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

Kuo hoko ʻa e PWM dimming, fakanounou ʻo e Pulse Width Modulation dimming, ko ha tekinolosia malohi mo angamaheni ʻi he mamani ʻo e maama LED, tautautefito ki he fakaʻuli LED mo e ngaahi koloa ʻo e maʻuʻanga ʻuhila. ʻI hono uho, ko ha founga ia ke puleʻi ʻaki ʻa e ngingila ʻo ha LED ʻaki hono fakamoʻui mo tamateʻi vave ʻa e mama. ʻOku fakaʻaongaʻi ʻe he PWM dimming ha fakaʻilonga fakaʻilekitulonika ke maʻu ʻa e ola tatau, ʻo ʻikai hange ko e analog dimming, ʻa ia ʻoku ne fakasiʻisiʻi ʻa e ngingila ʻaki hono hokohoko hifo ʻa e lolotonga ʻoku tafe mai ʻi he LED. ʻOku ʻoange ʻe he faikehekehe mahuʻinga ko ʻeni ki he PWM ha ngaahi lelei mahuʻinga, ʻa ia ko e founga ia ʻoku saiʻia ai ki he ngaahi polokalama lahi, mei he maama mo e meʻangaue ki he siteisi ki he ngaahi foʻi ʻuhila mo e fakaʻaliʻali ʻo e maama ʻi mui. ʻOku faingofua ʻaupito ʻa e tefitoʻi moʻoni, ka ʻoku kau ʻi hono fakahoko ʻa e potupotutatau ʻo e ngaahi meʻa fakaʻilekitulonika mo e fakakaukau ʻa e tangata ke maʻu ha fakapoʻuli molemole, tauʻataina, mo fakapoʻuli maʻu pe ʻa e lanu. ʻOku mahuʻinga ke mahino ʻa e founga ngaue ʻa e PWM, hono malohinga, mo hono ngaahi drawbacks 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. Fakakaukau ki ha circuit faingofua ʻoku ʻi ai ha maʻuʻanga tokoni ʻo e ʻaho maʻu pe, ko ha afo ʻo e LEDs, mo ha transistor MOS (ko ha faʻahinga meʻa kamosi fakaʻilekitulonika). ʻOku fakafehokotaki ʻa e maʻuʻanga tokoni tuʻumaʻu 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 tuʻumaʻu mo totonu. ʻOku fakafehokotaki ʻa e cathode (tafaʻaki kovi) ʻo e afo LED ki he fakatafenga vai ʻo e transistor MOS, pea ʻoku fehokotaki ʻa e maʻuʻanga tokoni ʻo e transistor ki he kelekele. Ko e matapa ʻo e MOS transistor ko e feituʻu ia ʻoku 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 MOS transistor, ʻo fakakakato ʻa e circuit pea fakaʻata ʻa e ʻau ke tafe maʻu pe ʻi he LEDs, ʻa ia ʻoku ulo ʻi he ngingila 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 ʻavalisi ʻo e ngingila 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 ngaue. ʻOku ʻuhinga ʻa e 100% duty cycle ʻoku ulo maʻu pe ʻa e mama, ʻi he maama kakato. ʻOku ʻuhinga ʻa e 50% duty cycle ʻoku vaeua ʻa e taimi mo e 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 lelei mo manakoa taha ko ʻene malava ke tauhi ʻa e lanu totonu ʻi he kotoa ʻo e dimming. ʻI he analog dimming, ʻe lava ke liliu ʻa e 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 hono palani lolotonga ʻi he taimi ʻoku fakamoʻui ai. Tatau ai pe pe ʻoku fakasiʻisiʻi ʻa e mama ki he 10% pe 90%, ʻoku ʻi he kakato ʻa e pulses ʻo e "on" ʻi he lolotonga totonu, ʻo fakapapauʻi ʻoku kei tuʻu maʻu pe ʻa e mafana ʻo e lanu mo e chromaticity. ʻOku hoko ʻeni ko e PWM ko e fili lelei pe ia ki he ngaahi polokalama ʻoku mahuʻinga taha ai ʻa e tuʻunga lelei ʻo e lanu, hange ko e maama ʻo e musiume, faʻu ʻo e filimi mo e televisone, mo e ngaahi fokotuʻutuʻu maʻolunga ʻo e langa. Ko e lelei lahi hono ua ko ʻene dimming tonu makehe 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 dimming hamolemole mo stepless 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 PWM dimming, ʻo tupu ai ha aʻusia ʻoku ʻikai ke ʻi ai ha kemo ʻoku ne taʻofi ʻa e ongosia mo e ongosia ʻo e mata.

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

Ko e liliu ʻo e lanu ʻi he LEDs ʻi he ngaahi ʻau kehekehe ko ha ʻulungaanga ʻiloa ia ʻo e fisiki semiconductor. ʻOku kiʻi fakafalala ʻa e wavelength pau ʻo e maama ʻoku tuku mai ʻe ha LED chip 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 ʻo fakatupu ha liliu ʻi he lanu ʻoku ongoʻi. ʻOku fakatokangaʻi ʻeni ʻi he LED hinehina, ʻa ia ʻoku angamaheni ʻaki ʻa e chips 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 dimming mei he palopalema kotoa ko ʻeni. ʻOku ʻikai ke ne liliu ʻa e lolotonga. ʻOku ne fakamoʻui mo tamateʻi pe ʻa e ʻau maʻu pe. Ko ia ai, ʻi he lolotonga ʻo e pulse "on" kotoa pe, ʻoku ngaue ʻa e LED ʻi he ngaahi tuʻunga totonu ʻo hono fokotuʻutuʻu, ʻo maʻu 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 maama lanu maʻu pe, ʻo fakatokangaʻi ha lanu tatau ʻi ha faʻahinga tuʻunga poipoila pe. Ko e tefitoʻi ʻuhinga ʻeni ʻoku hoko ai ʻa e PWM ko e tuʻunga koula ki hono tauhi ʻo e faitotonu ʻo e lanu ʻi he ngaahi maama LED dimmable. ʻOku ne toʻo ʻa e puleʻi ʻo e ngingila mei he fisiki ʻo e LED chip, ʻo ʻoange ʻa e puleʻi ki ha timer fakaʻilekitulonika totonu.

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

Neongo hono ngaahi lelei lahi, ʻoku ʻikai taʻe ʻi ai ha ngaahi faingataʻa mo ha ngaahi kovi ʻe ala hoko ʻi he PWM, ʻa ia kuo pau ke tokangaʻi fakalelei 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 lolotonga ʻo fakafou ʻi he fakaʻuli LED mo e LEDs ʻa e ngaahi konga pau ke tetetete. ʻOku moʻoni ʻeni tautautefito ki he ceramic capacitors, ʻa ia ʻoku faʻa fakaʻaongaʻi ʻi he tuʻunga output ʻo e LED drivers koeʻuhi ko honau siʻisiʻi mo e ngaahi ʻulungaanga fakaʻuhila lelei. ʻOku faʻa ngaohi ʻa e capacitors ʻumea 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 capacitors ko ʻeni ʻi he tuʻo lahi ko ia, ʻo fakatupu ha kiʻi longoaʻa pe tangi ʻoku 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 palopalema ʻe taha ʻoku fekauʻaki ia mo hono fili ʻo e tuʻo lahi ʻo e PWM. Kapau ʻoku fuʻu siʻisiʻi 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 ki he moʻui 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 mei he fanongo ʻa e tangata, fakaleleiʻi ʻa e palopalema ʻo e longoaʻa, ka ʻoku ne ʻomi ha ngaahi faingataʻa foʻou. ʻI he tuʻo lahi 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 ʻi he on/off ke hoko ʻo taʻefeʻunga mo fakasiʻisiʻi ʻa e tonu ʻo e dimming. ʻOku ʻi ai ha feituʻu lelei ke maʻu, pea ʻoku fie maʻu ki ai ha ʻenisinia lelei.

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 dimming. Ko e founga fakahangatonu taha ko hono fakalahi ʻo e tuʻo lahi ʻo e feliliuaki ʻa e 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 heʻene ngaue ʻi he 25 kHz pe maʻolunga ange, ʻoku hoko ai ha longoaʻa ʻoku fakatupu ʻe he tetetete ko e ultrasonic pea ʻikai lava ke ongoʻi ʻe he 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 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 e talanoa fakahangatonu ki he tupuʻanga ʻo e longoaʻa: ʻa e ngaahi konga. Ko e tefitoʻi tukuakiʻi ʻoku faʻa hoko ko e capacitors output ceramic. Ko ha founga angamaheni ke fetongi ʻa e ngaahi capacitors ko ʻeni ʻaki ʻa e tantalum capacitors. ʻOku ʻikai fakahaaʻi ʻe he capacitors ʻo e tantalum ʻa e ola tatau ʻo e piezoelectric pea ʻoku fakalongolongo ange. Neongo ia, ʻoku ʻi ai hono ngaahi fetongi ʻi he founga ko ʻeni. ʻOku faingataʻa ange ke maʻu ʻa e capacitors tantalum voltage maʻolunga, ʻe lava ke mamafa ange ia ʻi honau ngaahi hoa ʻumea, pea ʻoku ʻi ai ʻa e 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 ange mo e ngaahi konga fakalongolongo ange, ko ha fili fakaʻenisinia mahuʻinga ia ʻoku ne uesia ʻa e fakamole, lahi mo e ngaue ʻa e koloa fakaʻosi. ʻOku fakatahaʻi ʻe he ngaahi fakaʻuli maʻolunga ʻe niʻihi ʻa e ongo founga fakatouʻosi, ʻo fakaʻaongaʻi ha ngaahi konga kuo fili fakalelei, tuʻo lahi feʻunga mo e tuʻunga maʻolunga, longoaʻa maʻulalo ke maʻu ʻa e longonoa, tauʻataina ʻa e kemo, mo e tonu ʻaupito ʻa e dimming.

Ko e ha ʻa e tuʻo lahi lelei taha 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 ʻa e ngaahi fakahinohino mahino ʻoku makatuʻunga ʻi he ngaahi fie maʻu ʻa e sisitemi sio ʻa e tangata pea 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 ia ko e 100 Hz, ka ko e siʻisiʻi taha ʻeni pea ʻe kei lava pe ke fakatokangaʻi ia ʻe he niʻihi fakafoʻituitui ʻoku ongoʻingofua ʻa e sio, tautautefito ki 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 mahuʻinga ki he tuʻunga totonu ʻo e fakaʻilonga pe fuʻu lahi ʻa e mole ʻi he fakaʻuli. Ki he ngaahi polokalama ʻoku hoko ai ʻa e longoaʻa ko ha tefitoʻi hohaʻa ki ai, hange ko e ngaahi feituʻu nofoʻanga pe studio, 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 faʻu mo e ngaahi faingataʻa lahi ange ʻo e electromagnetic interference (EMI) pea mo e fie maʻu ke maʻolunga ange ʻa e circuitry ʻo e fakaʻuli ʻo e matapa ke tauhi ʻa e ngaahi tapa maʻa mo vave ʻo e feliliuaki. Ko hono fakanounou, ʻoku fakapapauʻi ʻa e tuʻo lahi lelei taha 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 ongoʻingofua ʻo 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 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 ʻa e 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, ʻoku mahino lelei kinautolu pea ʻe lava ke tokangaʻi lelei kinautolu ʻo fakafou 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 ia ki he ngaahi polokalama maama taʻefaʻalaua.

Ngaahi Fehuʻi ʻOku Faʻa ʻEke Fekauʻaki mo e LED PWM Dimming

ʻOku kovi ʻa e PWM dimming ki ho mata?

ʻOku ʻikai ke kovi ʻa e dimming ʻo e PWM. ʻOku malava ke mafasia 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 tuʻo lahi ʻo e 200 Hz pe maʻolunga ange pea 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 kemo.

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 lelei 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 lava ʻo dimmable ʻi ha circuit PWM ʻo fakatupu ʻa e flickering, buzzing, mo e maumau ki he foʻi ʻuhila pe 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 meʻafaitaa smartphone ʻa e dimmming ʻo e PWM. Fokotuʻu ʻa e meʻafaitaa hoʻo telefoni ki he "slow motion" pe "pro" mode mo ha vave ʻo e shutter pea tuhu ki he maama ʻoku fakapoʻuli. Kapau ʻoku ke sio ki ha ngaahi foʻi laine fakapoʻuli pe kemo ʻi he screen, ʻoku ngalingali ʻoku fakapoipoifuʻi ʻa e mama ʻaki ʻa e PWM. ʻOku ʻuhinga ʻeni koeʻuhi he ʻoku maʻu ʻe he rolling shutter ʻo e meʻafaitaa ʻa e vave ʻo e on/off cycles ʻoku ʻikai lava ke sio ki ai ho mata.