Patents Assigned to Davis Controls Corporation
  • Patent number: 5221877
    Abstract: A control system for reducing power used by an inductive lighting installation, usually plural fluorescent lamps and a ballast, includes an A.C. power input circuit to the installation with a signal-actuated, normally-closed primary switch in series in the circuit; a signal-actuated normally-open secondary switch is in shunt with the load. The two switches are actuated substantially simultaneously in each half-cycle of the A.C. power input, once for power reduction for a time interval T1-T2 and once for harmonic distortion reduction for a time T3-T4 that encompasses each A.C. power zero-crossing time TX. The control system has N different timing programs for times T1-T2 and T3-T4, each program corresponding to one type of ballast. In each program times T3 and T4 are constant; only the times T1 and T2 are varied for a series of successively greater power reductions; the maximum power reduction may be as much as 30 to 40 percent.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: June 22, 1993
    Assignee: Davis Controls Corporation
    Inventor: Keith R. Falk
  • Patent number: 4973885
    Abstract: A lighting device using a fluorescent lamp adapted to be powered from a low voltage direct current source. Operation of the lamp is facilitated by the inclusion of a stabilized blocking oscillator circuit which provides high voltage alternating current for ignition and operation of the lamp as well as power for operating the filamentary heaters when included in the lamp. Operation at a very high frequency improves the efficiency of the fluorescent lamp, thus providing greater light output.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: November 27, 1990
    Assignee: Davis Controls Corporation
    Inventor: Richard G. Kerwin
  • Patent number: 4870340
    Abstract: The proposed invention is an energy saving load control device primarily intended for inductive loads (i.e., fluorescent lighting, motors, etc.) operating from an alternating current (AC) source. The proposed device switches the load voltage off at arbitrary positions in the sine wave and simultaneously provides a commutating path for any inductive current. By switching the load voltage on and off and providing a commutating current path reduced energy consumption is realized.
    Type: Grant
    Filed: February 3, 1989
    Date of Patent: September 26, 1989
    Assignee: Davis Controls Corporation
    Inventor: Kevin D. Kral