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，當充電器轉入涓電(dian)流(liu)(liu)浮充(chong)(chong)充(chong)(chong)電(dian)階段(duan)時(shi)，充(chong)(chong)電(dian)器紅色二(er)極管LED1兩端變為零電(dian)壓(ya)熄滅(充(chong)(chong)電(dian)器綠色二(er)極管則(ze)發光)，此時(shi)VT3也(ye)因(yin)基極零電(dian)壓(ya)而截止，電(dian)源調整(zheng)管VT4正(zheng)常導(dao)通(tong)，輸(shu)出2.1V直流(liu)(liu)電(dian)源，石英小鬧鐘得(de)電(dian)開始計時(shi)，當(dang)計時(shi)到預先設定值時(shi)，石英小鬧鐘輸(shu)出低電(dian)平(ping)音頻(pin)脈(mo)(mo)沖訊響(xiang)信號(hao)，該低電(dian)平(ping)音頻(pin)脈(mo)(mo)沖信號(hao)通(tong)過VT2放大整(zheng)流(liu)(liu)經(jing)電(dian)容C5濾波輸(shu)出一直流(liu)(liu)電(dian)壓(ya)，使VT1飽和(he)導(dao)通(tong)，開關S1電(dian)磁(ci)脫鉤(gou)線(xian)圈得(de)電(dian)產(chan)生磁(ci)力(li)，使開關按鈕脫鉤(gou)跳開，斷(duan)開交流(liu)(liu)電(dian)源，從而實(shi)現自動結束充(chong)(chong)電(dian)。

   智能定(ding)時插座的電(dian)(dian)(dian)路(lu)見(jian)圖，共由交流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)開(kai)關(guan)、電(dian)(dian)(dian)磁(ci)脫鉤線(xian)圈驅動電(dian)(dian)(dian)路(lu)、定(ding)時電(dian)(dian)(dian)路(lu)、直流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)路(lu)4部分(fen)組(zu)成(cheng)。將該電(dian)(dian)(dian)路(lu)插上電(dian)(dian)(dian)源(yuan)(yuan)插頭，按(an)下交流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)開(kai)關(guan)S1按(an)鈕，接(jie)通220V交流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)即可開(kai)始工作。220V交流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)一(yi)路(lu)經14V電(dian)(dian)(dian)源(yuan)(yuan)變壓器(qi)T降壓、橋式整流(liu)(liu)(liu)電(dian)(dian)(dian)路(lu)整流(liu)(liu)(liu)、濾(lv)波(bo)(bo)電(dian)(dian)(dian)容C1濾(lv)波(bo)(bo)、三端穩(wen)壓集成(cheng)電(dian)(dian)(dian)路(lu)IC1穩(wen)壓、濾(lv)波(bo)(bo)電(dian)(dian)(dian)容C2濾(lv)波(bo)(bo)產生(sheng)穩(wen)定(ding)的+12V直流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)，該+12V分(fen)三路(lu)輸出：(1)經R4加(jia)到(dao)LED2作+12V直流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)工作指示。(2)經R3、VD2、LED3串(chuan)聯穩(wen)壓后經C3濾(lv)波(bo)(bo)加(jia)到(dao)穩(wen)壓調整管(guan)VT4基(ji)極(ji)，使VT4將+12V穩(wen)壓為2.1V，由VT4發射極(ji)輸出，該2.1V經C4濾(lv)波(bo)(bo)后加(jia)到(dao)石英小鬧鐘電(dian)(dian)(dian)源(yuan)(yuan)正負極(ji)為其提(ti)供直流(liu)(liu)(liu)電(dian)(dian)(dian)源(yuan)(yuan)(提(ti)示一(yi)點：2.1V高了些(xie)，石英小鬧鐘走(zou)時稍快一(yi)些(xie)，定(ding)時值按(an)4~5小時即可)。(3)加(jia)到(dao)開(kai)關(guan)S1的電(dian)(dian)(dian)磁(ci)脫鉤線(xian)圈上。

　　元件選擇
　　元件選(xuan)(xuan)(xuan)(xuan)擇如電(dian)(dian)(dian)路(lu)原(yuan)理圖上的(de)標(biao)注：VT1、VT3、VT4選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)S8050型三極(ji)管，VT2選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)S8550型三極(ji)管，IC1選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)LM7812，VD1選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)IN4148型二(er)極(ji)管，VD2～D6選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)IN4007型二(er)極(ji)管，LED1、LED2選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)普(pu)通(tong)紅色發光二(er)極(ji)管，LED3選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)普(pu)通(tong)綠色發光二(er)極(ji)管，R1選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)2kΩ普(pu)通(tong)電(dian)(dian)(dian)阻，R2選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)10kΩ普(pu)通(tong)電(dian)(dian)(dian)阻，R3、R4選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)1kΩ普(pu)通(tong)電(dian)(dian)(dian)阻，開關S1選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)KDC-A01-06Y型的(de)，P1和J1分別選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)普(pu)通(tong)單聲道耳機插(cha)頭、插(cha)孔。變壓(ya)器T選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)3W/14V電(dian)(dian)(dian)源(yuan)變壓(ya)器，C1選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)1000μF/25V電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)，C2、C3、C4選(xuan)(xuan)(xuan)(xuan)470μF/25V電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)，C5選(xuan)(xuan)(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)47μF/25V電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)。