INDEX

In this condition light intensity for LDR(4+3) will be greater than that for LDR(1+2). Therefore,Voltage across LDR(4+3),V4+3 > Voltage across LDR(1+2),V1+2 We can see in the circuit diagram that voltage across LDR 4 and 3 are added to form V4+3, similarly for V1+2. Now these signals are fed to a differential amplifier whose gain almost 100. This gain is the factor which will depend the efficiency of this system (maximum efficiency implies it will be strictly perpendicular to sun rays), ie with high efficiency even a small inclination can be tracked out. Therefore here,Y4+3 >Y1+2 IMPLIES Yd = A(Y4+3-Y1+2). So in this case Yd will be positive.
This positive voltage will drive output of opx to positive saturation and output of opy to negative saturation ie Md = +Vcc to opx. Also Mu = -Vee to opy.

Thereby motor will rotate in such a way that gd will decrease, and until gd < Vmin, motor will rotate. Vmin is the voltage given to inputs of opamp(other than output from differential amplifier). This is done because, due to inertia the mechanism move some more extra distance, This makes the opx to -Vee and Vee to opy, this process continues just like a damping motion. This is avoided in such a way that a small voltage difference will be set between the sensors. That voltage will decide the preciseness of ckt. Less voltage more precise it will be. The same circuit is provided for the second direction.