Abstract: Protection against potentially destructive arcs which may occur within a gas-filled incandescent lamp when the energized filament fails is achieved by partly embedding separate inner and outer lead-in conductors in an hermetic seal that is formed on one end of the lamp envelope and electrically connecting the conductors by a short uncoiled fuse element that is located entirely within the confines of the envelope. In the case of a halogen-cycle type lamp having a press-sealed envelope, the fuse element comprises a tungsten wire which is preferably from about 1% to 10% larger in diameter than the filament wire and is fastened to the inner lead-in conductor at a point located inside the envelope, and to the outer lead-in conductor at a point which is located within the press seal. Reliable arc-suppression is thus achieved in a practical inexpensive manner with rugged components that are readily made integral parts of the finished lamp.

Abstract: A strobe light circuit adapted for use with a battery including a transformer and oscillator connected to charge a storage capacitor disposed across a discharge tube. A fourth winding in the transformer provides the trigger signal to the tube. By this arrangement the trigger pulse becomes progressively higher with increasing charge on the storage capacitor utilizing to best advantage the parameter relationships of the tube.