Last night was the first time the Atlas LED was powered for an extended period of time. The daylight white LED was powered for 65 minutes without changing colors or burning out. The same heatsink was used; however, the warm white LED was removed. The heatsink slowly increases in temperature, but remains touchable for the entire 65 minutes. The heat seems to cap at around 30 minutes. After 30 minutes, you can touch the heatsink for about 3 seconds before it starts to be too hot for comfort. A small low-speed fan would probably enable us to use that one heatsink for both LEDs.
So the heatsink we have now for testing could be said to be sufficient for one LED (though I suspect the warm white produces slightly less heat…if not, the same) if the heatsink is not enclosed, i.e., if it’s air-cooled.
I thought the light output from one daylight white LED was sufficient to be used as a task lamp at 12 inches high with ambient lighting.
O, and I was afraid the ceramic-encased resistor was going to fry so I used a medicine dropper to apply some cold water every now and then. You can see if fizz on the resistor, but not on the heatsink.
I hope to start building some actual prototypes from wood and/or cardboard to test out the joints mainly.
