Patent ID: 8350494

Claim:
A fluorescent lighting system including at least one fluorescent lamp, a dimming ballast for powering the lamp, a user operated switch for selectively connecting the ballast to a source of electrical power, and a ballast controller, the dimming ballast having powered dimming control signal input terminals for receiving a dimming control command from the ballast controller and being operative to adjust the power applied to the lamp from the power source through the switch and a connecting power carrying conductor, the ballast controller comprising: a sensor for sensing electrical power present on said connecting conductor and for developing a corresponding sense signal; a microprocessor responsive to said sense signal and operative to detect interruptions of power present on said connecting conductor caused by at least one change of state of the electrical power present on said connecting conductor, and to develop a corresponding control signal; and circuit means connected to the control signal input terminals of the ballast, and operative to extract power therefrom to power said microprocessor, said circuit means being further operative to use said control signal to command the ballast to change the power applied to the lamp.