31
Scott H Rumbaugh, R Thomas Hawkins II: Cavity thickness compensated etalon filter. Apeldyn Corporation, William A Birdwell & Associates, January 20, 1998: US05710655 (23 worldwide citation)

A cavity thickness compensated etalon filter. A tuning medium is placed in a Fabry-Perot etalon cavity. The index of refraction of the tuning medium varies as a function of voltage applied across the medium. The etalon is formed of two generally flat substrates disposed substantially parallel to one ...


32
Paul Wells: Current sensor assembly and method. IIMorrow, William A Birdwell & Associates, December 15, 1992: US05172052 (23 worldwide citation)

An electric current sensor assembly and method. A housing containing a Hall effect device is provided with at least one curved, concave surface for placement against a wire carrying a current. The housing is attached to the wire by a strap that fastens around the housing and the wire and fits in gro ...


33
Scott H Rumbaugh: Liquid crystal cell retarder with driving beyond retardance value and two cells for high speed. William A Birdwell & Associates, September 13, 1994: US05347382 (22 worldwide citation)

A fast response liquid crystal optical retarder system. A liquid crystal retarder system employs one or more liquid crystal cells and corresponding drive circuits. The drive circuits provide to the cell a rectangular wave ac voltage signal whose RMS voltage is controlled. To switch from one retardan ...


34
Ronald Hager, Michael Payne: Swimming pool cover elevation device. William A Birdwell & Associates, November 9, 1993: US05259077 (21 worldwide citation)

A swimming pool cover elevation device. A substantially rigid pole is provided with a plurality of ropes attached at one end to the bottom thereof and having hooks disposed at the other end thereof for attachment to structure at or outside the rim of a swimming pool. A cup is provided to be affixed ...


35
Richard C Cabot: Method and apparatus for fast response and distortion measurement. Audio Precision, William A Birdwell & Associates, May 5, 1998: US05748001 (21 worldwide citation)

A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input o ...


36
Daniel G Knierim: F.sub.T doubler amplifier. Tektronix, William A Birdwell, Boulden G Griffith, March 21, 1995: US05399988 (21 worldwide citation)

A transistor amplifier having a main amplifier exhibiting a substantially doubled f.sub.T characteristic and having error cancellation circuitry, wherein the standing current of the error cancellation circuitry is reused in powering the main amplifier. The main amplifier comprises an outer different ...


37
Lawrence D Braddock: Method and apparatus for carrying and supporting a portable bench top saw. Trojan Manufacturing, William A Birdwell & Associates, July 14, 1998: US05778953 (20 worldwide citation)

A method and apparatus for carrying and supporting a portable bench top saw wherein the saw has a body housing a saw blade, the body being generally adapted for four-corner screw attachment downwardly into a table, the apparatus comprising a carrying frame having a transversely adjustable member for ...


38
Gerald A Hollenbach, Patrick McLean: Lamp. Ranger Enterprises, William A Birdwell & Associates, April 23, 1996: US05510970 (19 worldwide citation)

A lamp employs a halogen light fixture which includes a fitting threadably engaging a conduit entry "L". A standard electrical cord is provided to the entry "L" and connects inside the entry "L" with the pigtail wiring of the light fixture. The entry "L" also receives a spring clamp, securely mounte ...


39
Gregory A Mosbrucker: Multi-purpose square. William A Birdwell & Associates, October 19, 1993: US05253426 (19 worldwide citation)

A layout square having a handle and two legs that extend away from the handle in the same direction, both perpendicular to the handle. The handle includes a level to allow angular measurements against level, as well as for plumbing and leveling purposes. The legs correspond in width to standard dime ...


40
Gordon Melby: Height adjustable bed and storage unit for small living quarters and method of use thereof. William A Birdwell & Associates, December 1, 1998: US05842586 (19 worldwide citation)

A height adjustable bed and storage unit for small living quarters in which substantially vertical posts are fixedly attached to the floor and ceiling of the living quarters. Each post includes a mating structure for mating to a cross-member at a plurality of vertical positions, the cross-member bei ...