Portable Solar Tracker (No microcontroller required!)
Ever wanted to keep your solar panel in full sun all day long without having to constantly move it? A solar tracker may be the answer. This tracker has the advantage of being portable - if you move it, the tracker will automatically adjust back to the sun, unlike the chronological solar trackers. Another strong point of this solar tracker is its cost - there is no microcontroller or other expensive parts.

Principle of operation:
To track the sun, this device uses 4 photoresistors arranged in a wheatstone bridge configuration. A quad comparator controls movement. One comparator acts as an oscillator to have the device turned on a small fraction of the time. 2 comparators 'decide' whether to yaw or pitch the solar panel, and the other comparator acts as an inverter.

Step 1: Round up the parts

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Parts List:
1 breadboard

1 L298N H-Bridge motor driver

preformed jumper wires

4 male-to-female wires (this is a pack of 40)

AWG 24 wire (for connecting solar panel to breadboard)

1 lm324 quad operational amplifier IC

solar panel of your choice with mounting holes (I used a 20V solar panel, but as long as your solar panel is between 5V and 32V, you should be fine). If the solar panel is over 32V, you will exceed the maximum supply voltage to the lm324. If the solar panel is below 12V, you may need a 12V battery to power the H-bridge.

1 220uF capacitor (make sure the voltage rating is greater than or equal to the voltage of your solar panel. You only need 1 of these, even though the link shows a pack of 25).

4 2200uF capacitors. (make sure the voltage rating is greater than or equal to the voltage of your solar panel. You will need a capacitor with a higher voltage rating than this one if your solar panel exceeds 25V. You only need 4, but the link shows a pack of 20. If you want higher surge current capability, you can use all 20).

1 motorized rotating base (I used a "Hoberman Actuator" (which I believe is no longer sold). here is a similar item You need something that you can attach your solar tracker to that rotates slowly)

4 photoresistors (comes in pack of 20. You only need 4 photoresistors)

1 IRF3205 N-MOSFET transistor (comes in a pack of 5. You only need 1 MOSFET, but these puppies are fragile. I reccomend buying a pack of at least 2 in case you break one).

4 signal switching diodes (This is a pack of 30. You only need 4)

Resistors (You may want to buy a resistor kit if you plan to build other circuits. Just be sure your resistor kit contains all the resistors required for this project)
-1 100
-4 1K
-3 3.3K
-3 10K
-1 47K
-3 100K
-1 1.5M

1 geared motor (I used a K'nex motor. Must have a shaft to which a string can be tied)

Wood Pieces:
1 1/2" thick wooden board, approx. same length, width of the solar panel (From now on, this piece will be called "wood1")
1 1"x2"xA" board, where A is about 2" to 3" more than solar panel width (From now on, this piece will be called "wood2")
1 1"x2"xB" board, where B is about 1" more than the solar panel width (From now on, this piece will be called "wood3")
2 1"x2"xC" board, where C is approx. solar panel length (From now on, this piece will be called "wood4")
2 1.5"x1.5"x1/2" wood blocks (From now on, this piece will be called "wood5")
2 3" long, 3/8" diameter wood dowels (From now on, this piece will be called "wood6")
1 1"x3"x1/16" wood strip(From now on, this piece will be called "wood7")
1 1/2"x1/2"x2" wood block(From now on, this piece will be called "wood8")
1 breadboard-sized wood piece(From now on, this piece will be called "wood9")

Fasteners:
6 1.5" long wood screws
6 3/4" long screws
3 bolts
3 nuts that fit the bolts
wood glue
optional parts:
1 tactile button switch (This is a 10-pack. You only need 1). By using this optional switch, you can turn on the H-Bridge at any time without having to wait until the oscillator signals to turn on.

1 330K resistor (must use this if you you the tactile button switch)

Tools requried:
drill
screwdriver (phillips and flat head)
adjustable wrench
allen wrench

Step 2: Drill holes in wood1

Portable Solar Tracker (No microcontroller required!)
Drill pilot holes for the 2" wood screws as indicated by the red marks in the picture.

Any other holes in the picture do not need to be drilled.

Step 3: Drill holes in wood2

Portable Solar Tracker (No microcontroller required!)
Drill pilot holes for the 2" wood screws as indicated by the red and green marks in the picture. The distance between the green holes should equal the distance between the red holes for wood1 as they should line up.

Any other holes in the picture do not need to be drilled.

Step 4: Drill holes in wood3

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Drill pilot holes for the 3/4" wood screws as indicated by the red marks in the picture. Drill holes for the bolts as indicated by the green marks. If the bolts cannot fit their shafts entirely through the wood, you can drill holes wide enough for the bolt heads as indicated by the green marks in the 2nd picture of this step. The distance between the green holes should equal the distance between the mounting holes in the solar panel.

Any other holes in the picture do not need to be drilled.

Step 5: Drill holes in wood4

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
First picture:
Drill holes in wood4 for the 3/8" diameter dowels (wood6) as indicated by the red marks. The dowels should fit snugly.

Second picture:
Drill pilot holes for the wood screws about 1" deep in each piece of wood4. These holes should line up with the holes marked in red that were drilled in wood2 (step 3).

Any other holes in the picture do not need to be drilled.

Step 6: Drill holes in wood5

Portable Solar Tracker (No microcontroller required!)
Drill holes in the centre of each block of wood5. The dowels should fit the holes loosely.

Step 7: Drill holes in wood7

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Drill a hole for a bolt through wood7. Then drill 8 small holes for the photoresistor leads. Make sure these holes can surround wood8. These small holes are grouped 2 per photoresistor. When you drill these holes, insert a photoresistor in each pair of holes. You can use glue to secure the photoresistors.

Step 8: Attach wood8

Portable Solar Tracker (No microcontroller required!)
Glue wood8 to wood7 as shown in the picture.

Step 9: Screw wood5 into wood3

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Screw in a wood 5 piece at each end of wood3. Use the 3/4" screws.

Step 10: Bolt wood3 to the solar panel

Portable Solar Tracker (No microcontroller required!)
Use 2 nuts and 2 bolts to attach wood3 to the solar panel.

Step 11: Attach wood7

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Push the bolt through wood7 and a solar panel mounting hole. Thread on a nut and tighten.

Now check everything attached to the solar panel. It should look like the 2nd picture (minus the wires).

Step 12: Wire up the photoresistors

Portable Solar Tracker (No microcontroller required!)
Twist one of each of the photoresistor leads together as shown. Twist long (approx. 18") wires to each of the remaining leads as shown.

Step 13: Screw wood4 into wood2

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Line up wood4 with wood2 as shown in the picture. Screw the pieces together. Repeat with the other piece of wood4 at the other end of wood2.

Step 14: Screw wood2 into wood1

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Line up the hole and screw together. The base has been made.

Step 15: Attach solar panel assembly to the base

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Line up the hole in wood5 to the hole in wood4. Then push a dowel through. The solar panel should be able to pivot freely.

Step 16: Attach geared motor to base

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
I used a K'nex motor, so mine is different than the one in the parts list (in step 1). You can probably figure out how to do this on your own (zip ties, perchance?)

Step 17: Attach the string to the motor shaft and solar panel

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Tie a string through a mounting hole in the solar panel. Tie the other end to the shaft of the motor and wrap it around.

Step 18: Screw in the H-bridge motor driver

Portable Solar Tracker (No microcontroller required!)
Portable Solar Tracker (No microcontroller required!)
Use 2 of the 3/4" long screws to attach the H-bridge to the base. You may need to drill pilot holes.

Step 19: Build the breadboard circuit

Unzip the .zip file and there is a fritzing file of the schematic and breadboard view. There are also jpg images of the schematic and breadboard views. If you don't have fritzing, download it. Be sure to use the male-to-female wire to connect the breadboard to the H-bridge. Also, the geared motor that is attached to the base is called "pitch" in the schematic. The motor of the rotating base is called "yaw".
Portable Solar Tracker (No microcontroller required!)
Fritzing.zip1 MB

Step 20: Screw breaboard to wood1

Portable Solar Tracker (No microcontroller required!)
Make sure the solar panel can pivot about the dowels without hitting the breadboard.

Step 21: Place the solar panel atop the motorized turntable

Portable Solar Tracker (No microcontroller required!)
Simple as that. Be sure you connect the wires from the turntable motor to the H-bridge. The turntable motor is labeled "yaw" in the fritzing schematic (step 19).

Congratulations! You have completed the project. Send me a message on Instructables if you have any questions or suggestions.
 
 

Tag cloud

make build easy simple arduino making homemade solar laser printed portable cheap mini building custom cardboard wooden create super lego turn paracord chocolate your paper light intel