ULwesibili Dec 21 21:38:37 CST 2021
Imakrofoni ye-Electret iqukethe ukuguqulwa kukagesi we-acoustic kanye nokuguqulwa kwe-impedance.Isici esiyinhloko sokuguqulwa kwe-acoustoelectric yi-electret diaphragm.Ifilimu yepulasitiki emincane kakhulu, lapho ungqimba lwefilimu yegolide ehlanzekile luhwamuka ohlangothini olulodwa.Khona-ke, ngemva kwe-electret yenkundla kagesi yamandla aphezulu, kuba nezindleko ze-anisotropic nhlangothi zombili.Indawo yegolide ehwamukile ye-diaphragm ingaphandle futhi ixhunywe negobolondo lensimbi.Olunye uhlangothi lwe-diaphragm luhlukaniswa ne-metal plate ngendandatho encane evikelayo.Ngale ndlela, i-capacitance yakheka phakathi kwefilimu yegolide ehwamukile kanye nepuleti lensimbi.Lapho i-electret diaphragm ihlangana nokudlidliza kwe-acoustic, inkambu kagesi emikhawulweni yomibili ye-capacitor iyashintsha, okuholela ekutheni i-voltage eshintshayo ihluke ngokushintsha kwe-acoustic wave.Amandla phakathi kwe-electret diaphragm ne-metal plate mancane kakhulu, ngokuvamile amashumi e-PF.Ngakho-ke, inani layo le-impedance eliphumayo liphezulu kakhulu (XC = 1/2 ~ TFC), cishe amashumi ama-megaohms noma ngaphezulu.I-impedance ephezulu kangaka ayikwazi ukufaniswa ngokuqondile ne-amplifier yomsindo.Ngakho-ke, i-junction field effect transistor ixhunywe kumakrofoni ukuze kuguqulwe i-impedance.I-FET ibonakala ngokufakwa okuphezulu kwe-impedance kanye nenani eliphansi lomsindo.I-FET evamile inama-electrode amathathu: ama-electrode asebenzayo (ama), i-electrode yegridi (g) ne-drain electrode (d).Lapha, kusetshenziswa i-FET ekhethekile enenye i-diode phakathi komthombo wangaphakathi negridi.Inhloso ye-diode ukuvikela i-FET kumthelela wesignali onamandla.Isango le-FET lixhunywe epuleti lensimbi.Ngale ndlela, kunemigqa emithathu yokukhipha imakrofoni ye-electret.Okusho ukuthi, umthombo s ngokuvamile intambo yepulasitiki eluhlaza okwesibhakabhaka, idrayivu D ngokuvamile intambo yepulasitiki ebomvu kanye nentambo eyisivikelo elukiweyo exhuma igobolondo lensimbi.
Isikhathi sokuthumela: Aug-28-2023