This project isn't a kit (and won't ever be) so the instructions are more laissez-faire, with many opportunities for the maker to change elements or modify the design. Take it more as a guideline (and use common sense) than a rigorous step-by-step!Parts list
To make this project you'll need:
- 36 or 37 1+ Watt LEDs. there are 2 Watt LEDs that are now easily available. For color versatility you can use 12 each of red green and blue. Or you can go with 18 each of green/blue for more effective dazzling. These range around $3 each. Look on eBay or other closeouts to get slightly-older LEDs for less. We used some older Cree XLamp XR-E 7090
- You'll also need lenses/optics for each LED. Go with narrow-beam lenses, about 20mm diameter. 6 or 5 degree will be most effective. (Like this, but make sure you get ones that match your LED)
- Balancing resistors, one for each LED. I used 1.0 ohm 1210's
- For red LEDs (and maybe green/blue depending on your power supply) you may need a choke resistor 0.5 ohm at 5W may be OK. The internal resistance of the battery and Rds of the FET will make a difference, so do math and measurements!
- 6" diameter LED plate, see the downloads page for layout. This holes the LEDs and lenses. In theory a aluminum core LED is helpful but we found that for quick blasting, FR4 with copper fill worked just fine.
- 16 or 18 gauge wire for connecting things up
- 6 N Channel logic level power MOSFETs. We used FDP6030BLs. Nearly anything that can sink 2A is just fine.
- Arduino or other microcontroller. The AVR atmegax8 series such as found in the arduino is handy because it has 6 hardware PWMs. We used a DC boarduino and attached an FTDI cable to upload the firmware
- Battery capable of sourcing 4A at 4V+. 3 D cells or a lead acid is a good choice. We used a 4A 6V SLA that came with the lantern
- Heatsink. A spare AMD processor heatsink and fan worked nicely and was free!
- 9V battery + holder with switch for the arduino, seperate supplies prevent noise issues when driving such large loads
- Enclosure. We repurposed a cheap yet enormous flashlight from Sears. It was pricey at $40 but had the benefit of including a lead acid battery (which would have run almost $20 with shipping) and a basic lead acid charger.
- Power supply for testing, a ATX power supply is a good way to generate 5A+ at 5V