Patents by Inventor Roy D. Hoffer

Roy D. Hoffer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5146147
    Abstract: A motor drive system for driving a single-phase PSC motor, in which the two motor windings are conductively isolated from each other, from a two phase power source. In one embodiment, the PSC motor is supplied from a two phase inverter circuit. The PSC motor is also connectable through a four-pole double-throw switch to either a single phase source including a run capacitor or the two phase inverter circuit.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: September 8, 1992
    Assignee: York International Corporation
    Inventors: Frank E. Wills, Harold R. Schnetzka, II, Roy D. Hoffer
  • Patent number: 5136216
    Abstract: A motor drive system for driving a conventional single phase PSC motor from a two-phase power source. In one embodiment, the PSC motor is supplied from a three-phase inverter that is controlled to generate two-phase power. In another embodiment, the PSC motor is connectable through a double-pole double-throw switch to either a single phase source including a run capacitor or a two-phase inverter source.
    Type: Grant
    Filed: February 15, 1991
    Date of Patent: August 4, 1992
    Assignee: York International Corporation
    Inventors: Frank E. Wills, Harold R. Schnetzka, II, Roy D. Hoffer
  • Patent number: 4798998
    Abstract: A limited power, gaseous discharge lighting system, particularly suitable for use with suspended ceilings and for safe installation without shock and/or fire hazard and for rearrangement by non-electricians without special tools or experience, the light output of which is controlled by an electronic controller which responds to the ambient light available. The system uses non-armored flexible cables to supply individual relocatable gaseous discharge lighting fixtures and dimmers, and the cables are individually plugged into receptacles which furnish power strictly limited to permit the safe use of the cables, plugs and receptacles. High frequency operation permits efficient operation with rated light output and an electronic controller furnishes additional versatility and economy.
    Type: Grant
    Filed: December 15, 1986
    Date of Patent: January 17, 1989
    Assignee: Armstrong World Industries, Inc.
    Inventors: J. Marshall Hemphill, Roy D. Hoffer
  • Patent number: 4697122
    Abstract: A room lighting control system which controls the electrical power supplied to the artificial lighting in an area based on the ambient light available. A photocell controlled digital lamp dimming circuit with particularly high stability for time and temperature is combined with a slow response time to avoid short term adjustments. A digital counter is used to determine a large number of steps over the adjustment range and the driving clock operates at a very low frequency, so that changes in light level take a relatively long time, and it takes an exceptionally long time to span the entire adjustment range.
    Type: Grant
    Filed: August 1, 1986
    Date of Patent: September 29, 1987
    Assignee: Armstrong World Industries, Inc.
    Inventor: Roy D. Hoffer