Requirement: To make Scheffler rotate automatically w.r.to sun motion.
The Scheffler dish (Parabolic dish solar concentrator) is situated in Vigyan Ashram, Pabal, Maharashtra. It is used for cooking purposes. Always Focus point of the scheffler must be on cooking object. Horizontal movement of focus is done by using driving wheel which is provided near the gear box. Generally driving wheel is rotated by a wiper motor w. r. to the sun motion. Vertical movement is done seasonally using the levers and screws mechanism which is provided on upper and lower side. Scheffler dish is vertical w.r.to ground during winters and flat during summers.
- Study: Studied various methods & possibilities for automatic rotation.
- Delay and time of rotation: Calculated time interval required for the scheffler to rotate to keep focus point at position. It’s delay = 4 minutes, time of rotation = 15 seconds
- Motor Connections: Worked and tried different connections for Forward and Reversal of wiper motor (12V). Finally decided to go with 2 relay-centre tap connection.
- Battery sizing: Calculated Battery size required to run motor approximately for 2 & 1/2 hours. Battery used – 12V, 4.5AH Lead Battery.
- Arduino Programming: Program for automatic rotation is written mainly using ‘for’ loop and ‘delay’ functions. Through this program Arduino controls 2 module relay which in turn operates motor.
- Arduino Supply: A DC step down converter is used to step down voltage from Battery (12v) to Arduino (5V).
- Installation of Solar Panel: To make control circuit and Motor supply circuit independent of grid a Solar Panel (17.2V, 37W) is installed on Scheffler window room. The size of the solar panel is calculated based on load (motor) usage.
- Charge controller: A Charge controller (12V, 5A) is used to control Battery charging from Solar panel and Battery discharging to the load.