In this site I have already published one axis solar tracker system circuit which is intended for automatically adjusting the solar panel face such that it stays perpendicular to the incident sun rays at all instants. throughout the day.
However for this to happen whole set up involves many complex mechanisms and circuitry which may not be easy for all to assemble and implement.
If you are ready to sacrifice and ignore a few of the luxuries provided by the above dual axis tracker, then probably you would like to go with the concept explained in the present article.
The previously discussed solar tracker post included some sensors in the form of LDRs for monitoring the sun's "position in the sky" and accordingly providing the commands to the control circuit and the motor so that necessary adjustments are quickly made to the panel for maintaining the required accuracy of the panel with the sun rays.
The system requires some critical setting and adjustments, however once these are completed you just watch the whole thing do the rest for the rest of your life providing 100% efficiency with the involved electrification of your house.
Here, since we do not incorporate any sensor and the system is a single axis type can eb built very easily and quickly, but you will have to do some tedious settings in the beginning and keep repeating it once every month or so. The efficiency of this system may well be 100% in the initial stages but will go on deteriorating as weeks progress until you refresh and restore the original settings. This must be done in response to th changing sunrise/sunset positions of the sun through out the year.
Now let's talk about the single axis solar tracker circuit discussed here. The concept is all about implementing a kind of primitive algorithm in the circuit.
The concept is simple, we just note down the average time for which the sun remains active or live over the sky. Then we adjust the speed of the motor such that it rotates the panel from sun rise to sun set more or less facing the sun throughout its rotation. The speed of the motor thus gets adjusted which moves the panel through a angle of may be around 50 to 60 degrees throughout the stipulated period, imitating to be following the sun's track.
The circuit used for adjusting the motor speed is obviously a PWM circuit and the motor used may be a stepper type of motor or even an ordinary brush-less type will also do.
The adjustment of the speeds in response to the daylight period must be optimized for many days for making the system as efficient as possible. The date and the relevant of the setting of the speeds must be noted down for records so that the same setting can be applied without monitoring for the future seasons.
The following figure shows a simple motor and gear mechanism which may employed for the proposed system. The blue colored plate is the solar panel, which is fixed with the larger gear's central rod.
The lower frame must be firmly fixed on the ground.
The following design shows the motor control module for the proposed single axis solar tracker which involves a simple circuit made from a cheap 555 IC and some other important semiconductor parts. Pot P1 should be mounted outside the enclosure in which the circuit may be covered. P1 is the main component which may be used for adjusting the motor speeds during different seasons of the year such that the panel rotation remains more or less synchronized with the sun "movements".
In fact P1 may have to be adjusted very carefully such that the motor operates at some fixed speed. The gear mechanism should be arranged such that the smaller gear and the larger gear diameters produce a constant angular movement to the panel in order to keep the panel face more or less perpendicular to the sun throughout the day.
The setting of P1 should be noted down each time the settings are refreshed corresponding to the different months of the year. This data may then be repeated for the future years.
R1 = 10K
P1 = 220K
All diodes = 1N4148
T1 = 30V, 10amp mosfet
C1 = 5nF
C2 = 10nF
C3 = 100uF/25V