Tue Zvita 21 21:38:37 CST 2021
Electret maikorofoni ine acoustic yemagetsi shanduko uye impedance shanduko.Chinhu chakakosha chekushandura kweacoustoelectric ndeye electret diaphragm.Iyo firimu yepurasitiki yakaonda kwazvo, umo mutsetse wegoridhe rakachena firimu rinoputika kune rumwe rutivi.Zvadaro, mushure me electret ye high voltage electric field, kune anisotropic charges kumativi ose maviri.Iyo goridhe yakanyungudutswa pamusoro pe diaphragm iri kunze uye yakabatana negoko resimbi.Rimwe divi re diaphragm rakapatsanurwa kubva parata resimbi nemhete yakatetepa inodzivirira.Nenzira iyi, capacitance inoumbwa pakati peiyo evaporated goridhe firimu uye simbi ndiro.Kana iyo electret diaphragm ikasangana neacoustic vibration, nzvimbo yemagetsi kumigumo yese yecapacitor inoshanduka, zvichikonzera kuchinjika kwemagetsi kusiyanisa nekuchinja kweacoustic wave.Iyo capacitance pakati pe electret diaphragm nesimbi ndiro idiki, kazhinji makumi ePF.Naizvozvo, kuburitsa kwayo impedance kukosha kwakakwira zvakanyanya (XC = 1/2 ~ TFC), anenge makumi ema megaohms kana kupfuura.Iyo yakakwira impedance haigone kuenzaniswa zvakananga neaudio amplifier.Naizvozvo, junction field effect transistor yakabatana mumaikorofoni yekushandura impedance.FET inoratidzirwa nepamusoro pekuisa impedance uye yakaderera ruzha nhamba.Iyo yakajairika FET ine matatu maelectrode: anoshanda erekitidhi (s), grid electrode (g) uye drain electrode (d).Pano, FET yakakosha ine imwe diode pakati pemukati sosi uye grid inoshandiswa.Chinangwa che diode ndechekudzivirira iyo FET kubva kune yakasimba chiratidzo chekuita.Gedhi reFET rakabatana nendiro yesimbi.Nenzira iyi, kune matatu mitsara yekubuda ye electret maikorofoni.Kureva kuti, kwacho s kazhinji iwaya yepurasitiki yebhuruu, iyo D inogara iri waya yepurasitiki tsvuku uye waya yakarukwa yekudzivirira inobatanidza goko resimbi.
Nguva yekutumira: Aug-28-2023