I wanted a replacement for my 250 watt halogen--a lamp which, while sufficiently bright, was so hot that it was impossible to work with for any length of time. Enter the world of high-powered LEDs.
In this Instructable I'll show you how to construct a 50-watt LED lamp. 50 watts doesn't sound like a lot compared to 250, but LEDs are around 5-6 times as bright as incandescent per watt. The 250 watt halogen puts out 3600 lumens--this LED puts out over 4000!
The materials should be less than $100, depending on what you can scrounge together and how exactly you construct it.
The hard parts--the machined mount for the LED--I did on the manual mills at TechShop. TechShop has everything you need for this entire project, even soldering irons and the like in case you don't have one. Most of you probably don't have access to a mill otherwise, so sign up today!
WARNING: Parts of this Instructable require experience with AC line power. If you're uncomfortable with this, get someone to help you out! If you make this at TechShop, just ask around and someone can give you guidance.
Step 1: Gather your materials
- An old CPU cooler. LEDs need cooling, and you'll want a pretty beefy heatsink and fan to keep things cool. Almost any model will do.
- A reflector. This part is optional--you can use it if you need a bit more directionality to your light. This one I got from Deal Extreme, part number 39963, "20~100W Silver Plated Plastic Smooth Reflector (58mm)", $2.10.
- A machined mounting plate. I'll show you later how to make this at TechShop. You'll want a (approximately) 2x2x0.5" block of aluminum for this part.
- The LED plate! Deal Extreme part number 157806, "50W 3000K 5000lm 50-LED Emitter Warm White Light Plate (32 ~34V)", $16.00.
- The LED driving circuit. This is a constant-current circuit that takes AC input and converts to ~34 V output at 1.5 A. Deal Extreme part number 132902, "JR-50W LED AC Power Driver for 50W LED Light Lamp Bulb", $18.80.
- Some miscellaneous screws. I needed 4x 3 mm screws and 1x 4 mm. The exact screws don't matter much, but you'll need taps for whatever thread you choose.
- The mount itself. I used a "Photo Studio Lighting Light Stand Magic Clamp" from eBay for $14.99, but you can use whatever you think works best.
- Some 2 watt resistors, approximately 400-500 ohms. This is to reduce the 34 volts of the power supply down to the 8 or so the fan needs.
- An aluminum case. Aluminum is good because it dissipates the heat of the driver circuit.
- 22 gauge wire. Not too critical; just make sure it can handle 1.5 amps.
- Rubber grommets. For the cabling holes in the aluminum case.
- A GFCI plug. I cut this one from a $9 hair dryer on Amazon! Standalone cables were closer to $20, so this seemed like the better option. I highly recommend a GFCI plug for safety!