labarai

Capacitors na ɗaya daga cikin abubuwan da aka fi amfani da su akan allunan da'ira.Yayin da adadin na'urorin lantarki (daga wayar hannu zuwa motoci) ke ci gaba da ƙaruwa, haka kuma buƙatar capacitors ke ƙaruwa. Cutar ta Covid 19 ta kawo cikas ga tsarin samar da kayan aikin duniya daga semiconductor. zuwa abubuwan da ba su dace ba, kuma capacitors sun kasance masu ƙarancin wadata1.
Tattaunawa a kan batu na capacitors za a iya sauƙi juya zuwa littafi ko ƙamus. Na farko, akwai nau'o'in capacitors daban-daban, irin su electrolytic capacitors, film capacitors, yumbu capacitors da sauransu. Sannan, a cikin nau'i ɗaya, akwai daban-daban. dielectric kayan.Haka kuma akwai nau'o'i daban-daban. Dangane da tsarin jiki, akwai nau'ikan capacitor biyu-terminal da uku-uku. Akwai kuma nau'in capacitor nau'in X2Y, wanda shine ainihin nau'i na Y capacitors a cikin daya. Menene game da supercapacitors. Gaskiyar ita ce, idan kun zauna kuma ku fara karanta jagororin zaɓin capacitor daga manyan masana'antun, zaku iya ciyar da ranar cikin sauƙi!
Tun da wannan labarin yana game da abubuwan yau da kullun, zan yi amfani da wata hanya dabam kamar yadda aka saba. Kamar yadda aka ambata a baya, ana iya samun jagororin zaɓi na capacitor a cikin gidajen yanar gizon masu ba da kaya 3 da 4, kuma injiniyoyin filin galibi suna iya amsa mafi yawan tambayoyi game da capacitors.A cikin wannan labarin, Ba zan maimaita abin da za ku iya samu akan Intanet ba, amma zan nuna yadda za a zaɓa da amfani da capacitors ta hanyar misalai masu amfani. Wasu ƙananan sanannun abubuwan zaɓi na capacitor, irin su lalatawar capacitance, za a rufe su.Bayan karanta wannan labarin, ku Ya kamata a sami kyakkyawar fahimtar amfani da capacitors.
Shekaru da suka wuce, lokacin da nake aiki a cikin wani kamfani wanda ke yin kayan lantarki, muna da tambayoyin tambayoyi ga injiniyan lantarki na lantarki.A kan zane-zane na samfurin da ake ciki, za mu tambayi 'yan takara masu yiwuwa "Menene aikin haɗin wutar lantarki na DC. capacitor?"da "Menene aikin yumbu capacitor kusa da guntu?"Muna fatan cewa madaidaicin amsar ita ce capacitor bas na DC Ana amfani dashi don ajiyar makamashi, ana amfani da capacitors na yumbu don tacewa.
Amsar "daidai" da muke nema a zahiri tana nuna cewa kowa da kowa a cikin ƙungiyar ƙira yana kallon capacitors daga hangen nesa mai sauƙi, ba daga yanayin ka'idar filin ba. Ma'anar ka'idar kewayawa ba daidai ba ne. A ƙananan ƙananan (daga kHz kaɗan). zuwa 'yan MHz), ka'idar kewayawa yawanci na iya bayyana matsalar da kyau.Wannan shi ne saboda a ƙananan mitoci, siginar ya fi dacewa a cikin yanayi daban-daban. Yin amfani da ka'idar kewayawa, zamu iya ganin capacitor da aka nuna a cikin Hoto 1, inda daidaitattun juriya na juriya (juriya). ESR) da kuma daidaitattun jerin inductance (ESL) suna canza canjin capacitor tare da mita.
Wannan samfurin ya bayyana cikakken bayanin aikin da'irar lokacin da aka kunna kewayawa a hankali.Duk da haka, yayin da mitar ya karu, abubuwa suna ƙara daɗaɗawa. yana da iyakoki.
A yau, idan an yi min tambaya guda ɗaya, zan sa gilashin kallon ka'idar filin na kuma in ce duka nau'ikan capacitor sune na'urorin ajiyar makamashi.Bambanci shine cewa masu ƙarfin lantarki na iya adana makamashi fiye da yumbu capacitors.Amma dangane da watsa makamashi. , Ƙwararrun yumbura na iya watsa makamashi da sauri.Wannan ya bayyana dalilin da yasa ake buƙatar sanya masu amfani da yumbura kusa da guntu, saboda guntu yana da mafi girma na sauyawa da saurin sauyawa idan aka kwatanta da babban wutar lantarki.
Daga wannan hangen zaman gaba, za mu iya kawai ayyana biyu yi nagartacce ga capacitors.Daya ne nawa makamashi da capacitor iya adana, da kuma sauran shi ne yadda sauri wannan makamashi za a iya canjawa wuri.Dukansu dogara a kan masana'antu Hanyar na capacitor, da dielectric abu. dangane da capacitor, da sauransu.
Lokacin da mai kunnawa a cikin kewayawa ya rufe (duba Hoto 2), yana nuna cewa nauyin yana buƙatar makamashi daga tushen wutar lantarki. Gudun da wannan maɓallin ke rufe yana ƙayyade gaggawar buƙatar makamashi.Tun lokacin da makamashi ke tafiya a gudun haske (rabi) gudun haske a cikin kayan FR4), yana ɗaukar lokaci don canja wurin makamashi. Bugu da ƙari, akwai rashin daidaituwa tsakanin tushen da layin watsawa da kuma kaya. zagaye tafiye-tafiye5, wanda shine dalilin da ya sa idan maɓalli ya kunna da sauri, muna ganin jinkiri da ƙara a cikin yanayin sauyawa.
Hoto 2: Yana ɗaukar lokaci kafin makamashi ya yadu a sararin samaniya;rashin daidaituwa na impedance yana haifar da tafiye-tafiye da yawa na canja wurin makamashi.
Gaskiyar cewa canja wurin makamashi yana ɗaukar lokaci da tafiye-tafiye da yawa yana gaya mana cewa muna buƙatar gano tushen makamashi a kusa da kaya kamar yadda zai yiwu, kuma muna buƙatar nemo hanyar canja wurin makamashi da sauri.Na farko yawanci ana samun ta ta hanyar rage jiki ta jiki. nisa tsakanin kaya, sauyawa da capacitor. Ana samun karshen ta hanyar tara rukuni na capacitors tare da ƙananan impedance.
Ka'idar filin kuma ta bayyana abin da ke haifar da hayaniyar yanayin gama gari.A takaice dai, ana haifar da amo na yau da kullun lokacin da makamashin da ake buƙata na kaya bai cika ba yayin sauyawa.Saboda haka, za a samar da makamashin da aka adana a cikin sarari tsakanin kaya da masu gudanarwa na kusa don tallafawa. Bukatar mataki. Wuraren da ke tsakanin kaya da masu gudanarwa na kusa shine abin da muke kira parasitic / mutual capacitance (duba hoto 2).
Muna amfani da misalan da ke gaba don nuna yadda ake amfani da masu amfani da wutar lantarki, masu ƙarfin yumbura masu yawa (MLCC), da masu ƙarfin fim.Dukansu kewayawa da ka'idar filin ana amfani da su don bayyana ayyukan da aka zaɓa na capacitors.
Ana amfani da masu amfani da wutar lantarki a cikin hanyar haɗin DC a matsayin babban tushen makamashi. Zaɓin capacitor na electrolytic sau da yawa ya dogara da:
Don aikin EMC, mafi mahimmancin halaye na capacitors shine impedance da halayen mitar. Sauƙaƙe-ƙarashin da aka gudanar koyaushe yana dogara ne akan aikin haɗin haɗin haɗin DC.
Rashin haɗin haɗin DC ya dogara ba kawai a kan ESR da ESL na capacitor ba, har ma a kan yanki na madauki na thermal, kamar yadda aka nuna a cikin Hoto 3.A mafi girma thermal madauki yankin yana nufin cewa makamashi canja wurin daukan tsawon lokaci, don haka yi aiki. za a shafa.
An gina maɓalli na DC-DC mai saukowa don tabbatar da wannan. Saitin gwajin EMC da aka rigaya ya cika wanda aka nuna a cikin Hoto 4 yana yin sikanin fitar da iska tsakanin 150kHz da 108MHz.
Yana da mahimmanci don tabbatar da cewa capacitors da aka yi amfani da su a cikin wannan binciken duk sun fito ne daga masana'anta guda ɗaya don kauce wa bambance-bambance a cikin halayen impedance.Lokacin da aka sayar da capacitor a kan PCB, tabbatar da cewa babu dogon jagoranci, saboda wannan zai kara ESL na the capacitor.Hoto na 5 yana nuna tsarin guda uku.
Ana nuna sakamakon da aka gudanar na waɗannan saiti guda uku a cikin Hoto 6. Ana iya ganin cewa, idan aka kwatanta da guda ɗaya na 680 µF capacitor, 330 µF capacitors guda biyu sun cimma aikin rage amo na 6 dB a kan kewayon mitar mita mai faɗi.
Daga ka'idar kewayawa, ana iya cewa ta hanyar haɗa capacitors guda biyu a cikin layi daya, duka ESL da ESR sun ragu. Duk da haka, a mafi girma mitoci, da bambanci tsakanin biyu 330 µF capacitor da daya 680 µF capacitor zai ragu.Wannan shi ne saboda babban mita amo yana nuna rashin isasshen matakin makamashi amsa.Lokacin da matsar da wani 330 µF capacitor kusa da. da sauyawa, muna rage lokacin canja wurin makamashi, wanda ya inganta yadda ya dace da matakin mayar da martani na capacitor.
Sakamakon ya gaya mana wani darasi mai mahimmanci.Ƙara ƙarfin ƙarfin capacitor guda ɗaya ba zai goyi bayan matakin buƙatar ƙarin makamashi ba. Idan zai yiwu, yi amfani da wasu ƙananan abubuwan da aka gyara. magana, don girman kunshin guda ɗaya, farashin capacitor yana ƙaruwa da yawa tare da ƙimar capacitance.Yin amfani da capacitor guda ɗaya na iya zama mafi tsada fiye da amfani da ƙananan capacitors da yawa.Dalilin na biyu shine girman girman.Maƙasudin ƙayyadaddun ƙira a cikin ƙirar samfur yawanci tsayin tsayi. na abubuwan da aka gyara.Don manyan masu ƙarfin ƙarfin ƙarfi, tsayin daka sau da yawa yana da girma don ƙirar samfura.Dalili na uku shine aikin EMC da muka gani a cikin binciken binciken.
Wani abin da za a yi la'akari da shi lokacin amfani da capacitor na electrolytic shine cewa lokacin da kuka haɗa capacitors guda biyu a jere don raba wutar lantarki, kuna buƙatar madaidaicin resistor 6.
Kamar yadda aka ambata a baya, yumbu capacitors su ne ƙananan na'urori waɗanda za su iya samar da makamashi da sauri. Sau da yawa ana tambayar ni tambaya "Nawa capacitor nake bukata?" Amsar wannan tambaya ita ce, ga yumbu capacitors, darajar capacitance kada ta kasance mai mahimmanci. Muhimmin la'akari a nan shi ne don ƙayyade wane mita gudun canja wurin makamashi ya isa ga aikace-aikacenku. Idan watsi da aka gudanar ya kasa a 100 MHz, to, capacitor tare da ƙananan impedance a 100 MHz zai zama zabi mai kyau.
Wannan wani rashin fahimta ne na MLCC.Na ga injiniyoyi suna ciyar da makamashi mai yawa suna zaɓar capacitors yumbura tare da mafi ƙarancin ESR da ESL kafin haɗa capacitors zuwa ma'anar RF ta hanyar dogon burbushi.Yana da kyau a ambaci cewa ESL na MLCC yawanci yana da yawa ƙasa da inductance haɗi a kan allo.Haɗin haɗin haɗin kai har yanzu shine mafi mahimmancin ma'auni wanda ke shafar babban ƙarfin mita na yumbura capacitors7.
Hoto na 7 yana nuna misali mara kyau. Dogayen burbushi (0.5 inci tsawo) suna gabatar da akalla 10nH inductance. Sakamakon kwaikwayo ya nuna cewa rashin ƙarfi na capacitor ya zama mafi girma fiye da yadda ake tsammani a mita mita (50 MHz).
Ɗaya daga cikin matsalolin da MLCCs shine sun kasance suna jin dadi tare da tsarin inductive akan allon. Ana iya ganin wannan a cikin misalin da aka nuna a cikin Hoto 8, inda amfani da 10 µF MLCC yana gabatar da sauti a kusan 300 kHz.
Kuna iya rage sauti ta hanyar zabar wani sashi tare da ESR mafi girma ko kuma kawai sanya ƙaramin ƙima mai ƙima (kamar 1 ohm) a cikin jerin tare da capacitor. Wannan nau'in hanyar yana amfani da abubuwan da ba a so ba don kashe tsarin. darajar don matsar da resonance zuwa ƙarami ko mafi girma wurin resonance.
Ana amfani da capacitors na fim a aikace-aikace da yawa. Su ne capacitors na zaɓi don manyan masu canza DC-DC kuma ana amfani da su azaman EMI suppression filters a fadin wutar lantarki (AC da DC) da kuma daidaita yanayin tacewa na kowa. Muna ɗaukar capacitor X kamar yadda misali don kwatanta wasu mahimman abubuwan amfani da capacitors na fim.
Idan abin da ya faru na karuwa ya faru, yana taimakawa wajen iyakance ƙarancin wutar lantarki akan layi, don haka yawanci ana amfani da shi tare da mai hana wutar lantarki mai wucewa (TVS) ko varistor oxide (MOV).
Wataƙila kun riga kun san duk waɗannan, amma kun san cewa ƙimar capacitance na capacitor X na iya raguwa sosai tare da shekaru masu amfani? X capacitor kawai ya ragu zuwa kashi kaɗan na ƙimar darajarsa a cikin shekara ɗaya ko biyu, don haka tsarin da aka tsara da farko tare da capacitor X ya rasa duk wani kariya da capacitor na gaba zai iya samu.
To, me ya faru? Danshi iska na iya zubo a cikin capacitor, sama da waya da kuma tsakanin akwatin da epoxy potting fili.The aluminum metallization za a iya sa'an nan a oxidized.Alumina ne mai kyau lantarki insulator, game da shi rage capacitance.Wannan shi ne matsala da cewa. Batun da nake magana game da shi shine kauri na fim. Samfuran capacitor masu daraja suna amfani da fina-finai masu kauri, wanda ke haifar da manyan capacitors fiye da sauran nau'ikan. kuma da wuya ta warke.
Idan X capacitor ba a haɗa ta har abada zuwa wutar lantarki ba, to ba kwa buƙatar damuwa. Misali, don samfurin da ke da matsananciyar sauyawa tsakanin wutar lantarki da capacitor, girman yana iya zama mafi mahimmanci fiye da rayuwa, kuma sannan zaka iya zabar capacitor siriri.
Duk da haka, idan capacitor ne har abada alaka da ikon Madogararsa, dole ne a sosai amintacce.The hadawan abu da iskar shaka na capacitors ba makawa.If capacitor epoxy abu ne mai kyau quality da capacitor ba sau da yawa fallasa zuwa matsananci yanayin zafi, da digo a cikin. darajar ya zama kadan.
A cikin wannan labarin, an fara gabatar da ka'idar filin ra'ayi na capacitors. Misalai masu dacewa da sakamakon kwaikwayo suna nuna yadda za a zaɓa da kuma amfani da nau'in capacitor na yau da kullum.Da fatan wannan bayanin zai iya taimaka maka fahimtar rawar da capacitors a cikin ƙirar lantarki da EMC mafi mahimmanci.
Dokta Min Zhang shi ne wanda ya kafa kuma babban mashawarcin EMC na Mach One Design Ltd, wani kamfanin injiniya na Burtaniya wanda ya kware a fannin tuntubar juna, warware matsalar da kuma horar da EMC. Zurfafan iliminsa a fannin lantarki, na'urorin lantarki, injina da kera kayayyaki ya amfana. kamfanoni a duniya.
In Compliance shine babban tushen labarai, bayanai, ilimi da kwarjini ga ƙwararrun injiniyan lantarki da na lantarki.
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