Abstract: A fluorescent lighting device includes an arc tube, an exhaust tube extending from the arc tube, and an amalgam. A resistive heater is located adjacent to at least one of the arc tube and the exhaust tube. A power supply circuit is operatively coupled with the resistive heater. When the fluorescent lighting device is switched from an OFF state to an ON state, the power supply circuit temporarily energizes the resistive heater, thereby heating the at least one of the arc tube and the exhaust tube while the resistive heater is energized, and automatically de-energizing the resistive heater after said heating.

Abstract: A fluorescent lighting device includes a ballast and a tube. An amalgam is located within the tube. A resistive heater is operatively coupled with the ballast, to receive electrical power from the ballast while the fluorescent lighting device is in an OFF state. The resistive heater is mounted near the amalgam to transfer heat to the amalgam while the fluorescent lighting device is in the OFF state.

Abstract: A ballast or drive circuit is located between a dimmer switch and at least one light source or lamp. The ballast includes an electromagnetic interference (EMI) filter operatively disposed between the dimmer switch and the at least one lamp. The EMI filter includes an inductor. A low pass filter, preferably an inductor, is serially connected to the inductor of the EMI filter and situated between the dimmer switch and EMI filter for addressing currency ringing, reducing high current peaks, and decreasing flickering that would otherwise result with multiple light sources when the lamp is turned on.

Abstract: Ballasts and LED drivers are presented for powering at least one light source, in which a shunt circuit provides a high impedance to allow operation of the light source when the AC input power exceeds a power threshold value, and provides a low impedance when the AC input power is below the power threshold value to prevent an output power stage from providing power to the light source.