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Macapacitor ndechimwe chezvinhu zvinonyanya kushandiswa pamabhodhi edunhu.Sezvo huwandu hwemidziyo yemagetsi (kubva panharembozha kusvika kumotokari) huri kuramba huchiwedzera, ndizvo zviri kuramba zvichiwedzera kudiwa kwema capacitor. Denda reCovid 19 ravhiringa chikamu chepasi rose chekutengesa kubva kumasemiconductors. kune passive components, uye capacitors anga ari mushomeka1.
Hurukuro pamusoro penyaya ye capacitors inogona kushandurwa nyore nyore kuva bhuku kana duramazwi.Kutanga, kune marudzi akasiyana-siyana e-capacitors, akadai se electrolytic capacitors, film capacitors, ceramic capacitors nezvimwe zvakadaro.Zvino, mumhando imwe chete, pane zvakasiyana-siyana. dielectric zvinhu.Kunewo makirasi akasiyana-siyana.Nezve chimiro chemuviri, kune maviri-terminal uye matatu-terminal capacitor marudzi.Kunewo X2Y type capacitor, iyo inonyanya kuvharwa kweY capacitors yakavharwa mune imwe.Ko nezve supercapacitors ?Chokwadi ndechekuti, kana ukagara pasi wotanga kuverenga madhairekitori ekusarudza capacitor kubva kuvagadziri vakuru, unogona kupedza zuva zviri nyore!
Sezvo chinyorwa ichi chiri pamusoro pezvinyorwa, ini ndichashandisa nzira yakasiyana-siyana semazuva ose.Sezvambotaurwa kare, mazano ekusarudza capacitor anogona kuwanikwa nyore nyore pawebsite yevatengesi 3 uye 4, uye mainjiniya emunda anogona kazhinji kupindura mibvunzo yakawanda pamusoro pe capacitors.Munyaya ino, Handizodzokorora zvaunogona kuwana paInternet, asi ndicharatidza nzira yekusarudza uye kushandisa capacitors kuburikidza nemienzaniso inoshanda.Zvimwe zvishoma-zvinozivikanwa zvekusarudza capacitor, zvakadai se capacitance degradation, zvichavharwawo.Mushure mekuverenga chinyorwa ichi, iwe inofanira kuva nekunzwisisa kwakanaka kwekushandiswa kwema capacitors.
Makore apfuura, pandakanga ndichishanda mune imwe kambani yaigadzira michina yemagetsi, takava nemubvunzo wekubvunzurudza kune injiniya yemagetsi.Pamufananidzo wechirongwa chezvigadzirwa zviripo, tichabvunza vangangove vakakwikwidza kuti "Ndeipi basa reDC link electrolytic capacitor?"uye "Ndeipi basa receramic capacitor padyo nechip?"Tinovimba kuti mhinduro chaiyo ndeye DC bhazi capacitor Inoshandiswa kuchengetedza simba, ceramic capacitors inoshandiswa kusefa.
Mhinduro "yakarurama" yatinotsvaka inonyatsoratidza kuti munhu wose ari muboka rekugadzira anotarisa capacitors kubva kune imwe nzvimbo yedunhu, kwete kubva kune imwe nzvimbo yezvinyorwa. kusvika MHz vashoma), redunhu dzidziso anogona kazhinji kutsanangura dambudziko zvakanaka.Izvi imhaka yokuti panguva yakaderera frequencies, chiratidzo kunyanya vari differential mode.Kushandisa redunhu dzidziso, tinogona kuona capacitor inoratidzwa Figure 1, apo akaenzana akatevedzana kuramba ( ESR) uye yakaenzana yakatevedzana inductance (ESL) inoita iyo impedance ye capacitor ichinje ne frequency.
Uyu muenzaniso unotsanangura zvizere kushanda kwedunhu kana dunhu richishandurwa zvishoma nezvishoma.Zvisinei, sezvo kuwanda kunowedzera, zvinhu zvinowedzera uye zvakanyanya kuoma.Pane imwe nguva, chikamu chinotanga kuratidza chisingaiti-linearity.Kana iyo yakawanda inowedzera, iyo iri nyore LCR model. ine ganhuriro dzayo.
Nhasi, dai ndakabvunzwa mubvunzo wakafanana wekubvunzurudza, ndaizopfeka magirazi ekucherechedza munda wangu uye ndinotaura kuti zvose capacitor marudzi ndiwo magetsi ekuchengetedza magetsi.Musiyano ndewokuti electrolytic capacitors inogona kuchengeta simba rakawanda kupfuura ceramic capacitors.Asi maererano nekufambisa simba , Ceramic capacitors inogona kutumira simba nekukurumidza.Izvi zvinotsanangura kuti sei ceramic capacitors inoda kuiswa pedyo nechip, nokuti chip ine yakakwirira yekushandura frequency uye kushandura kukurumidza kuenzaniswa nemagetsi makuru emagetsi.
Kubva pane maonero aya, tinogona kungotsanangura maitiro maviri ekushanda kwe capacitor.Imwe ndeye simba rakawanda sei iyo capacitor inogona kuchengeta, uye imwe inokurumidza sei simba iri rinogona kuendeswa.Zvose zvinoenderana nenzira yekugadzira ye capacitor, dielectric material, iyo yekubatanidza ne capacitor, zvichingodaro.
Kana shanduko yedunhu yakavharwa (ona Mufananidzo 2), inoratidza kuti mutoro unoda simba kubva kune simba remagetsi.Kukurumidza iyo inovhara inovhara inotarisa kukurumidza kwekuda kwesimba.Sezvo simba rinofamba nekumhanya kwechiedza (hafu kukurumidza kwechiedza mu FR4 zvinhu), zvinotora nguva kuendesa simba.Uyezve, kune impedance mismatch pakati pechitubu uye mutsara wekutumira uye mutoro.Izvi zvinoreva kuti simba harizombofa rakatamiswa mune imwe rwendo, asi mune dzakawanda. kutenderera nzendo5, ndosaka kana switch ichichinja nekukurumidza, tinoona kunonoka uye kurira mune switching waveform.
Mufananidzo 2: Zvinotora nguva kuti simba ripararire muchadenga;impedance kusawirirana kunokonzeresa nzendo dzakawanda dzekutenderera dzekutamisa simba.
Ichokwadi chokuti simba rekufambisa rinotora nguva uye nzendo dzakawanda dzekutenderera rinotiudza kuti tinoda kutsvaga simba remagetsi pedyo nemutoro sezvinobvira, uye tinoda kutsvaga nzira yekuendesa simba nokukurumidza.Iyo yekutanga inowanzoitwa nekuderedza muviri. chinhambwe pakati pemutoro, chinja uye capacitor.Iyo yekupedzisira inowanikwa nekuunganidza boka re capacitors rine diki impedance.
Field theory inotsanangurawo kuti chii chinokonzera common mode noise.Muchidimbu, common mode ruzha runogadzirwa kana simba remutoro rekutakura risati rasangana panguva yekuchinja.Saka, simba rakachengetwa munzvimbo pakati pemutoro uye ma conductors ari pedyo achapiwa kutsigira. danho rinodiwa.Nzvimbo iri pakati pemutoro nemakondakita ari pedyo ndiyo yatinoti parasitic/mutual capacitance (ona Mufananidzo 2).
Isu tinoshandisa mienzaniso inotevera kuratidza nzira yekushandisa electrolytic capacitors, multilayer ceramic capacitors (MLCC), uye film capacitors.Both circuit and field theory inoshandiswa kutsanangura kushanda kweakasarudzwa capacitors.
Electrolytic capacitors inonyanya kushandiswa muDC link seyo huru simba sosi.Sarudzo ye electrolytic capacitor inowanzoenderana ne:
Nezve EMC performance, iyo inonyanya kukosha maitiro e capacitors ndeye impedance uye frequency maitiro.Low-frequency inoitwa emissions nguva dzose zvinoenderana nekuita kweDC link capacitor.
Iyo impedance yeDC link inotsamira kwete chete paESR uye ESL yecapacitor, asiwo panharaunda yeiyo thermal loop, sezvakaratidzwa muFigure 3.A hombe yekushisa loop nzvimbo inoreva kuti kufambisa kwesimba kunotora nguva yakareba, saka kuita. zvichakanganiswa.
A nhanho-pasi DC-DC converter yakavakwa kuratidza izvi.The pre-kutevedza EMC bvunzo setup inoratidzwa Figure 4 inoita yakaitwa emission scan pakati 150kHz uye 108MHz.
Zvakakosha kuve nechokwadi kuti ma-capacitors anoshandiswa munyaya iyi yose anobva kumugadziri mumwe chete kuti arege kusiyanisa maitiro e impedance.Paunenge uchitengesa capacitor paPCB, iva nechokwadi chokuti hapana marefu anotungamira, sezvo izvi zvichawedzera ESL ye iyo capacitor.Mufananidzo 5 unoratidza magadzirirwo matatu.
Mhedzisiro yakaitwa yezvigadziriso zvitatu izvi inoratidzwa muMufananidzo 6. Zvinogona kuonekwa kuti, zvichienzaniswa ne680 µF capacitor, maviri 330 µF capacitor anowana kuita kwekudzikisa ruzha kwe6 dB pane yakakura frequency renji.
Kubva pamusangano wedunhu, zvinogona kutaurwa kuti nekubatanidza ma capacitors maviri mukufanana, zvose ESL uye ESR zvakapetwa. , zvinobudirira kuderedza nguva yose yekufambisa simba.Zvisinei, pamatunhu akakwirira, musiyano pakati pemaviri 330 µF capacitor uye imwe 680 µF capacitor ichaderera.Izvi imhaka yekuti ruzha rukuru runoratidza kusakwana kwesimba remhinduro.Kana uchifambisa 330 µF capacitor pedyo ne chinja, tinoderedza nguva yekufambisa simba, iyo inobudirira inowedzera danho remhinduro ye capacitor.
Chigumisiro chinotiudza chidzidzo chakakosha zvikuru.Kuwedzera simba re capacitor imwe chete hakuzobatsiri danho rekudiwa kwesimba rakawanda.Kana zvichibvira, shandisa zvimwe zvikamu zviduku zve capacitive.Pane zvikonzero zvakawanda zvakanaka zveizvi.Chekutanga imari.Kazhinji. kutaura, nokuda kwehukuru hwepakiti imwechete, mari ye capacitor inowedzera zvakanyanya ne capacitance value.Kushandisa capacitor imwe chete kunogona kudhura kudarika kushandisa maduku maduku akawanda.Chikonzero chechipiri hukuru.Chikonzero chekugadzirisa mukugadzirwa kwechigadzirwa kunowanzova kureba yezvikamu.Kune mahombe-capacitor, kureba kunowanzove kwakakura zvakanyanya pakugadzirwa kwechigadzirwa.Chikonzero chechitatu ndechekuita kweEMC yatakaona munyaya yekuongorora.
Chimwe chinhu chekufunga kana uchishandisa electrolytic capacitor ndechekuti kana iwe ukabatanidza maviri capacitor munhevedzano kugovera voltage, iwe unozoda balancing resistor 6.
Sezvambotaurwa kare, ceramic capacitors maminiature midziyo inogona kukurumidza kupa simba.Ndinowanzobvunzwa mubvunzo "Ndinoda yakawanda sei capacitor?"Mhinduro yemubvunzo uyu ndeyokuti kune ceramic capacitors, capacitance value haifaniri kunge yakakosha. Chinokosha chekufungisisa pano ndechekuona kuti inguva ipi iyo simba rekufambisa simba rinokwana kushandiswa kwako.Kana iyo yakaitwa yakakundikana pa 100 MHz, ipapo capacitor ine diki impedance pa 100 MHz ichava sarudzo yakanaka.
Uku ndiko kumwe kusanzwisisa kweMLCC.Ndakaona mainjiniya vachipedza simba rakawanda vachisarudza ceramic capacitors ine yakaderera ESR uye ESL vasati vabatanidza ma capacitor kune RF referensi point kuburikidza nematehwe marefu.Zvakakodzera kutaura kuti ESL yeMLCC inowanzo nyanya. yakaderera pane yekubatanidza inductance pabhodhi.Connection inductance ichiri iyo inonyanya kukosha parameter inobata high frequency impedance ye ceramic capacitors7.
Mufananidzo 7 unoratidza muenzaniso wakaipa.Kutsvaga kwenguva refu (0.5 inches kureba) kunozivisa zvishoma 10nH inductance. Mugumisiro wekufananidza unoratidza kuti impedance ye capacitor inova yakakwirira kudarika inotarisirwa pafrequency point (50 MHz).
Rimwe rematambudziko neMLCCs nderekuti dzinowanzoita resonance pane inductive structure pabhodhi.Izvi zvinogona kuonekwa mumuenzaniso wakaratidzwa mumufananidzo 8, apo kushandiswa kwe10 µF MLCC kunosuma resonance inenge 300 kHz.
Iwe unogona kuderedza resonance nekusarudza chikamu ne ESR yakakura kana kungoisa diki diki resistor (yakadai se 1 ohm) mumutsara ne capacitor.Iyi nzira yenzira inoshandisa kurasikirwa kwezvikamu kudzvinyirira system.Imwe nzira ndeyokushandisa imwe capacitance. kukosha kwekufambisa resonance kune yakaderera kana yepamusoro resonance point.
Firimu capacitors anoshandiswa mune zvakawanda zvikumbiro.Iwo ndiwo ma capacitor esarudzo epamusoro-simba DC-DC converters uye anoshandiswa seEMI suppression filters pamagetsi emagetsi (AC neDC) uye zvinowanzo-mode filtering configurations.Tinotora X capacitor se. muenzaniso wekuratidza dzimwe pfungwa huru dzekushandisa mafirimu capacitor.
Kana chiitiko chekuvhiya chikaitika, chinobatsira kudzikisira peak voltage stress pamutsara, saka inowanzo shandiswa ne transient voltage suppressor (TVS) kana metal oxide varistor (MOV).
Iwe unogona kunge watoziva zvose izvi, asi waiziva here kuti capacitance value ye X capacitor inogona kuderedzwa zvakanyanya nemakore ekushandiswa?Izvi zvinonyanya kuitika kana iyo capacitor inoshandiswa munzvimbo ine hunyoro.Ndakaona kukosha kwekugadzirisa iyo X capacitor inongodonha kusvika pashoma muzana yehuwandu hwayo yakayerwa mukati megore kana maviri, saka sisitimu yakatanga kugadzirwa neX capacitor yakarasikirwa nedziviriro yese iyo yekumberi-yekupedzisira capacitor ingave nayo.
Saka, chii chakaitika?Mhepo yehunyoro inogona kudonhedza mu capacitor, kumusoro waya uye pakati pebhokisi uye epoxy potting compound.The aruminiyamu metallization inogona kubva oxidized.Alumina yakanaka magetsi insulator, nokudaro kuderedza capacitance.Iri idambudziko kuti ese mafirimu capacitor achasangana nawo.Nyaya yandiri kutaura nezvayo ndeyekukobvu kwefirimu.Marudzi ane mukurumbira wepacitor anoshandisa mafirimu akakora, zvichikonzera macapacitor akakura kupfuura mamwe mabhurendi.Firimu rakatetepa rinoita kuti capacitor isasimba pakuremedza (voltage, current, kana temperature), uye hazvibviri kuzviporesa.
Kana iyo X capacitor isingabatanidzwe zvachose kune magetsi, saka haufaniri kunetseka.Somuenzaniso, kune chigadzirwa chine shanduko yakaoma pakati pemagetsi uye capacitor, ukuru hungave hwakakosha kudarika hupenyu, uye ipapo iwe unogona kusarudza yakaonda capacitor.
Zvisinei, kana iyo capacitor yakabatanidzwa zvachose kune simba remagetsi, inofanira kuva yakavimbika zvikuru.Iyo oxidation ye capacitors haidzivisiki.Kana iyo capacitor epoxy zvinhu ndeyehutano hwakanaka uye capacitor haiwanzo kuratidzwa kune kutonhora kwakanyanya, kudonha mukati kukosha kunofanira kuva kushoma.
Muchikamu chino, chakatanga kuunza maonero emunda we capacitors.Mienzaniso inoshanda nemigumisiro yekufananidza inoratidza kuti ungasarudza sei uye ushandise mhando dzakawanda dze capacitor.Tariro iyi ruzivo runogona kukubatsira kuti unzwisise basa re capacitors mumagetsi uye EMC kugadzira zvakanyanya.
Dr. Min Zhang ndivo muvambi uye mukuru EMC consultant weMach One Design Ltd, UK-based engineering company inyanzvi muEMC consulting, troubleshooting and training.Ruzivo rwake rwakadzama mumagetsi emagetsi, emagetsi edhijitari, mota nekugadzirwa kwechigadzirwa kwabatsira. makambani pasi rose.
MuKuteerera ndiko kunobva nhau, ruzivo, dzidzo uye kurudziro yemagetsi nemagetsi einjiniya nyanzvi.
Aerospace Automotive Communications Consumer Electronics Dzidzo Simba neSimba Indasitiri Ruzivo rweTekinoroji Kurapa Mauto neNyika Dziviriro.