CN204465989U - A kind of PWM light modulating device - Google Patents
A kind of PWM light modulating device Download PDFInfo
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- CN204465989U CN204465989U CN201520168775.XU CN201520168775U CN204465989U CN 204465989 U CN204465989 U CN 204465989U CN 201520168775 U CN201520168775 U CN 201520168775U CN 204465989 U CN204465989 U CN 204465989U
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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
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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Abstract
The utility model provides a kind of PWM light modulating device, comprising: dim signal interface circuit, receives dim signal; Drive circuit, outputting drive voltage or drive current, its work period is Td; Driving power output interface circuit, connects load; Control circuit, described control circuit receives described dim signal from described dim signal interface circuit, generate pwm signal, export described drive circuit to, wherein control circuit is when PWM light modulation is carried out and generate the pwm signal of different frequencies when lighting apparatus normally works.After have employed such light-dimming method, make this PWM light modulating device can the different dimmer switch of compatible light adjusting grade, thus can effectively avoid stroboscopic to occur when normal work, while can obtain more smooth-going soft dimming effect.
Description
Technical field
The utility model relates to a kind of PWM light modulating device.
Background technology
Along with the development of the rapid technology of LED, increasing LED light source instead of traditional light source.As everyone knows, LED has many advantages as light source, and easy light modulation toning is one of great advantage of LED.Along with development and the popularization of Internet of Things and Smart Home, dimming light source demand is got more and more, and also more and more higher to the quality requirement of light modulation.So the light regulating technology of LED needs constantly progressive, the advantage of competence exertion self, complies with the development spring tide of Smart Home.
At present, the most frequently used LED dimming mode is PWM light modulation, and its principle utilizes pwm signal to control Buck/Boost type switching power circuit, according to the dutyfactor value of pwm signal, exports corresponding electric current and voltage value.The switching frequency of Buck/Boost type Switching Power Supply is higher as shown in Figure 1, generally between tens of Khz to hundreds of Khz.The frequency of PWM, generally between hundreds of to a few Khz, carrys out the electric current on/off of control switch power supply first-harmonic by the High/Low of PWM level.The cycle of pwm signal is generally the integral multiple in switching power circuit cycle, because, if when the part Δ t that increases of PWM pulsewidth PWM HIGH time is just in time positioned at the LOW of switching power circuit one-period as shown in Figure 1, the increase of such PWM pulsewidth is exactly invalid for output current, the electric current that LED is exported in rear end is unchanged, can not play actual light modulation effect.And consider the stationary problem of two signals, therefore in existing PWM control program, effective light adjusting grade of PWM equals switching power circuit frequency f
bdivided by PWM frequency f
p(L
eff=f
b/ f
p).
Adjusting control circuit in usual lighting apparatus and light modulation interface are corresponding, as, the dimmer switch of point gear on metope, the frequency of its light adjusting grade and pwm signal matches, but, along with the requirement in people's focus ring border is more and more higher, everybody generally recognizes when PWM frequency is low, easily there is stroboscopic in LED light source, when taking LED light source with picture pick-up device, can see obvious ripple.Now a lot of lighting apparatus all improves this state by improving PWM frequency, and change the lighting apparatus after frequency just and original dimmer switch cannot mate, extremely bother if corresponding dimmer switch will be reinstalled, also can increase the expense expenditure of client.
Utility model content
The purpose of this utility model is to solve the problem, provide a kind of can the PWM light modulating device of compatible high light adjusting grade dimmer switch.
The utility model is for realizing above-mentioned functions, and the technical scheme adopted is to provide a kind of PWM light modulating device, comprising:
Dim signal interface circuit, receives dim signal;
Drive circuit, outputting drive voltage or drive current, its work period is T
d;
Driving power output interface circuit, connects load;
Control circuit, described control circuit receives described dim signal from described dim signal interface circuit, generate pwm signal, export described drive circuit to, it is characterized in that described control circuit adopts aforesaid PWM light-dimming method to generate pwm signal, described control circuit comprises computing module and pwm signal Executive Module, described computing module calculates pwm signal characteristic value according to described dim signal, and described pwm signal Executive Module generates control signal according to described pwm signal characteristic value and exports described drive circuit to.
Preferably, described control circuit comprises:
Computing module receives described dim signal from described dim signal interface circuit, and calculates pwm signal characteristic value according to described dim signal, sends dimmer command;
Frequency control module receives the dimmer command that described computing module sends, and calculates and output frequency signal;
Pwm signal generator receives the frequency signal that described computing module calculates pwm signal characteristic value and the described frequency control module output obtained, and generates described pwm signal, exports described drive circuit to.
Preferably, described frequency control module comprises frequency generator, and described frequency generator, according to described dimmer command, sends different frequency signal values in the different time, and described frequency signal value is light modulating frequency f
por operating frequency f
w.
Preferably, described frequency control module also comprises frequency computation part module, described frequency computation part module calculates the frequency signal value of each time point according to described dimmer command, and controls described frequency generator and at the appointed time send the frequency signal value corresponding with the described fixed time.
Preferably, described frequency computation part module also comprises a timer.
Preferably, described control circuit also comprises a memory cell, in order to deposit described pwm signal characteristic value.
Preferably, described drive circuit is switching mode circuit.
Preferably, described pwm signal characteristic value is pwm value or dutyfactor value.
Technical scheme provided by the utility model adopts different PWM frequency when PWM light modulation is carried out and when lighting apparatus normally works, make it can the different dimmer switch of compatible light adjusting grade, and can effectively avoid stroboscopic to occur when normal work, more smooth-going soft dimming effect can be obtained simultaneously.
Accompanying drawing explanation
Fig. 1 is the waveform schematic diagram of existing PWM light-dimming method;
Fig. 2 is the structural representation of the PWM light modulating device meeting the utility model preferred embodiment;
Fig. 3 is the flow chart of the utility model PWM light-dimming method.
Embodiment
Below in conjunction with the drawings and specific embodiments, a kind of PWM light-dimming method that the utility model proposes, PWM light modulating device are described in further detail.
Please refer to Fig. 2, be the structural representation of a preferred embodiment of a kind of PWM light modulating device that the utility model proposes shown in Fig. 2, this PWM light modulating device comprises dim signal interface circuit 1, control circuit 2, drive circuit 3, drive circuit output interface circuit 4.Dim signal interface circuit 1 receives the dimming control signal that transmits outside and sends control circuit 2 to, is resolved by control circuit 2 pairs of dimming control signals, and produces control signal and be sent to drive circuit 3.Dimming control signal is produced by all kinds of interface with user interactions, mutual interface can be revolving switch, the button dividing gear, remote controller or handheld mobile device, and control signal is by the pwm signal of the particular duty cycle corresponding with dimming control signal, drive circuit 3 exports corresponding driving voltage current value according to the dutyfactor value of pwm signal, and exports to corresponding light source by driving power output interface circuit 4.Drive circuit 3 is Buck/Boost type switching power circuit in the present embodiment.Control circuit 2 can be built by some resolution elements and also can be realized by a MCU.Certain complete light modulating device also can comprise power supply, AC/DC circuit etc. (not shown in Fig. 2), and this can do corresponding configuration according to the practical situation of reality.
The main distinction of the utility model and existing light adjusting system is the processing method of control circuit.In existing PWM light modulating device, general control circuit is by obtaining PWM dutyfactor value to the computing of outside dimming control signal, and pwm signal generator realizes light modulation according to this duty ratio output pwm signal.Such light-dimming method is completely no problem when the light adjusting grade of user interface and pwm signal frequency match, but when the light adjusting grade of user interface is greater than attainable light adjusting grade, is namely greater than drive circuit frequency f
bwith PWM frequency f
pbusiness (L
eff=f
b/ f
p), system just cannot realize light modulation smoothly.And solution of the present utility model adopts different PWM frequency in light modulation stage and normal work stage, in the utility model preferred embodiment, drive circuit frequency f
bfor 100khz, by prior test, determine PWM frequency when lighting apparatus normally works, i.e. operating frequency f
wfor 4khz, under this PWM frequency, the stroboscopic of light source, the effect of shooting ripple can meet the user demand of client, and when light modulation is carried out, determine PWM frequency and light modulating frequency f according to the light adjusting grade of institute's User Interface
p, because light adjusting grade L
eff=f
b/ f
p, our L here
effvalue is 200, such f
pjust equal 500hz.To operationally adopt higher frequency to avoid stroboscopic in the present embodiment, therefore operating frequency f
wbe greater than light modulating frequency f
p.In order to realize such scheme, the structure of control circuit also must do corresponding improvement, first must have a computing module 21 in control circuit, this computing module 21 is input as dimming control signal, and output is characteristic value and the dimmer command of each pwm signal in the control signal cycle.This pwm signal characteristic value can be expressed as the duty ratio of pwm signal, also can represent the pulsewidth becoming pwm signal.Also comprise a frequency control module 23 in control circuit 2, the dimmer command that this frequency control module 23 sends according to computing module 21, calculate and output frequency signal.A pwm signal generator 24 is also had in addition in control circuit 2, pwm signal generator 24 receives the frequency signal that described computing module 21 calculates pwm signal characteristic value and frequency control module 23 output obtained, generate the pwm signal of corresponding frequencies and pulsewidth, export drive circuit 3 to.Computing module 21 can export corresponding pwm signal characteristic value in each pwm signal cycle to pwm signal generator 24, but it is obvious so economical not, therefore in the present embodiment, also comprise a memory cell 22, computing module 21 only carries out once-through operation when detecting that dimming control signal changes, then by operation result write storage unit 22, described memory cell 22 can be a hardware storage device, also can be realized by data structures such as array, stack, queues.
Comprise frequency of signal generator 2301 at frequency control module 23, frequency of signal generator 2301 can send different frequency signals according to dimmer command, and the frequency signal value that namely frequency of signal generator 2301 sends when receiving dimmer command equals light modulating frequency f
p, and the frequency signal value that frequency of signal generator 2301 sends when not having dimmer command equals operating frequency f
w.Whole dimming process can be expressed as, and computing module 21 receives dimming control signal, calculates and obtains PWM characteristic value and send dimmer command simultaneously, and after frequency control module 23 receives dimmer command, frequency of signal generator 2301 sends value for light modulating frequency f
pfrequency signal, pwm signal generator 24 receives this frequency signal and new PWM characteristic value, and generate the pwm signal with the new duty ratio calculated, then dimming cycle terminates, and it is operating frequency f that frequency of signal generator 2301 sends value
wfrequency signal, pwm signal generator 24 generated frequencies are operating frequency f
wnamely, pulsewidth remains unchanged and the pwm signal of the same duty ratio for new calculating just now.If dimming cycle is here only a PWM cycle, the too short change that cannot perceive brightness with the vision of people on the time, therefore needs pwm signal to maintain light modulating frequency f within a certain period of time
ptherefore in frequency control module 23, a timer 2 303 is also comprised, fill the time value preset to timer 2 303 when receiving dimmer command, after timer 2 303 covers the timing of setting, the numerical value of frequency of signal generator 2301 frequency signal is by light modulating frequency f
pbecome operating frequency f again
w, thus complete the light modulation stage.And this timing choosing value scope is 10 ~ 100ms, preferably 20 ~ 50ms is 30ms in the present embodiment.In addition because the frequency of pwm signal is at light modulating frequency f
pwith operating frequency f
wchange between the two, and drive circuit output is also a pulse signal, although pwm signal characteristic value remains unchanged, after pwm signal and drive circuit Signal averaging, when frequency change, the electric current and voltage value of actual output has a small change, is not therefore directly by operating frequency f in the present embodiment
wbecome light modulating frequency f
p, but by being arranged on another functional module in frequency control module 23, frequency computation part module 2302, carrying out substep and carrying out frequency change, namely in the present embodiment PWM frequency by f
wprogressively be reduced to f
p(N can be divided to walk, the low (f of each step-down
w-f
p)/N), vice versa, and PWM frequency is at f
prise to f
walso point multistep realizes (M can be divided into walk).N with M can be identical, also can be different, and the value of N or M depends primarily on f
wwith f
pfrequency distance, if gap little N value can be smaller, single step step-length is preferably 100hz ~ 1000hz, the 400hz of single step value in the present embodiment, thus calculates the value of N.And each step can stay for some time, therefore aforementioned timer 2303 also can be a part of frequency computation part module 2302, often complete a timing, frequency computation part module 2302 sends a signal to frequency of signal generator 2301, makes it change frequency signal value.
Flow chart below with regard to specific embodiment is described PWM light-dimming method of the present utility model, and Fig. 3 is the flow chart of the utility model preferred embodiment, and it comprises four basic steps:
Steps A receives dim signal, is calculated the pwm signal characteristic value of pwm signal by computing module 21;
Step B by the frequency of pwm signal from operating frequency f
wbecome light modulating frequency f
p;
Step C changes the pwm signal characteristic value of described pwm signal;
Step e by the frequency of pwm signal from light modulating frequency f
pbecome operating frequency f
w.
PWM light-dimming method described above is the most basic example of the present utility model, namely the existing dim signal of hypothesis transmits, then exports control signal by computing, and this is a basic step.But the light modulation demand of user is uncertain in actual applications, constantly check whether light modulation demand, therefore we this provide detection determining step, namely steps A comprises two sub-steps, namely detect dimming control signal, dimming control signal and current brightness value are compared, as the execution calculation step that changes, unchanged, continue to detect, that is only need just to perform calculation step when changing in brightness.When system is run first, current brightness value is zero, as long as open light fixture so just to have monochrome information and come thus enter calculation step, and carry out follow-up step B successively, and end is here only the end of dimming process after completing steps E, just come back to steps A as long as no turning off the light, thus detect with keeping, once find that the change of light modulation brightness just starts to perform step B.
And as previously mentioned, operating frequency f in a preferred embodiment
wprogressively become light modulating frequency f through N step
p, therefore and as shown in Figure 3, step B refinement can be decomposed into following steps further:
Step B1 i=1, f
p(i)=f
w;
Step B2 f
p(i)=f
p(i)-i*(f
w-f
p)/N;
Step B3 judges i=N, and equation is set up and terminated, and is false, and i=i+1 also continues to perform step B2.
The step e corresponding with step B is also the process of a progressively change frequency, and therefore as shown in Figure 3, step e refinement can be decomposed into following steps further:
Step e 1 j=1, f
p(j)=f
p;
Step e 2 f
p(j)=f
p(j)+ j*(f
w-f
p)/M;
Step e 3 judges j=M, and equation is set up and terminated, and is false, and j=j+1 also continues to perform step B2.
As previously mentioned, after the change completing pwm signal characteristic value, pwm signal can first at light modulating frequency f simultaneously
plower maintenance a period of time, therefore as shown in Figure 3 before step e also have a step D, step D be a delaying step, through one time of delay T continue subsequent step again.
To illustrate and describing to the description of the utility model preferred embodiment above, and undesired is the utility model limit or be confined to disclosed concrete form, obviously, many modifications and variations may be made, these modifications and variations may be obvious to those skilled in the art, should be included within the scope of the present utility model that defined by appended claims.
Claims (8)
1. a PWM light modulating device, comprising:
Dim signal interface circuit, receives dim signal;
Drive circuit, outputting drive voltage or drive current, its work period is Td;
Driving power output interface circuit, connects load;
Control circuit, described control circuit receives described dim signal from described dim signal interface circuit, generate pwm signal, export described drive circuit to, it is characterized in that, described control circuit comprises computing module and pwm signal Executive Module, and described computing module calculates pwm signal characteristic value according to described dim signal, and described pwm signal Executive Module generates control signal according to described pwm signal characteristic value and exports described drive circuit to.
2. PWM light modulating device according to claim 1, is characterized in that described control circuit comprises:
Computing module receives described dim signal from described dim signal interface circuit, and calculates pwm signal characteristic value according to described dim signal, sends dimmer command;
Frequency control module receives the dimmer command that described computing module sends, and calculates and output frequency signal;
Pwm signal generator receives the frequency signal that described computing module calculates pwm signal characteristic value and the described frequency control module output obtained, and generates described pwm signal, exports described drive circuit to.
3. PWM light modulating device according to claim 2, it is characterized in that described frequency control module comprises frequency generator, described frequency generator, according to described dimmer command, sends different frequency signal values in the different time, and described frequency signal value is light modulating frequency fP or operating frequency fW.
4. PWM light modulating device according to claim 3, it is characterized in that described frequency control module also comprises frequency computation part module, described frequency computation part module calculates the frequency signal value of each time point according to described dimmer command, and controls described frequency generator and at the appointed time send the frequency signal value corresponding with the described fixed time.
5. PWM light modulating device according to claim 4, is characterized in that described frequency computation part module also comprises a timer.
6. PWM light modulating device according to claim 3, is characterized in that described control circuit also comprises a memory cell, in order to deposit described pwm signal characteristic value.
7. PWM light modulating device according to claim 1, is characterized in that described drive circuit is switching mode circuit.
8., according to the arbitrary described PWM light modulating device of claim 1 to 7, it is characterized in that described pwm signal characteristic value is pwm value or dutyfactor value.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520168775.XU CN204465989U (en) | 2015-03-25 | 2015-03-25 | A kind of PWM light modulating device |
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|---|---|---|---|
| CN201520168775.XU CN204465989U (en) | 2015-03-25 | 2015-03-25 | A kind of PWM light modulating device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106163024A (en) * | 2015-03-25 | 2016-11-23 | 欧普照明股份有限公司 | A kind of PWM light-dimming method and PWM light modulating device |
| CN110381654A (en) * | 2019-08-06 | 2019-10-25 | 福建鸿博光电科技有限公司 | A kind of plant factor's switching pulse alternating illumination control method |
-
2015
- 2015-03-25 CN CN201520168775.XU patent/CN204465989U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106163024A (en) * | 2015-03-25 | 2016-11-23 | 欧普照明股份有限公司 | A kind of PWM light-dimming method and PWM light modulating device |
| CN106163024B (en) * | 2015-03-25 | 2019-03-12 | 欧普照明股份有限公司 | A kind of PWM light-dimming method and PWM dimming device |
| CN110381654A (en) * | 2019-08-06 | 2019-10-25 | 福建鸿博光电科技有限公司 | A kind of plant factor's switching pulse alternating illumination control method |
| CN110381654B (en) * | 2019-08-06 | 2021-06-25 | 福建鸿博光电科技有限公司 | Plant factory switch pulse alternate illumination control method |
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Granted publication date: 20150708 |
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