Ko e ha ʻa e LED PWM dimming pea ko e ha ʻoku fuʻu lahi ai hono fakaʻaongaʻi?

Kuo hoko ʻa e PWM dimming, fakanounou ʻo e Pulse Width Modulation dimming, ko ha tekinolosia mahuʻinga mo angamaheni ʻi he mamani ʻo e maama LED, tautautefito ki he fakaʻuli LED mo e ngaahi koloa ʻoku maʻuʻanga ʻuhila. Ko hono uho, ko ha founga ia ke puleʻi ʻaki ʻa e maama ʻo ha LED ʻaki hono fakamoʻui mo tamateʻi vave ʻa e mama. ʻOku fakaʻaongaʻi ʻe he PWM dimming ha fakaʻilonga fakaʻilekitulonika ke aʻusia ʻa e ola tatau. ʻOku ʻoange ʻe he faikehekehe mahuʻinga ko ʻeni ʻa e PWM ki ha ngaahi lelei mahuʻinga, ʻa ia ko e ʻuhinga ia ʻoku fie maʻu ai ki he ngaahi polokalama lahi, mei he maama mo e meʻangaue ʻi he siteisi ki he ngaahi foʻi ʻuhila mo e fakaʻaliʻali ʻo e backlighting. ʻOku faingofua ʻa e tefitoʻi moʻoni, ka ʻoku kau ʻi hono fakahoko ha potupotutatau ʻo e ngaahi meʻa fakaʻilekitulonika mo e fakakaukau ʻa e tangata ke maʻu ha fakapoʻuli molemole, ʻikai ke kemo mo fakapoʻuli ʻa e lanu. ʻOku mahuʻinga ke mahino ʻa e founga ngaue ʻa e PWM, hono ngaahi malohinga, mo hono ngaahi drawbacks ʻe ala hoko ki ha taha pe ʻoku kau ʻi hono fakamahinoʻi, fokotuʻutuʻu, pe fokotuʻu ʻo e ngaahi maama LED tuʻunga maʻolunga.

ʻOku ngaue fefe ʻa e PWM Dimming ʻi he tuʻunga ʻo e circuit?

ʻOku fakaʻofoʻofa mo fakahangatonu ʻa e tefitoʻi moʻoni ʻo e PWM dimming ʻi ha circuit LED ʻaonga. Fakakaukauloto ki ha kiʻi circuit faingofua ʻoku ʻi ai ha maʻuʻanga tokoni ʻoku tuʻu maʻu pe, ko ha ngaahi LEDs, mo ha transistor MOS (ko ha faʻahinga meʻa kamosi fakaʻilekitulonika). ʻOku fakafehokotaki ʻa e maʻuʻanga tokoni ʻo e lolotonga maʻu pe ki he anode (tafaʻaki lelei) ʻo e afo LED, ʻo fakapapauʻi ko e taimi ʻoku tapuni ai ʻa e circuit, ʻoku maʻu ʻe he LEDs ha ʻau ʻoku tuʻu maʻu mo totonu. ʻOku fakafehokotaki ʻa e cathode (tafaʻaki kovi) ʻo e afo LED ki he tafe ʻo e transistor MOS, pea ʻoku fehokotaki ʻa e maʻuʻanga ʻo e transistor ki he kelekele. Ko e matapa ʻo e transistor MOS ko e feituʻu ia ʻoku ne puleʻi. ʻOku fakaʻaongaʻi ha fakaʻilonga PWM, ʻa ia ko ha peau tapafa fakaʻilekitulonika, ki he matapa ko ʻeni. ʻOku fetongitongi ʻa e peau tapafa ko ʻeni ʻi he vahaʻa ʻo e voltage maʻolunga (e.g., 5V) mo e voltage maʻulalo (0V). ʻI he taimi ʻoku maʻolunga ai ʻa e fakaʻilonga PWM, ʻoku ne fakamoʻui ʻa e transistor MOS, fakakakato ʻa e circuit pea fakaʻata ʻa e ʻau maʻu pe ke tafe mai ʻi he LEDs, ʻa ia ʻoku ulo ʻi he maama kakato. ʻI he taimi ʻoku maʻulalo ai ʻa e fakaʻilonga PWM, ʻoku "tamateʻi" ʻa e transistor, maumauʻi ʻa e circuit, pea mate ʻaupito ʻa e LEDs. ʻI hono fakamoʻui mo tamateʻi vave ʻa e transistor ʻi ha tuʻo lahi ʻoku fuʻu maʻolunga ke fakatokangaʻi ʻe he mata ʻo e tangata, ʻoku hange ʻoku ulo maʻu pe ʻa e LEDs, ka ʻi ha maama fakaʻavalisi ʻoku fakapapauʻi ʻe he ratio ʻo e taimi "on" ki he taimi "mate". ʻOku ʻiloa ʻa e fika ko ʻeni ko e siakale ʻo e fatongia. ʻOku ʻuhinga ʻa e 100% duty cycle ʻoku ulo maʻu pe ʻa e mama, ʻi he maama kakato. ʻOku ʻuhinga ʻa e 50% ʻo e siakale ʻo e ngaue ʻi he vaeua ʻo e taimi pea mate ʻi he vaeua ʻo e taimi, ʻo maʻu ai ha maama ʻo e 50%.

Ko e ha ʻa e ngaahi tefitoʻi lelei ʻo e PWM Dimming ki he LEDs?

Kuo maʻu ʻe he PWM dimming ʻa hono ʻiloa koeʻuhi ko ha ngaahi lelei malohi ʻoku ne fakamatalaʻi fakahangatonu ʻa e ngaahi fakangatangata ʻo e ngaahi founga dimming kehe. Ko e ʻuluaki mo e lelei taha ko ʻene malava ke tauhi ʻa e tuʻunga tatau ʻo e lanu ʻi he kotoa ʻo e dimming. ʻI he analog dimming, ʻe lava ke fakatupu ʻe hono fakasiʻisiʻi ʻo e ʻau ki ha LED ha liliu ʻi he mafana ʻo e lanu. Hange ko ʻeni, ʻe lava ke kiʻi lanu mata pe pingikii ʻa e LED hinehina ʻi he ʻau maʻulalo ange. ʻOku fakaʻehiʻehi ʻaupito ʻa e PWM mei he meʻa ni koeʻuhi he ʻoku ngaue maʻu pe ʻa e LED ʻi he taimi ʻoku fakamoʻui ai. Tatau ai pe pe ʻoku fakapoʻuli ʻa e mama ki he 10% pe 90%, ʻoku ʻi he lolotonga kakato ʻa e pulses "on", ʻo fakapapauʻi ʻoku tuʻu maʻu ʻa e mafana ʻo e lanu mo e chromaticity. ʻOku hoko ʻeni ko e PWM ko e fili pe ia ʻe taha ki he ngaahi polokalama ʻoku mahuʻinga taha ai ʻa e tuʻunga lelei ʻo e lanu, hange ko e maama ʻi he musiume, faʻu ʻo e filimi mo e televisone, pea mo e ngaahi fokotuʻutuʻu maʻolunga ʻo e langa. Ko e lelei lahi hono ua ko hono tonu ʻo e dimming mo e lahi ʻo e adjustable range. Koeʻuhi ʻoku fakafalala ʻa e PWM ki he taimi fakaʻilekitulonika totonu, te ne lava ʻo mapuleʻi lelei ʻa e siakale ʻo e fatongia, ʻo fakaʻata ai ʻa e fakapoʻuli mei he 100% ki he 0.1% pe maʻulalo ange. ʻOku faingataʻa ke aʻusia ʻa e tuʻunga ko ʻeni ʻo e tonu ʻi he ngaahi founga analog. Fakaʻosi, ʻi he taimi ʻoku fakahoko ai ʻi ha tuʻo lahi feʻunga (angamaheni ʻi ʻolunga ʻi he 200 Hz), ʻoku ʻikai fakatokangaʻi ʻe he mata ʻo e tangata ʻa e dimming ʻo e PWM, ʻo tupu ai ha aʻusia ʻoku ʻikai ke ʻi ai ha flicker ʻoku ne taʻofi ʻa e ongosia mo e ongosia ʻa e mata.

Ko e ha ʻoku taʻofi ai ʻe he PWM Dimming ʻa e liliu ʻo e lanu ʻi he LEDs?

Ko e feliliuaki ʻo e lanu ʻi he LEDs ʻi he malumalu ʻo e ngaahi ʻau kehekehe ko ha ʻulungaanga ʻiloa ia ʻo e fisiki ʻo e semiconductor. ʻOku kiʻi fakafalala ʻa e wavelength pau ʻo e maama ʻoku tuku mai ʻe ha chip LED ʻi he density lolotonga ʻoku tafe mai ai. ʻI hoʻo holoki hifo ʻa e ʻau ʻi ha analog dimming system, ʻe lava ke liliu ʻa e wavelength ʻoku puleʻi, ʻo fakatupu ha liliu ʻi he lanu ʻoku ʻiloʻi. ʻOku fakatokangaʻi ʻeni ʻi he LEDs hinehina, ʻa ia ʻoku angamaheni ʻaki ʻa e lanu pulu mo ha phosphor coating. ʻE lava foki ke uesia ʻa e ola lelei ʻo e ului ʻa e phosphor ʻe he malohi ʻo e maama lanu puluu ʻoku ne fakafiefiaʻi ia. ʻOku fakaʻehiʻehi lelei ʻa e PWM mei he palopalema kotoa ko ʻeni. ʻOku ʻikai ke ne liliu ʻa e lolotonga. ʻOku ne fakamoʻui mo tamateʻi maʻu pe ʻa e ʻau kakato. Ko ia ai, ʻi he lolotonga ʻo e pulse "on" kotoa pe, ʻoku ngaue ʻa e LED ʻi he ngaahi tuʻunga totonu ʻo e fokotuʻutuʻu, ʻo maʻu ai ʻa e maama ʻi he mafana ʻo e lanu ʻoku fakataumuʻa ki ai. ʻOku fakatahaʻi ʻe he mata mo e ʻuto ʻo e tangata ʻa e ngaahi ta vave ko ʻeni ʻo e maama lanu maʻu pe, ʻo ne fakatokangaʻi ha lanu tatau ʻi ha faʻahinga tuʻunga fakapoʻuli pe. Ko e tefitoʻi ʻuhinga ʻeni ʻoku hoko ai ʻa e PWM ko e tuʻunga koula ki hono tauhi ʻo e faitatau ʻo e lanu ʻi he ngaahi maama LED dimmable. ʻOku ne toʻo ʻa e puleʻi ʻo e maama mei he fisiki ʻo e LED chip, ʻo ʻoatu ʻa e puleʻi ki ha timer fakaʻilekitulonika totonu.

Ko e ha ʻa e ngaahi kovi mo e ngaahi faingataʻa ʻo e fakapoʻuli ʻo e PWM?

Neongo hono ngaahi lelei lahi, ʻoku ʻikai taʻe ʻi ai ha ngaahi faingataʻa mo ha ngaahi drawbacks ʻe ala hoko ʻi he PWM, ʻa ia kuo pau ke fakaleleiʻi ʻe he kau ʻenisinia ʻi heʻenau ngaahi fokotuʻutuʻu. Ko e palopalema angamaheni taha ko e longoaʻa. ʻE lava ke fakatupu ʻe he liliu vave ʻo e ʻau ʻi he fakaʻuli LED mo e LEDs ha ngaahi konga pau ke tetetete. ʻOku moʻoni ʻeni tautautefito ki he ceramic capacitors, ʻa ia ʻoku faʻa fakaʻaongaʻi ʻi he tuʻunga ʻo e output ʻo e LED drivers koeʻuhi ko honau siʻisiʻi mo e ngaahi ʻulungaanga fakaʻuhila lelei. ʻOku faʻa ngaohi ʻa e ceramic capacitors mei he ngaahi naunau ʻoku ʻi ai ʻa e ngaahi koloa piezoelectric, ʻa ia ko hono ʻuhinga ʻoku nau kiʻi deform ʻi he taimi ʻoku fakaʻaongaʻi ai ha voltage. ʻI he taimi ʻoku moʻulaloa ai ki he 200 Hz PWM pulse, ʻe lava ke tetetete ʻa e ngaahi capacitors ko ʻeni ʻi he tuʻo lahi ko ia, ʻo maʻu ai ha kiʻi longoaʻa siʻisiʻi pe tangi ʻoku ʻi loto ʻi he tuʻunga ʻo e fanongo ʻa e tangata. ʻE lava ke fakaʻita ʻeni ʻi ha ʻatakai longonoa hange ko ha loki mohe pe laipeli. Ko e pole ʻe taha ʻoku fekauʻaki ia mo e fili ʻo e tuʻo lahi ʻo e PWM. Kapau ʻoku fuʻu maʻulalo ʻa e tuʻo lahi (ʻi lalo ʻi he 100 Hz), ʻe lava ke fakatokangaʻi ʻe he mata ʻo e tangata ʻa e kemo, ʻa ia ʻoku fakatou taʻefakafiemalie pea ʻe lava ke ne fakatupu ha ngaahi palopalema fakaemoʻui lelei hange ko e langa ʻulu mo e ongosia ʻa e mata. Kapau ʻoku fuʻu maʻolunga ʻa e tuʻo lahi (ʻi ʻolunga ʻi he 20 kHz), ʻe lava ke hao ia mei he fanongo ʻa e tangata, fakaleleiʻi ʻa e palopalema ʻo e longoaʻa, ka ʻoku ne ʻomi ha ngaahi faingataʻa foʻou. ʻI he tuʻunga maʻolunga ʻaupito, ʻe lava ke fakakeheʻi ʻe he parasitic inductances mo e capacitances ʻi he circuit ʻa e ngaahi tapa masila ʻo e peau tapafa PWM, ʻo fakatupu ai ʻa e liliu ʻo e on/off ke hoko ʻo taʻefeʻunga pea fakasiʻisiʻi ʻa e tonu ʻo e dimming. ʻOku ʻi ai ha feituʻu lelei ke maʻu, pea ʻoku fie maʻu ki ai ha ʻenisinia tokanga.

ʻE lava fefe ke fakaleleiʻi ʻa e palopalema ʻo e longoaʻa ʻi he PWM dimming?

Kuo faʻufaʻu ʻe he kau ʻenisinia ha ngaahi founga lelei ke fakafepakiʻi ʻaki ʻa e longoaʻa ʻoku fekauʻaki mo e fakapoʻuli ʻo e PWM. Ko e founga fakahangatonu taha ko hono fakalahi ʻo e tuʻo lahi ʻo e fetongi PWM ki ʻolunga ʻi he 20 kHz, ʻa ia ʻoku faʻa lau ko e fakangatangata maʻolunga taha ia ʻo e fanongo ʻa e tangata. ʻI he ngaue ʻi he 25 kHz pe maʻolunga ange, ʻoku hoko ha longoaʻa ʻoku fakatupu ʻe he tetetete ko e ultrasonic pea ʻikai lava ke fanongo ki ai ʻa e tangata. Neongo ia, hange ko ia kuo lave ki ai, ʻoku fie maʻu ʻe he meʻa ni ha faʻufaʻu fakaʻofoʻofa ange ke puleʻi ʻa e ngaahi nunuʻa ʻo e parasitic mo tauhi ʻa e tuʻunga totonu ʻo e fakaʻilonga, ʻa ia ʻe lava ke fakalahi ai ʻa e fakamole mo e faingataʻa ʻo e fakaʻuli. Ko e founga hono ua, pea ʻoku faʻa fepoupouʻaki, ko hono tokangaʻi fakahangatonu ʻa e tupuʻanga ʻo e longoaʻa: ʻa e ngaahi konga ʻiate kinautolu pe. Ko e tefitoʻi tukuakiʻi ʻoku faʻa hoko ko e ceramic output capacitors. Ko ha founga angamaheni ke fetongi ʻa e ceramic capacitors ko ʻeni ʻaki ʻa e tantalum capacitors. ʻOku ʻikai fakahaaʻi ʻe he Tantalum capacitors ʻa e ola piezoelectric tatau pea ʻoku fakalongolongo ange. Neongo ia, ʻoku ʻi ai hono ngaahi fetongi ʻo e founga ko ʻeni. ʻOku faingataʻa ange ke maʻu ʻa e high-voltage tantalum capacitors, ʻe lava ke mamafa ange ia ʻi honau ngaahi hoa ʻumea, pea ʻoku ʻi ai ha ngaahi ʻulungaanga fakaʻuhila kehekehe kuo pau ke fakamatalaʻi ʻi he palani. Ko ia ai, ko e fili ʻi he vahaʻa ʻo ha tuʻo lahi ange ʻo e fetongi mo e ngaahi konga mamafa ange, pe ko ha tuʻo lahi maʻulalo ange mo e ngaahi konga fakalongolongo ange, ko ha fili fakaʻenisinia mahuʻinga ia ʻoku ne uesia ʻa e fakamole, lahi mo e ngaue ʻo e koloa fakaʻosi. ʻOku fakatahaʻi ʻe he kau fakaʻuli maʻolunga ʻe niʻihi ʻa e ongo founga fakatouʻosi, ʻo fakaʻaongaʻi ha ngaahi meʻa kuo fili fakalelei, tuʻo lahi mo e tuʻunga maʻolunga, longoaʻa maʻulalo ke maʻu ʻa e fakalongolongo, ʻikai ke ʻi ai ha kemo mo e fakapoʻuli tonu ʻaupito.

Ko e ha ʻa e tuʻo lahi lelei ʻo e PWM ki he LED dimming?

Ko hono fili ʻo e tuʻo lahi ʻo e PWM lelei taha ki he LED dimming ko ha ngaue potupotutatau, pea ʻoku ʻikai ha fika "haohaoa" ʻe taha ki he ngaahi polokalama kotoa pe. Neongo ia, ʻoku ʻi ai ha ngaahi fakahinohino mahino ʻo makatuʻunga ʻi he ngaahi fie maʻu ʻa e sisitemi sio ʻa e tangata mo e ngaahi fakangatangata ʻo e ngaahi meʻa fakaʻilekitulonika. Ko e tuʻo lahi taha ke fakaʻehiʻehi mei he kemo ʻoku ʻasi mai ʻoku faʻa lau ko e 100 Hz, ka ko e siʻisiʻi taha ʻeni pea ʻe kei lava pe ke fakatokangaʻi ʻe he niʻihi fakafoʻituitui ʻoku ongoʻipelengesi, tautautefito ʻi he vakai ki he tafaʻaki. Ko ha fili malu mo angamaheni ange ki he maama fakalukufua ko e 200 Hz ki he 500 Hz. ʻOku maʻolunga feʻunga ʻa e tuʻunga ko ʻeni ke taʻofi ʻa e kemo ʻoku ʻasi mai ki he tokolahi ʻo e kakai pea ʻoku maʻulalo feʻunga ke ʻoua naʻa ne ʻomi ha ngaahi palopalema lahi ʻi he tuʻunga totonu ʻo e fakaʻilonga pe fuʻu lahi ʻa e mole ʻi he fakaʻuli. Ki he ngaahi polokalama ʻoku tokanga taha ki ai ʻa e longoaʻa, hange ko e nofoʻanga pe loki, ʻoku faʻa teke ʻa e tuʻo lahi ʻi ʻolunga ʻi he 20 kHz ki he tuʻunga ultrasonic. ʻOku fakaʻaongaʻi ʻa e frequency hange ko e 25 kHz, 30 kHz, pe maʻolunga ange. Neongo ia, kuo pau ke fefaʻuhi ʻa e tokotaha fokotuʻutuʻu mo e ngaahi faingataʻa lahi ange ʻo e electromagnetic interference (EMI) pea mo e fie maʻu ke toe maʻolunga ange ʻa e circuitry ʻo e fakaʻuli matapa ke tauhi ʻa e ngaahi tapa ʻoku maʻa mo vave ʻa e feliliuaki. Ko hono fakanounou, ʻoku fakapapauʻi ʻa e tuʻo lahi lelei ʻe he ngaahi meʻa ʻoku fakamuʻomuʻa ʻe he polokalama: 200-500 Hz ki ha potupotutatau lelei ʻo e faingofua mo e ngaue, mo e >20 kHz ki he ngaue fakalongolongo ʻi he ngaahi ʻatakai ʻoku ongoʻingofua ʻa e longoaʻa.

Ngaahi lelei mo e kovi ʻo e PWM Dimming

ʻOku fakamatalaʻi fakanounou ʻe he tepile ko ʻeni ʻa e ngaahi lelei mo e kovi ʻo e tekinolosia PWM dimming ki he LEDs.

Ko hono fakaʻosi, ko e PWM dimming ko ha tekinolosia malohi mo versatile ia kuo hoko ko e tuʻunga moʻui ki hono puleʻi ʻo e maama LED tuʻunga maʻolunga. ʻOku ʻikai fakatataua ʻe he ngaahi founga analog ʻa ʻene malava ke ʻomi ha dimming tonu mo lahi ʻo ʻikai fakangaloku ʻa e tuʻunga tatau ʻo e lanu. Neongo ʻoku ʻi ai ʻa e ngaahi faingataʻa hange ko e longoaʻa mo e fie maʻu ke fili fakalelei ʻa e tuʻo lahi, ka ʻoku mahino lelei ia pea ʻe lava ke tokangaʻi lelei ia ʻi he ʻenisinia fakakaukau. Ko hono ola ko ha founga fakapoʻuli ʻoku ne ʻomi ha aʻusia lelei ange ʻa e tokotaha fakaʻaongaʻi, ʻo hoko ai ko e fili lelei taha ki he ngaahi polokalama maama taʻefaʻalaua.

Ngaahi Fehuʻi ʻOku Faʻa ʻEke Fekauʻaki mo e LED PWM Dimming

ʻOku kovi nai ʻa e fakapoʻuli ʻo e PWM ki ho mata?

ʻOku ʻikai kovi ʻa e fakapoʻuli ʻo e PWM. ʻOku maʻu ʻa e ongosia ʻa e mata mei he kemo maʻulalo (ʻi lalo ʻi he 100 Hz). ʻOku ʻikai fakatokangaʻi ʻa e tuʻunga maʻolunga ʻo e PWM dimming ʻoku fakahoko ʻi he frequency ʻo e 200 Hz pe maʻolunga ange pea ʻoku pehe ʻoku malu mo fakafiemalie. Kumi maʻu pe ʻa e LED "flicker-free", ʻa ia ʻoku ne fakahaaʻi ʻa e tuʻo lahi ʻo e PWM pe ko hono fakaʻaongaʻi ʻo e ngaahi tekinolosia kehe ʻoku ʻikai ke flicker.

ʻE lava ke fakapoʻuli ʻa e ngaahi foʻi ʻuhila LED kotoa pe ʻaki ʻa e PWM?

ʻIkai, ʻoku ʻikai ke dimmable ʻa e ngaahi foʻi ʻuhila LED kotoa pe. Kuo pau ke ke fakatau ha ngaahi foʻi ʻuhila ʻoku fakahingoa pau ko e "dimmable." ʻIkai ngata ai, ke ngaue totonu ʻa e PWM dimming, kuo pau ke fokotuʻutuʻu ʻa e fakaʻuli ʻi loto ʻo e foʻi ʻuhila ke ne tali mo tali ha fakaʻilonga PWM. ʻE lava ke fakatupu ʻe hono fakaʻaongaʻi ʻo ha LED ʻoku ʻikai ke fakasiʻisiʻi ʻi ha circuit PWM ʻa e fetapaki, ngungu, mo e maumau ki he foʻi ʻuhila pe ko e dimmer.

Te u lava fefe ʻo tala pe ʻoku fakaʻaongaʻi ʻe heʻeku LED dimmer ʻa e PWM?

ʻE lava ke faʻa fakahaaʻi ʻe ha kiʻi sivi faingofua ʻaki ha meʻafua smartphone ʻa e fakapoʻuli ʻo e PWM. Seti hoʻo meʻafaitaa telefoni ki he "slow motion" pe "pro" mode ʻaki ha vave ʻo e shutter pea tuhu ki he maama fakapoʻuli. Kapau ʻoku ke sio ki ha ngaahi foʻi haʻi fakapoʻuli pe kemo ʻi he screen, ʻoku ngalingali ʻoku fakasiʻisiʻi ʻa e mama ʻaki ʻa e PWM. ʻOku ʻuhinga ʻeni koeʻuhi he ʻoku maʻu ʻe he meʻafaitaa ʻa e ngaahi siakale vave ʻoku ʻikai lava ke sio ki ai ho mata.