Patents Represented by Attorney, Agent or Law Firm Seed IP Law Group, PLL
  • Patent number: 6249099
    Abstract: A method drives a three-phase motor having first, second, and third coils. The method electrically connects the first coil to a first voltage reference and the second coil to a second voltage reference while leaving the other coil floating during a first driving phase. During a second driving phase, the first coil is electrically connected to the first voltage reference and the third coil is electrically connected to the second voltage reference while the second coil is left floating. During a transition phase that immediately follows the fast driving phase and immediately precedes the second driving phase, the second coil is electrically connected alternately to the first and second voltage references. By alternately connecting the second coil to the first second voltage references and during the transition phase, the method causes the current through the second coil to reduce to zero at a slower rate than prior methods.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: June 19, 2001
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Maurizio Nessi, Ezio Galbiati, Pierandrea Savo, Giorgio Sciacca, Luca Schillaci