Patents by Inventor Kazunori Oyabe
Kazunori Oyabe 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).
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Patent number: 7773400Abstract: A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.Type: GrantFiled: August 27, 2007Date of Patent: August 10, 2010Assignee: Fuji Electric Systems Co., Ltd.Inventors: Akira Nakamori, Kazunori Oyabe, Manabu Watanabe
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Patent number: 7592853Abstract: A drive circuit for an insulated gate device includes a constant current source generating a constant current, and a switching circuit, wherein a gate of the insulated gate device is connected to a power supply potential side via the constant current source at the time of turn-on and to a ground potential side at the time of turn-off. Whereby a drive circuit for the insulated gate device can be reduced loss at the time of turn-on and reduced temperature dependency of noise.Type: GrantFiled: August 30, 2007Date of Patent: September 22, 2009Assignee: Fuji Electric Device Technology Co., LtdInventors: Akira Nakamori, Kazunori Oyabe
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Patent number: 7507023Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.Type: GrantFiled: April 14, 2006Date of Patent: March 24, 2009Assignee: Fuji Electric Device Technology Co., Ltd.Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
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Publication number: 20080094111Abstract: A drive circuit for an insulated gate device includes a constant current source generating a constant current, and a switching circuit, wherein a gate of the insulated gate device is connected to a power supply potential side via the constant current source at the time of turn-on and to a ground potential side at the time of turn-off. Whereby a drive circuit for the insulated gate device can be reduced loss at the time of turn-on and reduced temperature dependency of noise.Type: ApplicationFiled: August 30, 2007Publication date: April 24, 2008Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Akira NAKAMORI, Kazunori OYABE
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Publication number: 20080094121Abstract: A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.Type: ApplicationFiled: August 27, 2007Publication date: April 24, 2008Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventors: Akira NAKAMORI, Kazunori OYABE, Manabu WATANABE
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Publication number: 20060255361Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.Type: ApplicationFiled: April 14, 2006Publication date: November 16, 2006Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
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Patent number: 6934139Abstract: An intelligent power module includes semiconductor switching devices, drive circuits, a variety of detecting circuits and warning circuits for detecting a fatal abnormal condition and a precursory abnormal condition thereof in the switching devices, the drive circuits and so forth, abnormal condition detecting logic devices and drive circuits for protecting the switching devices when the detecting circuits and the warning circuits detect the abnormal condition, and control circuits and a transmission circuit for outputting a signal based on detection of the abnormal condition. The transmission circuit has an output terminal for outputting alarm signals when the fatal abnormal condition is detected, and an output terminal for outputting abnormality factor discrimination signals indicating abnormality factors contributing to the fatal abnormal condition and the precursory abnormal condition.Type: GrantFiled: May 1, 2001Date of Patent: August 23, 2005Assignee: Fuji Electric Device Technology Co., Ltd.Inventors: Naoki Kumagai, Kazunori Oyabe, Naotaka Matsuda
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Patent number: 6404659Abstract: When an alarm signal provided by an inverter forming an I/F provided for the circuit on the high side enters an active (L) state, the output of the inverter indicates an H state. Then, the N-channel MOS type FET enters an ON state. At this time, the N-channel MOS type FET is connected to the I/F on the low side using a diode. Therefore, when the diode enters a normal bias state, that is, when the reference potential of the above mentioned two I/Fs approach each other, an electric current flows from the power supply to the N-channel MOS type FET through a resistor. As a result, by a voltage drop, a voltage arises in the resistor, and the output of the inverter indicates the H state. Since the output of the inverter is connected to a control unit, the control unit performs a process according to an alarm signal.Type: GrantFiled: October 19, 2000Date of Patent: June 11, 2002Assignee: Fuji Electric Co., Ltd.Inventor: Kazunori Oyabe
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Publication number: 20020039269Abstract: An intelligent power module includes semiconductor switching devices, drive circuits, a variety of detecting circuits and warning circuits for detecting a fatal abnormal condition and a precursory abnormal condition thereof in the switching devices, the drive circuits and so forth, abnormal condition detecting logic devices and drive circuits for protecting the switching devices when the detecting circuits and the warning circuits detect the abnormal condition, and control circuits and a transmission circuit for outputting a signal based on detection of the abnormal condition. The transmission circuit has an output terminal for outputting alarm signals when the fatal abnormal condition is detected, and an output terminal for outputting abnormality factor discrimination signals indicating abnormality factors contributing to the fatal abnormal condition and the precursory abnormal condition.Type: ApplicationFiled: May 1, 2001Publication date: April 4, 2002Inventors: Naoki Kumagai, Kazunori Oyabe
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Patent number: 5811996Abstract: A gate drive circuit device for a voltage-driven semiconductor element reduces the time to dissipate inductively stored electromagnetic energy and reduces current consumption by using cyclically charged capacitative storage to produce a control signal that is about twice the supply voltage. This permits full-ON dissipation of the stored energy after the circuit cuts off power to the inductive element. In one embodiment, the dissipation is chiefly in a voltage-regulator diode connected to limit the voltage appearing across a transistor. In another embodiment, a voltage regulator diode permits a transistor to operate in the full-on condition, while limiting the voltage across it to a value below its withstand voltage, whereby a maximum power dissipation current flows in the transistor. In a further embodiment a gate drive signal generator eliminates a voltage regulator diode from the conventional gate drive circuit device.Type: GrantFiled: December 17, 1996Date of Patent: September 22, 1998Assignee: Fuji Electric Co., Ltd.Inventors: Kazunori Oyabe, Tatsuhiko Fujihira, Kazuhiko Yoshida, Yukio Yano
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Patent number: 5621601Abstract: The disclosed invention is designed to prevent the oscillation which often occurs in an over-current protection apparatus for an insulated gate controlled transistor. The apparatus improves the response in current detection, to prevent oscillation, and improves protection speed against over-current.Type: GrantFiled: September 28, 1994Date of Patent: April 15, 1997Assignee: Fuji Electric Co., Ltd.Inventors: Tatsuhiko Fujihira, Shin Kiuchi, Kazuhiko Yoshida, Yukio Yano, Kazunori Oyabe, Shoichi Furuhata, Tetsuhiro Morimoto
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Patent number: 5587655Abstract: A constant current circuit of the invention supplies a constant current to a load. The constant current circuit is formed of a current source device for providing an input current having a predetermined value with temperature dependence, a voltage divider device connected to the current source device, and an output transistor device. A reference transistor device or an adjusting transistor device is attached to the current source device. In case the reference transistor device is used, the voltage divider device divides a reference voltage of the reference transistor device to thereby generate a control voltage. In case the adjusting transistor device is used, an adjusting voltage from the voltage divider device is supplied to the adjusting transistor device to generate a control voltage. The output transistor device is connected to the load for controlling an output current supplied to the load in response to the control voltage.Type: GrantFiled: August 11, 1995Date of Patent: December 24, 1996Assignee: Fuji Electric Co., Ltd.Inventors: Kazunori Oyabe, Kazuhiko Yoshida, Tatsuhiko Fujihira