Parabolic reflector

[davidt]

Whats up everyone

There is one component of flashlights that seems complicated to me. The parabolic reflector seems like it must be designed for the specific light source.

My question for the flashlight modders on this forum is how do you guys get maximum efficiency out of the reflectors. How do you know the right shape and reflector dimension to choose? When designing a flashlight where do you guys get your reflectors from besides commercially manufactured flashlight? Is there a website that sells reflectors alone?

Sorry for all the questions, but I always wanted to create a super bright flashlight but I never knew what to do about the reflector. I had to get these questions off my chest.

 

[LukeA]

Most parabolas will work as reflectors as long as the light source is at the parabola's focus.

 

[OhMyGosh]

Reflectors tend to be easier and smaller to make for LED's because the light only comes out the front half. By the time you add an OP surface (Orange Peel texture) which randomizes and smooths the beam, You can make something like a 60 degree straight wall which works pretty well.

 

[adamr999]

Picture a Cartesian coordinate system (x,y graph) with a parabola opening to the positive x direction and the vertex being on the y axis. The reflective property of the parabola states that a light source transmitted from the focus in any direction will reflect parallel to the x axis.


Here is a applet that shows how a parabola works.
http://www.falstad.com/ripple/ex-parabola.html

 

[GarageBoy]

Parabolic needs a POINT source, no?

 

[LukeA]

Parabolic needs a POINT source, no?

The 1mm square die of the LED is close enough.

 

[Nitro]

Aside from what has already been mentioned. In order to get the most throw, you need one of two things. Either a Large diameter reflector, or a Small point of light. If you had a light source with a smaller point of light, you could get the same throw with a smaller reflector.