Wii Sensor Bar using 1.6 forward voltage IR LEDs from Adafruit:
https://www.adafruit.com/product/387
And this 5 ohm resistor:
https://www.jameco.com/z/CR5-5-0-RC-Xicon-Resistor-Wirewound-5-Ohm-5-5-Watt-plusmn-400ppm-deg-C-Axial-Through-Hole_660295.html
I'm using a 9V source because it's really common. You could use a 9V 2.1mm DC in, a PP3 battery, or even 6 double or triple A's (non-recharcheable only in this case)
Each side has the LEDs wired in series and then each set is wired in parallel.
