Abstract: In an error correction device, a frame generation section receives pulse signals as temperature information of a power switching element transmitted from a PWM comparator. The frame generation section sets a first correction pulse signal, a second correction pulse signal and the temperature information sequentially into each frame. A pulse width of the first correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 100%. A pulse width of the second correction pulse signal corresponds to a pulse width when a time ratio thereof becomes 50%. A microcomputer receives the temperature information through a photocoupler and corrects the received temperature information. The microcomputer calculates a temperature detection value of the power switching element on the basis of the corrected temperature information.

Abstract: A first-path connects an input-terminal and an output-terminal of a high-potential-side switching-element and includes a high-potential-side rectifying-device and a high-potential-side passive-element. A second-path connects the output-terminal of the high-potential-side switching-element and the output-terminal of a low-potential-side switching-element and includes a low-potential-side rectifying-device and a low-potential-side passive-element. A high-potential-side applying-unit applies voltage to a connecting point between the high-potential-side rectifying-device and the high-potential-side passive-element. A high-potential-side determining-unit determines that an overcurrent is flowing between the input-terminal and the output-terminal of the high-potential-side switching-element by using a first-value. A limiting-unit limits a current between the low-potential-side rectifying-device and the output-terminal of the high-potential-side switching-element if the overcurrent is flowing.

Abstract: A physical quantity detecting apparatus includes a plurality of physical quantity conversion circuits, an output selection circuit and a signal conversion circuit. Each of the plurality of physical quantity conversion circuits converts a physical quantity to be detected into a voltage corresponding to the physical quantity and outputs the voltage. The output selection circuit is electrically connected to the plurality of physical quantity conversion circuits to select a maximum voltage from among the voltages outputted from the plurality of physical quantity conversion circuits. The signal conversion circuit is electrically connected to the output selection circuit to convert the voltage outputted from the output selection circuit into a pulse signal having a pulse width or frequency corresponding to the voltage and output the pulse signal.

Abstract: A discharge control device in an electric power conversion system mounted to a motor vehicle turns off a relay in order to instruct an electric power conversion circuit to supply a reactive current into a motor generator, and thereby to decrease a capacitor voltage to a diagnostic voltage. After this process, the discharge control device outputs an emergency discharging instruction signal dis in order to turn on both power switching elements at high voltage side and a low voltage side in the electric power conversion circuit. This makes a short circuit between the electrodes of the capacitor in order to discharge the capacitor, and executes a discharging control to detect whether or not an emergency discharging control is correctly executed and completed. The discharge control device detects whether or not the electric power stored in the capacitor is discharged on the basis of the voltage of a voltage sensor.

Abstract: A discharge controller carries out discharge control by determining a voltage to be applied to a conduction control terminal of each of switching elements such that a current in a non-saturation region of one of the switching elements is lower than a current in a non-saturation region of the other thereof, and applying the voltage to the conduction control terminal of each switching element with an opening-closing member opening an electrical path to turn on the switching elements, resulting in short-circuit of both electrodes of a capacitor so that a discharge current is outputted from the capacitor based on the discharge control. A manipulator manipulates, based on a value of the discharge current, how to apply the voltage to the conduction control terminal of the one of the switching elements, thus controlling an amount of heat to be generated in the one of the switching elements.

Abstract: 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.

Abstract: A transmission circuit transmits a header pulse signal which has signal length being equal to or more than twice as long as reference time, pulse period having predetermined ratio thereof to the signal length, and pulse stop period being successive and longer than the reference time via transmission path. The transmission circuit subsequently and successively transmits a plurality of data pulse signals which have signal length being the same as the reference time, pulse period having predetermined ratio thereof to the signal length associated with data, and pulse stop period being located before and after the pulse period via the transmission path. A reception circuit receives pulse signals via the transmission path, detects the header pulse signal based on the pulse stop period of the received pulse signal, and obtains a plurality of pieces of data based on the pulse period of pulse signals following the header pulse signal.

Abstract: 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.

Abstract: A power converter includes a backup power source Eb provided separately from a power source Es and designed to supply power during a discharge period, and a discharging driver Mb that turns on/off an upper-arm (one) switching element in series-connected switching elements Qu and Qd based on a drive signal that has at least one of a voltage and a frequency, and drives a lower-arm (the other) switching element Qd such that it is always on, the at least one of the voltage and the frequency of the drive signal being within a predetermined range lower than a drive signal outputted from a normal driver Mu, Md.

Abstract: A motor control apparatus 1 includes an inverter 10, a smoothing capacitor 11, power-converting drivers 120 to 125, a power-converting power supply circuit 13, and discharging drivers 140 and 141. The inverter 10 includes switching circuits 100 to 102 comprised of series-connected two IGBTs. The power-converting drivers 120 to 125 apply an output voltage of the power-converting power supply circuit 13 to the switching circuits 120 to 125 to drive them, thus performing power conversion. The discharging drivers 140 and 141 simultaneously turn on IGBTs 100a and 100b of the switching circuit 100 to discharge the smoothing capacitor 11 when the output voltage of the power-converting power supply circuit 13 is equal to or lower than a threshold. This prevents discharging of the smoothing capacitor during power converting operations.

Abstract: 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.

Abstract: A failure information transmission apparatus includes a transmission circuit and a reception circuit. The transmission circuit transmits a plurality of pieces of failure information related to a plurality of failures as pulse signals different from one another via the same transmission path. The reception circuit receives the pulse signals transmitted by the transmission circuit via the same transmission path and identifies the failure information based on the pulse signal received. If the plurality of failures occurs at the same time, the transmission circuit transmits preferentially transmits failure information with higher priority of transmission.

Abstract: A drive circuit supplies a charging current via a charging path to drive the control terminal of a voltage-controlled switching device, with a resistor and a switching device being connected in series in the charging path. A control circuit in an integrated circuit of the drive circuit operates an internal switching device such as to selectively enable/interrupt the charging current and to regulate the voltage drop across the resistor to a fixed value. The switching device connected in the charging path can be readily changed from the internal switching device to an external switching device, in accordance with the operating requirements of the driven switching device.

Abstract: An electronic system has IGBT, on driving FET and off driving FET connected with the gate of the IGBT, and a control circuit. The on driving FET in an on state supplies electric charge to the IGBT gate. The off driving FET in an on state releases the charge from the GET gate. The control circuit controls each of the on FETs according to a driving signal to be set in the on and off states every switching period of time and to control the voltage at the IGBT gate. When on-failure occurs in the on driving FET set in the on state so as to keep the on driving FET in the on state in spite of control of the control circuit, the control circuit controls a controlled element other than the off driving FET to set the IGBT in the off state.

Abstract: A discharge control device in an electric power conversion system mounted to a motor vehicle turns off a relay in order to instruct an electric power conversion circuit to supply a reactive current into a motor generator, and thereby to decrease a capacitor voltage to a diagnostic voltage. After this process, the discharge control device outputs an emergency discharging instruction signal dis in order to turn on both power switching elements at high voltage side and a low voltage side in the electric power conversion circuit. This makes a short circuit between the electrodes of the capacitor in order to discharge the capacitor, and executes a discharging control to detect whether or not an emergency discharging control is correctly executed and completed. The discharge control device detects whether or not the electric power stored in the capacitor is discharged on the basis of the voltage of a voltage sensor.

Abstract: A physical quantity detecting apparatus includes a plurality of physical quantity conversion circuits, an output selection circuit and a signal conversion circuit. Each of the plurality of physical quantity conversion circuits converts a physical quantity to be detected into a voltage corresponding to the physical quantity and outputs the voltage. The output selection circuit is electrically connected to the plurality of physical quantity conversion circuits to select a maximum voltage from among the voltages outputted from the plurality of physical quantity conversion circuits. The signal conversion circuit is electrically connected to the output selection circuit to convert the voltage outputted from the output selection circuit into a pulse signal having a pulse width or frequency corresponding to the voltage and output the pulse signal.