Patent ID: 7239092

Claim:
A lighting system, comprising: a first ballast input stage ( 21 ) and a second ballast input stage ( 21 ), said first ballast input stage ( 21 ) operable to oscillate at a first oscillating frequency (f 1 ) and said second ballast input stage ( 21 ) operable to oscillate at a second oscillating frequency (f 2 ), the first oscillating frequency (f 1 ) and the second oscillating frequency (f 1 ) being dissimilar upon an initial powering of said first ballast input stage ( 21 ) and said second ballast input stage ( 21 ); a first ballast output stage ( 23 ) and a second ballast output stage ( 23 ) connected in series, said first ballast output stage ( 23 ) in electrical communication with said first ballast stage ( 21 ) and said second ballast output stage ( 23 ) in electrical communication with said second ballast stage ( 21 ) to establish an open circuit voltage across said first ballast output stage ( 23 ) and said second ballast output stage ( 23 ) in response to an absence of a loading of a plurality of lamps ( 10 ) across said first ballast output stage ( 23 ) and said second ballast output stage ( 23 ); and means for, subsequent to the initial powering of said first ballast input stage ( 21 ) and said second ballast input stage ( 21 ) and in response to the absence of the loading of the plurality of lamps ( 10 ) across said first ballast output stage ( 23 ) and said second ballast output stage ( 23 ), impeding any parasitic loading across said first ballast output stage ( 23 ) and said second ballast output stage ( 23 ) from phase locking the first oscillating frequency (f 1 ) and the second oscillating frequency (f 2 ).