Abstract: The present invention relates to a switched power converter including a base plate on which at least one heat sink is arranged. The converter further includes at least one power transistor arranged on a side of the at least one heat sink. Further, at least one spring element is arranged to press against the power transistor arranged on a side of the at least one heat sink and an oppositely facing side of either an adjacent heat sink or a base plate end face parallel to the at least one heat sink.

Abstract: It is presented a protection circuit for a drive circuit of a permanent magnet motor being powered by a main DC source. The protection circuit comprises a protection circuit DC source; a changeover switch being arranged to select an input to a gate of a main drive switch of the drive circuit, the input being selectable between an output of the protection circuit DC source and a second control signal; and a changeover control device connected to control the changeover switch, which changeover control device is arranged to ensure that the changeover switch is connected to the output of the second side of the protection circuit DC source when an overvoltage is detected.

Abstract: The present invention relates to a switched power converter comprising a base plate on which at least one heat sink is arranged. The converter further comprises at least one power transistor arranged on a side of the at least one heat sink. Further, at least one spring element is arranged to press against the power transistor arranged on a side of the at least one heat sink and an oppositely facing side of either an adjacent heat sink or a base plate end face parallel to the at least one heat sink. This is highly advantageous in that a force is applied to the power transistor by the spring element. This will press the power transistor against the heat sink on whose side the transistor is arranged. Thermal contact is thus established between the power transistor and the heat sink, and heat dissipation from the transistor via the heat sink is greatly facilitated. Further, the spring elements are a cost-effective way of attaining a high compressive force on the power transistors.

Abstract: It is presented an inverter type motor drive device for feeding three phase AC electric power to an electric motor, the inverter type motor drive device comprising: an insulated metal substrate board on which, for each of the three phases, a plurality of power switches are mounted in straight lines in switch assemblies along a first direction, wherein two switch assemblies are assigned for each phase; a printed circuit board on which a plurality of capacitors are mounted, wherein the printed circuit board is essentially parallel to the insulated metal substrate board; and two DC power input terminals mounted on the printed circuit board.

Abstract: It is presented a gate driver circuit for driving an electric switch, the switch being arranged to control a main current using a gate signal. The gate driver circuit comprises: a non-linear capacitor means having a lower capacitance when an applied voltage is under a threshold voltage and a higher capacitance when an applied voltage is over the threshold voltage, wherein the non-linear capacitor is arranged to be connected between a high voltage connection point of the switch and a connection point for the gate signal; a current change rate sensor, the current change rate sensor being configured to detect changes in a main current of the electric switch and to control a gate signal of the electric switch depending on the current change; a gate buffer; and at least one current source, arranged to drive the gate buffer. The current change rate sensor is connected to control the current source to thereby control the gate signal of the electric switch.