Abstract: A gate drive device drives a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit. The gate drive device detects a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes. The gate drive device determines whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction.

Abstract: A gate drive device drives a gate of a semiconductor switching element constituting an upper or lower arm of a half bridge circuit which supplies an output current, which is alternating current, to a load. The gate drive device detects a peak value of an element voltage which is a voltage of a main terminal of the semiconductor switching element or a change rate of the element voltage when the semiconductor switching element is switching. The gate drive device acquires a maximum value among a plurality of peak values or a plurality of change rates during a predetermined detection period including a period in which the semiconductor switching element performs switching multiple number of times.

Abstract: A gate drive device drives a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit. The gate drive device detects a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes. The gate drive device determines whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction.

Abstract: A gate drive device drives a gate of a semiconductor switching element constituting an upper or lower arm of a half bridge circuit which supplies an output current, which is alternating current, to a load. The gate drive device detects a peak value of an element voltage which is a voltage of a main terminal of the semiconductor switching element or a change rate of the element voltage when the semiconductor switching element is switching. The gate drive device acquires a maximum value among a plurality of peak values or a plurality of change rates during a predetermined detection period including a period in which the semiconductor switching element performs switching multiple number of times.

Abstract: A drive circuit Dr for a switch that reduces a surge voltage caused when a switch SW is switched to an off state. The drive circuit Dr detects, as an on voltage Von, a collector-emitter voltage of the switch SW while the switch SW is in an on state. When the detected on voltage Von is large, the drive circuit Dr sets a resistance value Rd of a discharging resistor 53 when the switch SW is switched to an off state to be larger than the resistance value Rd when the detected on voltage Von is small. More specifically, the drive circuit Dr sets the resistance value Rd to a larger value as the detected on voltage Von is increased.

Abstract: A manufacturing method for a circuit board in which a pin inserted in a through-hole of a land is welded to the land is disclosed. The land is covered with a white layer, and an irradiation angle of a laser beam with respect to the circuit board is adjusted so that reflected light of the laser beam emitted to the pin reaches the white layer on the land. As the reflected light of the laser beam is allowed to reach a white region provided on the land, the reflected light is scattered on the white region. A rate of absorption of the laser beam by the land is decreased, and a temperature increase of the land is restrained. As a result, a damage of an insulating part around the land is restrained.

Abstract: A manufacturing method for a circuit board in which a pin inserted in a through-hole of a land is welded to the land is disclosed. The land is covered with a white layer, and an irradiation angle of a laser beam with respect to the circuit board is adjusted so that reflected light of the laser beam emitted to the pin reaches the white layer on the land. As the reflected light of the laser beam is allowed to reach a white region provided on the land, the reflected light is scattered on the white region. A rate of absorption of the laser beam by the land is decreased, and a temperature increase of the land is restrained. As a result, a damage of an insulating part around the land is restrained.

Abstract: A drive circuit Dr for a switch that reduces a surge voltage caused when a switch SW is switched to an off state. The drive circuit Dr detects, as an on voltage Von, a collector-emitter voltage of the switch SW while the switch SW is in an on state. When the detected on voltage Von is large, the drive circuit Dr sets a resistance value Rd of a discharging resistor 53 when the switch SW is switched to an off state to be larger than the resistance value Rd when the detected on voltage Von is small. More specifically, the drive circuit Dr sets the resistance value Rd to a larger value as the detected on voltage Von is increased.

Abstract: The drive circuit for driving voltage controlled switches includes: charge path connected to gate of the switch, through which gate charge current flows to turn the switch ON; discharge path connected to the gate and output terminal of the switch, through which gate discharge current flows to turn the switch OFF; and at least either, a charging side element disposed on charging side loop path having the gate, a part of the charge path and the output terminal, restricting current flow to be in one direction and not disturbing current flow of charge current; or a discharging side element disposed on a discharging side loop path having the gate, a part of the discharge path and the output terminal, restricting a current flow to be in one direction and not disturbing a current flow of discharge current.

Abstract: In a drive apparatus, a transmission unit mounted to a first region stops transmission of a pulse signal from a physical-quantity transmission terminal. The transmission unit transmits, from the failure information transmission terminal, a first signal indicative of an occurrence of the failure associated with the target switch when it is determined that the failure associated with the target switch has occurred, and transmits, from the physical-quantity transmission terminal, a second signal indicative of a content of the failure associated with the target switch. A controller mounted to a second region electrically isolated from the first region detects, based on the pulse signal from the physical-quantity transmission terminal, the physical quantity upon no input of the first signal to the controller. The controller identifies, based on the second signal transmitted from the physical-quantity transmission terminal, the content of the failure upon the first signal being input to the controller.

Abstract: A drive circuit drives a plurality of switching elements connected in parallel to each other. The drive circuit includes an operating unit that performs first and second switching processes. In the first switching process, under a condition that a first current detection value acquired before next time an on-command is received is determined to fall below a first threshold that is equal to or less than a threshold current, an on-operation target that is used the next time the on-command is received is set to a second switching element. In the second switching process, under a condition that the second current detection value acquired before the next time the on-command is received is determined to exceed a second threshold that is equal to or greater than the threshold current, the on-operation target that is used the next time the on-command is received is set to a first switching element.

Abstract: In a drive apparatus, a transmission unit mounted to a first region stops transmission of a pulse signal from a physical-quantity transmission terminal. The transmission unit transmits, from the failure information transmission terminal, a first signal indicative of an occurrence of the failure associated with the target switch when it is determined that the failure associated with the target switch has occurred, and transmits, from the physical-quantity transmission terminal, a second signal indicative of a content of the failure associated with the target switch. A controller mounted to a second region electrically isolated from the first region detects, based on the pulse signal from the physical-quantity transmission terminal, the physical quantity upon no input of the first signal to the controller. The controller identifies, based on the second signal transmitted from the physical-quantity transmission terminal, the content of the failure upon the first signal being input to the controller.

Abstract: A drive circuit drives a plurality of switching elements connected in parallel to each other. The drive circuit includes an operating unit that performs first and second switching processes. In the first switching process, under a condition that a first current detection value acquired before next time an on-command is received is determined to fall below a first threshold that is equal to or less than a threshold current, an on-operation target that is used the next time the on-command is received is set to a second switching element. In the second switching process, under a condition that the second current detection value acquired before the next time the on-command is received is determined to exceed a second threshold that is equal to or greater than the threshold current, the on-operation target that is used the next time the on-command is received is set to a first switching element.

Abstract: The drive circuit for driving voltage controlled switches includes: charge path connected to gate of the switch, through which gate charge current flows to turn the switch ON; discharge path connected to the gate and output terminal of the switch, through which gate discharge current flows to turn the switch OFF; and at least either, a charging side element disposed on charging side loop path having the gate, a part of the charge path and the output terminal, restricting current flow to be in one direction and not disturbing current flow of charge current; or a discharging side element disposed on a discharging side loop path having the gate, a part of the discharge path and the output terminal, restricting a current flow to be in one direction and not disturbing a current flow of discharge current.

Abstract: A charging current is supplied to the gate (control terminal) of a driven switching device during an on-state command interval, for raising the gate voltage to an on-state value. Otherwise, discharging of the gate capacitance is enabled, for decreasing the gate voltage to an off-state value. A second switching device is connected between the gate and a circuit point held at the off-state voltage value, and is maintained in an on state while the gate discharging is enabled. At a first time point, the gate voltage rises above a threshold value. At a second time point, a voltage detection circuit detects that that the gate voltage has risen above the threshold value, causing the second switching device to be set in the off state. It is ensured that the delay between the first and second time points is shorter than a minimum duration of an on-state command interval.

Abstract: A charging current is supplied to the gate (control terminal) of a driven switching device during an on-state command interval, for raising the gate voltage to an on-state value. Otherwise, discharging of the gate capacitance is enabled, for decreasing the gate voltage to an off-state value. A second switching device is connected between the gate and a circuit point held at the off-state voltage value, and is maintained in an on state while the gate discharging is enabled. At a first time point, the gate voltage rises above a threshold value. At a second time point, a voltage detection circuit detects that that the gate voltage has risen above the threshold value, causing the second switching device to be set in the off state. It is ensured that the delay between the first and second time points is shorter than a minimum duration of an on-state command interval.