object detection system is shown in Fig.11. As it is a prototype one, the units are separated for easy testing. The final product could be reduced to one or two units. In this prototype version a camera stand is used to hold the small pipe fitted with the photo transistor. Another pipe of similar size is attached just onto the first one, which serves as a kind of object-sight using naked eye.
Targeting the laser-lighted object through the pipe-hole will give an output signal at TP4, little adjusting the horizontal and azimuth of the tripod, maximizes the signal output. Now controlling the comparator-threshold just below the output level we can make the comparator-output zero, If the object is moved. The detection system is further simplified by removing the pipe positioned in front of the phototransistor, if there is nothing to scatter light behind tens of meters of the object of our interest.
Fig.11. The photograph of the distant object detection system.