Hi,
I have read this specific thread
https://www.electro-tech-online.com/threads/simple-solar-tracking-circuit.106625/
with great interest as I am an avid solar photographer using White light and Halpha filters in my Observatory.
My name is Rainer and I live in Mexico.
Now the presented circuit after having read a lot about other solar tracking circuits seems to satisfy my needs with the difference that instead of driving a motor I just need to pull down some TTL outputs to ground in order to activate what we call in astronomy an Auto Guide port of an Equatorial Telescope mount. Normally this ports have 1 common ground and 4 lines which when pulled down to ground activates a corresponding movement of the RA or DEC axis, be it forward or backward.
I am talking of German equatorial mounts where normally the only motor in movement is the RA motor following be it the Stars, Moon or Sun. For Autoduigin at night there are many solutions which work perfectly as one takes juts a star and the software calculates its center and when there is a deviation it actvates the corresponding movements.
I have tried similar solutions wioth the Sun building a Sol guider scope but the software is not able to digest the Suns intensity as a stars and it looses the center and so the Autoguding get crazy.
The last mentioned circuit in this thread seem to be interesting but I have a few questions about it.
I do not need to drive directly a motor. I thiink that is the simplest solition by just using tha LM339 comparators output as a switch and close the TTL output.
How accurate is the measuring of the Suns intensity eg how fine do the opposite situated LEDs react to minimal angle changes if the incoming Sun collimated rays do excite the LEDs, in order to create a voltage difference and activate the corresponding comparator output.
Yesterday I started to experiment with a simple circuit in order to understand how the LM339 works. First by using 2 voltage splitters on theinput of the comparator and then substitutin one pot for a led and turning the remaining pot and I manged to get a ON and OFF switching if an indicator LED connected to the output of the comparator.
I then tried with 2 LEDs but nothing happened as I assumed that every LED reacts different to incoming light and thought it would switch. OK, I have to admit I had no direct SUnlight and maybe there was the problem.
Using just the comparator with a positive V+ input voltage I assume makes the whole tracker more dificult as I need one reference voltage for each lead, so after reading this with the opposite placed LEDs makes it much easier.
Another problem I have is that I have no negative voltage supplies in the observatory. We do work all Positive be it 5V and 12V. I do not see if for my purposes I really need a positive and negative voltage as I just want to open or close the output of the LM339 for switching the TTL connections which in their case activate the motors.
If possible I would like to discuss this here and try to make a suitable circuit for testing it when I have full sun light and the necessary parts.
Sorry for the long introducing message and appreciate any help to get going the project using the presented circuit.
Perhaps my message is a bit confusing
Thanks and regards Rainer
I have read this specific thread
https://www.electro-tech-online.com/threads/simple-solar-tracking-circuit.106625/
with great interest as I am an avid solar photographer using White light and Halpha filters in my Observatory.
My name is Rainer and I live in Mexico.
Now the presented circuit after having read a lot about other solar tracking circuits seems to satisfy my needs with the difference that instead of driving a motor I just need to pull down some TTL outputs to ground in order to activate what we call in astronomy an Auto Guide port of an Equatorial Telescope mount. Normally this ports have 1 common ground and 4 lines which when pulled down to ground activates a corresponding movement of the RA or DEC axis, be it forward or backward.
I am talking of German equatorial mounts where normally the only motor in movement is the RA motor following be it the Stars, Moon or Sun. For Autoduigin at night there are many solutions which work perfectly as one takes juts a star and the software calculates its center and when there is a deviation it actvates the corresponding movements.
I have tried similar solutions wioth the Sun building a Sol guider scope but the software is not able to digest the Suns intensity as a stars and it looses the center and so the Autoguding get crazy.
The last mentioned circuit in this thread seem to be interesting but I have a few questions about it.
I do not need to drive directly a motor. I thiink that is the simplest solition by just using tha LM339 comparators output as a switch and close the TTL output.
How accurate is the measuring of the Suns intensity eg how fine do the opposite situated LEDs react to minimal angle changes if the incoming Sun collimated rays do excite the LEDs, in order to create a voltage difference and activate the corresponding comparator output.
Yesterday I started to experiment with a simple circuit in order to understand how the LM339 works. First by using 2 voltage splitters on theinput of the comparator and then substitutin one pot for a led and turning the remaining pot and I manged to get a ON and OFF switching if an indicator LED connected to the output of the comparator.
I then tried with 2 LEDs but nothing happened as I assumed that every LED reacts different to incoming light and thought it would switch. OK, I have to admit I had no direct SUnlight and maybe there was the problem.
Using just the comparator with a positive V+ input voltage I assume makes the whole tracker more dificult as I need one reference voltage for each lead, so after reading this with the opposite placed LEDs makes it much easier.
Another problem I have is that I have no negative voltage supplies in the observatory. We do work all Positive be it 5V and 12V. I do not see if for my purposes I really need a positive and negative voltage as I just want to open or close the output of the LM339 for switching the TTL connections which in their case activate the motors.
If possible I would like to discuss this here and try to make a suitable circuit for testing it when I have full sun light and the necessary parts.
Sorry for the long introducing message and appreciate any help to get going the project using the presented circuit.
Perhaps my message is a bit confusing
Thanks and regards Rainer