Patents by Inventor Nagatoshi Kadota

Nagatoshi Kadota 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: 5365397
    Abstract: A driving signal is supplied to the gate of an IGBT through a first switching element. The gate of the IGBT is grounded via a resistor and a second switching element. An output (short circuit detection signal) of an AND gate, to which the driving signal and an output signal of the IGBT are supplied, is supplied to the first switching element via a first delay circuit and supplied to the second switching element via a second delay circuit. The second delay time is larger than the first delay time. In the normal operation, the driving signal is set to an "L" level to instantaneously turn off the IGBT. The output of the AND gate is kept at the "H" level for the turn-off time and is returned to the "L" level after the turn-off operation is completed. The first switching element is turned off when the first delay time has passed after the level of the driving signal is changed. At this time, the IGBT is already turned off.
    Type: Grant
    Filed: April 27, 1993
    Date of Patent: November 15, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Nagatoshi Kadota