error amplifier 25 and the lowest point testing circuit 26, pwm signal is produced by described error amplifier 25 and the lowest point testing circuit 26 acting in conjunction, the output voltage Vcomp of described error amplifier 25 controls described pwm signal and jumps to low level by high level, pwm signal described in the output voltage control of described the lowest point testing circuit 26 by low transition to high level.
As shown in Figure 2, described control circuit 28 is connected to the output of described pulse width modulation circuit 27 and described adjusting control circuit 24, output signal is selected according to the comparative result Vdimo that described adjusting control circuit 24 exports, directly export high level signal when the comparative result Vdimo that described adjusting control circuit exports is low level, when the comparative result Vdimo that described adjusting control circuit exports is high level, output signal follows the pwm signal that described pulse width modulation circuit 27 exports.
As shown in Figure 2, described drive circuit 29 is connected between the control end of described control circuit 28 and described power tube M, and the signal exported by described control circuit 28 drives the gate voltage Vg of described power tube M.
The operation principle of above-mentioned LED switch constant-current drive circuit 2 is as follows:
Do not connect the situation that controllable silicon dimmer 212 or controllable silicon dimmer 212 are operated in 100% duty ratio.After internal power source voltage normally works, voltage input module 21 exports adjustable input voltage Vin, and as shown in Figure 3, input voltage vin is the commutating voltage after sinusoidal voltage rectification, with the half period before sinusoidal voltage for one-period exports.Alternating voltage exports through controllable silicon dimmer 212, electronic transformer 213 and rectification unit 214, obtain by the resistance R1 of detection module 23 and R2 dividing potential drop the detection voltage Vdim reacting input voltage vin phase state again, building-out capacitor C3 is by the frequency glitches filtering of Vdim.Because do not connect controllable silicon dimmer 212 or controllable silicon dimmer 212 normally works, so DIM holds the most of the time to be in higher current potential, the comparative result Vdimo that dimming controlling module 24 is exported is also high level, and as shown in Figure 4, Vdimo is the high signal of 5V.The now pwm signal of output signal afterpulsing width modulation circuit 27 output of control circuit 28, power tube M plays constant current effect.Another output signal Vref2 of dimming controlling module 24 is the result that detection voltage Vdim is multiplied with reference voltage Vref, Vref can be definite value also can be changing value, when Vdim is high level, Vref2 equals reference voltage Vref, as shown in Figure 5, reference voltage Vref 2 i.e. reference voltage Vref is definite value.The electric current flowing through LED string 221 is converted to sampled voltage Vfb on sampling resistor Rfb, and as shown in Figure 5, Vfb is the signal with the change of input voltage vin amplitude.Positive and negative two inputs of error amplifier 25 are input to together with the Vref2 that this voltage exports with dimming controlling module 24 simultaneously, two signals compare by error amplifier 25, obtain comparative result Vcomp, the external building-out capacitor C4 of output COMP of error amplifier 25, compensate for voltage stabilizing to loop, and also have filter action, shown in Fig. 6, Vcomp keeps constant at twice power frequency period or in longer cycle time, thus make the mean value of two input signal Vref2 and Vfb of error amplifier 25 realize dynamic following, as shown in Figure 5, Vref2 is constant, Vfb is variable, in average, Vref2 and Vfb is consistent.The lowest point testing circuit 26 is from the drain terminal SW Received signal strength of power tube M, when the drain terminal voltage of power tube M is lower than set point, sending control signal makes pwm signal saltus step be high level, power tube M is opened with this, raise the drain terminal voltage of power tube M, reduce loss during power tube M conducting, the control signal that the lowest point testing circuit 26 exports is input to pulse width modulation circuit 27 and produces pwm signal together with Vcomp, wherein voltage Vcomp controls pwm signal and jumps to low level by high level, the control signal that the lowest point testing circuit 26 exports controls pwm signal by low transition to high level.Pwm signal obtains the gate voltage Vg of power tube M after control circuit 28 and drive circuit 29, and as shown in Figure 7, the gate voltage Vg of power tube M is the switching signal with certain duty ratio.Frequency and the duty ratio of this voltage and pwm signal are basically identical, thus control the on off state of power tube M, and adjustment flows through the electric current of LED module 22 to reach the object of constant current.As shown in Figure 8, idis is the discharging current of inductance, iL is inductive current waveform, inductance L constantly doing the action of discharge and recharge, after system stability, along with the change of input voltage, Vcomp remains a constant voltage, and the ON time of the power tube determined by this voltage also can keep constant, therefore within the time of single work period, the average current of inductance, namely the average current of power tube and input voltage remain one linear or close to linear relation.The final effect that realizes of whole loop is the electric current I led=Vref/Rfb keeping flow through LED.
When controllable silicon dimmer 212 is operated in certain duty ratio D1, after internal power source voltage normally works, voltage input module 21 exports adjustable input voltage Vin, input voltage vin is the commutating voltage after sinusoidal voltage rectification, with the half period before sinusoidal voltage for one-period exports, as shown in Figure 9, when alternating voltage is less, the undercurrent flowing through controllable silicon dimmer 212 normally works to make it, so output voltage is 0V; When alternating voltage increases, the electric current flowing through controllable silicon dimmer 212 is enough to make it normally work, and output voltage uprises instantaneously.Alternating voltage exports through controllable silicon dimmer 212, electronic transformer 213 and rectification unit 214, obtain by the resistance R1 of detection module 23 and R2 dividing potential drop the detection voltage Vdim reacting input voltage phase state again, building-out capacitor C3 is by the frequency glitches filtering of Vdim.Because controllable silicon dimmer 212 is with the operation of duty ratio D1, so the waveform of Vdim is also rendered as the pulse signal of duty ratio D1, detect voltage Vdim to compare with reference voltage Vref through described adjusting control circuit 24, the synchronous pulse signal of same frequency of the comparative result Vdimo obtained also to be duty ratio be D1, as shown in Figure 10, Vdimo is low level when input voltage vin is 0, and after input voltage vin raises, saltus step is high level.When Vdimo is low level, control circuit 28 directly exports high level, then is drawn high by the gate voltage Vg of drive circuit 29 by power tube M, and make power tube M conducting, now power tube M plays earial drainage effect; When Vdimo is high level, the pwm signal of output signal afterpulsing width modulation circuit 27 output of control circuit 28, power tube M plays constant current effect.As shown in figure 13, when controllable silicon dimmer 212 does not normally work, the gate voltage of power tube M is high level, is in conducting state; When controllable silicon dimmer 212 normally works, the gate voltage of power tube M is the switching signal of following pwm signal.Another output signal Vref2 of dimming controlling module 24 is the result that detection voltage Vdim is multiplied with reference voltage Vref, Vref can be definite value also can be changing value, Vref2 be with detect voltage Vdim same frequency, with the pulse signal of reference voltage Vref with amplitude, be the waveform schematic diagram of reference voltage Vref 2 in one-period as shown in figure 11, when Vdim is low level, Vref2 is 0; When Vdim is high level, Vref2 equals Vref.The electric current flowing through LED string 221 is converted to sampled voltage Vfb on sampling resistor Rfb, and as shown in figure 11, the mean value of Vfb and Vref2 realizes dynamic following at twice power frequency period or in longer cycle time, and in average, Vref2 and Vfb is consistent.Vfb and Vref2 is simultaneously input to positive and negative two inputs of error amplifier 25, two signals compare by error amplifier 25, obtain comparative result Vcomp, the external building-out capacitor C4 of output COMP of error amplifier 25, loop is compensated for voltage stabilizing, and also has filter action, shown in Figure 12, Vcomp keeps constant at twice power frequency period or in longer cycle time, and this value is less than the amplitude in duty ratio 100% situation.The lowest point testing circuit 26 is also input to pulse width modulation circuit 27 from the drain terminal SW Received signal strength of power tube M and produces pwm signal after process together with Vcomp, wherein voltage Vcomp controls pwm signal and jumps to low level by high level, and the lowest point testing circuit 26 controls pwm signal by low transition to high level.Pwm signal obtains the gate voltage Vg of power tube M after control circuit 28 and drive circuit 29, and as shown in figure 13, when detecting voltage Vdim low level, the gate voltage Vg of power tube M is high; When detecting voltage Vdim high level, the gate voltage Vg of power tube M and pwm signal are consistent, frequency and the duty ratio of this voltage and pwm signal are basically identical, thus control the on off state of power tube M, and adjustment flows through the electric current of LED module 22 to reach the object of constant current.As shown in figure 14, when controllable silicon dimmer 212 is idle, electric current is not had to flow through inductance L, when after controllable silicon dimmer 212 normally work, electric current flows through inductance L, simultaneously after system stability, in the time of single work period, the average current of inductance and input voltage remain one linearly or close to linear relation.The final effect that realizes of whole loop is the electric current keeping flow through LED
It is more than the course of work within single cycle 10ms.Other time is the work in this cycle of repetition.
In sum, LED switch constant-current drive circuit of the present invention 2 keeps linear by the current average that controls to flow through in the single switch cycle inductance L with the input voltage vin after rectification unit 214 or close to linear relation, by loop control make twice power frequency period or the LED average current maintenance more in the large period time constant; Simultaneously by detecting the phase state of the input voltage vin after rectification, convert the pulse signal Vdimo of the corresponding duty ratio of same frequency to, when controllable silicon dimmer 212 is closed, this pulse signal is low level, when controllable silicon dimmer 212 is opened, this pulse signal is high level, and then go the anode input of departure amplifier 25 or negative terminal to input or output with this signal, and then by loop, the average output current of the LED LED current be modulated into when not having dimming arrangement is multiplied by the duty ratio of dimmer pulse signal, thus realize light modulation.The Vdimo generated is imported in logic control circuit, when Vdimo is low level, is set high by the gate voltage of power tube, power tube conducting; When Vdimo is high level, the pwm signal that the gate voltage of power tube is produced by constant current loop determines.LED switch constant-current drive circuit 2 of the present invention adopts Boost framework, just can compatible silicon controlled dimmer and electronic transformer without the need to jumbo electrochemical capacitor, realizes stable current constant control; In addition, without the need to external current by pass, also without the need to built-in special earial drainage power tube, multiplexing unique high power valve, completes the function of earial drainage and constant current simultaneously, effectively can reduce the cost of chip and system application.So the present invention effectively overcomes various shortcoming of the prior art and tool high industrial utilization.
Above-described embodiment is illustrative principle of the present invention and effect thereof only, but not for limiting the present invention.Any person skilled in the art scholar all without prejudice under spirit of the present invention and category, can modify above-described embodiment or changes.Therefore, such as have in art usually know the knowledgeable do not depart from complete under disclosed spirit and technological thought all equivalence modify or change, must be contained by claim of the present invention.
Claims (10)
1. a LED switch constant-current drive circuit, is characterized in that, described LED switch constant-current drive circuit at least comprises:
Voltage input module, described voltage input module comprises AC power, is connected to the controllable silicon dimmer of described AC power, is connected to the electronic transformer of described controllable silicon dimmer output and is connected to the rectification unit of described electronic transformer output;
Inductance, first end is connected to the positive output end of described voltage input module, for providing energy storage when input voltage is too low to load;
Diode, its anode is connected to the second end of described inductance, as fly-wheel diode;
LED module, its input is connected to negative electrode, the output head grounding of described diode, as load;
Power tube, its drain terminal is connected between described inductance and diode, source ground connection, size of current is adjusted by the switching frequency and/or duty ratio that regulate the gate voltage of described power tube, make the electric current flowing through described controllable silicon dimmer and electronic transformer be greater than its respective maintenance electric current, and realize the constant current of described LED module;
Detection module, is parallel to described Power Entry Module, is detected the phase state of input voltage by described detection module;
Dimming controlling module, be connected to the output of described detection module and be connected with a reference voltage, for detection voltage and described reference voltage are made comparisons and exported comparative result, described detection voltage be multiplied with described reference voltage simultaneously and export new reference voltage;
Error amplifier, is connected to described dimming controlling module and described LED module, and the sampled voltage that the reference voltage export described dimming controlling module and described LED module export is made comparisons, and exports comparative result;
The lowest point testing circuit, is connected to the drain terminal of described power tube, for detecting the source-drain voltage of described power tube, regulating pwm signal that described power tube is opened, reduce loss during described power tube conducting when this voltage is in the lowest point;
Pulse width modulation circuit, be connected to the output of described error amplifier and the lowest point testing circuit, pwm signal is produced by described error amplifier and the lowest point testing circuit acting in conjunction, the comparative result that described error amplifier exports controls described pwm signal and jumps to low level by high level, pwm signal described in the output voltage control of described the lowest point testing circuit by low transition to high level;
Control circuit, be connected to the output of described pulse width modulation circuit and described adjusting control circuit, output signal is selected according to the comparative result that described adjusting control circuit exports, directly export high level signal when the comparative result that described adjusting control circuit exports is low level, when the comparative result that described adjusting control circuit exports is high level, output signal follows the pwm signal that described pulse width modulation circuit exports;
Drive circuit, between the control end being connected to described control circuit and described power tube, drives the gate voltage of described power tube by the output signal of described control circuit.
2. LED switch constant-current drive circuit according to claim 1, is characterized in that: described controllable silicon dimmer be forward position controllable silicon or after along controllable silicon.
3. LED switch constant-current drive circuit according to claim 1, it is characterized in that: described rectification unit comprises two groups of diode groups in parallel, each diode group comprises two diodes of series connection, and the two poles of the earth of described electronic transformer are connected between two diodes of each diode group.
4. LED switch constant-current drive circuit according to claim 1, is characterized in that: the voltage that described voltage input module exports is the commutating voltage after sinusoidal voltage rectification.
5. LED switch constant-current drive circuit according to claim 1, is characterized in that: also comprise a filter capacitor, described filter capacitor one end is connected with the output of described voltage input module, other end ground connection.
6. LED switch constant-current drive circuit according to claim 1, is characterized in that: described detection module comprises at least 2 grades of divider resistances of series connection.
7. LED switch constant-current drive circuit according to claim 1, is characterized in that: described LED module comprises the LED string that multiple LED is composed in series; The sampling resistor of connecting with described LED string, the other end ground connection of described sampling resistor; The filter capacitor in parallel with described LED string and sampling resistor.
8. LED switch constant-current drive circuit according to claim 1, it is characterized in that: also comprise a building-out capacitor, described building-out capacitor one end is connected with the output of described error amplifier, other end ground connection, for stablizing the output voltage of described error amplifier.
9. LED switch constant-current drive circuit according to claim 1, is characterized in that: also comprise a building-out capacitor, described building-out capacitor one end is connected with the output of described detection module, other end ground connection, for stablizing the output voltage of described detection module.
10. LED switch constant-current drive circuit according to claim 1, is characterized in that: the reference voltage being connected to described dimming controlling module input is default definite value or changing value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310705124.5A CN103648219B (en) | 2013-12-19 | 2013-12-19 | Light-emitting diode (LED) switch constant-current driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310705124.5A CN103648219B (en) | 2013-12-19 | 2013-12-19 | Light-emitting diode (LED) switch constant-current driving circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103648219A CN103648219A (en) | 2014-03-19 |
| CN103648219B true CN103648219B (en) | 2015-07-15 |
Family
ID=50253345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310705124.5A Expired - Fee Related CN103648219B (en) | 2013-12-19 | 2013-12-19 | Light-emitting diode (LED) switch constant-current driving circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103648219B (en) |
Families Citing this family (36)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103024994B (en) | 2012-11-12 | 2016-06-01 | 昂宝电子（上海）有限公司 | Use dimming control system and the method for TRIAC dimmer |
| CN103957634B (en) | 2014-04-25 | 2017-07-07 | 广州昂宝电子有限公司 | Illuminator and its control method |
| CN104168697B (en) * | 2014-08-07 | 2017-02-01 | 深圳天源中芯半导体有限公司 | Output current control circuit used for switch section dimming of LED driving power supply |
| CN105898958B (en) * | 2015-08-05 | 2019-04-12 | 肖志军 | The constant current driving method and circuit of LED light tunable optical |
| CN105101560B (en) * | 2015-08-25 | 2017-05-10 | 无锡中感微电子股份有限公司 | LED drive circuit and LED drive system using same |
| CN105282934B (en) * | 2015-10-30 | 2018-02-13 | 上海路千电子科技有限公司 | The linear constant current LED drive circuit and method of a kind of compatible silicon controlled light modulator |
| CN107654853B (en) * | 2016-07-26 | 2024-04-05 | 上海莱托思电子科技有限公司 | Self constant current LED filament |
| CN107171554B (en) * | 2017-07-04 | 2023-08-01 | 东莞市微视激光科技有限责任公司 | Voltage-regulating power supply of pulse xenon lamp pumping laser welding machine |
| CN107645804A (en) | 2017-07-10 | 2018-01-30 | 昂宝电子（上海）有限公司 | System for LED switch control |
| CN107682953A (en) | 2017-09-14 | 2018-02-09 | 昂宝电子（上海）有限公司 | LED illumination System and its control method |
| CN107864532B (en) * | 2017-11-03 | 2023-09-26 | 杰华特微电子股份有限公司 | LED dimming circuit and method and LED control circuit |
| CN107787092B (en) * | 2017-11-23 | 2024-05-07 | 广东新昇电业科技股份有限公司 | Constant voltage dimming four-in-one circuit and method thereof |
| CN107995730B (en) | 2017-11-30 | 2020-01-07 | 昂宝电子（上海）有限公司 | System and method for phase-based control in connection with TRIAC dimmers |
| CN108200685B (en) | 2017-12-28 | 2020-01-07 | 昂宝电子（上海）有限公司 | LED lighting system for silicon controlled switch control |
| CN108617054B (en) * | 2018-05-29 | 2020-01-14 | 上海源微电子科技有限公司 | Silicon controlled dimmer detection circuit for linear LED driving |
| CN108575038A (en) * | 2018-05-31 | 2018-09-25 | 赛尔富电子有限公司 | A kind of intelligent electric power and the auxiliary monitoring method for intelligent electric power |
| CN108834259B (en) * | 2018-07-11 | 2024-04-05 | 深圳市明微电子股份有限公司 | Linear constant current control circuit and method for LED lamp and LED device |
| CN108990213A (en) * | 2018-08-06 | 2018-12-11 | 杭州士兰微电子股份有限公司 | LED drive circuit and its dimming controlling method |
| CN108856979B (en) * | 2018-08-09 | 2023-11-03 | 南京力仕达焊接科技有限公司 | Semi-automatic wire feeding welding machine of battery type self-protection |
| CN109922564B (en) | 2019-02-19 | 2023-08-29 | 昂宝电子（上海）有限公司 | Voltage conversion system and method for TRIAC drive |
| CN110099484A (en) * | 2019-04-28 | 2019-08-06 | 上海登芯微电子科技有限公司 | A kind of LED light adjusting circuit |
| CN110493913B (en) | 2019-08-06 | 2022-02-01 | 昂宝电子（上海）有限公司 | Control system and method for silicon controlled dimming LED lighting system |
| CN110572900A (en) * | 2019-08-23 | 2019-12-13 | 南通金茂电子科技有限公司 | novel LED dimming drive circuit |
| CN112738946B (en) * | 2019-10-15 | 2023-04-07 | 松下知识产权经营株式会社 | Lighting circuit and synchronization method thereof |
| CN112738947B (en) * | 2019-10-15 | 2023-08-22 | 松下知识产权经营株式会社 | Lighting circuit and synchronization method thereof |
| CN112839407B (en) * | 2019-11-07 | 2023-05-26 | 华润微集成电路(无锡)有限公司 | Linear LED driving system and driving method |
| CN110831295B (en) | 2019-11-20 | 2022-02-25 | 昂宝电子（上海）有限公司 | Dimming control method and system for dimmable LED lighting system |
| CN110831289B (en) | 2019-12-19 | 2022-02-15 | 昂宝电子（上海）有限公司 | LED drive circuit, operation method thereof and power supply control module |
| CN111031635B (en) | 2019-12-27 | 2021-11-30 | 昂宝电子（上海）有限公司 | Dimming system and method for LED lighting system |
| CN111432526B (en) | 2020-04-13 | 2023-02-21 | 昂宝电子（上海）有限公司 | Control system and method for power factor optimization of LED lighting systems |
| CN112770446B (en) * | 2021-02-19 | 2022-06-10 | 南京工业职业技术大学 | Visual perception self-adaptive LED dimming compatible method |
| CN114468393B (en) * | 2022-01-04 | 2024-03-15 | 西安稳先半导体科技有限责任公司 | Constant power control circuit and method, tobacco stem and electronic cigarette |
| CN114928919B (en) * | 2022-05-24 | 2025-02-11 | 大连宗益科技发展有限公司 | A constant current control method for dimmer based on sliding mode control |
| CN115201650B (en) * | 2022-06-30 | 2025-03-18 | 昆山九华电子设备厂 | Shortwave power amplifier drain valley voltage detection circuit and voltage regulation method |
| CN115175399A (en) * | 2022-07-29 | 2022-10-11 | 宁波赛耐比光电科技有限公司 | Novel silicon controlled constant voltage digital dimming circuit |
| CN115411832A (en) * | 2022-08-02 | 2022-11-29 | 上海空间电源研究所 | Space energy bleeder circuit |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2225004A1 (en) * | 1997-12-17 | 1999-06-17 | Martin Malenfant | Voltage booster for enabling the power factor controller of a led lamp upon low ac or dc supply |
| CN102014536A (en) * | 2009-09-04 | 2011-04-13 | 登丰微电子股份有限公司 | Drive circuit and light emitting diode drive controller |
| CN201563272U (en) * | 2009-10-31 | 2010-08-25 | 比亚迪股份有限公司 | LED dimming drive circuit |
| CN103313472B (en) * | 2010-05-19 | 2016-02-03 | 成都芯源系统有限公司 | LED drive circuit with dimming function and lamp |
| TWI452790B (en) * | 2011-03-08 | 2014-09-11 | Green Solution Tech Co Ltd | Converting controller |
| CN103066872B (en) * | 2013-01-17 | 2015-06-17 | 矽力杰半导体技术(杭州)有限公司 | Integration switch power supply controller and switch power supply using the same |
| CN203722869U (en) * | 2013-12-19 | 2014-07-16 | 上海莱托思电子科技有限公司 | LED switch constant-current drive circuit |
-
2013
- 2013-12-19 CN CN201310705124.5A patent/CN103648219B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN103648219A (en) | 2014-03-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103648219B (en) | Light-emitting diode (LED) switch constant-current driving circuit | |
| CN102065600B (en) | LED dimming driving system | |
| CN104427688B (en) | LED alternating-current drive circuit | |
| CN106470509B (en) | Driving circuit and lighting device for light emitting diode | |
| US8569956B2 (en) | Apparatus, method and system for providing AC line power to lighting devices | |
| CN102711307B (en) | Dimmable light-emitting diode (LED) drive circuit and lamp | |
| CN101916548B (en) | Control circuit of light-emitting diode (LED) lamp tube of liquid crystal display | |
| CN104661392B (en) | A kind of LED switch constant-current drive circuit | |
| US9750099B2 (en) | Light emitting device with low voltage-endurance components | |
| CN105101551A (en) | Multipath LED constant current controller and control method | |
| CN102202449A (en) | LED driving control circuit and method | |
| CN103503563A (en) | Dimmable LED driver and method for controlling same | |
| CN102143639A (en) | LED (Light Emitting Diode) driving circuit | |
| CN105898958A (en) | Constant current driving method and circuit for LED lamp light adjustment | |
| CN203675371U (en) | LED constant current drive circuit | |
| CN103037597A (en) | Multi-channel LED (Light Emitting Diode) constant current control circuit and LED light source control system | |
| CN202050563U (en) | Flyback dimming LED (light-emitting diode) drive circuit | |
| CN203722869U (en) | LED switch constant-current drive circuit | |
| CN104703329B (en) | A kind of constant current driver circuit for LED | |
| CN104661408A (en) | LED dimming circuit and LED lamp | |
| CN104768271B (en) | Automatic dimming LED constant current drive circuit | |
| CN203590562U (en) | LED switch constant current driving circuit | |
| CN104602387B (en) | Dummy load circuit | |
| CN107231719B (en) | LED driving light modulation feedback control circuit | |
| CN202425146U (en) | A driving circuit for an LED lighting device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150715 Termination date: 20191219 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |