12V, 3W High Power LED Assembly

thingiverse

This design showcases a 12V LED board, sized for fabrication by iTead Studios at approximately $13 for a lot of 10. The fully populated BOM costs under $3 per board, with power LEDs being the most expensive component at $0.30 each. With specified resistor sizes, the board consumes about 4W of power and uses a 4-pin molex connector (KK) for connection to a floppy power connector on a standard ATX power supply. Two power connectors are included to facilitate chaining multiple modules. An optional power transistor and control header are also featured, allowing the board to be connected to spare 3.3/5V I/O lines for digital control. If there's interest, CAM files can be provided for easy submission to iTead Studios. The BOM includes one board, three 1W white LEDs, four 36 ohm, 1/4W resistors (or larger), two right-angle locking pin headers for the 4-pin molex connectors, and four #6 screws for mounting. For digital control, an IRF8714 N-channel MOSFET (or equivalent) and a straight locking pin header are needed. The board assembly process requires using EagleCAD to generate CAM files for PCB fabrication, soldering LEDs with thermal paste for heat dissipation, attaching connectors and resistors, and optionally connecting the control connector and FET for digital control. Note that early versions had incorrect resistor values and wiring issues, which have been updated in the current design.