Teaser post to prove that this is not forgot. Also, sorry, I have too many things in motion to do a complete post on this. I don't know how common of an audience I have with my posts but some may be aware that I have a few projects with my TDI here on the forums... Anyhow, enough rambling.
LED Driver consumption: 1.5 A @ 13.25 V = ~19.88 W
LED Array consumption: 1.21 A @ 5.65 V
* 2 = ~13.67 W
(I measured the current of one branch of 4 LEDs so this stands to reason that it needs to be doubled as you see)
Efficiency = ~68% peak (This improves to this as things warm up)
LED Headlamp Schematic:
The power supply is a simple buck regulator with a constant 5.6-5.7 V output. LEDs "should" be driven at constant current, but that complicates this type of product and will result in cascading failure if 1 of the 8 LEDs fails. However, if one LED fails with this setup, it will take out it's partner it;s in series with and the failure stops at there. The datasheet specifies ~700 mA as nominal drive current though it was clear that the measurements I made places that @ ~600 mA, much to my surprise actually. This puts the luminair at ~1750 lumens whereas a standard H7 bulb is ~1500 lumens for the 6500K LED.
Teaser pics taken with one of my
reflectors w/ no glass, some dust, and a few flakes of reflector missing and taken with my cell phone. I have new reflectors arriving next month.
6500K, 70 CRI LEDs
And with 4000K, 90 CRI LEDs
The square pattern you see is actually the front of the individual LEDs. Distracting? Quite? Practical problem in real life use? I doubt it.