This is a single LED light. The above image shows it going from dim to bright. The trick is to have a solid black circle as the base. Then place a sphere of any color above it with the diffusion turned all the way up. Adjust the brightness so that it animates from dim to bright. It also helps to add a tiny bit of specular to the sphere.

Download: LED

You will need the "Digital 7" font installed on your computer for the knob file to render properly. You can get it from the author here. Be sure to read the EULA.

Download: Numeric Display