Photoelectric conversion remote control circuit of glass bottle counter

(1) Working principle of the circuit When counting glass bottles on the conveyor belt. First, the running glass bottles should be converted into pulse signals, and then
the pulse signals (one pulse for each bottle) should be sent to the counter for automatic counting. The circuit shown in Figure 7-17 is a photoelectric conversion
circuit for a glass bottle counter .   When there is no glass bottle on the belt, the photosensitive musk tube 3DU has low resistance when exposed to direct light, and the photocurrent burns; 'Vr'1 is cut off, which is resistant to VT2 saturation. ． VT3 cut off. At the moment when the glass bottle blocks light, the phototransistor shows high resistance. lb. increases, VT1 is saturated , and Ucl drops from +5v to o. This negative jump is differentiated by RC to obtain a negative pulse, which triggers the monostable circuit, causing 1rF2 to cut off and VT3 to conduct. The monostable circuit automatically returns to the original state after a period of time and obtains a wider pulse, which avoids the phenomenon of multiple signals caused by one bottle due to flash, etc.     YF1-YF5 form an integral shaping circuit, which is also a monostable circuit. It can narrow the above-mentioned wider pulses to meet the counting requirements.     Because the glass bottle is transparent, the photocurrent and dark current of the photoelectric tube change in a wider range. Small, in order to make VT1 reliably saturated and cut off. , adjust the potentiometer RP carefully and repeatedly .     (2) Component selection VT1~VT3 all use 3DG6.3>50 transistors. YF1-YF5 choose 74Lsoo type integrated circuit "NAND" gate. Ruler and R. The value of t should be determined according to the shading time of each bottle, which can be calculated according to CR =2r (f is the shading time). Other component type female parameters