Abstract: Provided is a deuterium lamp power supply circuit capable of preventing the application of a high switch-to-ground voltage to a switch when applying a voltage between a positive electrode and negative electrode to light a deuterium lamp. The power supply circuit includes a capacitor for applying a voltage between the positive electrode and the negative electrode, with one terminal of the capacitor being connected to the positive electrode; a power supply, installed between the capacitor and the negative electrode, for charging the capacitor; and a two-terminal switch connected in parallel to the power supply. The switch is placed at a location close to ground, and thus a high switch-to-ground voltage is not applied to the switch.

Abstract: The invention relates to a method for producing a commutator ring (10) for a commutator of an electrical machine, in which the laminas (12) of the commutator ring and fastening means (18) are formed out of a band material (27), and a selectable number of laminas (12) are then closed to form the commutator ring. The fastening means are produced with a special tool (35) in the form of dovetail grooves (22) by means of a so-called furrowing operation, which is done simultaneously from both face ends of the laminas (12).

Abstract: An energy-saving instant-start series-sequence fluorescent lamp system includes power-reducing capacitor means connected in series circuit arrangement with one or both lamps in a two-lamp system. A protective device is connected in circuit with a first lamp of the system so that in the event the second lamp fails to operate and causes a high current to flow through the first lamp, the protective device reacts to prevent the system from being damaged. A lamp incorporating the power-reducing capacitor and protective device is also disclosed.