Abstract: The invention relates to a diaphragm pump having a delivery space, which encloses a working volume, at least one deflectable diaphragm, which can be moved into a suction position and a pump position, an inlet valve arranged on a suction side of the diaphragm pump and an outlet valve arranged on the pressure side of the diaphragm pump. In order to make it possible to deliver fine-grain powder, for example, non-flowable powders having particle sizes of 0.01 ?m to 100 ?m, using a diaphragm pump, it is proposed that a gas feed for introducing a gas into the delivery space be arranged at the delivery space. In addition, the invention relates to a method for delivering fine-grain powder.

Abstract: The invention relates to a selector switch (1) for tap-changing transformers. The selector switch (1) has a tap selector (37) in the oil tank (18) of said selector switch (1). In accordance with the invention, two separate zero contacts (73, 74) belong to each phase (L1, L2, L3) to be switched by the tap selector (37). The zero contacts (73, 74) are each arranged on a wall (17) of the oil tank (18) and reach through the wall (17). The invention also relates to a support arm (62) of a tap selector (37) of a selector switch (1). The support arm (62) has a first lateral rib (65) and a second lateral rib (66) and at least one web-like elevation (67) extending along a length (L) of the support arm (62) is formed between the first lateral rib (65) and the second lateral rib (66).

Abstract: The invention relates to a device and a method for conveying powder. A container is provided for the powder, where the powder defines a surface in the container. A suction means has a suction opening for sucking in the powder from the surface. A moving means serves for producing a relative movement between the suction opening and the surface of the powder. During the relative movement, the powder is sucked in, a speed of the relative movement being variable in such a way that there is a constant mass flow.

Abstract: A tap-changer selector for uninterrupted switching between two winding taps of a tapped transformer has fixed contacts arranged circularly in several horizontal planes at a selector housing and a centrally extending rotatable drive shaft in an interior of the selector housing and in each of the horizontal planes of the fixed contacts carries at least one movable contact for connection thereof. The selector housing consists of a plurality of honeycomb segments, and the honeycomb segments are arranged adjacent to one another in the circle in a horizontal plane. A plurality of honeycomb segments arranged in a plane in the circle are arranged vertically one above the other and the honeycomb segments have mounting regions and are so interconnectible by these mounting regions to form when at least two honeycomb segments are connected a mechanically positive connection between at least two mounting regions of the individual honeycomb segments.

Abstract: The invention relates to a tap changer having vacuum interrupters for switching over between winding taps of a tapped transformer without interruption. The tap changer according to the invention having vacuum interrupters is based on the general idea of combining the functionalities of at least one conventional vacuum switching contact which switches under load and a further mechanical switching means according to the prior art in just one single vacuum interrupter with two separately moving contact systems.

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 tap changer for voltage regulation with semiconductor switching components on a regulating transformer having a regulating winding. The tap changer is of a modular design and each module comprises, respectively, one partial winding of the regulating winding that is connectable or disconnectable by means of semiconductor switching components. Varistors and capacitors are additionally integrated for protecting the semiconductor switching components against high voltages.

Abstract: A tap changer with vacuum-switching tubes for controlling a transformer having taps has a selector for power-free selection of a one of the taps to be switched and a load-changeover switch for actual switching over from the connected tap to a new, pre-selected one of the taps. A first cam disk is fixed against rotation on a rotatable switch shaft, and a rocker lever arrangement has a first roller for actuating the vacuum-switching tubes. A second cam disk is also rotationally fixed on the switch shaft, and there are two further arms of U-shaped construction on the rocker lever arrangement. A lever has a free end provided with a second roller that co-operates with the second cam disk. This lever is between the further arms and mounted to be rotatable about an axis. A compression spring is provided between the lever and the further arms.

Abstract: A container for powder, a method for marking of the containers for the powder and an apparatus for use of a powder. At least one radio-frequency identification chip provided in the container, wherein the radio-frequency identification chip stores at least one set of parameters for material characterization of the powder in the container. A unique key is assigned to every type of powder by means of which the data in the radio-frequency identification chip located in the container are readable, writeable and updateable via an antenna arranged outside the container.

Abstract: An on-load tap changer for uninterrupted changeover between winding taps of a tapped transformer has a separate selector for power-free preselection of the winding tap to be switched to, a separate load changeover switch for the actual load changeover from the previous to the preselected new winding tap, a rotatable drive shaft, and a force accumulator with at least one force-accumulator spring that for each load changeover is initially stressed by the drive shaft and after triggering thereof abruptly actuates the load changeover switch. A gear operatively connected with the drive shaft can load the force accumulator. A first mechanical freewheel between the gear and the force accumulator temporarily decouples the force accumulator from rotation with the drive shaft in such a manner that the force accumulator can be stressed with a delay in time after the start of actuation of the drive shaft.

Abstract: A method and an apparatus (1) for weatherability testing of a material sample (3) are disclosed. The material sample (3) is exposed to a testing atmosphere (12) in a testing chamber (2). The testing atmosphere (12) is formed by a plasma (10). Testing atmosphere (12) is withdrawn from the testing chamber (2) and resupplied to the plasma generation as a process gas (5G), after filtering and/or conditioning. At least one further substance (8S) may be added to a process gas (5G) for plasma generation, in order to obtain a desired chemical composition of the testing atmosphere (12). Parameters of the testing atmosphere (12) like temperature and chemical composition may be controlled. The material sample (3) may furthermore be exposed to UV light (25), which preferably is generated by an electric arc.

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: We describe a controller (130) for controlling a power semiconductor switching device (132) into a selected one of a plurality of states, the states including a fully-off state, a saturated-on state, and at least one intermediate state. The switching device controller includes a voltage sense input (142) to sense a voltage on the device; a current sense input (current feedback) to sense a current passing through the device; a negative feedback control circuit (138) coupled to the sense inputs, a control output (136) to provide to the power semiconductor switching device a drive signal with a response dependent on one or more adjustable parameters; and a circuit controller (140) to control the adjustable parameters responsive to state command data, to control the switching device into a selected state, in particular by controlling an effective resistance of the device. Preferred intermediate states include an active low current state and an active low voltage state.

Abstract: The invention relates to a method for monitoring an on-load tap changer according to the known “windowing technique,” wherein for synchronization, the current (I) on the diverter switch is continuously detected, the effective value (Ieff) is calculated, which in turn is differentiated. The corresponding point in time, at which the maximum or minimum of the differentiated value occurs, is evaluated to be the moment for the diverter switch leap (tLU), and produces the synchronization impulse.

Abstract: A tap changer for uninterrupted switching over between winding taps of a tapped transformer has two load branches each for a respective phase to be switched. Each load branch has a vacuum switching contact acting as main contact and parallel thereto at least one series connection of a switch-over resistance and a respective further vacuum switching contact. The two load branches are connected with a common load shunt or connectable by mechanical switching elements. Two respective vacuum switching contacts of each load branch are constructionally combined to form a single vacuum switching tube with two separate movable contacts actuatable independently of one another and a common fixed contact. The common fixed contact is connected with the common load shunt or connectable mechanical switching contacts.

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 an on-load tap changer for switching among winding taps of a step transformer without interruption. According to the invention, in each auxiliary current branch of the on-load tap changer, which operates with vacuum switching tubes as switching elements, additional switches are provided in series with the vacuum switching tubes and the respective winding tap. Said additional switches cause a complete galvanic isolation of the vacuum switching tubes in the auxiliary current branches in steady-state operation.