The whiteness and stability of a polyolefin have been found to be improved upon addition of a first phosphite, an arylalkyl diphosphite, and a second phosphite selected from a second arylalkyl disphosphite or a triarylphosphite. The stator is composed of a magnetic flux tube and a plurality of field windings. The second lighting unit comprises an LED light unit. A first current source is coupled to the first loop filter node and a second current source is coupled to the second loop filter node.