HELP!!! Solar Tracker

[jmarmontgomery]

Here is the the Solar Traccer Design That I Am Using...However, I Got it hooked Up to the breadboard and it is not working...I Believe I Have It Hooked Up Correctly, but Id Rather get my Design Reviewed first, then check to see if I have solid connections on my breadboard.

I am using the ever so common:
OP AMP 741
400 mA/0.5 V Solar Panel
10 Ω Resistor as R1
10M Ω Resistor as R2
3.0 V Power Source-------> (In The Diagram, I have it listed as 1.5V)
a Small DC Motor..

FIrst things first, I know the motor works, I connected it to my 3.0v Power Supply (a Battery Pack wired in Series)...Solar Panels Works....So now, I Need everyone's Help to verify that my diagram is correct.

PLEASE PAY SPECIAL ATTENTION To the Polarity of the Power Supply in Regards to the OP AMP...
<a href="http://smg.photobucket.com/albums/v350/gdupgodfather/?action=view&current=CircuitDiagram.jpg" target="_blank"><img src="http://img.photobucket.com/albums/v350/gdupgodfather/CircuitDiagram.jpg" border="0" alt="Photobucket"></a>

 

[Nigel Goodwin]

For a start you can't feed a DC motor from a 741.

 

[jmarmontgomery]

I Cant? Why Not?

 

[jmarmontgomery]

What Can I Use?

 

[Nigel Goodwin]

I Cant? Why Not?

It can only provide a tiny amount of power, no where near enough for a motor.

 

[jmarmontgomery]

Well What Kind of OP AMP can I Use?

 

[Boncuk]

Look up my reply of your PM.

 

[Willbe]

I don't see how you're going to track the sun with only one motor even if you lived on the equator or at the poles.

 

[jmarmontgomery]

using a "A" or "V" shaped configuration... s solar panel on each side...On the "A" configuration the panels would face away from each other. On the "V" configuration the solar panels would be mounted on the inside of the V facing each other.

 

[AllVol]

Here is the the Solar Traccer Design That I Am Using...However, I Got it hooked Up to the breadboard and it is not working...I Believe I Have It Hooked Up Correctly, but Id Rather get my Design Reviewed first, then check to see if I have solid connections on my breadboard.

I am using the ever so common:
OP AMP 741
400 mA/0.5 V Solar Panel
10 Ω Resistor as R1
10M Ω Resistor as R2
3.0 V Power Source-------> (In The Diagram, I have it listed as 1.5V)
a Small DC Motor..

FIrst things first, I know the motor works, I connected it to my 3.0v Power Supply (a Battery Pack wired in Series)...Solar Panels Works....So now, I Need everyone's Help to verify that my diagram is correct.

PLEASE PAY SPECIAL ATTENTION To the Polarity of the Power Supply in Regards to the OP AMP...
<a href="http://smg.photobucket.com/albums/v350/gdupgodfather/?action=view&current=CircuitDiagram.jpg" target="_blank"><img src="http://img.photobucket.com/albums/v350/gdupgodfather/CircuitDiagram.jpg" border="0" alt="Photobucket"></a>

Try this tracker that works:

www.josepino.com/other_projects/index.php?simple_sun_tracker.jpc

 

[Boncuk]

Try this tracker that works:

www.josepino.com/other_projects/index.php?simple_sun_tracker.jpc

That's no tracker. It's a simple drive!

 

[Boncuk]

Solar tracker

Hi gmarmontgomery,

here is the circuit for one axis. Use 10mm red LEDs with clear domes for maximum voltage output.

The "sensor" panel in the photo is equipped with two LEDs of that kind. The second pair (for elevation) has been removed for clearness. Not the dividing X-shaped tin in the center. It is necessary to have only one LED exposed at at a time when the LEDs don't face the sun.

Boncuk

 

[Willbe]

using a "A" or "V" shaped configuration... s solar panel on each side...On the "A" configuration the panels would face away from each other. On the "V" configuration the solar panels would be mounted on the inside of the V facing each other.

My bad; I assumed you wanted the sun to be absolutely 90° to the surface of a single panel at all times.
I don't much mess with solar cells - you might get pretty good power output even with sun being 45° to the panels' surfaces.

I should go on the Internet more. . .


Actually, with this two panel arrangement, you just need a motor that turns once in 23 hours, 56 minutes and 04. 09053 seconds, more or less, and has the shaft pointing at the North star. A 24 hr plug-in wall timer motor, for example.
At the sunny end of a cloudy day you wouldn't have to reacquire the sun - the motor already knows where it has to be.

 

[jmarmontgomery]

Boncuk,

is it possible to just use the 10mm LED's, the 2N2222 Transistor, LM741, small DC motor and a 3V or 6V power supply? im trying to avoid buying anymore components.. I have 10M Ohm resistors and 10 Ohm resistors... As of this point, im lost and desperate and learning as I go. The transistors (2N2222) are rated for 800mA; however, I believe I will be pushing around 1200 mA. so wat should I do... All help is greatly appreciated.

 

[jmarmontgomery]

So, after more research, o realized that I need a rheostat(variable resistor) and a protection diode...but damn, its the process of speccing everything for my needs and the circuit diagram.

 

[Boncuk]

Hi jmar,

resistors are really the cheapest parts within a circuit, approximately 1Cent per piece. You can't replace a 4.7KΩ resistor with one of 10MΩ. The variable resistor in the schematic drawn from the output to the inverting input of the OpAmp might be replaced by a fixed value transistor of 22KΩ. It's not a rheostat, but a trimmable resistor. (trimpot)

Concerning the power supply you'd better off using 6V instead of 3V. If you are afraid to fry the 2N2222 you might choose a BD140 which can drive more power to the motor.

I assumed the motor is one you salvaged from a toy car. If it runs at 3V it shouldn't draw that much current.

Also, please note, that that circuit makes the motor rotate in one direction only. If the circuit works alright with the motor turning the wrong direction just reverse the motor terminals for connection.

Boncuk

 

[jmarmontgomery]

oh ok... well I went ahead and got the components I needed... the capacitors, resistors, and variable resistor that were in the circuit diagram....
however, I need the motor to reverse direction according to the largest imput from the LED sensors...also I will go ahead and run the 6v power supply...

 

[jmarmontgomery]

Would This Work?

 

[Boncuk]

OK, I will alter the design to have the motor rotate in either direction. This means of course more components like additional transistors.

However if you just have to demonstrate the function just one direction will be fine as well. The sun never moves west to east though.

There is a small correction to the transistor I suggested. The BD140 is a PNP type. The circuit requires an NPN type. Choose the BD139 instead.

Boncuk

 

[Torben]

Would This Work?

The protection diode is upside down, and all the diodes are drawn inside-out. The diode symbol looks like a isosceles triangle with a line balanced on its point.


Torben