# Concentrating sunlight to creat different extream temperatures

1. Sep 11, 2007

### douglasg14b

I am wondering of a way to concentrate sunlight to an extent to create high temperatures that vary depending on how many mirrors, lenses....etc i use and so on......it is an idea i have for a physics project any suggestions on how i might go about this would be muchly appreciated.

2. Sep 12, 2007

In the 1970's I bought a plastic, 12" x 12" x .2" Fresnel lens from Edmund Scientific Company for $6. I would guess that in full sunlight it generated over 1500o F. Paper would catch fire in a couple of seconds; in general, organic material would easily vaporize. It would take out not just an ant, but the whole anthill. I believe I melted lead with it; I have heard said that it could melt a penny. It seemed to ablate concrete. I probably have some eye damage thanks to my youthful nonchalance. 3. Sep 12, 2007 ### robphy 4. Sep 14, 2007 ### douglasg14b using non-imaging optics to concentrate sunlight how might i go about using mirrors and a large lens or 2 to concenrate sunlight enough to attain 3500-8500k or the closest i can within limited funds [physics project] and also how i might measure the temp. 5. Sep 14, 2007 ### Captain Barbosa *tsk tsk* They're called welding goggles my friend... The biggest lens I have is a 8.5"x11" fresnel page magnifier. Douglas, your question might be easier to answer if we had a general ballpark on your budget. 6. Sep 14, 2007 ### douglasg14b can you expand on that.....if you are saying i need space i live on a farm so i have abundant space. and would concentrating light on a large lens using mirrors increase the concentration of sunlight on the other side of the lens thus increasing the temperature? 7. Sep 14, 2007 ### Captain Barbosa Assuming the lens could survive the already concentrated energy, I don't see why not. For the budget thing, how can we keep a limited budget in mind if we have no idea what that budget is? Are we talking tens, hundreds, or thousands of dollars here? Last edited: Sep 14, 2007 8. Sep 14, 2007 ### douglasg14b we are speaking the budget that one would use or a advanced high school physics project[year long] like 100 to150$ im not going to spend allot on a grade.

9. Sep 14, 2007

### Staff: Mentor

Last edited: Sep 14, 2007
10. Sep 14, 2007

### AlephZero

This might not sound as much fun as a solar furnace, but you can easily heat up small objects to 1000C in a few minutes, using the light from a a 12V halogen car headlight bulb instead of sunlight.

We had a test rig for doing high temp experiments on objects about 1mm cube that used that method for heating, with a feedback loop and a controller to vary the lamp output once the object had got up to the working temperature.

The bulbs already contain a parabolic reflector, so you don't need any fancy optics to make this work.

11. Sep 14, 2007

### Staff: Mentor

So did you use a 2nd (no bulb) headlight to concentrate the light from the source headlight?

12. Sep 14, 2007

### Captain Barbosa

Here is a 20.5" x 36" fresnel I just found that you can buy for 80 bucks plus shipping. giant retina frying device

Some of them are a bit out of your price range, but here are some more to choose from if you want. http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=2040 [Broken]

Last edited by a moderator: May 3, 2017