Patent application number | Description | Published |
20110058400 | POWER CONVERSION APPARATUS - The power conversion apparatus includes a power conversion circuit including parallel-connected pairs of a high-side switching element and a low-side switching element connected in series, high-side driver circuits to drive the high-side switching elements, low-side driver circuits to drive the low-side switching elements, and a transformer to supply voltages to drive the high-side switching and low-side switching elements to the high-side and low-side driver circuits. The high-side switching elements are mounted in a row along a first direction on a wiring board, and the low-side switching elements are mounted in a row along the first direction on the wiring board side by side with the row of the high-side switching elements. The transformer is mounted on the wiring board on the side of the row of the high-side switching elements opposite to the row of the low-side switching elements. | 03-10-2011 |
20110163706 | DRIVE DEVICE FOR ELECTRIC POWER CONVERSION CIRCUIT - A drive device has a break circuit. The break circuit inputs phase-current values transferred from phase-current sensors mounted on an electrical path of a motor generator. A power switching element is equipped with a freewheel diode connected in parallel with each other. An inverter has pairs of the power switching elements. In each pair, the power switching element in a high voltage side and the power switching element in a low voltage side are connected in series. It is detected for the freewheel diode to be in a freewheel mode when a forward current flows in the freewheel diode. The break circuit detects the freewheel mode when the phase-current value is not less than a predetermined threshold value. The break circuit detects the freewheel mode where the current flows in the freewheel diode in an upper arm when the phase-current value is not more than the threshold current value. | 07-07-2011 |
20120025875 | APPARATUS FOR DRIVING VOLTAGE CONTROLLED SWITCHING ELEMENTS - An apparatus is provided to drive a voltage controlled switching element having a conduction control terminal. In the apparatus, it is determined whether or not voltage at the conduction control terminal is at a first voltage which is lower than a second voltage and which is equal to or more than a threshold voltage. The second voltage is a voltage provided when the switching element is in a normal on-state thereof. The threshold voltage is voltage at which the switching element is switched on. When it is determined that the voltage at the conduction control terminal is at the first voltage, the switching element is forcibly switched off. | 02-02-2012 |
20120075761 | ELECTRONIC DEVICE - An electronic device that is capable of detecting an abnormal state such that a switching element is unable to be turned off in spite of a drive signal instructing turn-off of the switching element. The device includes a switching element that is driven by controlling a voltage on its control terminal, a drive circuit that controls the voltage on the control terminal of the switching element on the basis on an inputted drive signal to drive the switching element. In cases where there exists a current flowing through the switching element in spite of the drive signal instructing turn-off of the switching element, the drive circuit determines that the switching element is in an abnormal state, and cuts off supply of voltage from a drive power supply circuit to the control terminal of the switching element to thereby turn off the switching element. | 03-29-2012 |
20120126858 | LOAD DRIVING APPARATUS - A load driving apparatus for driving a load with a constant current includes a shunt resistor and a driver circuit. A shunt current corresponding to the constant current flows though the shunt resistor. The driver circuit is connected to a first end of the shunt resistor to supply the constant current corresponding to the shunt current to the load. The driver circuit includes a reference voltage source for generating a predetermined reference voltage. The driver circuit adjusts the magnitude of the constant current by performing a feedback-control of the magnitude of the shunt current in such a manner that a first voltage corresponding to the reference voltage and a second voltage corresponding to a voltage at the first end of the shunt resistor become equal to each other. | 05-24-2012 |
20120126859 | LOAD DRIVER WITH CONSTANT CURRENT VARIABLE STRUCTURE - A load driver includes a switching element connected to a load, a constant current generator that generates a constant current, and a driver circuit that turns on the switching element for an on-period, which depends on a value of the constant current and is shortened with an increase in the value of the constant current. The constant current generator supplies a first constant current having a first current value to the driver circuit during the on-period, and supplies a second constant current having a second current value smaller than the first current value after the on-period has elapsed and the switching element reaches an on state. | 05-24-2012 |
20120217937 | DRIVE CIRCUIT FOR SWITCHING ELEMENT - A drive circuit is used for driving a switching element. The drive circuit includes a detection unit and an integrated circuit. The detection unit detects a state of a controlled switching element and outputs a voltage signal corresponding to a detection result of the state. The integrated circuit receives the voltage signal via an input terminal for the detection result and controls the switching element based on the received voltage signal. The input terminal includes at least two input terminals that are connected to each other so as to receive the same voltage signal from the detection unit. | 08-30-2012 |
20120242376 | LOAD DRIVE APPARATUS AND SEMICONDUCTOR SWITCHING DEVICE DRIVE APPARATUS - A load drive apparatus includes a switching device, a gate drive circuit, a clamp circuit, a temperature detection circuit, and an arithmetic device. The switching device controls an on-off state of current supply to a load. The gate drive circuit turns on the switching device by controlling a gate voltage of the switching device so that the switching device operates in a full-on state. The clamp circuit clamps the gate voltage of the switching device to a clamp voltage lower than the gate voltage in the full-on state and higher than a mirror voltage. The temperature detection circuit detects a temperature of the switching device. The arithmetic device calculates a voltage corresponding to a variation in a mirror voltage based on the detected temperature and controls the clamp voltage in the clamp circuit so as to be the calculated voltage. | 09-27-2012 |
20120249020 | DRIVE CIRCUIT FOR SWITCHING ELEMENT - A drive circuit for a switching element includes a constant-current control unit and a restriction unit. The constant-current control unit performs a constant-current control for charging an open/close control terminal of a switching element to be driven which is a voltage-controlled switching element with electric charge for turning on the switching element. The restriction unit restricts, to a reference voltage, a voltage between the open/close control terminal and a first end of a pair of ends of a current flow path of the switching element for a predetermined period following a start of the constant-current control within a charging process period during which the open/close control terminal is charged with the electric charge such that the switching element is turned on. | 10-04-2012 |