Old Stuff : This was posted many years ago to my old-ass website – thought i’d not let it go to waste. This is some time from 2015.
Old Stuff – The 100 Watt LED Torch Project
Have you ever looked at a little pocket torch and wanted more power? If the answer is yes, and I expect being on this website it is, then you are in the right place.
This page explains how to build your own 100 Watt LED torch, which is more or less equivalent to a 500 Watt halogen flood light.
The parts in this project are very cheap and readily available on eBay.
I believe this project is noteworthy because it can be done dirt cheap, as well as producing a torch of almost unspeakable brightness. Wielding masks may be required.
100 Watt LED Module
This concept of building a 100 Watt LED torch is nothing new, It has been featured in several YouTube videos.
There are a total of 100 LEDs inside the module, 10 in series and 10 sets in parallel, giving a forward voltage of around 30 ‘ish’ volts.
They require about 30-33 volts DC to light up and will consume about 3 amps, so a total of 100 watts.
Their lifetime can be extended by current limiting, as voltage limiting is not recommended.
eBay Number – 271581926123 – 100 Watts, Input range of 30-33 volts.
Of course, there’s no point having a LED with a input voltage of 30 as there’s hardly any standard that it would work with, 12 or 24 volts is too low, and 36 volts will cause a abrupt end of life of the LED.
There are several expensive drivers available that I am sure will work fine but there are also cheaper alternatives. So called “Adjustable Boost Converters” are available on eBay and are suitable.
They come with voltage limiting, and some also come with current limiting, and these are preferred as with current and volt meters you can calculate and set the exact power output.
The limits are set by turning the potentiometer on the boost converters.
eBay Number [with current limiting] – 321607880015 – 250 Watts, Output range of 12-50 volts. Will need additional heatsinking.
eBay Number [without current limiting] – 301123733767 – 150 Watts, Output range of 10-32 volts.
The LED module is going to need a heatsink, and any CPU heatsink or similar will do. Can be found cheaply on eBay.
Cut off the molex motherboard plug, figure out 12V and ground and connect to your supply.
eBay Number – 201375540040
Diagrams & Setup
The diagrams above show how to connect up the LED, driver and cells. You must make sure that the cells of the battery are not shorted out and connected correctly.
I would recommend that the 18650 cells are held in a cell holder so they can be remove easily and charged regularly. As this project does not include any protection for the cells it is key you measure the cells voltage regularly.
A switch is also a good idea.
DO NOT leave the torch on and let the batteries drain. Just don’t do it. 18650s don’t like being abused.
You may or may not choose to install a lens as this helps focus the light into a torch like source of light.
I found that 8x 18650 cells were enough to power the torch without compromising on the power output of the LED, as well as not drawing over the recommended current draw of the cells.
Some photographs of the prototype
Update – November 2015
So I finally sorted my life out and decided to return to this project. As of November 2015 I am done with this project as I have other things to do.
The body is made from a combination of “Laser Grade Ply” and threaded M5 rod and M5 bolts. Photos are worth a thousand words and I also hated English at school so please have a detailed look at the photos.
I will upload the CAD files as well as soon as I can gather them all together.
Although I have not had any issues with cooling, in hindsight maybe black acrylic might have looked cooler than wood.
I also constructed custom 18650 battery packs, which I will do a write up on some time. Basic construction is Laser cut acrylic and hot glue. Lots of hot glue.
I built them for a future project, but they work very well in this application.