220V交流電源另一路經定時插座加到充電器，當充電器還未轉入浮充充電狀態時，充電器的紅燈LED1得電發光，LED1兩端的2V電壓經插頭P1、插孔J1、電阻R2加到VT3基極，VT3飽和導通，將2.1V穩壓調整管VT4基極短路到地，穩壓調整管VT4截止，石英小鬧鐘無直流電源供給而不工作，當充電器轉入(ru)涓電(dian)(dian)(dian)流(liu)(liu)浮充充電(dian)(dian)(dian)階段時(shi)，充電(dian)(dian)(dian)器(qi)紅色二極管LED1兩(liang)端(duan)變為零(ling)電(dian)(dian)(dian)壓熄滅(充電(dian)(dian)(dian)器(qi)綠(lv)色二極管則(ze)發光)，此時(shi)VT3也(ye)因基極零(ling)電(dian)(dian)(dian)壓而(er)(er)截止，電(dian)(dian)(dian)源(yuan)調整管VT4正常導通，輸出(chu)2.1V直流(liu)(liu)電(dian)(dian)(dian)源(yuan)，石(shi)英小鬧鐘(zhong)得(de)電(dian)(dian)(dian)開(kai)始(shi)計時(shi)，當(dang)計時(shi)到(dao)預先(xian)設定(ding)值時(shi)，石(shi)英小鬧鐘(zhong)輸出(chu)低電(dian)(dian)(dian)平音頻(pin)脈沖訊響信(xin)號，該低電(dian)(dian)(dian)平音頻(pin)脈沖信(xin)號通過VT2放大整流(liu)(liu)經電(dian)(dian)(dian)容C5濾(lv)波輸出(chu)一直流(liu)(liu)電(dian)(dian)(dian)壓，使VT1飽和導通，開(kai)關S1電(dian)(dian)(dian)磁(ci)脫鉤(gou)線圈得(de)電(dian)(dian)(dian)產生(sheng)磁(ci)力，使開(kai)關按鈕脫鉤(gou)跳開(kai)，斷開(kai)交流(liu)(liu)電(dian)(dian)(dian)源(yuan)，從而(er)(er)實現自動結(jie)束充電(dian)(dian)(dian)。

   智能定(ding)時插(cha)座(zuo)的電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)見圖，共由交(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)開關、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)脫鉤線圈(quan)驅動電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、定(ding)時電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)4部分組成(cheng)(cheng)。將該電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)插(cha)上電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)插(cha)頭，按(an)下交(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)開關S1按(an)鈕(niu)，接通220V交(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)即可開始(shi)工作。220V交(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)一路(lu)(lu)(lu)經(jing)14V電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)(ya)(ya)器T降壓(ya)(ya)(ya)(ya)、橋式整(zheng)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)整(zheng)流(liu)、濾(lv)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)C1濾(lv)波(bo)、三(san)端穩(wen)(wen)壓(ya)(ya)(ya)(ya)集(ji)成(cheng)(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(lu)IC1穩(wen)(wen)壓(ya)(ya)(ya)(ya)、濾(lv)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)C2濾(lv)波(bo)產生穩(wen)(wen)定(ding)的+12V直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)，該+12V分三(san)路(lu)(lu)(lu)輸出：(1)經(jing)R4加(jia)(jia)到LED2作+12V直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)工作指示(shi)。(2)經(jing)R3、VD2、LED3串聯穩(wen)(wen)壓(ya)(ya)(ya)(ya)后(hou)經(jing)C3濾(lv)波(bo)加(jia)(jia)到穩(wen)(wen)壓(ya)(ya)(ya)(ya)調整(zheng)管(guan)VT4基(ji)極(ji)(ji)，使(shi)VT4將+12V穩(wen)(wen)壓(ya)(ya)(ya)(ya)為(wei)2.1V，由VT4發射極(ji)(ji)輸出，該2.1V經(jing)C4濾(lv)波(bo)后(hou)加(jia)(jia)到石英(ying)小鬧(nao)鐘電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)正負(fu)極(ji)(ji)為(wei)其提供直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)(提示(shi)一點：2.1V高(gao)了些(xie)，石英(ying)小鬧(nao)鐘走時稍(shao)快一些(xie)，定(ding)時值按(an)4~5小時即可)。(3)加(jia)(jia)到開關S1的電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)脫鉤線圈(quan)上。

　　元件選擇
　　元件(jian)選(xuan)(xuan)(xuan)擇如電(dian)(dian)路原理圖上的標注：VT1、VT3、VT4選(xuan)(xuan)(xuan)用(yong)(yong)(yong)S8050型三(san)極(ji)管(guan)，VT2選(xuan)(xuan)(xuan)用(yong)(yong)(yong)S8550型三(san)極(ji)管(guan)，IC1選(xuan)(xuan)(xuan)用(yong)(yong)(yong)LM7812，VD1選(xuan)(xuan)(xuan)用(yong)(yong)(yong)IN4148型二(er)極(ji)管(guan)，VD2～D6選(xuan)(xuan)(xuan)用(yong)(yong)(yong)IN4007型二(er)極(ji)管(guan)，LED1、LED2選(xuan)(xuan)(xuan)用(yong)(yong)(yong)普(pu)通(tong)(tong)(tong)紅(hong)色發(fa)光(guang)二(er)極(ji)管(guan)，LED3選(xuan)(xuan)(xuan)用(yong)(yong)(yong)普(pu)通(tong)(tong)(tong)綠色發(fa)光(guang)二(er)極(ji)管(guan)，R1選(xuan)(xuan)(xuan)用(yong)(yong)(yong)2kΩ普(pu)通(tong)(tong)(tong)電(dian)(dian)阻(zu)，R2選(xuan)(xuan)(xuan)用(yong)(yong)(yong)10kΩ普(pu)通(tong)(tong)(tong)電(dian)(dian)阻(zu)，R3、R4選(xuan)(xuan)(xuan)用(yong)(yong)(yong)1kΩ普(pu)通(tong)(tong)(tong)電(dian)(dian)阻(zu)，開(kai)關S1選(xuan)(xuan)(xuan)用(yong)(yong)(yong)KDC-A01-06Y型的，P1和J1分(fen)別選(xuan)(xuan)(xuan)用(yong)(yong)(yong)普(pu)通(tong)(tong)(tong)單聲(sheng)道耳機(ji)插頭、插孔。變壓(ya)器T選(xuan)(xuan)(xuan)用(yong)(yong)(yong)3W/14V電(dian)(dian)源(yuan)變壓(ya)器，C1選(xuan)(xuan)(xuan)用(yong)(yong)(yong)1000μF/25V電(dian)(dian)解(jie)(jie)電(dian)(dian)容(rong)，C2、C3、C4選(xuan)(xuan)(xuan)470μF/25V電(dian)(dian)解(jie)(jie)電(dian)(dian)容(rong)，C5選(xuan)(xuan)(xuan)用(yong)(yong)(yong)47μF/25V電(dian)(dian)解(jie)(jie)電(dian)(dian)容(rong)。