Picture of Full Spectrum Flashlight
I've wanted to build a full spectrum flashlight for a while and seeing the Flashlight Contest advertisement enticed me to build it, asap.  Once I finished this flashlight it turned out a lot better than i had expected.  I now want to make modifications to it to improve it for my next flashlight. I will definitely use this at work now.

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Step 1: Obtain Part and Tools

Picture of Obtain Part and Tools

Used or new flashlight casing. I used Military type Flashlight P/N MX-991/U

The following can be found at Radioshack
4.5 vdc power supply (make sure it will fit inside casing with the wires)
     I used a 3v battery holder in series with a 1.5 volt battery holder
     White LED
     Ultraviolet LED
     Infrared LED
     Red LED
     Yellow LED     
     Green LED
     Blue LED
Round PCB (to fit inside flashlight casing and also backside painted silver to help reflect)
     2x 33 Ohm      IR
     100 Ohm         Red
     47 Ohm           Yellow
     68 Ohm           Green
     15 Ohm           Blue
     33 Ohm           UV
     22 Ohm          White
6 Position Switch
22 AWG wire


Soldering Iron
Dremel or Drill
Silver spray paint (not absolutely necessary)
soldering iron

Step 2: Observe Wiring Diagram

Picture of Observe Wiring Diagram
Check out wiring diagram so you know what wires go to what component. Since i was only able to find a 6 position switch i had to chose only six colors to use. I chose IR, Red, Green, Blue, UV, and White. I know i'm missing a few colors to make it an absolute full spectrum, but you can add more LED's if you desire.
SIRJAMES093 years ago
that round board you used...
THAT can be bought at Radio shack?? and it does not have to be cut down?
I have a 2 cell(3 volt) flashlight that I want to convert to LED, & with that round board, I can see me using that + about 18 - 20 LEDs... :)

TY for sharing Sir.
hanlin_y3 years ago
You can try adding near IR, deep red, red, red-orange, amber, yellow, green, cyan, blue, royal-blue, violet, near UV, and white. The CRI should be as good as using a halogen lamp.
codongolev3 years ago
I'm doing a similar project, but I'm trying to give each color its own potentiometer so that there's an infinite number of color possibilities.
sukinmaru4 years ago
So, I'm guessing that this doesn't give off radio waves, microwaves, x-rays, and gamma rays! Boy, what a cool invention that would be...
LOL, instant superhero: just set to gamma rays, point, and click!
more like instant cancer!
Esmagamus4 years ago
I often thought about converting my tactical flashlight to LEDs. The damn things eat batteries, and then not only you have to pay for the batteries, you also have to carry spares batteries and bulbs! I'd definitely convert one to work with white LEDS if I hadn't lost mine and eventually needed to buy a new one. The full spectrum would have no use for me. Adding a switch on the outside would make it inherently less reliable (there's one more element that can fail) and I'd still get all the colours I needed using filters. If you'd do a "tactical flashlight that won't make you carry a pound of extra batteries" instructable, I'd give it a 10, just like that.
I also use a tactical flash light ( a right angle torch) with lenses and as good as it is the only problem with it is it is awkward to change the lenses in the dark without loosing any and the lenses also dim the light.
krmartin3 (author)  Esmagamus4 years ago
Good suggestion! I'll keep that in mind for the modification update for this mod. I've got some other ideas to improve this as well that you may like.
KGood4 years ago
Could you be more descriptive about how to go about soldering/wiring this? Also, how do you control which LED is on?
krmartin3 (author)  KGood4 years ago
yes, as soon as I get time (within a week or two) I plan on improving this instructable with a better wiring diagram and more descriptive instructions on how to build it. The six position switch on the bottom of the flashlight controls the current flow through the appropriate resistor connected to the appropriate diode. On the center pin of the switch is the ground wire which is connected to all the diodes grounds (cathodes) through the on off switch built into the flashlight. When you turn the six position switch you control which diode lights up.
perlpower4 years ago
You don't need any more led's too achieve a full (visible) colour spectrum, in fact you don't even need the yellow and white. Contrary to what Sharp would want you to believe you can generate the entire visible spectrum using just red, green, and blue. You would just need to create a better way of controlling it as you would need to mix different values of each of the leds/led (you can get RGB leds) Though you could go with adding all the colours between and extend it just through simple blending like this. Overall nice instructable, I might have to build my own full spectrum flashlight now. It would be nice to have a high brightness one for photography (though it would have to be very bright >_>)
Hi, someone already made a RGB flashlight, including mixing colours and brightness control: RGBW led is driven by microcontroler driver, modes are being changed using only a single on/off tail switch ;)
That would be quite hard to be able to control how much of each color you get, but it is possible.
Well a simple way would be to have one potentiometer for each led, so you can manually control the colour, and it would allow for added mixing like, UV+red+green or IR+UV.
Still not an easy way to control it.
SiderAnne4 years ago
This'll be great for watching the Persied meteor shower! I won't lose my nightvision looking at the star chart or finding my way back to the car!