Abstract: A drive circuit is provided for driving a plurality of object switches mutually connected in parallel. The drive circuit includes: an off holding switch provided for each of the object switches, short-circuiting between a control terminal of each object switch and a reference potential unit to which discharge from the control terminal is discharged; and off control units each provided for the off holding switch. The off holding switch is driven by an own control unit and other control units. The own control unit is provided as an off control unit corresponding to own off holding switch, among the off control units. Other control units are at least one of the off control units other than the own control unit.

Abstract: A drive circuit drives a plurality of switches and sets a target threshold as a threshold compared to a physical quantity correlated with current flowing to a switching completion switch driven to complete switching from one of first and second states to the other. In the first state, a flow of current to at least one of the switches is allowed. In the second state, a flow of current to all of the switches is blocked. The drive circuit sets the target threshold to a first target threshold during at least a part of a first on-driving period in which only a switching completion switch is being on-driven and sets the target threshold to a second target threshold during at least a part of a second on-driving period in which all of the plurality of switches are being on-driven. The first target threshold is greater than the second target threshold.

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: An insulation power source apparatus for power conversion circuit provided with series connected circuits each composed of an upper arm switching element and a lower arm switching element. A power source control unit is disposed at one side of a connection region in a specific direction parallel to a plate surface of the substrate, an upper arm transformers are arranged between the power source control unit and the connection region in the specific region, and the lower arm transformer is arranged closer to the power source control unit in the specific direction than to an end portion of the connection region which is opposite side of a portion where the power source control unit is arranged.

Abstract: An electronic circuit includes: a bus bar connected to a power source having a positive terminal and a negative terminal; and a plurality of object switching elements as driving objects connected to the bus bar, the object switching elements forming a parallel connected circuit. The object switching elements include minimum on-resistance elements having minimum on-resistance compared to other object switching elements in a corresponding current region among mutually different current regions; and connection points between the minimum on-resistance elements and the bus bar are located at different locations to have mutually different inductance of respective conduction paths between the power source to the connection points located at the different locations.

Abstract: An insulation power source apparatus for power conversion circuit provided with series connected circuits each composed of an upper arm switching element and a lower arm switching element. A power source control unit is disposed at one side of a connection region in a specific direction parallel to a plate surface of the substrate, an upper arm transformers are arranged between the power source control unit and the connection region in the specific region, and the lower arm transformer is arranged closer to the power source control unit in the specific direction than to an end portion of the connection region which is opposite side of a portion where the power source control unit is arranged.

Abstract: A drive circuit is provided for driving a plurality of object switches mutually connected in parallel. The drive circuit includes: an off holding switch provided for each of the object switches, short-circuiting between a control terminal of each object switch and a reference potential unit to which discharge from the control terminal is discharged; and off control units each provided for the off holding switch. The off holding switch is driven by an own control unit and other control units. The own control unit is provided as an off control unit corresponding to own off holding switch, among the off control units. Other control units are at least one of the off control units other than the own control unit.

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 switches and sets a target threshold as a threshold compared to a physical quantity correlated with current flowing to a switching completion switch driven to complete switching from one of first and second states to the other. In the first state, a flow of current to at least one of the switches is allowed. In the second state, a flow of current to all of the switches is blocked. The drive circuit sets the target threshold to a first target threshold during at least a part of a first on-driving period in which only a switching completion switch is being on-driven and sets the target threshold to a second target threshold during at least a part of a second on-driving period in which all of the plurality of switches are being on-driven. The first target threshold is greater than the second target threshold.

Abstract: A signal transmission circuit transmitting abnormality signals from a primary side circuit to a secondary side circuit is provided, in which the primary side circuit includes switching elements driven by drive circuits, the secondary circuit including a receiving unit receiving the abnormality signals transmitted from the primary side circuit. The signal transmission circuit includes: a plurality of isolation elements that electrically isolate the primary side circuit and the secondary side circuit, and allows the abnormality signals to be transmitted therethrough; and a logic circuit that receives the abnormality signals from the isolation elements, outputting a predetermined signal indicating an occurrence of an abnormality when at least one of the switching elements shows the abnormality.

Abstract: A signal transmission circuit transmitting abnormality signals from a primary side circuit to a secondary side circuit is provided, in which the primary side circuit includes switching elements driven by drive circuits, the secondary circuit including a receiving unit receiving the abnormality signals transmitted from the primary side circuit. The signal transmission circuit includes: a plurality of isolation elements that electrically isolate the primary side circuit and the secondary side circuit, and allows the abnormality signals to be transmitted therethrough; and a logic circuit that receives the abnormality signals from the isolation elements, outputting a predetermined signal indicating an occurrence of an abnormality when at least one of the switching elements shows the abnormality.

Abstract: An electronic circuit includes: a bus bar connected to a power source having a positive terminal and a negative terminal; and a plurality of object switching elements as driving objects connected to the bus bar, the object switching elements forming a parallel connected circuit. The object switching elements include minimum on-resistance elements having minimum on-resistance compared to other object switching elements in a corresponding current region among mutually different current regions; and connection points between the minimum on-resistance elements and the bus bar are located at different locations to have mutually different inductance of respective conduction paths between the power source to the connection points located at the different locations.

Abstract: A resolver abnormality detection apparatus for a resolver having first and second secondary windings includes a first resistor section including a first pull-up resistor for pulling up the first secondary winding, a first pull-down resistor for pulling down the first secondary winding, a second resistor section including a second pull-up resistor for pulling up the second secondary winding and a second pull-down resistor for pulling down the second secondary winding, and first and second differential input sections connected across the first secondary winding and across the second secondary winding, respectively. The resolver abnormality detection apparatus detects presence of an abnormality in each of the first and second secondary windings based on outputs of the first and second differential input sections, a DC voltage between the first resistor section and the first differential input section and a DC voltage between the second resistor section and the second differential input section.

Abstract: A resolver abnormality detection apparatus for a resolver having first and second secondary windings includes a first resistor section including a first pull-up resistor for pulling up the first secondary winding, a first pull-down resistor for pulling down the first secondary winding, a second resistor section including a second pull-up resistor for pulling up the second secondary winding and a second pull-down resistor for pulling down the second secondary winding, and first and second differential input sections connected across the first secondary winding and across the second secondary winding, respectively. The resolver abnormality detection apparatus detects presence of an abnormality in each of the first and second secondary windings based on outputs of the first and second differential input sections, a DC voltage between the first resistor section and the first differential input section and a DC voltage between the second resistor section and the second differential input section.

Abstract: A failure detecting apparatus that detects an isolation failure between a plurality of coils included in a signal detection apparatus. The failure detecting apparatus includes a voltage applying unit that applies a DC voltage to a coil in the plurality of coils; a differential signal generating unit that generates a differential signal from a voltage at the coil and a predetermined voltage; a threshold voltage setting circuit that outputs a threshold voltage; and a comparator that compares the differential signal with the threshold voltage, thereby detecting whether or not an isolation failure exists. The differential signal generating unit includes either first setting unit for setting an absolute value of the differential signal to be amplified with a predetermined gain or second setting unit for setting the predetermined voltage to be different from a ground potential, and the predetermined gain is set to a value different from one and zero.