TfCD Optic Lighting System

More natural sunlight inside, that is the goal of the technology we are exploring here. Normally, sunlight gets in your home via the windows, but it isn't able to reach every corner of your house. So you need artificial lights to compensate for the lack of natural light, only this is bad for the environment and your wallet. Next to those points, sunlight also provides good effects towards your well-being, so having more sunlight inside will increase your health.

A new technology using optic fibers can be used to light up your house at places where the sunlight normally couldn't enter. In this instructable we will show via a prototype how an optic lighting system works. Also, we explain how you could adapt it to a real life situation.

Step 1: Supplies

The following parts where used in the prototype:

• Fresnel lens (can be taken from overhead projector)
• Cardboard box
• Optic fibre, 2 mm diameter, 5 meters in length
• Duplex tape
• Duct tape
• Metal Sheet (+- 3 mm), alternative material to make flat ring which can hold the lens can be used
• Round metal bar (+- 3 mm), alternative material to make a strong axis to hold the lens can be used
• Pingpong ball

For making a usable version for in home some materials need to be changed.

• Cardboard box is absent, this is the wall of your house.
• Optic fibre, take the amount needed to reach the position you want to light.
• Glue the lens on its place instead of using Duplex tape
• Rubber wire coating for around the optic fibres instead of Duct tape.
• Instead of the pingpong ball use an other larger plastic object with a thin wall thickness.

Step 2: Bundle the Optic Fibres

The optic fibres need to be put together into a bundle to have a larger area to focus the incoming sunlight on. To also supply an even amount of light to every fibre the length of all the pieces should be the same. The fibers can be easily cut by using scissors. Marking the location it has to be cut can be marked with a pen. You can wipe it off after you are done cutting.

For the prototype we cut pieces of 10cm. These pieces were bundled by using duct tape. If you cut it right and the tips are even on one side, the other side should also be correct.

Step 3: Light Collector

Optic light system that can be bought use very expensive sun collectors, which track the position of the sun. With the position of the sun, the light can be optimally concentrated on the optic fibres. The optimal effect would be that the sunlight doesn't arrive on the fibres in an angle.

For this prototype, a simple variant is used which does not track the sun. To optimalise it without a tracking system you can calculate the sun angles during the year on your position. This is not that difficult to do. From this you take the average sun angle to get the best results.

We used a fresnel lens to concentrate the light. This lens has the advantage that light can come from many angles and still be bundled to one spot. The fresnel lens which is used has a diameter of 9 cm. To support the lens a ring is made to hold it. The ring should have a inside diameter of 8 cm and outer diameter of 11 cm to fit the lens. Two holes needs to be made on the ring. In here we will later put axes to hold the lens. For this prototype a metal sheet is used for the ring, but it's up to you if you would like to use a alternative materials which are strong enough to hold the lens.

The lens is attached with duplex tape to the ring in our case. This can be seen in the first image. We didn't want to permanently join them together. For longer used we recommend other joining materials like glue. The result of both parts attached to each other is shown in the second picture.

Now two round bars can be put through the holes in the ring. These bars give you the opportunity to move the lens around to find optimal focus point of light. After this position is determined you can keep it this way or make it permanent.

For real situation we also recommend to make a sort of jacked for around the lens to the optic fibers. This can keep out dirt.

Step 4: Putting It Together

For showing the working principle of an optic lighting system we used a cardboard box as a stand in for the outside wall of an house. By piercing the box with the metal bars we attached the lens to the box. Normally, this would require you to drill some holes in your wall. Make sure when placing the second bar (image 1) that it is on the same height as the first and that the distance corresponds with the holes in the metal ring.

With the bars placed you can put the lens on it again as seen in image 2. Now you can determine the focus point of the light on your wall. Determine how far the lens needs to be from your wall.

On the location where the light focuses you should make an other hole. This is the optimal position to put the optic fibres. Generally, this should be in the middle of the two bars. It can depend on the angle of the light. In image 3 the red circle indicates our optic fibres in the box.

Step 5: End Result

Now, the prototype is completed and is able to get light from outside the box inside the box. By shining with a flashlight at the lens, we tested if this really works. And yes it does, in image 1 you can already see a vague glow coming from the optic fibres while normal lighting is on at the same time.

Only what we found is that because the light is bundle it also gets in the box as a bundle. It doesn't light up a lot of the room as seen in image 2. By placing a pingpong ball or similar plastic at the end of the bundle, the light can be made diffuse which creates a more ambient light. This is show in the last image.

So via these steps you should be able to make an ambient lighting powered by the sun in your own home.