A closed loop control system was designed to track the sun around the N-S axis. This system consists of a DC motor, a speed reduction unit, a photo resistance sensor unit and a controller. Two photo resistances (RR and RL) are located on either side of the parabolic reflector. When the solar beam plane is normal to the aperture of the collector, the two resistances must have almost equal resistance. A slight change in the sun’s position will cause different beam intensity on the photo resistance and, thus, different resistance. The photo resistances are used as part of a Wheatstone bridge circuit to give zero voltage when the radiation plane is normal to the aperture area of the reflector (sun in centre of the parabola). If the incident angle changes, the sensors give a voltage proportional to that change. The controller amplifies this voltage and sends a signal to the motor to track the sun by keeping Wheatstone bridge output voltage equal to zero.