Abstract: The invention relates to a method for regulating the voltage of a transformer (1) having different winding taps (3). The problem addressed by the invention is that of providing a method with which different load flow directions can be regulated with conventional transformers (1) and voltage regulators (7) in order to ensure a safe and reliable supply of voltage. The general inventive concept consists in determining, using a method in which a quadrant system (11) is used, the phase angle of the conduction current (I) and thus the load flow direction, thereby preventing deviation from the voltage range as a result of power input that is too high, by controlling the load tap changer (4).

Abstract: The invention relates to a transformer with a tap changer, wherein optionally the primary or secondary side can be regulated by the tap changer, and wherein, on the side of the transformer to be regulated, a main winding and at least one regulating winding, which is connectable by the tap changer, are provided. According to the invention, the main winding is divided into two main winding parts, and the at least one regulating winding and the tap changer (3) connecting the regulating winding are arranged electrically between the two main winding parts (1, 2).

Abstract: Disclosed is a device and method for reducing network feedback during operation of an electric-arc furnace (10). The electric-arc furnace (10) has three lines (7) with one electrode (4) each. A sensor (15) for measuring the currently flowing current and a sensor (16) for measuring the currently applied voltage are provided in each line. A control and regulating unit (30) calculates an electrical actual value (Eist1, Eist2, Eist3). A semiconductor tap changer (20) is assigned to the furnace transformer (6) such that, by suitably selecting three target winding taps (TSOLL1, TSOLL2, TSOLL3) of a primary side (P) of the furnace transformer (6), a target current (IS1, IS2, IS3) is adjustable in each line (7).

Abstract: Disclosed is a device and a method for regulating an electric arc furnace (10) in the initial phase of a smelting process. A sensor (16) for measuring the present voltage and a sensor (15) for measuring the presently flowing current are provided in each line (7) of the electric arc furnace (10). The actual impedance (Zist) is time-dependently calculated by a control and regulating unit (30). An on-load tap changer (20) that is constructed as a semiconductor tap changer, is assigned to a furnace transformer (6) with a primary side (6P) and a secondary side (6S). The semiconductor tap changer (20) realizes a cycle time of a few milliseconds.

Abstract: The invention relates to a drive unit for a step switch for actuating switch contacts. The problem addressed by the invention is that of providing a drive unit for a step switch which is arranged closer to the step switch, guarantees a fast and safe actuation of the step switch and also has a compact design. The problem is solved by a drive unit which consists of a lift magnet arranged directly on the switch contact, which opens or closes the switch contact by applying a voltage.

Abstract: The invention relates to a control transformer that is designed as a phase-shifting transformer, wherein semiconductor switching components are provided for each phase at a regulating winding with several partial windings. According to the invention, an additional connecting line with an additional electronic switching component is provided in each phase wherein each of these connecting lines connects a module of the respective phase with the end of the main winding of the adjacent phase.

Abstract: The invention relates to a power transformer with electronic components. The aim of the invention is to arrange the energy supply of the electronic components of a power transformer closer to the components and thus eliminate the disadvantages of the prior art. According to the invention, a stray field collector is brought into a stray field of the power transformer, whereby a voltage is generated.

Abstract: The invention relates to a transformer with a tap changer, wherein optionally the primary or secondary side can be regulated by the tap changer, and wherein, on the side of the transformer to be regulated, a main winding and at least one regulating winding, which is connectable by the tap changer, are provided. According to the invention, the main winding is divided into two main winding parts, and the at least one regulating winding and the tap changer (3) connecting the regulating winding are arranged electrically between the two main winding parts (1, 2).

Abstract: The invention relates to a tap changer for voltage regulation, comprising semiconductor switch units (S1.1, . . . , S1.6; S2.1, . . . , S2.6) on a variable transformer having a regulating winding, wherein two parallel load branches (1, 2) are provided, in each of which several series-connected semiconductor switch units are arranged. Parts of the regulating winding (W1, W2, W3) and bridges (B1, B2) are provided alternately and run parallel between the two load branches, alternating such that by corresponding connection of the semiconductor switch units in both load branches, the parts of the regulating wiring can be operated arbitrarily in a subtractive and/or additive manner.

Abstract: The invention relates to a stepping switch for voltage control, comprising semiconductor switch elements on a variable transformer having associated regulating windings. The stepping switch has a modular design, wherein each module comprises a respective sub-winding of the regulating winding which can be activated or deactivated by semiconductor switch elements.

Abstract: The invention relates to a tap changer for regulating voltage, comprising semiconductor switching elements on a regulating transformer having a regulating winding. The tap changer is modularly constructed, wherein each module comprises a sub-winding of the regulating winding that can be switched on or off by semiconductor switching elements.

Abstract: The invention relates to a flow monitor for monitoring the flow of flowing media, wherein a paddle projecting into the flow transfers the rotating movement of the paddle onto a display device by means of a magnetic gear comprising a plurality of individual magnets corresponding with each other.

Abstract: The invention relates to a flow monitor for monitoring the flow of flowing media, wherein a paddle projecting into the flow transfers the rotating movement of the paddle onto a display device by means of a magnetic gear comprising a plurality of individual magnets corresponding with each other.

Abstract: The invention relates to a method for controlling a heatable dehumidifier. The heating of the dehumidifier is to be actuated only when several congruent time windows within which a temperature gradient is greater than or equal to 0 could be determined during a certain period of time, i.e. the heating is to be actuated only when no air flows into the interior of the expansion vessel of the transformer.

Abstract: A dehumidifier for an electrical-equipment air intake has an outer housing wall and a floor of a material with a high specific thermal conductivity downwardly closing the outer housing wall, having a downwardly tapering funnel-shaped inner surface formed with a central downwardly open port, and having a rounded edge where the surface meets the port. An inner air-permeable housing inside the outer housing wall holds a moisture-absorbing mass so that air drawn in through the port can pass through the mass and then into a space between the inner and outer housings. A moisture sensor is provided between the housings and a heater in the mass. A controller connected between the heater and the sensor energizes the heater and cooks moisture out of the mass such that the moisture condenses on the floor and runs over the edge out through the port.

Abstract: The invention relates to a method for controlling a heatable dehumidifier. The heating of the dehumidifier is to be actuated only when several congruent time windows within which a temperature gradient is greater than or equal to 0 could be determined during a certain period of time, i.e. the heating is to be actuated only when no air flows into the interior of the expansion vessel of the transformer.

Abstract: The invention relates to a method for dehumidifying air and to an air dehumidifier. To this end, a filter element is provided that is filled with granular material that can be regenerated by baking out. For effecting this baking out, a heating device is provided that is only actuated when both a humidity sensor indicates that a humidity limit value has been exceeded as well as a relative pressure sensor or a comparable technical means indicates that, at the moment, no flow toward the oil expansion tank is recorded.

Abstract: The invention relates to a method for dehumidifying air and to an air dehumidifier. To this end, a filter element is provided that is filled with granular material that can be regenerated by baking out. For effecting this baking out, a heating device is provided that is only actuated when both a humidity sensor indicates that a humidity limit value has been exceeded as well as a relative pressure sensor or a comparable technical means indicates that, at the moment, no flow toward the oil expansion tank is recorded.

Abstract: An electric power apparatus has a oil-filled vessel in which a float is connected to a float shaft that rotates as the float rises and falls with the level of oil. A level indicator has a display shaft extending along and pivotal about an axis, and coupled to the float shaft. An indicia display adjacent the shaft is swept by a pointer fixed on the shaft and juxtaposed with the indicia display go that the level of the oil in the vessel is indicated by the pointer. A disk fixed to the shaft has an outer periphery with a region of a shape having a radius varying angularly from one end of the region to an opposite end of the region. A noncontact proximity sensor is radially spacedly juxtaposed with the region of the disk for producing an output corresponding to the radial distance between the region and the sensor.

Abstract: The invention relates to an oil filter installation for cleaning or cleaning and dessication of the oil in a tap changer at a power transformer or a plunger core coil, wherein a measuring device for detecting the volume flow of the throughflowing oil is provided and the electric pump motor is influenced by way of an interposed frequency converter in accordance with the result of a comparison of this measured value with a target value.