Patents by Inventor Yevgeny Shafir

Yevgeny Shafir 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).

  • Asymmetrical AC trigger simulation
    Patent number: 5854519
    Abstract: The present invention teaches a dimmer which incorporates an alternating current (AC) trigger which exhibits asymmetrical electrical characteristics. This eliminates the undesirable snap on hysteresis effect associated with conventional dimmers utilizing symmetrical AC triggers such as diacs and silicon bilateral switches (SBS). One embodiment of the present invention utilizes a zener diode to create the asymmetry. During one polarity of the AC source, the breakover voltage of the trigger is increased, forcing the trigger to breakover at a time later in the AC cycle than it would otherwise have with a symmetric trigger. This compensates for charge dumping of the phase control capacitor into the gate of the triac which would otherwise cause the snap on hysteresis effect.
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: December 29, 1998
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Bernard J. Gershen, Alfred J. Lombardi, Edward J. Krajci, Yevgeny Shafir
  • Asymmetrical AC trigger simulation
    Patent number: 5619081
    Abstract: The present invention teaches a dimmer which incorporates an alternating current (AC) trigger which exhibits asymmetrical electrical characteristics. This eliminates the undesirable snap on hysteresis effect associated with conventional dimmers utilizing symmetrical AC triggers such as diacs and silicon bilateral switches (SBS). One embodiment of the present invention utilizes a zener diode to create the asymmetry. During one polarity of the AC source, the breakover voltage of the trigger is increased, forcing the trigger to breakover at a time later in the AC cycle than it would otherwise have with a symmetric trigger. This compensates for charge dumping of the phase control capacitor into the gate of the triac which would otherwise cause the snap on hysteresis effect.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: April 8, 1997
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Bernard J. Gershen, Alfred J. Lombardi, Edward J. Krajci, Yevgeny Shafir