dlloyd:
Ahh! No! Driving high power LEDs with a constant voltage is not a recommended practice.
As long as the voltage is within spec AND the current is within spec, then the life expectancy will be within spec.
Is this true? I thought LEDs are not current limiting devices. I assume that the fact that these are 10W LEDs means "don't drive them over 10 watts" not "the LED will self-limit to 10 watts".
I wasn't quite specific enough...not current limiting. Just equivalent resistance @ 12V.
An ammeter would be useful to check the rate of current rise .. it won't register until you get near 9V, then it will climb to 1.05A as the voltage increases towards 12V.
The power supply has a fairly responsive ammeter built-in, and like I said, it ramps from 30mA which is no draw on the LEDs up to about 550mA. This is with the duty cycles currently programmed into my sketch. Also, this is for one and only one channel (color) at a time. If I was pushing this through all 3 channels I would already be over 1.65A on the LED. The issue is that the other thread responders seem to think what is happening is that those current reading are averaged and the current is actually a heck of a lot higher during the active part of the duty cycle. That is the conclusion that I came to after looking at the totality of the circuit, and that is why I posted this question.
But, and I stress this, it seems to be working. XD Good enough for amateur work?