Abstract: A starting system for an electrodeless metal halide discharge lamp includes a parallel tuned LC network including a fixed capacitor and a starting inductor, and also including a conductive plate for application to the starting inductor for detuning the network once the lamp has started. The detuned starting network produces insufficient voltage to maintain the starting plasma while the lamp is running. The conductive plate is removed from the starting inductor by a solenoid or other mechanical actuator during lamp starting.

Abstract: A CFL ballast includes complementary-type switching devices connected in series with their gates connected together at a control node. The switching devices supply a resonant tank circuit which is tuned to a frequency near, but slightly lower than, the resonant frequency of a resonant control circuit. As a result, the tank circuit restarts oscillations immediately following each zero crossing of the bus voltage. Such rapid restarts avoid undesirable flickering while maintaining the operational advantages and high efficacy of the CFL ballast.

Abstract: A fluorescent lamp ballast utilizes a single a transformer for providing both tank inductance and current mode feedback to the ballast driver circuitry. The transformer has an "EE" core with inductor windings on the center legs and gate windings on one of the outer legs. The center leg is gapped to avoid magnetic core saturation and to adjust inductance to a desired value. Coupling can be adjusted further by gapping one or the other of the outer legs.

Abstract: A current limiting system for a circuit limits current flow through the system. The current limiting system comprises at least one main switch comprising first and second main switch contacts and a contactor connecting the first and second main switch contacts; at least one current limiting device and at least one solid-state switch, which are mechanically unconnected to the main switch, and the at least one current limiting device and least one solid-state switch are arranged in series on a series side of the circuit; the at least one main switch is on a main switch side of the circuit arranged in parallel with the series side; a control that senses a predetermined condition of the circuit, and operably connected with the at least one solid state switch to open and it. Under normal operating conditions, most current flows through the at least one main switch side. When the predetermined condition causes the main switch to open, and the resistance increases in a main switch side.

Abstract: An electrodeless fluorescent lamp includes a feedthrough structure extending from the exterior to the interior of the lamp which is constructed of a suitable material, e.g., platinum or a combination of platinum and rhodium, for directly connecting an interior EMI shield to ground. The feedthrough is also suitable for supporting an amalgam flag.