Abstract: A discharge tube is driven by a multiple-phase drive circuit, and includes a discharge container having an internal discharge space and multiple electrodes that are secured to the discharge container and correspond to each phase of the multiple-phase drive circuit. The tips of the multiple electrodes protrude into the discharge space, and are oriented toward a predetermined single point of union. All of the electrodes located on one side of a virtual plane that includes the predetermined point of union. Furthermore, a discharge lamp having the discharge tube includes three electrodes, and electric discharge can take place between each pair of electrodes. When the discharge lamp is driven at maximum output, voltage is impressed to the three electrode terminals such that at least one of the voltages VeAB, VeBC, VeCA between the three electrode terminals will be in a discharge period.

Abstract: A photo-curing light system in which a modulation of the light intensity or output is controlled via an analogue control voltage to the control line output of the lamp power supply. The control signal results in the lamp current being reduced from its maximum value to a lower value on a continuous and repeated basis thereby modulating the light and reducing the heating value to surrounding material such as tooth structure during the curing process.