摘  要：通過直流電路驅(qū)動(dòng)紅外二級(jí)管發(fā)出的紅外光恒功率發(fā)射，紅外光經(jīng)過聚光透鏡，形成直徑為20 mm的光柱。帶材正常運(yùn)動(dòng)時(shí)處于光柱的中心位置，光電二極管接收到的光功率為一定值；當(dāng)帶材偏移時(shí)，引起接收管的光功率變化，導(dǎo)致光生電流變化，從而確定偏移量與光生電流的關(guān)系。在信號(hào)的放大與處理環(huán)節(jié)采用兩級(jí)運(yùn)算放大器相結(jié)合的電路，充分減少信號(hào)衰減與噪聲影響，并產(chǎn)生較大的電壓增益，試驗(yàn)表明該電路設(shè)計(jì)可行并達(dá)到一定的精度。   關(guān)鍵詞：紅外二級(jí)管；恒功率；糾偏探頭；光生電流；運(yùn)算放大器   中圖分類號(hào)：TP391.41；TN214        文獻(xiàn)標(biāo)識(shí)碼：A          文章編號(hào)：1672-4984（2008）03-0127-04   Design and validate excursion sensor based on infrared diode   KANG Jing， ZHAO Qing-hai   （School of Printing and Packing Engineering，Xi’an University of Technology，Xi’an 710048，China）   Abstract： The infrared diode was droved by DC circuit to send light with constant power. The rays passed through a condensing lens and formed a light pole with the diameter of 20 mm. When the web worked normally, it passed through the central axle of the light pole so that the optical power received by photosensitive diode was normal constant. On the contrary, if the web went with excursion, different luminous flux would be gotten by the photosensitive diode. Furthermore, the photocurrent which had a direct proportion relationship with the luminous flux would be changed too. Based on the above, the relationship between the excursion and the photocurrent could be determined. Using two operational amplifiers to amplify and deal with the current signals, it could lessen the signal attenuation and yawp infections and produce biggish voltage plus. The experimental results shows that this designed circuit is available and with certain accuracy.   Key words： Infrared diode; Constant power; Excursion sensor; Photocurrent; Operational amplifier   Editor：liyan