Greetings guys an other DIY-lover in the family : )

[D-the-Greek]

I am Dimitris and i finished school (a ver loooong time ago...as electrician.)
 
 I always wanted to go study electronics but i didnt had/have the wil to read a lot of stuff.... im more like just do it...leave the reading of the manual for the germans.... ( a joke we(Greeks but also italians) use.....when Germans are near a machine they first read the manual and then they try the joysticks.... Greeks and Italians start playing with joysticks and IF it breaks we read the manual.... Dont get angry it is just a self sarcastic joke...


Anyhow... I am gathering plans for many years on getting my self off-grid and become independent.

Solar energy, Solar heat, windturbine, stirlingen engines, HHO, PMG motors, water distilation, woodbending, aquaculture, aquaponics etc etc...you get the point.

 At the moment i am stuck with the solar tracker. I have found a lot of videos, instructions, pdf's opensource circuits, with LED or CDS LDR or PV cells.... what i see is the they have their ups and downs they either burn the relays or transistors.  Arduino is OUT of the question because it need a lot of messing with electronics and codes etc...it is like teaching a monkey to fly a plane.
 I prefer

a) simple            b)trustworthy          c)easy to fix if needed             b)low volt circuit   

 d)probably 2circuits (one for the tracking and second for the actual motor left-right direction.)

http://pcbheaven.com/circuitpages/Light_Dark_Activated_Relay/
http://solartracker.greenwatts.info/solar_tracker_LM339_parts.htm  (with LED or CDS)
http://www.youtube.com/watch?v=j_yqBdbuKpg   (solar cells)

 Laugh as mush as you want about the crappy attachment of the solar tracker....i copied it and used windows pain software... im no graphics specialist...

 Thank you for reading this.

[kam]

Hello Dimitri.

First of all, regarding the joke with the manual. As a cnc technician, playing with the joystick as you said without reading the manual first is out of the question. A mistake that can cost minimum 2k euro makes me sing all the way to the machin "RTFM RTFM RTFM RTFM"... which stands for Read The F@king Manual

So, regarding the solar tracker. Before you go into the electronics, you have some bigger problems to solve, and i mean bigger, like the mechanical. First you need to decide what motor you will be using. AC? DC? stepper? brushless? brushed? Then we can start talking about the solar tracker circuit. For me, the simplest method is to use a plain DC motor, and make a differential amplifier to control the motor. But to make the circuit reliable, you must use a microcontroller, otherwise you will need to design a huge circuit. You have to predict solutions for situations such as sudden cloud and staff.

When i was in the army, i had plenty of time to think (as a matter of fact i learned PIC in the army). During that time, i was also working on a "solar tracking" project but not for this application. The application was completely different. But after many hours of thinking and designs, it suddenly hit me: Solar Trackers are useless, totally! All you need to do is to find the position on earth that you will install the system and calculate the sun path. Level the system with the sea and that's all. Then get a microcontroller with an RTC and put it to work. This system will be so reliable, that it will follow the sun with astronomical precision, even if the sun is covered behind 10KM of black clouds. 

And don't let the microcontroller scare you. If you plan to go into electronics, the road eventually leads to microcontrollers.

[cheerio]

But if the Earth changes the orbit your headless circuit is screwed

[kam]

But if the Earth changes the orbit your headless circuit is screwed

Yes indeed : D

[_pike]

But if the Earth changes the orbit your headless circuit is screwed

Dimitri welcome to the forum!Without being an expert to stars i don't think earth changes orbit.The only thought that you must take in consideration is the fact that in winter the sunset comes more faster than the summer time(just timing calculations).We had the same conversation with kam some time ago and i NEVER THOUGHT the simpliest admission which is that the sun has always same course!!!!!

[D-the-Greek]

Hey guys

cheers for the warm welcoming

It is true and im not saying otherwise nor i was sugesting that a solar tracker is better than a already programmed chip.

My first problem is overcoming the fact that i know nothing about pic programming.(i am reading the really helpful quide of PCB to try understanding some things... you tube has also some videos i might watch)

 But that is the mainly problem i have. I know almost nothing about this. Next i want to have a a) really simple   b)trustworthy  c)easy to fix if needed    b)low volt circuit   

 Those are the conditions that will help me to choose a solar tracker.

http://www.youtube.com/watch?v=gowcctlv3Ac&NR=1&feature=endscreen 

(This video shows my idea as well. A simple circuit that goes to a double way relay or electromagnet or a small servo but something like this. This is the only way to have a very small simple low voltage circuit to operate with a small 5v battery(supported with some solar cells only for the solar tracker)

I dont know if i wil manage to learn pic programming as good as it is written, im still learning through seeing it happening infront of me.(i was always learning stuff at schoola and almost never learned stuff by actually reading at home....)

 Still i try and see what can i learn about it. A NE 555 is something im looking at the moment. It seems to be a pretty good chip.

[D-the-Greek]

biggest plus points of a microprocessor circuit is that it points at the standard sun posission and it never gets attracted by ambient light or clouds and shadows....

[kam]

As i said, there is no such thing as simple easy and reliable. You will make a simple starting circuit instead. The simplest circuit i can think of is a differential amplifier. What this amplifier does, it it gets two inputs (from your 2 photocells) and compares them. If photocell 1 has greater resistance than photocell 2, then the output is positive, otherwise it is negative. You then wanna add a hysteresis circuit, so that the circuit will operate only if the output of amplifier is greater than a specific value. This hysteresis can be done with a simple comparator. You need to use 2 comparators, one for the positive and one for the negative. Then, each of these comparators will drive the motor, one comparator will drive the motor clockwise, and the other counterclockwise.
There must be of course mechanical limit-switches so that of something goes bad, the motor will not rotate all the way around. If i was to build this solar tracker, i would begin with a circuit like the attached. Remember, i made this circuit in a rush, i would bet that it works but i might lost my money as well..

Without being an expert to stars i don't think earth changes orbit.

It does not change orbit, not unless an asteroid impact occurs. What changes is the tilt angle, but this happens very-very-very slow. So slow, that a noticeable change that could turn this circuit obsolete will occur when parts from this circuit will have decay into sand and other polymers.

[D-the-Greek]

Indeed Kammenos

 that was actually the first thing that came to my mind when i was trying to think of a way for a solar tracker. I then saw in ylurube that many were doin the same principle.

 I am reading various sites about microcontrollers(as you already said) and it seems to be really interesting. There are really many things to do with them.
 
 Ill make an other post about DIY pic controllers (if there is none already)