SST-50 homemade spotlight

[EasyB]

Hi everyone, I have just now joined the forums but they have been a source of knowledge and inspiration in the past. I became sort of obsessed with building this LED thrower.

A short focal length lens collects most of the light from the LED and the large fresnel lens focuses it far away. The LED is actually inside the focal length of the small lens, creating a virtual image that the large lens sees. The large fresnel lens is 13" in diameter.

The power source is two 18650 Li-ion batteries on the backside. The voltage is regulated and adjustable by turning the blue potentiometer. The voltage regulator is one made by fujitsu that I got from mouser.com. Its max output current is 8A.

Further away, the LED appears to fill the entire lens.

That tower is about 250 meters away. The current was about 5A in these pictures. I don't really have a good spot nearby to do beamshots, but I was able to illuminate a tower about 900 meters away before.

Thanks for looking.

 

[DM51]

WOW!! Welcome to CPF, EasyB !!

That is a spectacular first post - what a superb light! Brace yourself for a lot of questions and comments from admiring members!

 

[ninemm]

WOW!! Welcome to CPF, EasyB !!

That is a spectacular first post - what a superb light! Brace yourself for a lot of questions and comments from admiring members!

Yep, what he said! Welcome and awesome job. Very unique and the quality of the build looks great.

 

[John_Galt]

Super nice light, man!

Two things: What kind of 18650's are they? For such a high current drain, I would suggest a couple of AW brand IMR 18650's. They have noticeably lower capacity compared to some other cells out there, but they are able to be safely discharged at ridiculously high rates, with minimal voltage drop.

The other thing is more heatsinking. This is probably a short-time only thing, but to ensure maximum output for a long period, I would suggest finding another mounting point for the batteries, and putting a large CPU finned heat-sink on the back of that chunk of aluminum.

But again, very nice!

 

[Linger]

Sick.
Excellent beam-shots.
Thank-you.

 

[EasyB]

Super nice light, man!

Two things: What kind of 18650's are they? For such a high current drain, I would suggest a couple of AW brand IMR 18650's. They have noticeably lower capacity compared to some other cells out there, but they are able to be safely discharged at ridiculously high rates, with minimal voltage drop.

The other thing is more heatsinking. This is probably a short-time only thing, but to ensure maximum output for a long period, I would suggest finding another mounting point for the batteries, and putting a large CPU finned heat-sink on the back of that chunk of aluminum.

But again, very nice!

Thanks for the suggestions; you're right it is kind of a short term novelty light right now. It's a fairly sizable chunk of aluminum; after it being on for several minutes the metal was slightly warm to the touch.

I checked the battery voltage the other day and it was 3.93V per cell open circuit, 3.81V full power. They are Tenergy 2600 mAh cells from batteryjunction.

 

[mrartillery]

Nice light! :huh: And BTW +1 on excellent first post!

 

[gt40]

Great effort! Could you share more on the specific voltage regulator you used?

 

[JamisonM]

Bookmarked. I can't wait to see what it can do when it's really tested!

 

[EasyB]

Great effort! Could you share more on the specific voltage regulator you used?

Sure, here is the product page:
http://www.mouser.com/ProductDetail/Fujitsu/FPMR12TR7508PA/?qs=ESP0OwbMTIA5u7FiiObSlA==

The voltage specs are there. The output voltage is adjusted by changing the resistance between two contacts on the regulator. You can see it in the electronics closeup pic above. It's at the bottom right; about 3x1cm. The output voltage doesn't change when the load changes, which is a nice feature.

 

[kingofwylietx]

Very impressive first post.

That's a very cool spotlight....I like the skeletonized look.

 

[daytec]

very nice , where did you source the lenses............marty

 

[js-lots]

That is awesome, I cant wait to see what kind of edc's you start to make.

 

[Linger]

cant wait to see what kind of edc's you start to make.

Is that a fresnel in your pocket or are you just happy to edc?

 

[SmurfTacular]

+1 What an amazing dual lens design you got there! Great solution for all the dead light usually produced by normal fisheye flashlights

Where did you get those lens's!?

 

[Th232]

Very nice work.:thumbsup:

:welcome:

 

[Hack On Wheels]

Wow, I'll have to echo the others in saying that was an amazing first post!

It makes me want to try a dual optic Maglite mod... with something smaller like an XR-E or XP-E. I'd have no idea where to start though!

 

[EasyB]

Whoops I thought I mentioned this in the post; the lenses are from edmund optics. You can get somewhere a 4'x3' fresnel lens used in projection TVs. That would make a spotlight a bit less portable than mine, but it would shine something powerful.

 

[^Gurthang]

Easy,

Welcome and a tip 'o the hat for your project. Love the "light saber" pic, sorta like the Martian's heat ray from War of the Worlds all you need to add is the hissing sound....

 

[kramer5150]

oh Lordy!!! I just soiled my boxers @ that beamshot.

Awesome work, very impressed with your fabrication skills.:thumbsup:

Curious...
How come so much light is being spilled out to the immediate sides? The light thats illuminating you as you hold it... where is that light coming from? Is it being reflected back at you off the lens surfaces?