摘要:
The invention solves the technical problem of the too long connections between the output from the secondary winding and an output rectifier also reducing the need for intensive cooling of rectifier means by integrating the rectifier means in the form of power diodes or MOSFET transistors into the parts of the secondary winding, where the arrangement is not more complex compared to the conventional solutions, however, it enables substantially shorter output connections. The proposed modified structure changes the electrical parameters of the welding system in such a way that, despite the required unchanged maximum value of the welding current and the use of rectifier means in the form of power diodes or MOSFET transistors, it is possible to further reduce electrical losses in secondary connections that become shorter, while simplifying also the cooling of rectifier means in the form of power diode or MOSFET transistors, which, with the proposed integration of secondary windings with output rectifier means in the form of power diode or MOSFET transistors, is cooled indirectly simultaneously with the cooling of the secondary winding. The proposed embodiment allows a significant increase in the power density of the welding transformer with an output rectifier. Because of the change in the electrical properties of the secondary part of the system, it is also possible to operate at slightly higher frequencies than 1 kHz, without parallelizing the secondary winding.
摘要:
A device (1) and the method of the invention solve the problem of efficient gripping, transferring and actively releasing micro and nano objects, in which the gravitational force of an object is negligible in comparison with the van der Waals force between a surface and the object. The device (1) comprises a vacuum chamber (2), a manipulation device (7) with an arm, on which a one-finger gripper (8) with a tip (8b) is arranged, a table (10), cooling/heating bodies (9, 11) of the gripper and of the table, and a control unit. The method of the invention comprises gas suctioning from the vacuum chamber (2), water vapour supply to the vacuum chamber (2), bringing the tip (8b) of the gripper closer to the object to be transferred, cooling the tip to a temperature that lies in the diagram of the triple point of water close to the sublimation/deposition line at operating pressure (p d ), transferring the object to a desired position, and heating the tip (8b) of the gripper to a temperature that lies in the diagram of the triple point of water to the right of the sublimation/deposition line at operating pressure (p d ).
摘要:
Arrangement of a transformer with an output rectifier (30) comprising at least one primary winding (231) that consists of at least one segment made with several turns, wound at a suitable distance around the transformer axis (300), an iron core (236) electrically isolated from said primary winding, at least one secondary winding (233) electrically isolated from said primary winding and said iron core, comprising a first part (234) of said at least one secondary winding and a second part (235) of said at least one secondary winding, wherein both are wound at appropriate distances around the transformer axis (300), between which at least one primary winding coil is arranged, wherein said primary winding and said secondary winding overlap along the axis (500) in a part surrounded by an iron core and further, wherein the said primary winding and the said secondary winding in the part of the winding heads, which are not surrounded by the iron core, overlap only partially or do not overlap, which allows straight and short arrangement of the connections of an output rectifier in the direction of the axis (500). As a result of the proposed transformer arrangement improved electromagnetic properties of the welding system are obtained, which provides a more homogeneous distribution of magnetic field in the iron core and a homogeneous distribution of electric currents in conductive parts, which affects the reduction of transformer power loss and operation with the higher frequency of the supply voltage. The arrangement of the secondary winding according to the present invention at the same time enables a much simpler production of the cooling of the welding transformer with output rectifier by liquid coolant by making bores of the adequate dimensions.
摘要:
A device and a procedure is presented for saturation detection of a welding transformer's iron core that solves the technical problem of the saturation detection of the welding transformers' iron cores by utilising measurement of the primary current of the transformer. The existing solutions are based on the incorporation of additional sensors hence the device's structure is modified. Amongst other consequences, these modifications may alter the properties of the device, increase its complexity, increase the production costs and reduce the robustness of the entire welding system. The presented technical problem is solved in an effective and inexpensive way that is based on an analysis of the measured primary current of the welding transformer. Using utilisation of the proposed solutions, additional sensors arc unnecessary as measurement of the primary current is needed in any case due to other reasons, such as control of the welding current, protecaion, diagnostics, etc. In this way, the additional components within the welding systems arc unnecessary. Therefore, all negative effects and aspects of usage of these components involving additional sensors and auxiliary devices for the saturation detection of thc magnetic cores of the welding transformers are avoided.