A process for controlling a brightness of a lamp includes, in at least one aspect, detecting input to control a brightness of a fluorescent lamp operated by a driving signal, and in response to detecting the input, modifying the driving signal to control the brightness of the fluorescent lamp, wherein modifying the driving signal comprises alternately applying a first duty cycle and a second duty cycle to the driving signal, wherein the first duty cycle and the second duty cycle are substantially complementary to each other.