rollerce:
I did some testing today at school with a current regulated PSU, and at 400mA, they were VERY bright and didn't warm up anything beyond what the aluminum core could easily dissipate.Now, here's the really interesting part. Being as I ordered quite a few extra (and could get away with sacrificing a couple to the altar of science), I opened up the amperage and let the LED's do as they would. Both the cold white and warm white bars pulled ~500mA, and wouldn't draw any more, despite my de-regulating the current. Any theories? They also didn't warm up much more than at 400mA.
You say nothing about the voltage you set the PSU to, and what voltage you actually measured it outputting. That's kind of important.
Here's another suggestion I didn't see brought up yet: NCP3065
Up to 1.5 A Constant Current
Switching Regulator for LEDs
The NCP3065 is a monolithic switching regulator designed to
deliver constant current for powering high brightness LEDs. The
device has a very low feedback voltage of 235 mV (nominal) which is
used to regulate the average current of the LED string. In addition, the
NCP3065 has a wide input voltage up to 40 V to allow it to operate
from 12 Vac or 12 Vdc supplies commonly used for lighting
applications as well as unregulated supplies such as Lead Acid
batteries. The device can be configured in a controller topology with
the addition of an external transistor to support higher LED currents
beyond the 1.5 A rated switch current of the internal transistor. The
NCP3065 switching regulator can be configured in Step−Down
(Buck) and Step−Up (boost) topologies with a minimum number of
external components.
Seems like exactly what you would need if the strips don't already have a current limit in them. With 40V max you could drive 3 in series with one regulator.
EDIT: actually, on closer inspection 40V is the input voltage limit. I don't see a limit for boosting the output voltage. I don't think there is one, and it would be all up to the inductor, Schottky, and output cap to withstand it.