Patent ID: 8102125

Claim:
Apparatus for controlling the delivery of electrical power to fluorescent light fixtures, said electrical power having a phase which has a substantially sinusoidal waveform which has repetitive zero crossings separated from one another by a nominal time period T, said apparatus comprising: (a) a plurality of controllers; and (b) a plurality of electronic switches; wherein during use of the apparatus: (i) each electronic switch is in series with at least one fluorescent light fixture; (ii) each electronic switch is operatively connected to a controller that sends an electronic signal to the switch to cause the switch to transition between non-conducting and conducting states, said electronic signal being sent during each half cycle of the phase's waveform at a switching time t(j) measured from the waveform's zero crossing, where j indicates the controller sending the electronic signal and where 0≦t(j)≦T for each j; and (iii) for at least two of the controllers j 1 ,j 2 , on at least a statistical basis, t(j 1 )≠t(j 2 ).