Patents Assigned to Flinn & Dreffein Engineering Company
  • Power control circuit
    Patent number: 4078168
    Abstract: Electric process heating control includes a combination of (1) pyrometric temperature controller providing a DC control signal wherein the ratio of "on" time to "off" time is proportional to the deviation of temperature from set-point value and to the duration of such deviation, (2) phase-angle-fired power controller, and (3) current limiter for altering the phase angle firing of the power controller.
    Type: Grant
    Filed: September 17, 1976
    Date of Patent: March 7, 1978
    Assignee: Flinn & Dreffein Engineering Company
    Inventor: Richard A. Kelly