Abstract: An induction RF fluorescent lamp configuration provides reduced EMI, including a lamp envelope with a re-entrant cavity both covered on the partial vacuum side with phosphor and filled with a working gas mixture, a tubular ferromagnetic core on the non-vacuum side said re-entrant cavity wound directly on the said core with two windings having different numbers of turns, a first active winding having one end connected to an RF ballast and the other end connected to local ground, and a second passive winding having one end grounded and the other end free.

Abstract: An electrodeless discharge lamp device comprises an induction coil, a pair of cores 1a, 1b, and thermal conductor 2. The cores 1a, 1b are configured to generate a high-frequency electromagnetic field for exciting a discharge gas with receiving a high frequency electric power. Each of the cores is arranged to give an overall circumference around which the induction coil is wound. The thermal conductor is formed into an approximately cylindrical shape and inserted into the space so as to be thermally coupled with the cores for radiating heat generated at the cores. The core has its inside face at least center portion of which is spaced radially from the thermal conductor by a predetermined distance.

Abstract: A simple and less expensive high voltage pulse generating circuit including a low voltage direct current voltage source having one output terminal connected to another output terminal via a series circuit of a first switch with a low withstand voltage, an inductance storing inductive energy and a second switch with a high withstand voltage, and a branch circuit including a free-wheel diode connected between the other output terminal of the direct current voltage source and a common connection point between the first switch and the inductance. After storing inductive energy in the inductance by turning “on” the first and second switches, these first and second switches are turn “off” to commutate the energy stored in the inductance into a capacitive load connected across the second switch to charge the load abruptly and generate a high voltage pulse having a very narrow width without using a complicated and expensive magnetic compression circuit.

Abstract: A simulated load circuit for measuring the impedance of the arc discharge of an electrodeless discharge lamp of the type having an arc tube and an excitation coil for exciting the arc discharge in an ionizable fill contained therein includes: a secondary coil spaced apart from the excitation coil by a distance which is varied in order to vary the coupling coefficient between the secondary coil and the excitation coil; a fixed load resistance coupled to the secondary coil; and a variable matching network coupled in series or parallel with the load resistance, the impedance of the matching network being varied in order to vary the ratio of reactance to resistance of the load circuit. The distance between the secondary coil and the excitation coil is varied, and the impedance of the matching network is varied, until the input impedance of the load circuit is substantially equivalent to the operating impedance of the lamp.