Automatic solar tracking system

Figure 4.1: Solar Cell 
The photo sensors
 
used in the prototype are Light Dependent Resistors. 

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HARDWARE PROTOTYPE 
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AEIE, RCCIIT 
Light Dependent Resistor
 
The conundrum of light dependent resistor and photoresistor is used in a supplementary and in a 
complementary manner inter alia in a synonymous form. By being the light-sensitive devices, it’s 
an embodiment of resistivity which is the function of incident electromagnetic radiation. 
Photoconductors and photoconductive cells or simple photocells are some of the names by which 
such devices are also designated. Constituted out of semiconductor materials, these devices are 
substantiated with high resistance. Symbolic balkanization is the means to indicate the LDR, one 
of the most commonly used symbol is shown in the figure below. The arrow indicates light falling 
on it. 
Figure 4.2: Symbol of LDR 
4.1.2 The Controlling Circuit
The controlling circuit is designed with a microcontroller. The microcontroller is inscribed with 
some algorithm to compare and detect the direction of light intensities being maximum. The 
microcontroller uses the inputs from the photo sensors and then forwards the results after 
computation to the driving module. The microcontroller we use in our design is NodeMcu, which 
is an IoT based platform. 

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HARDWARE PROTOTYPE 
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AEIE, RCCIIT 
Figure 4.3: Circuit Diagram 
Current Sensor 
A proportional signal is produced, when the current sensor sense electricity flowing through the 
wire. The proportional signal that is being produced can be either of the three types, i.e. analog 
voltage, current or digital output. The initiator signal can be further utilized for the measurement 
of current, by an ammeter. It can also be stored for future assessments in the field of data 
acquisition or can be implemented for controlling purposes.