Abstract:
The invention provides a drive control device that comprises: inverters that are connected to a motor; a variable resistive element that is connected between the motor and each of the inverters; a current/voltage detection device connected between the motor and each of the inverters; and a controller that, when detecting a fault of an inverter that drives the motor based on a detection signal from the current/voltage detection device, gradually increases a resistance value of a variable resistive element provided between the faulty inverter and the motor at a velocity of a resistance variation such that a surge voltage has a voltage value for which the variable resistive element and the motor are not damaged, and executes drive control of the motor by a normal inverter other than the faulty inverter.
Abstract:
A semiconductor device capable of rapidly and accurately sensing the information regarding the temperature of a semiconductor transistor contained therein. A MOSFET includes a plurality of cells, and includes a main cell group including a cell for supplying a current to a load among the plurality of cells, and a sense cell group including a cell for sensing temperature information regarding the temperature of the MOSFET thereamong. The main cell group and the sense cell group have different temperature characteristics showing changes in electrical characteristics to changes in temperature. A temperature sensing circuit senses the temperature of the MOSFET based on, for example, a value of a main current flowing through the main cell group and a value of a sense current flowing through the sense cell group.
Abstract:
A power semiconductor module includes an element pair formed by connecting, in anti-parallel to each other, an IGBT and an FWD group in which an FWD, a voltage drop characteristic of which during conduction has a negative temperature coefficient, and an FED, a voltage drop characteristic of which during conduction has a positive temperature coefficient, are connected in series and an element pair formed by connecting, in anti-parallel to each other, an IGBT and an FWD group in which a FWD, a voltage drop characteristic of which during conduction has a negative temperature coefficient, and an FWD, a voltage drop characteristic of which during conduction has a positive temperature coefficient, are connected in series. The element pairs are connected in parallel.
Abstract:
A semiconductor device capable of rapidly and accurately sensing the information regarding the temperature of a semiconductor transistor contained therein. A MOSFET includes a plurality of cells, and includes a main cell group including a cell for supplying a current to a load among the plurality of cells, and a sense cell group including a cell for sensing temperature information regarding the temperature of the MOSFET thereamong. The main cell group and the sense cell group have different temperature characteristics showing changes in electrical characteristics to changes in temperature. A temperature sensing circuit senses the temperature of the MOSFET based on, for example, a value of a main current flowing through the main cell group and a value of a sense current flowing through the sense cell group.
Abstract:
A drive circuit wherein any abnormality of a semiconductor element is prevented from being erroneously sensed in a case where a gate “ON” command has entered in a state in which a gate voltage of the semiconductor element has not lowered fully. A detection process for a controlled variable of the semiconductor element is permitted only within a period which corresponds to a controlled variable of the semiconductor element at the time when an “ON” signal has been inputted to a control circuit, and a detected controlled variable which is detected within the period and a comparison controlled variable which is set in correspondence with the controlled variable are compared so as to output an abnormality signal, whereby the semiconductor element is turn-off at a speed lower than in normal turn-off.
Abstract:
A capacitor for memory devices including a barium strontium titanate system dielectric film, the film being formed from a chemical vapor deposition source material including a liquid solution of respective organometallic compounds of barium, strontium, and titanium dissolved in tetrahydrofuran.
Abstract:
The multi-source raw material are dissolved in the tetra-hydrofuran, in a liquid state and evaporated simultaneously and stably transported to the reactor, thereby the dielectric thin film used for capacitor having a good performance is formed with a good repeatability. The present invention provides CVD raw material for oxide-system dielectric thin film wherein organic metal raw material is dissolved in the tetra-hydrofuran and the metal atom of the organic metal raw material is selected at least among Pb, Ti, Zr or alkaline earth metal. As a result, a stable dielectric thin film can be formed by CVD method and the dielectric thin film can be used for a capacitor for memory devices.
Abstract:
A method for manufacturing the oxide superconductor according to the present invention comprises the steps of: mixing a starting material including Bi, Sr, Ca and Cu such that a mole ratio of Bi, Sr, Ca and Cu is 2:2+a:1+b:2+c, wherein a.gtoreq.0, b.gtoreq.0, c.gtoreq.0, and 0
Abstract:
A gate driving circuit for driving a voltage-driven switching device is provided with a current limiting circuit for limiting a gate current ig that flows into a gate terminal through a gate resistor at turn-on to a current limit value IL which defines an upper limit value. The current limit value IL is set at a value which is larger than a gate current value I2 at turn-on of the switching device during a period when the Miller effect occurs but is smaller than a gate current value I1 at a point in time when a main current begins to flow at turn-on in a case where the gate current ig is not limited by the current limiting circuit. This arrangement makes a variation in a collector current of the switching device moderate at turn-on thereof when the collector current begins to flow, thereby reducing high-frequency noise.
Abstract:
A power semiconductor module includes an element pair formed by connecting, in anti-parallel to each other, an IGBT and an FWD group in which an FWD, a voltage drop characteristic of which during conduction has a negative temperature coefficient, and an FED, a voltage drop characteristic of which during conduction has a positive temperature coefficient, are connected in series and an element pair formed by connecting, in anti-parallel to each other, an IGBT and an FWD group in which a FWD, a voltage drop characteristic of which during conduction has a negative temperature coefficient, and an FWD, a voltage drop characteristic of which during conduction has a positive temperature coefficient, are connected in series. The element pairs are connected in parallel.