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本电路用于检测纸张等反光物体上的黑色条纹,完成定位、计数等光电转换.该电路曾用于制证翻拍机中“九二相纸”检测定位,效果较为满意.电路工作原理 电路原理如图1所示,一体化红外发射接收头中的发射管D导通,发出红外光线,经反射物体反射到接收管BG上,使BG的C、E间电阻变小,端电位变低,输出端为高电平,继电器J不吸合.当红外光线照到移动或转动的反光物体上的黑色条纹时,反射到BG上的光量减少,BG的C、E间电阻变大,电压比较器反相输入端电位高于同相输入端,电路反转,输出低电平,继电器J吸合,从而达到控制其它电路的目的.R_4、D_3除作为电路的输出指示,还给电压比较器的OC输出端提供上拉电平.R_5、D_2接在电压比较器的选通端,用以控制电路的工作和锁定,当在G点加低电平控制信号时,不论同、反相输入端上的输入失调电压为何值,电路均不反转,输出端锁定在高电平状态,二极管D_1、为电路接感性负载时保护比较器输出电路不致于因断电自感电压太高而击穿损坏.
This circuit is used to detect black stripe on paper and other reflective objects, complete positioning, counting and other photoelectric conversion. This circuit was used to make the card machine “nine two paper” detection and positioning, the effect is more satisfactory. As shown in FIG. 1, the transmitting tube D in the integrated infrared transmitting and receiving head is turned on, emits infrared light and is reflected by the reflecting object to the receiving tube BG, so that the resistance between BG and E of the BG becomes smaller and the terminal potential becomes lower, The output is high, the relay J does not pull in. When the infrared light shines on the moving or rotating reflective black stripes on the object, the amount of light reflected on the BG decreases, BG resistance between C, E becomes larger, the voltage comparison The inverting input of the inverter is higher than the non-inverting input, the circuit is inverted, the output is low, and the relay J is sucked in to achieve the purpose of controlling other circuits. R_4 and D_3 are not only used as output signals of the circuit, but also returned to the voltage comparator OC output provides pull-up level. R_5, D_2 connected to the voltage comparator gated end to control the operation of the circuit and the lock, when the control signal plus low level G, no matter with the inverting input On the input offset voltage value, the circuit is not inverted, the output Locked in the high state, the diode D_1, the protection circuit when the comparator output is connected to the inductive load circuit inductance voltage as not too high due to power breakdown.