I have a question about power a portable LED light source. I understand the various ways to power an LED array but my question is more about the best practical approach. I have created a portable “LED Light Bar”/“Book Light” for lighting sheet music. In order to spread out the light for a more even cast with less shadows, I have created the following layout:
12 LEDs, each LED has the following specs: 6.1 V / 117 lm / 150 mA / 4000 K / 90 CRI (Luminus Devices MP-3030-2100-40-90), that are paralleled and spaced 10 mm from each other on a 10 mm x 200 mm aluminum PCB.
I would like to power this with a 2S LiPo (7.4 V – 8.4 V) supply. I wanted the supply to be as small, simple and fail-proof as possible. The light will only be needed for about 30 min per use so battery efficiency is not a concern. I was thinking about using just a single resistor or a single AL5809 (SOD123 120 mA CCS AL5809-120P1-7) on each of the 12 LEDs. I was leaning a little more toward the AL5809 since the level of light would remain more constant as the battery voltage changes.
One other thought I had in order to not use resistors or CCS on each LED, was just to power the LED board through a 5.6 V linear regulator, which is below the 6.1 V drop of the LED.
Again the goal is for the smallest, simplest, fail-safe, portable LED light source that produces a good quality of light for 30 min at a time.