Abstract: A switching control circuit includes voltage application means that applies a first voltage to a gate of a power device in a first period and applies a second voltage to the gate of the power device in a second period, wherein the first period starts when the power device is turned on; current detection means that detects whether a current flowing through the power device exceeds a threshold; and voltage decrease means that decreases the voltage with a first speed if the current detection means detects that the current exceeds the threshold in a second detection period, decreases the gate voltage with a second speed, lower than the first speed, if the current detection means detects that the current exceeds the threshold in a third detection period, and does not decrease the gate voltage if the current detection means detects that the current exceeds the threshold in the first period.

Abstract: A substrate unit includes a conductive case, an insulating case arranged in the conductive case, a first screw member having conductivity, arranged in the conductive case and fixing the insulating case to an inner wall surface of the conductive case, a circuit substrate provided opposite to the inner wall surface with respect to the insulating case and fixed to the insulating case, and a second screw member having conductivity and fixing the circuit substrate to the insulating case. The first screw member and the second screw member are screwed in toward the inner wall surface. The first screw member and the second screw member are spaced from each other. The first screw member and the second screw member are connected to each other with a connecting member having conductivity.

Abstract: A switching control circuit includes voltage application means that applies a first voltage to a gate of a power device in a first period and applies a second voltage to the gate of the power device in a second period, wherein the first period starts when the power device is turned on; current detection means that detects whether a current flowing through the power device exceeds a threshold; and voltage decrease means that decreases the voltage with a first speed if the current detection means detects that the current exceeds the threshold in a second detection period, decreases the gate voltage with a second speed, lower than the first speed, if the current detection means detects that the current exceeds the threshold in a third detection period, and does not decrease the gate voltage if the current detection means detects that the current exceeds the threshold in the first period.

Abstract: An overheating protection control apparatus for an inverter driving a rotating electric machine comprising: a temperature sensor for measuring the temperature of a power control element in the inverter, and a control device restricting the load factor of the rotating electric machine when the temperature measured by the temperature sensor reaches a threshold value. The control device modifies the threshold value based on a parameter affecting heat radiation or cooling of the inverter. Preferably, the inverter includes a plurality of power control elements. The temperature sensor detects the temperature of one or more, but not all of the plurality of power control elements. The parameter is a physical quantity affecting the temperature difference between the one or more power control elements and another power control element included in the inverter. Preferably, the inverter is cooled by a coolant medium. The parameter is the temperature of the coolant medium.

Abstract: A substrate unit includes a conductive case, an insulating case arranged in the conductive case, a first screw member having conductivity, arranged in the conductive case and fixing the insulating case to an inner wall surface of the conductive case, a circuit substrate provided opposite to the inner wall surface with respect to the insulating case and fixed to the insulating case, and a second screw member having conductivity and fixing the circuit substrate to the insulating case. The first screw member and the second screw member are screwed in toward the inner wall surface. The first screw member and the second screw member are spaced from each other. The first screw member and the second screw member are connected to each other with a connecting member having conductivity.

Abstract: A switching element driving device has a first transistor that decreases the gate voltage of a power element at a faster rate than during a normal turn-off, and a second transistor that decreases the gate voltage of the power element at a slower rate than during a normal turn-off. If the gate voltage detected by the gate voltage monitoring means when an overcurrent in the power element is detected by overcurrent detection means is greater than a predetermined value, the gate voltage is decreased by the first transistor, and then, while the power element remains on, the gate voltage is decreased by the second transistor. If the gate voltage detected by the gate voltage monitoring means when an overcurrent in the power element is detected by overcurrent detection means is less than or equal to the predetermined value, the gate voltage is decreased only by the second transistor.

Abstract: A switching element driving device has a first transistor that decreases the gate voltage of a power element at a faster rate than during a normal turn-off, and a second transistor that decreases the gate voltage of the power element at a slower rate than during a normal turn-off. If the gate voltage detected by the gate voltage monitoring means when an overcurrent in the power element is detected by overcurrent detection means is greater than a predetermined value, the gate voltage is decreased by the first transistor, and then, while the power element remains on, the gate voltage is decreased by the second transistor. If the gate voltage detected by the gate voltage monitoring means when an overcurrent in the power element is detected by overcurrent detection means is less than or equal to the predetermined value, the gate voltage is decreased only by the second transistor.