solar tracker

[skilkhan]

i have downloaded electronic circuit and ATMEGA 16 based solar tracker,i simulated it on pspice and compiled its code on atmel studio.
But I cannot understand how to balance variable resistor in this circuit,please help if anbody do,,
i am attaching it picture downloaded after googling.
thx in advance

 

[KrisBlueNZ]

Where did you get that design? It's not very good. Apart from the fact that the +12V output voltage from the comparators could damage the AVR, there's the problem with using four separate comparators instead of comparing the illumination levels on the pairs of LDRs with each other.

I guess it's possible that the firmware does a regular seeking operation in both directions and measures the distance until the illumination drops below the threshold on each LDR, then calculates the optimum position and returns the motors to that position. So that arrangement would work if the firmware behaves like that.

If that's the case, you can adjust the variable resistors by pointing the tracker abouto 30~45 degrees off-axis in each direction and adjusting the variable resistor until the output of the corresponding op-amp changes state.

With a design like that, a single variable resistor, setting the thresholds on all four op-amps, would be simpler.

Can you provide a link to the location that you got this project from?

 

[skilkhan]

tnx for ur suggestion
link is
http://www.cheers4all.com/2012/07/avr-based-solar-tracking-system-using-stepper-motor/
programming for this tracker is also given in this link

if u have any other better idea please let me know,

if i use lm7805 after 741,can controller be protected from damage?

 

[KrisBlueNZ]

OK, that's a pretty poorly designed solar tracker. The firmware doesn't do anything clever to track accurately, and there is no automatic adjustment for brightness changes, so when a cloud crosses the sun it will track around randomly or track way too far in one direction.

Edit: Correction. I haven't worked out how the code would handle that situation; I don't know what it would do, and there are no comments in the code to explain what it's supposed to do.

There must be other solar tracker projects around. Look for one that compares the illumination of the two LDRs in each direction, instead of using fixed thresholds. The whole thing can be done in the analogue domain; there is no real need for a microcontroller.

You could protect the MCU from damage using a voltage divider but I strongly suggest that you ditch this design completely.

 

[skilkhan]

tnx,,i'll google for a better one

 

[foTONICS]

I was working on a solar tracker for a bit as a school project and did my fair share of searching.

here is the link to a discussion I started a little while back:

https://www.electronicspoint.com/solar-tracker-t258794.html

I went the analog route, seemed simpler but it's entirely up to you

 

[skilkhan]

tnx it looks good
i will try its simmulation in pspice in few days