1. Ngā take o te EMC me ngā mahi tiaki
I roto i ngā motuka kore paraihe tere-teitei, ko ngā raruraru EMC te kaupapa matua me te uaua o te kaupapa katoa, ā, he roa te wā e pau ana ki te tukanga arotau i te EMC katoa. Nō reira, me mārama tika tātou ki ngā take mō te EMC e hipa ana i te paerewa me ngā tikanga arotau e pā ana i te tuatahi.
Ko te arotautanga EMC ka tīmata i ngā huarahi e toru:
- Whakapai ake i te pūtake o te pokanoa
I roto i te whakahaere i ngā motuka kore paraihe tere-teitei, ko te pūtake nui o te pokanoa ko te ara iahiko taraiwa i titoa e ngā taputapu whakawhiti pēnei i te MOS me te IGBT. Mā te whakaiti i te auau kawe MCU, te whakaiti i te tere whakawhiti o te ngongo whakawhiti, me te whiriwhiri i te ngongo whakawhiti me ngā tawhā tika ka taea te whakaiti i te pokanoa EMC.
- Te whakaiti i te ara hononga o te pūtake pokanoa
Mā te arotau i te ara me te tahora o te PCBA ka taea te whakapai ake i te EMC, ā, ka nui ake te pokanoa i te hononga o ngā raina tetahi ki tetahi. Ina koa mō ngā raina tohu auau-tiketike, ngana ki te karo i ngā koropiko e hanga ana i ngā tohu me ngā pūihi e hanga ana i ngā tohu. Mena e tika ana, ka taea te whakanui ake i te paparanga tiaki hei whakaiti i te hononga.
- Ngā tikanga hei aukati i te pokanoa
Ko te mea e whakamahia whānuitia ana i roto i te whakapai ake i te EMC ko ngā momo inductances me ngā capacitors, ā, ka tīpakohia ngā tawhā e tika ana mō ngā momo pokanoa rerekē. Ko te capacitor Y me te inductance aratau noa mō te pokanoa aratau noa, ā, ko te capacitor X mō te pokanoa aratau rerekē. Ka wehea hoki te mowhiti aukume inductance ki te mowhiti aukume auau teitei me te mowhiti aukume auau iti, ā, e rua ngā momo inductances me tāpiri i te wā kotahi ina hiahiatia.
2. Te take arotautanga EMC
I roto i te arotautanga EMC o tētahi mōtini paraihe kore 100,000-rpm a tā mātou kamupene, anei ētahi o ngā kōrero matua e tumanako ana ahau ka whai hua ki te katoa.
Hei whakatutuki i te tere teitei o te motuka ki te kotahi rau mano hurihanga, ka whakatakotoria te auau kawe tuatahi ki te 40KHZ, he rua te teitei ake i ētahi atu motuka. I tēnei take, kāore i taea e ētahi atu tikanga arotau te whakapai ake i te EMC. Ka whakaitihia te auau ki te 30KHZ, ā, ka whakaitihia te maha o ngā wā whakawhiti MOS mā te 1/3 i mua i te whakapainga nui. I taua wā anō, i kitea he pānga te Trr (wā whakaora whakamuri) o te diode whakamuri o te MOS ki te EMC, ā, i tīpakohia he MOS he tere ake te wā whakaora whakamuri. Ko ngā raraunga whakamātautau e whakaaturia ana i te pikitia i raro nei. Kua piki ake te tawhā o te 500KHZ~1MHZ mā te 3dB pea, ā, kua papatahi te ngaru tītaha:
Nā te whakatakotoranga motuhake o te PCBA, e rua ngā aho hiko ngaohiko teitei me hono atu ki ētahi atu aho tohu. I muri i te whakawhiti i te aho ngaohiko teitei ki te takirua miro, ka iti ake te taupatupatu i waenga i ngā taura. Ko ngā raraunga whakamātautau e whakaatuhia ana i te pikitia i raro nei, ā, kua piki ake te tawhiti 24MHZ mā te 3dB pea:
I tēnei take, e rua ngā inductors aratau-noa e whakamahia ana, ko tētahi he mowhiti aukume auau-iti, me te inductance tata ki te 50mH, e whakapai ake ana i te EMC i te awhe o te 500KHZ~2MHZ. Ko tētahi atu he mowhiti aukume auau-tiketike, me te inductance tata ki te 60uH, e whakapai ake ana i te EMC i te awhe o te 30MHZ~50MHZ.
Kei te pikitia i raro nei ngā raraunga whakamātautau o te mowhiti aukume auau-iti, ā, kua piki ake te tawhē whānui mā te 2dB i te awhe o te 300KHZ~30MHZ:
Kei te pikitia i raro nei ngā raraunga whakamātautau o te mowhiti aukume auau-tiketike, ā, kua piki ake te tawhē mā te neke atu i te 10dB:
Ko tāku tumanako ka taea e te katoa te whakawhitiwhiti whakaaro me te rapu whakaaro mō te arotautanga EMC, me te kimi i te otinga pai rawa atu i roto i te whakamātautau tonu.
Wā tuku: Pipiri-07-2023