A starting device for discharge lamps including an ignitor and a ferromagnetic ballast, composed of a toroidal core, equipped with at least an air gap, and an electric coil wound around the toroidal core.

A system provides post-match control of microwaves in a radial waveguide. The system includes the radial waveguide, and a signal generator that provides first and second microwave signals that have a common frequency. The signal generator adjusts a phase offset between the first and second signals in response to a correction signal. The system also includes first and second electronics sets, each of which amplifies a respective one of the first and second microwave signals. The system transmits the amplified, first and second microwave signals into the radial waveguide, and matches an impedance of the amplified microwave signals to an impedance presented by the waveguide. The system also includes at least two monitoring antennas disposed within the waveguide. A signal controller receives analog signals from the monitoring antennas, determines the digital correction signal based at least on the analog signals, and transmits the correction signal to the signal generator.

The invention relates to a driving circuit comprising a first bridge circuit, a second bridge circuit, a first protection device and a second protection device. The first bridge circuit comprising a first positive input terminal, a first negative input terminal, a first positive output terminal and a first negative output terminal is coupled to an AC voltage source to output a first voltage. The second bridge circuit comprising a second positive input terminal, a second negative input terminal, a second positive output terminal and a second negative output terminal is coupled to the AC voltage source to output a second voltage. The second and the first negative output terminals are both coupled to the ground potential. The first protection device is coupled between the second positive input terminal and the AC voltage source. The second protection device is coupled between the second negative input terminal and the AC voltage source.

A ballast transformer and system using the ballast transformer to couple power to a plasma load. The ballast transformer has a magnetic core, a first primary winding on a primary side of the magnetic core, a secondary winding on a secondary side of the magnetic core, and a second primary winding connected in series with the first primary winding and wound in proximity to the secondary winding on the secondary side of the magnetic core. The first primary winding is connectable to the AC power source, and the secondary winding is connectable to the plasma load via a coaxial cable.

A ballast transformer and system using the ballast transformer to couple power to a plasma load. The ballast transformer has a magnetic core, a first primary winding on a primary side of the magnetic core, a secondary winding on a secondary side of the magnetic core, and a second primary winding connected in series with the first primary winding and wound in proximity to the secondary winding on the secondary side of the magnetic core. The first primary winding is connectable to the AC power source, and the secondary winding is connectable to the plasma load via a coaxial cable.