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Nā kānana Passive Band Passhiki ke hana ma ka hoʻohui ʻana i kahi kānana ala haʻahaʻa me kahi kānana ala kiʻekiʻe

Hiki ke hoʻohana ʻia ka Passive Band Pass Filter no ka hoʻokaʻawale ʻana a i ʻole kānana ʻana i kekahi mau alapine e waiho ana i loko o kahi pūna a i ʻole ka nui o nā alapine. Hiki ke hoʻomalu pono ʻia ke alapine ʻoki ʻoki a i ʻole ƒc i kahi kānana passive RC maʻalahi me ka hoʻohana ʻana i hoʻokahi resistor i ka pūʻulu me kahi capacitor non-polarized, a ma muli o ke ala a puni lākou e pili ai, ua ʻike mākou ua loaʻa kahi kānana Low Pass a i ʻole kahi kānana High Pass.

ʻO kahi hoʻohana maʻalahi no kēia mau ʻano kānana passive aia i nā noi hoʻonui leo a i ʻole nā kaapuni e like me nā kānana crossover loudspeaker a i ʻole nā mana leo pre-amplifier. I kekahi manawa, pono e ho'ohele i kekahi mau alapine 'a'ole e ho'omaka ma 0Hz, (DC) a i 'ole e pau ma kekahi wahi alapine ki'eki'e, akā aia i loko o kekahi laula a i 'ole ka pū'ulu alapine, he haiki a laula paha.

Ma ka hoʻohui ʻana a i ʻole "ka hoʻokahe" i hoʻokahi kaapuni ʻo Low Pass Filter me kahi kaapuni ʻo High Pass Filter, hiki iā mākou ke hana i kekahi ʻano kānana RC passive e hele ana i kahi ākea i koho ʻia a i ʻole "band" o nā alapine hiki ke haiki a ākea paha i ka wā e hoʻemi ana i nā mea āpau ma waho o kēia pae. Hoʻopuka kēia ʻano hou o ka hoʻonohonoho kānana passive i kahi kānana koho alapine i ʻike maʻamau ʻia ʻo Band Pass Filter a i ʻole BPF no ka pōkole.

ʻAʻole e like me ka kānana ala haʻahaʻa e hāʻawi wale i nā hōʻailona o ke alapine haʻahaʻa a i ʻole ka kānana alapine kiʻekiʻe e hele ana i nā hōʻailona o ke alapine kiʻekiʻe, ʻo ka Band Pass Filters e hāʻawi i nā hōʻailona i loko o kekahi "band" a i ʻole "spread" o nā alapine me ka hoʻohuli ʻole i ka hōʻailona hoʻokomo a i ʻole ka hoʻokomo ʻana i ka walaʻau hou. Hiki i kēia pūʻulu alapine ke ʻano ākea a ʻike ʻia ʻo ia ʻo nā kānana Bandwidth.

ʻO ka Bandwidth ka mea maʻamau i wehewehe ʻia ma ke ʻano o ke alapine e loaʻa ana ma waena o ʻelua mau kikoʻoki ʻoki alapine (ƒc), ʻo ia ka 3dB ma lalo o ke kikowaena kiʻekiʻe a i ʻole ka resonant peak i ka wā e hoʻemi ana a hoʻonāwaliwali paha i nā mea ʻē aʻe ma waho o kēia mau helu ʻelua.

A laila no nā alapine ākea ākea, hiki iā mākou ke wehewehe i ka huaʻōlelo "bandwidth", ʻo BW ka ʻokoʻa ma waena o ke alapine ʻoki haʻahaʻa haʻahaʻa (ƒcLOWER) a me nā helu ʻoki kiʻekiʻe (ƒcHIGHER). ʻO ia hoʻi, BW = ƒH – ƒL. Akaka no ka holo pono ana o kahi kānana pass band, pono e ʻoi aku ke kiʻekiʻe o ke alapine ʻoki ʻia o ka kānana ala haʻahaʻa ma mua o ke alapine ʻoki ʻia no ka kānana ala kiʻekiʻe.

Hiki ke hoʻohana ʻia ka "mea maikaʻi" Band Pass Filter e hoʻokaʻawale a kānana i kekahi mau alapine e waiho ana i loko o kahi hui o nā alapine, no ka laʻana, ka hoʻopau ʻana i ka walaʻau. ʻIke ʻia nā kānana band pass ma ke ʻano he kānana papa ʻelua, (ʻelua-pole) no ka mea, loaʻa iā lākou "ʻelua" ʻāpana reactive, nā capacitors, i loko o kā lākou hoʻolālā kaapuni. Hoʻokahi capacitor ma ke kaapuni ala haʻahaʻa a me kekahi capacitor ma ka kaapuni ala kiʻekiʻe.

Hōʻike ka Bode Plot a i ʻole ka pihi pane alapine ma luna i nā ʻano o ka kānana band pass. Eia ka hōʻailona ma nā alapine haʻahaʻa me ka piʻi ʻana o ka puka ma kahi piʻi o +20dB/Decade (6dB/Octave) a hiki i ke alapine i ke kiko "ʻoki haʻahaʻa" ƒL. Ma kēia alapine, ʻo 1/√2 = 70.7% o ka hōʻailona hōʻailona hoʻokomo a i ʻole -3dB (20*log(VOUT/VIN)) o ka hoʻokomo.

Ke hoʻomau nei ka hoʻopuka i ka loaʻa kiʻekiʻe a hiki i ka helu "ʻoki ʻoki luna" ƒH kahi e hoʻemi ai ka hoʻopuka ma ka helu o -20dB/Decade (6dB/Octave) e hōʻemi ana i nā hōʻailona alapine kiʻekiʻe. ʻO ka helu o ka loaʻa kiʻekiʻe o ka loaʻa ʻana, ʻo ia ke kumu geometric o ka waiwai ʻelua -3dB ma waena o nā wahi ʻoki lalo a me luna a ua kapa ʻia ʻo "Centre Frequency" a i ʻole "Resonant Peak" waiwai ƒr. Ua helu ʻia kēia ʻano waiwai geometric ma ke ʻano he ƒr 2 = ƒ(UPPER) x ƒ(LOWER).

Akānana band passua manaʻo ʻia he kānana ʻano papa ʻelua (ʻelua pole) no ka mea he "ʻelua" ʻāpana reactive i loko o kona ʻano kaapuni, a laila e palua ka huina o nā kānana o nā kānana papa mua, ʻo ia hoʻi, 180o. ʻO ka huina o ka hōʻailona hoʻopuka e alakaʻi i ka hoʻokomo ʻana e +90o a hiki i ke kikowaena a i ʻole ke alapine resonant, ƒr helu inā lilo ia i "zero" degere (0o) a i ʻole "in-phase" a laila hoʻololi i LAG i ka hoʻokomo ʻana e -90o i ka piʻi ʻana o ka alapine puka.

Hiki ke ʻike ʻia nā helu alapine o luna a me lalo no kahi kānana band pass me ka hoʻohana ʻana i ke ʻano like me kēlā no nā kānana pass haʻahaʻa a kiʻekiʻe, No ka laʻana.