石英鐘價廉物美,大多數家庭都具備。以下天成照明來介紹幾種用石(shi)英鐘(zhong)(zhong)芯(xin)制作(zuo)的閃爍(shuo)示電(dian)路,LED通(tong)過引線安裝(zhuang)在石(shi)英鐘(zhong)(zhong)外,也 可直接裝(zhuang)在石(shi)英鐘(zhong)(zhong)上,為英鐘(zhong)(zhong)增添光(guang)彩。

圖1是最(zui)間單的爍電(dian)路。

在(zai)石英(ying)鐘驅動步進電(dian)機的兩 個輸出(chu)端OUT1和OUT2,每秒輪(lun)流輸出(chu)一個寬度為(wei)31.25ms 的低電(dian)平脈沖。因LED的發光導(dao)通電(dian)壓約1.8V,原1.5V電(dian) 池(chi)供電(dian)不(bu)能使其(qi)發光,故增加一節1.5V電(dian)池(chi)。這樣紅、 綠LED便可輪(lun)流閃爍顯示。

該(gai)電路由于LED 的工作(zuo)電流直接灌入OUT1端或OUT2端,因此只有在經試 不影(ying)響石英鐘走時精度的情況(kuang)下(xia)可以采用。 

圖2電路在(zai)OUTI、OUT2兩個輸出(chu)端(duan)輪(lun)流輸出(chu)低電平 驅動步進電機的(de)同時,還驅使晶體管1與(yu)V2輪(lun)流導通, 使雙色(se)LD交替發出(chu)紅色(se)和綠色(se)光。

該(gai)電路(lu)流(liu)(liu)入OUT1 、OUT2端的(de)附(fu)加電流(liu)(liu)是(shi)數值較小的(de)晶體管基極電流(liu)(liu),一(yi)般不 會景(jing)晌石英鐘走時精度。

圖3電(dian)路的(de)特點是直(zhi)接使(shi)用(yong)石英鐘(zhong)原1.5V電(dian)池，就可 使(shi)LED閃爍。電(dian)路中晶體(ti)管(guan)采用(yong)e-b結(jie)壓降為0.2V的(de)鍺管(guan)。

工(gong)作原理(li)是:

當(dang)石英鐘芯未輸(shu)出低(di)電(dian)(dian)(dian)(dian)平(ping)(ping)脈(mo)沖時(shi)其(qi)工(gong)作電(dian)(dian)(dian)(dian)流(liu)(liu) 亦(yi)(yi)即(ji)晶(jing)體(ti)管(guan)基(ji)極電(dian)(dian)(dian)(dian)流(liu)(liu)很小(xiao)，晶(jing)體(ti)管(guan)處于截(jie)止狀態，這期間電(dian)(dian)(dian)(dian) 池經二極管(guan)、電(dian)(dian)(dian)(dian)阻對電(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)，當(dang)石英鐘芯輸(shu)出低(di)電(dian)(dian)(dian)(dian)平(ping)(ping)脈(mo)沖 驅動步進電(dian)(dian)(dian)(dian)機動作時(shi). 石英鐘工(gong)作電(dian)(dian)(dian)(dian)流(liu)(liu)亦(yi)(yi)即(ji)晶(jing)體(ti)管(guan)基(ji)極電(dian)(dian)(dian)(dian)流(liu)(liu) 增大，晶(jing)體(ti)管(guan)導通，這時(shi)電(dian)(dian)(dian)(dian)阻上電(dian)(dian)(dian)(dian)壓與電(dian)(dian)(dian)(dian)容上電(dian)(dian)(dian)(dian)壓相疊加，可使LED發光。

石英(ying)鐘芯(xin)內的(de)兩(liang)(liang) 個輸出端(duan)OUT1和OUT2可(ke)(ke)從 一個大線圈(quan)的(de)兩(liang)(liang)個焊點(dian)處引出。此信息有(you)天成照明小編收集整(zheng)理希望對你有(you)用(yong)，有(you)任何問題均(jun)可(ke)(ke)留言咨詢。