American Atomics Corporation

Monolith Technologies Corporation

George J Radda

Thomas E Caffarella

David J Watts

Harry H Dooley, Jr

Kun Lin

A digital-to-analog converter (DAC) for generating a pulse width modulated (PWM) signal. A dual-DAC implementation includes a read-only memory (ROM) containing a plurality of addressable output signals, respective shift left and shift right registers configured to simultaneously receive an output signal from the ROM, and respective first and second DACs are configured to receive the left shifted output and right shifted output, respectively, from the shift left and shift right registers. Both DAC outputs are applied to an analog summer which generates an output signal indicative of the sum of the outputs from the two DACs.

Methods and apparatus for the quantization and analog conversion of

A glass tube, laser sealed at its ends, has an elongated cross section, two wide side faces, and two narrow side faces. The tube contains a radioactive gas and a transducer, such as a phosphor compound, responsive to the gas. The narrow side faces of the tube are thicker than the wide side faces. Preferably, the wide side faces are outwardly bowed and the narrow side faces are semicylindrical to form an oval cross section. The ratio of the total glass thickness of the wide side faces to the spacing between the wide side faces is approximately 0.7.

Miniature radioactive light source and method of its manufacture

A focused laser beam is directed at the wide side surface of a long, sealed, gas-filled, glass tube having a longitudinal axis and an elongated cross section. Repeated relative back and forth movement is introduced between the laser beam and the wide surface of the tube transverse to its longitudinal axis to heat and soften the tube along a cut line until the tube divides to form ends and collapses to seal the divided ends. Preferably, the tube is held in fixed position, while the laser beam is scanned across both of its wide side surfaces. The intensity and/or the velocity of the laser beam are modulated. After the tube divides along the cut line, the divided ends are annealed while still in the tube holder by defocusing the laser beam. In one embodiment, plural simultaneous cuts are made by directing a plurality of focused laser beams onto the tube at spaced intervals along its longitudinal axis.

Method and apparatus for subdividing a gas filled glass tube with a laser

An elongated glass tube light source containing a luminophor and a radioactive gas is subdivided into a plurality of light sources by a plurality of laser beams directed at the tube at spaced points along the length of the tube. The laser beams are scanned back and forth transversely of the length of the tube to heat the tube and fuse the glass at each of the spaced points. The tube is rigidly supported on either side of each of the points to hold the tube stationary during the cutting operation. A single source of a continuous laser beam is divided into a plurality of beams by beam splitters. Mirrors direct the beams to the spaced points along the length of the tube and mirrors are oscillated to provide the desired scanning motion of the beams across the width of the tube.

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Tucson, AZ, United States of America

George J Radda