Abstract: An electronic ballast for supplying operating power to a high-intensity discharge (HID) lamp. The ballast includes a full-wave rectifier connected to an AC power line to produce an unregulated pulsating DC output which is applied to a power factor correction (PFC) circuit. The PFC circuit includes a first semiconductor electronic switch whose activation is controlled to bring the input current and voltage in time-phase with one another, thereby imparting a high power factor rating to the ballast. The pulsating DC output of the PFC circuit is applied to a storage capacitor circuit which is charged thereby, the capacitor circuit including a second electronic switch whose activation is controlled to discharge the capacitor so as to cause the capacitor circuit to yield in its output, a regulated DC which is fed to a power control (PC) circuit. The PC circuit includes a third electronic switch whose activation is controlled to maintain the wattage of power supplied to the HID lamp at the rated wattage of the lamp.

Abstract: A track lighting hybrid illumination system comprising a power supply circuit (11, 41, 22) having an input for connecting to a voltage source (12, 42) of low frequency for providing an output voltage with altered electrical characteristics, and a pair of conductors (19, 23, 43, 48) coupled to an output of the power supply circuit. A first lamp (29, 25, 31) is coupled to the conductors via a second power supply circuit (28, 26, 34), and at least one further lamp (29, 24, 25, 31) with electrical power requirements of a different characteristic to the first lamp coupled to the conductors.

Abstract: An electronic ballast for supplying operating power to a high-intensity discharge (HID) lamp. The ballast includes a full-wave rectifier connected to an AC power line to produce an unregulated pulsating DC output which is applied to a power factor correction (PFC) circuit. The PFC circuit includes a first semiconductor electronic switch whose activation is controlled to bring the input current and voltage in time-phase with one another, thereby imparting a high power factor raring to the ballast. The pulsating DC output of the PFC circuit is applied to a storage capacitor circuit which is charged thereby, the capacitor circuit including a second electronic switch whose activation is controlled to discharge the capacitor so as to cause the capacitor circuit to yield in its output, a regulated DC which is fed to a power control (PC) circuit. The PC circuit includes a third electronic switch whose activation is controlled to maintain the wattage of power supplied to the HID lamp at the rated wattage of the lamp.

Abstract: A track lighting hybrid illumination system comprising a power supply circuit having an input for connecting to a voltage source of low frequency for providing an output voltage with altered electrical characteristics, and a pair of conductors coupled to an output of the power supply circuit. A first lamp is coupled to the conductors via a second power supply circuit, and at least one further lamp with electrical power requirements of a different characteristic to the first lamp coupled to the conductors.

Abstract: An electronic transformer for lighting includes a rectifier coupled to an inverter an output transformer (T1, T10) and a drive transformer (T2, T11). A protection mechanism (VR1, VR2) is responsively coupled to a winding of the output transformer and to a winding of the drive transformer such that the voltage across each of the windings are approximately equal and opposite during normal operation but differ substantially during a short-circuit.