Abstract: A reactor arrangement for alternating electrical currents includes, for each alternating electrical current, different coils (105, 107, 105a, 107a) for positive and negative half-cycles of that alternating electrical current. The negative and positive half-cycles of the alternating electrical current are directed to the different coils with the aid of unidirectional electrical components (106, 108, 106a, 108a) such as, for example, diodes. All coils are arranged to magnetize a common magnetic core element (104) in a same direction. Therefore, from the viewpoint of the magnetization of the magnetic core element, the flowing directions of the alternating electrical currents are not significant. Hence, the common-mode inductance of the reactor arrangement has substantially a same value as the differential-mode inductance.

Abstract: A reactor arrangement for alternating electrical current includes different coils (105, 107) for positive and negative half-cycles of the alternating electrical current. The negative and positive half-cycles of the alternating electrical current are directed to the different coils with the aid of unidirectional electrical components (106, 108) such as, for example, diodes. The both coils are arranged to magnetize a common magnetic core element (104) in a same direction. The reactor arrangement further includes at least one permanent magnet (109) that generates, into the magnetic core element, a biasing magnetic flux component having an opposite direction than that of magnetic flux components generated with the coils. Therefore, the biasing magnetic flux component generated with the permanent magnet relieves magnetic saturation of the magnetic core element. Hence, the size and the weight of the magnetic core element can be reduced.

Abstract: This disclosure relates to a cooling structure for an electronic device including an inlet for conveying a flow in a first flow direction towards a first component and an outlet for conveying the flow further. To deter dirt particles from proceeding to electronic components, the cooling structure can include a second flow channel, which starts from a port oriented transversely to the first flow direction or away therefrom and receives part of the flow from the inlet, and which conveys the part of the flow to an electronic component located in the second flow channel.

Abstract: A mechanical construction of an electrical module includes two or more electrical components (102-105). Each of the electrical components has a contact surface (106-109) that is capable of forming a galvanic contact with an external electrical conductor. The electrical module includes a holder element (101) that includes flexible material arranged to flexibly support the electrical components with respect to each other in such a way that the contact surfaces of the electrical components are capable of aligning with external surfaces independently of each other.

Abstract: A method and a circuit for controlling a thyristor (V1) into conducting state, the thyristor (V1) being in a rectifier, which rectifier supplies DC voltage to a DC voltage circuit. The circuit comprising a trigger capacitor (C2) adapted to be charged from the voltage difference across the thyristor (V1) when the anode-to-cathode voltage of the thyristor is positive, a zener diode (V5) adapted to be triggered with the voltage of the trigger capacitor (C2), when the voltage of the trigger capacitor (C2) exceeds the breakdown voltage of the zener diode (V5), and an auxiliary thyristor (V3) adapted to be triggered with the current from the trigger capacitor (C2) flowing via the zener diode (V5), wherein the cathode of the auxiliary thyristor (V3) is connected to the gate of the thyristor (V1) for triggering the thyristor (V1) with the current from the trigger capacitor (C2) flowing via the auxiliary thyristor (V3) for using the thyristor (V1) in a diode mode.

Abstract: In a method for detaching a web threading tail from a moving surface in a fiber web machine, the web threading tail (12) is detached from a moving surface (23) by means of air that flows from a blow-off blow channel (19) included in a blade holder (14). A trailing blow (26) is directed to the web threading tail (12) using air that flows from a trailing blow channel (17) included in the blade holder (14). The blade holder (14) includes a flow surface (32), and the trailing blow (26) is blown to the same direction with or in a small angle relative to the flow surface (32). The invention also relates to a corresponding blade holder and a doctor apparatus for detaching a web threading tail from a moving surface in a fiber web machine.

Abstract: A method and an arrangement of measuring inverter current, where the inverter is connected to and supplied by a DC intermediate circuit having two or more parallel capacitor branches connected between the positive and negative rail of the DC intermediate circuit, and the capacitance of the capacitor branches being known. The method comprises the steps of measuring the current of one of the parallel capacitor branches, and determining from the measured current the magnitude of the inverter current.

Abstract: A method is disclosed for controlling a semiconductor component which includes a voltage controlled gate. The method includes determining and storing, prior to use of the semiconductor component, reference values of a gate voltage to be given to the gate of the semiconductor component during a change of operating states. The method also includes providing a pulse width modulated voltage from a driver circuit to a resistor connected to the gate of the semiconductor component according to the stored reference values of the gate voltage when a change in operating states of the semiconductor component is desired.

Abstract: A method and a circuit for controlling a thyristor (V1) into conducting state, the thyristor (V1) being in a rectifier, which rectifier supplies DC voltage to a DC voltage circuit. The circuit comprising a trigger capacitor (C2) adapted to be charged from the voltage difference across the thyristor (V1) when the anode-to-cathode voltage of the thyristor is positive, a zener diode (V5) adapted to be triggered with the voltage of the trigger capacitor (C2), when the voltage of the trigger capacitor (C2) exceeds the breakdown voltage of the zener diode (V5), and an auxiliary thyristor (V3) adapted to be triggered with the current from the trigger capacitor (C2) flowing via the zener diode (V5), wherein the cathode of the auxiliary thyristor (V3) is connected to the gate of the thyristor (V1) for triggering the thyristor (V1) with the current from the trigger capacitor (C2) flowing via the auxiliary thyristor (V3) for using the thyristor (V1) in a diode mode.

Abstract: A circuit for controlling a thyristor (V1) into conducting state, the thyristor (V1) being in a rectifier, which rectifier is adapted to supply DC voltage to a DC voltage circuit. The circuit comprises a pulse transformer (T1), means for generating voltage pulses on the primary winding of the pulse transformer (T1), a trigger capacitor (C2) adapted to be charged from the voltage pulses in the secondary winding of the pulse transformer, a zener diode (V5) adapted to be triggered with the voltage of the trigger capacitor (C2) when the voltage of the trigger capacitor (C2) exceeds the breakdown voltage of the zener diode (V5), and an auxiliary thyristor (V3) adapted to be triggered with the current from the trigger capacitor (C2) flowing via the zener diode (V5), wherein the cathode of the auxiliary thyristor (V3) is connected to the gate of the thyristor (V1) for triggering the thyristor (V1) with the current from the trigger capacitor (C2) flowing via the auxiliary thyristor (V3).

Abstract: A reactor arrangement for alternating electrical current includes different coils (105, 107) for positive and negative half-cycles of the alternating electrical current. The negative and positive half-cycles of the alternating electrical current are directed to the different coils with the aid of unidirectional electrical components (106, 108) such as, for example, diodes. The both coils are arranged to magnetize a common magnetic core element (104) in a same direction. The reactor arrangement further includes at least one permanent magnet (109) that generates, into the magnetic core element, a biasing magnetic flux component having an opposite direction than that of magnetic flux components generated with the coils. Therefore, the biasing magnetic flux component generated with the permanent magnet relieves magnetic saturation of the magnetic core element. Hence, the size and the weight of the magnetic core element can be reduced.

Abstract: A reactor arrangement for alternating electrical currents includes, for each alternating electrical current, different coils (105, 107, 105a, 107a) for positive and negative half-cycles of that alternating electrical current. The negative and positive half-cycles of the alternating electrical current are directed to the different coils with the aid of unidirectional electrical components (106, 108, 106a, 108a) such as, for example, diodes. All coils are arranged to magnetize a common magnetic core element (104) in a same direction. Therefore, from the viewpoint of the magnetization of the magnetic core element, the flowing directions of the alternating electrical currents are not significant. Hence, the common-mode inductance of the reactor arrangement has substantially a same value as the differential-mode inductance.

Abstract: A mechanical construction of an electrical module includes two or more electrical components (102-105). Each of the electrical components has a contact surface (106-109) that is capable of forming a galvanic contact with an external electrical conductor. The electrical module includes a holder element (101) that includes flexible material arranged to flexibly support the electrical components with respect to each other in such a way that the contact surfaces of the electrical components are capable of aligning with external surfaces independently of each other.

Abstract: The present invention is a consistency transmitter for the measurement of consistency, viscosity, and other properties of matter. The transmitter consists of a measuring element, attached to a bearing-mounted shaft and rotated in the matter to be measured by a direct drive motor that is positioned coaxially with the measuring element and its shaft. The stator of the direct drive motor is integrated into the consistency transmitter body, its rotor into the shaft. The stator is coaxially attached to a first flange that transmits the torsional force of the motor with flexible elements to a second flange positioned on the shaft. The first and second flanges are attached to differential elements with which the phase angle between the flanges is measured using measuring elements located near the flanges. The shaft of the measuring element is bearing-mounted inside a tubular torsion shaft.