文档介绍：东海科学技术学院毕业论文(设计)题目:金属探测仪系:学生姓名:专业:班级:指导教师:起止日期:金属探测仪器摘要本设计利用电子技术的知识设计了电缆探测仪,能够探测墙壁,地毯下的电缆。本次设计选用了电压反馈震荡器、方波振荡器、三极管的混频和反馈放大电路。探测线圈是整个电路的关键所在,通过探测线圈探测到金属在通过高频信号后产生的涡流信号,当探测线圈接近通有高频信号的电缆时,探测振荡器产生一个探测频率,此频率根据探测线圈距离电缆的位置来得到的;方波震荡器产生的振荡信号频率是固定的信号;在方波振荡器和探测电路处的电压反馈振荡器产生的两个频率,在三极管的混频电路处进行混频得到的有两个信号一个是频和一个是频差,在把两个信号通过选频处选频得到的一个频差信号,在输送到反馈放大器进行放大最后通过耳机输出,使得人能听到声音。既听声音的强弱来判断电缆的位子。三极管是进入零导通状态,在探测线圈没有探测到任何信号的时候探测电路处的振荡电路不会产生振荡信号,而方波振荡器仍旧能产生一个方波信号,输入到三极管混频电路中,由于没有外加信号使得不能产生混频信号,因此三极管混频电路不工作,把信号输入到接地处,整个电路不工作。本设计具有结构简单,性能可靠的优点。关键字:电缆探测仪;电压反馈震荡器;反馈放大电路AbstractThedesignoftheknowledgeoftheuseofelectronictechnologydesignedcabledetector[5],candetectwalls,,square-waveoscillator,,throughthedetectioncoiltodetectmetalinthehigh-frequencysignalgeneratedbytheeddycurrentsignal,whenthedetectioncoilclosetothehigh-frequencysignalsthroughacable,theprobefrequencyoscillatortogenerateaprobe,ordingtodetectioncoilpositionfromthecabletoget;squarewaveoscillatorsignalgeneratedbyoscillationsignalfrequencyisfixed;inthesquarewaveoscillatorandvoltagedetectioncircuitDepartmenttwofeedbackoscillatorfrequency,thetransistormixercircuitDepartmentformixingtwosignalsobtainedbyonefrequencyandoneisthefrequencydifference,thetwosignalsinthefrequencyofofficebytheelectionofaselectedfrequencybyfrequencydifferencesignaltothefeedbackamplifierinthetransmissiontoamplifythefinaloutputthroughheadphones,-state,inthedetectioncoilisnotthetimetodetectanysignalofoscillationcircuitdetectioncircuitDepartmentdoesnotproduceoscillationsignal,whilethesquarewaveoscillatorisstillabletoproduceasquarewavesignalinputtotransistormixercircuittheabsenceofexternalsignalsocannotproducemixingsignals,thetransistormixercircuitdoesnotwork,thesignalinputtogroundoffice,,reliableperformanceadvantagesK