ʻO nā capacitors kānana, nā inductors mode maʻamau, a me nā peʻa magnetic he mau helu maʻamau i nā kaʻa hoʻolālā EMC, a he ʻekolu mau mea hana ikaika e hoʻopau i ka hoʻopili electromagnetic.
No ka hana o keia mau mea ekolu i ka kaapuni, ke manao nei au he nui na enekinia i maopopo ole, ka 'atikala mai ka manao o ka kiko'ī kālailai o ka loina o ka hoopau ana i ekolu EMC sharpest.
1.Filter capacitor
ʻOiai ʻaʻole makemake ʻia ka resonance o ka capacitor mai ka manaʻo o ka kānana ʻana i ka walaʻau kiʻekiʻe, ʻaʻole ʻino mau ka resonance o ka capacitor.
Ke hoʻoholo ʻia ke alapine o ka walaʻau e kānana ʻia, hiki ke hoʻoponopono ʻia ka hiki o ka capacitor i hāʻule wale ke kiko resonant i ka alapine haunaele.
Ma ka ʻenekinia hana, ʻo ke alapine o ka walaʻau electromagnetic e kānana pinepine ʻia e like me ke kiʻekiʻe o nā haneli MHz, a ʻoi aku paha ma mua o 1GHz.No ka leo electromagnetic alapine kiʻekiʻe, pono ia e hoʻohana i ka capacitor through-core e kānana maikaʻi.
ʻO ke kumu ʻaʻole hiki i nā capacitor maʻamau ke kānana maikaʻi i ka walaʻau kiʻekiʻe ma muli o nā kumu ʻelua:
(1) Hoʻokahi kumu, ʻo ka inductance o ke alakaʻi capacitor ke kumu o ka capacitor resonance, e hōʻike ana i kahi impedance nui i ka hōʻailona kiʻekiʻe, a hoʻonāwaliwali i ka hopena bypass o ka hōʻailona kiʻekiʻe;
(2) ʻO kekahi kumu ʻo ka capacitance parasitic ma waena o nā uea e hoʻopili ana i ka hōʻailona kiʻekiʻe-frequency, e hōʻemi ana i ka hopena kānana.
ʻO ke kumu e hiki ai i ka capacitor through-core ke kānana maikaʻi i ka walaʻau kiʻekiʻe ʻo ia ka mea ʻaʻole i loaʻa i ka capacitor through-core ka pilikia ʻo ke alakaʻi inductance e haʻahaʻa loa ka capacitor resonance frequency.
A hiki ke hoʻokomo pololei ʻia ka capacitor through-core ma ka pā metala, me ka hoʻohana ʻana i ka panel metala e pāʻani i ke kuleana o ka hoʻokaʻawale kiʻekiʻe.Eia naʻe, i ka hoʻohana ʻana i ka capacitor through-core, ʻo ka pilikia e hoʻolohe i ka pilikia hoʻonohonoho.
ʻO ka nāwaliwali nui loa o ka capacitor through-core ka makaʻu i ke kiʻekiʻe o ka wela a me ka hopena o ka wela, kahi e hoʻopilikia nui ai i ka wā e hoʻopili ai i ka capacitor through-core i ka panel metala.
Nui nā capacitors i pōʻino i ka wā wili.ʻOi aku ka nui o ka nui o nā capacitor kumu e pono e hoʻokomo ʻia ma ka panel, inā lōʻihi ka pōʻino, paʻakikī ke hoʻoponopono, no ka mea, i ka wā e wehe ʻia ai ka capacitor i poino, e hōʻino ʻia i nā capacitor kokoke.
2. Common mode inductance
No ka mea ʻo nā pilikia e kū nei i ka EMC ka mea maʻamau o ka hoʻopili ʻana i ke ʻano maʻamau, ʻo nā inductors mode maʻamau kekahi o kā mākou mea hoʻohana maʻamau.
ʻO ka mea inductor mode maʻamau he mea hana hoʻopiʻi hoʻopiʻi maʻamau maʻamau me ka ferrite e like me ke kumu, aia i ʻelua coils o ka nui like a me ka helu like o nā huli symmetrically ʻeha ma ke apo ferrite magnetic core e hana ai i kahi mea ʻehā-terminal. Loaʻa i kahi hopena hoʻopiʻi inductance nui no ka hōʻailona mode maʻamau, a me kahi inductance leakage liʻiliʻi no ka hōʻailona mode differential.
ʻO ke kumumanaʻo i ka wā e kahe ai ke ʻano maʻamau o kēia manawa, ʻoi aku ka nui o ka flux magnetic i ke apo magnetic i kekahi i kekahi, no laila ke loaʻa ka inductance nui, ka mea e pale ai i ke ʻano maʻamau o kēia manawa, a i ka wā e kahe ai nā coils ʻelua ma ke ʻano ʻokoʻa o kēia manawa, ʻo ka flux magnetic. i loko o ke apo magnetic e kāpae i kekahi i kekahi, a ʻaneʻane ʻaʻohe inductance, no laila hiki ke hele ke ʻano ʻokoʻa i kēia manawa me ka ʻole o ka attenuation.
No laila, hiki i ka inductor mode maʻamau ke hoʻopau pono i ka hōʻailona interference mode maʻamau i ka laina kaulike, akā ʻaʻohe hopena i ka hoʻoili maʻamau o ka hōʻailona mode differential.
Pono nā inductors mode maʻamau e hoʻokō i kēia mau koi i ka wā i hana ʻia ai lākou:
(1) Pono e hoʻokaʻawale ʻia nā uea i ʻeha ma ke kumu wili i mea e hōʻoia ai ʻaʻohe haki kaapuni pōkole ma waena o ka huli ʻana o ka wili ma lalo o ka hana o ka overvoltage koke;
(2) Ke kahe ka wili i ke au nui koke, ʻaʻole pono e hoʻopiha ʻia ke kumu magnetic;
(3) Pono e hoʻokaʻawale ʻia ke kumu magnetic i loko o ka coil mai ka wili e pale ai i ka haki ʻana ma waena o nā mea ʻelua ma lalo o ka hana o ka overvoltage koke;
(4) Pono e ʻeha ka coil i kahi papa hoʻokahi e like me ka hiki, i mea e hōʻemi ai i ka capacitance parasitic o ka coil a hoʻonui i ka hiki o ka coil e hoʻouna i ka overvoltage transient.
Ma lalo o nā kūlana maʻamau, ʻoiai e hoʻolohe ana i ke koho ʻana i ke alapine e pono ai e kānana, ʻoi aku ka nui o ka impedance mode maʻamau, ʻoi aku ka maikaʻi, no laila pono mākou e nānā i ka ʻikepili o ka mīkini i ke koho ʻana i ka inductor mode maʻamau, e like me ka kaha alapine impedance.
Eia kekahi, i ke koho ʻana, e hoʻolohe i ka hopena o ka impedance mode differential ma ka hōʻailona, e nānā nui ana i ka impedance mode differential, ʻoi aku ka nānā ʻana i nā awa kiʻekiʻe.
3. Magnetic bead
I loko o ka huahana kikohoʻe kaapuni EMC hoʻolālā kaʻina hana, mākou pinepine hoʻohana i ka magnetic beads, ferrite mea he hao-magnesium alloy a iron-nickel alloy, keia mea i ka kiʻekiʻe magnetic permeability, hiki ia i ka inductor ma waena o ka coil wili i ka hihia o ke kiʻekiʻe. ka alapine a me ke kū'ē kiʻekiʻe i hana ʻia ka capacitance liʻiliʻi.
Hoʻohana pinepine ʻia nā mea Ferrite i nā alapine kiʻekiʻe, no ka mea ma nā alapine haʻahaʻa ko lākou mau hiʻohiʻona inductance nui e liʻiliʻi loa ka poho ma ka laina.I nā alapine kiʻekiʻe, ʻo ia ka mea nui o ka reactance character ratios a hoʻololi me ke alapine.Ma nā noi kūpono, hoʻohana ʻia nā mea ferrite e like me nā attenuators kiʻekiʻe no nā kaʻa alapine radio.
ʻO ka ʻoiaʻiʻo, ʻoi aku ka maikaʻi o ka ferrite me ka parallel o ke kū'ē a me ka inductance, ua pōkole ke kū'ē i ka inductor i ka haʻahaʻa haʻahaʻa, a ua kiʻekiʻe ka impedance inductor i ke alapine kiʻekiʻe, no laila e hele nā mea āpau i ke kū'ē.
ʻO Ferrite kahi mea hoʻohana e hoʻololi i ka ikehu kiʻekiʻe i ka ikehu wela, i hoʻoholo ʻia e kona mau hiʻohiʻona pale uila.ʻOi aku ka maikaʻi o nā ʻano kānana alapine kiʻekiʻe ma mua o nā inductors maʻamau.
ʻO ka Ferrite ke kū'ē i nā alapine kiʻekiʻe, e like me ka inductor me kahi kumu haʻahaʻa haʻahaʻa, no laila hiki iā ia ke mālama i kahi impedance kiʻekiʻe ma luna o kahi ākea ākea, a laila e hoʻomaikaʻi ai i ka pono o ka kānana kiʻekiʻe.
I ke alapine haʻahaʻa haʻahaʻa, ua haku ʻia ka impedance me ka inductance.Ma ke alapine haʻahaʻa, he liʻiliʻi loa ka R, a he kiʻekiʻe ka permeability magnetic o ke kumu, no laila nui ka inductance.He koʻikoʻi ko L, a ua hoʻopaʻa ʻia ka interference electromagnetic e ka noʻonoʻo.A i kēia manawa, liʻiliʻi ka nalowale o ke kumu magnetic, he haʻahaʻa haʻahaʻa ka hāmeʻa holoʻokoʻa, nā hiʻohiʻona Q kiʻekiʻe o ka inductor, ua maʻalahi kēia inductor e hoʻoulu i ka resonance, no laila i ka haʻahaʻa haʻahaʻa haʻahaʻa, i kekahi manawa hiki ke hoʻonui i ka interference. ma hope o ka hoʻohana ʻana i nā ferrite magnetic beads.
I ke alapine kiʻekiʻe, ua haku ʻia ka impedance i nā ʻāpana kūʻē.I ka piʻi ʻana o ke alapine, e emi ana ka permeability o ka magnetic core, ka hopena i ka emi ʻana o ka inductance o ka inductor a me ka emi ʻana o ka ʻāpana reactance inductive.
Eia nō naʻe, i kēia manawa, piʻi ka nalowale o ke kumu magnetic, piʻi ka mea kū'ē, ka hopena i ka piʻi ʻana o ka impedance holoʻokoʻa, a i ka wā e hele ai ka hōʻailona kiʻekiʻe i ka ferrite, hoʻopili ʻia ka interference electromagnetic a hoʻololi ʻia i ke ʻano. o ka hoopau wela.
Hoʻohana nui ʻia nā mea hoʻopau Ferrite i nā papa kaapuni paʻi, nā laina mana a me nā laina ʻikepili.No ka laʻana, ua hoʻohui ʻia kahi mea hoʻopau ferrite i ka hopena inlet o ke kaula mana o ka papa i paʻi ʻia e kānana i ka hoʻopili alapine kiʻekiʻe.
Hoʻohana kūikawā ʻia ke apo magnetic Ferrite a i ʻole ka peʻa magnetic e hoʻopau i ka interference kiʻekiʻe a me ka interference kiʻekiʻe ma nā laina hōʻailona a me nā laina mana, a loaʻa iā ia ka hiki ke komo i ka electrostatic discharge pulse interference.Hoʻohana nui ʻia ka hoʻohana ʻana i nā pahu magnetic chip a i ʻole chip inductors i ka hoʻohana pono.
Hoʻohana ʻia nā inductors chip i nā kaapuni resonant.Ke hoʻopau ʻia ka leo EMI pono ʻole, ʻo ka hoʻohana ʻana i nā pahu magnetic chip ke koho maikaʻi loa.
Ka hoʻohana ʻana i nā pahu magnetic chip a me nā inductors chip
ʻO nā mea hoʻokomo chip:Lekiō alapine (RF) a me ke kelepona ʻole, nā ʻenehana ʻike ʻike, nā mea ʻike radar, nā uila uila, nā kelepona kelepona, nā pagers, nā lako leo, nā mea kōkua kikohoʻe pilikino (PDA), nā ʻōnaehana mamao mamao, a me nā modula lako mana haʻahaʻa.
ʻO nā lei magnetic chip:Nā kaapuni hana uaki, kānana ma waena o nā kaapuni analog a me nā kikohoʻe, nā mea hoʻopili i loko o I/O (e like me nā port serial, port parallel, keyboards, mice, telecommunications long-long, local area networks), RF circuits a me nā mea hoʻonaʻauao hiki ke loaʻa. ka hoʻopaʻa 'ana, ka kānana o ke alapine kiʻekiʻe i alakaʻi 'ia ke keakea i ka mana lako kaapuni, kamepiula, mīkini paʻi, wikiō hoʻopaʻa leo (VCRS), EMI ka leo hoʻopau i loko o ke kīwī nenoai a me nā kelepona hele.
ʻO ka ʻāpana o ka pahu magnetic he ohms, no ka mea, ʻo ka ʻāpana o ka peʻa magnetic he nominal e like me ka impedance i hana ʻia ma kahi alapine, a ʻo ka ʻāpana o ka impedance he ohms.
E hāʻawi maʻamau ka DATASHEET bead magnetic i ke alapine a me nā hiʻohiʻona impedance o ka pihi, ma ke ʻano he 100MHz ma ke ʻano maʻamau, no ka laʻana, i ka manawa o ka alapine o 100MHz ke like ka impedance o ka pahu magnetic me 1000 ohms.
No ke alapine a mākou e makemake ai e kānana, pono mākou e koho i ka nui o ka impedance o ka pahu magnetic, ʻoi aku ka maikaʻi, koho maʻamau i ka 600 ohm impedance a i ʻole.
Eia kekahi, i ke koho ʻana i nā bead magnetic, pono ia e hoʻolohe i ka flux o nā beads magnetic, ka mea maʻamau e hoʻemi ʻia e 80%, a pono e noʻonoʻo ʻia ka mana o ka impedance DC i ka hāʻule ʻana o ka uila i ka wā e hoʻohana ʻia ai i nā kaapuni mana.
Ka manawa hoʻouna: Iulai-24-2023