这电路有什么功能

这电路有什么功能

这个电路脚speecheroder。现在电话中的语音质量都非常的好，但是在有些场合（比如业余爱好、娱乐等）需要将这种好的声音质量还原成过去那种不好的声音质量，就需要这个电路了。这个电路的输入时麦克风或者其他声音源，输出是处理完的声音。具体过程，你看看下面这段英文就懂了。Nowadays,thespeechqualityonourtelephonesystemsisgenerallyverygood,irrespectiveofdistance.However,thereareoccasions,forinstance,inanamateurstageproduction,orjustforfun,whenitisdesiredtoreproducethespeechqualityofyesteryear.Theerodercircuitacceptsanacoustic(viaanelectretmicro-phone)orelectricalsignal.ThesignalsareappliedtothecircuitinputsviaC1andC2,whichblockanydirectvoltage.Theinputcablesshouldbescreened.Thesignalsarebroughtto(about)thesamelevelbyvariablepotentialdividersP1-R1-R4andP2-R2-R3,andthenappliedtothebaseoftransistorT1.Thelevelofthecombinedsignalsisraisedbythispreamplifier.Thepreamplifierisfollowedbyanactivelow-passfilterconsistingofT2–T4,C3,C4,R6–R8,andP4.Although,strictlyspeaking,P3servesmerelytoadjustthevolumeofthesignal,itssettingdoesaffectthefiltercharacteristic.Note,bytheway,thatthefilterisararelyencounteredcurrent-drivenoneinwhichC3andC4arethefrequency-determiningelements.IthasacertainsimilaritywithaWienbridge.TransistorsT3andT4,andresistorsR8andP4formavariablecurrentsink.ThepositionofP4determinestheslopeofthefiltercharacteristicandthedegreeofovershootatthecut-offfrequency.Thelow-passfilterisfollowedbyanintegratedamplifier,IC1,whoseamplificationismatchedtotheinputoftheelectroniccircuitsconnectedtotheeroderwithP5.Thefinalpassive,third-orderhigh-passfilterisdesignedtoremovefrequenciesaboveabout300Hz.Theresultingoutputisofatypicalnasalcharacter,justasintelephonesofthepast.Author:T.GiesbertsCopyright:ElektorElectronics让我奇怪的不是这个电路，奇怪的是楼主肿么对这个电路感兴趣？这个电路的用途比电路本身有意思。