Q. How many 3w LEDs wil this power?
A. Hi Lyle, thanks for your question. Unfortunately it is not possible to be specific without details of the 3W led you have in mind. Different colours will require different voltages and that will affect the number you can connect in series up to a combined voltage of 20VDC. Using 55-2007 as an example – firstly the LED requires an max current of 800mA – so will likely work at 600mA but 700mA is its ideal. It has a Vf of 2V min & 3V max – so you could run between 8 & 10 of these. We hope this helps.