Abstract: A circuit assembly is provided for producing a test voltage for testing a test object, comprising two high voltage sources for producing a positive and negative high voltage of variable amplitude at respective outputs thereof and a high voltage switch assembly, which is arranged between the outputs of the two high voltage sources and the test object and which can be switched suitably in order to successively charge and discharge the test object, wherein furthermore a closed-loop controller is provided, which measures the present test voltage on the test object and acts on the high-voltage switch assembly in order to charge and discharge the test object in a defined manner in dependence on the measured test voltage.

Abstract: A high-voltage transformer for providing an alternating voltage in the kV range, comprising at least one secondary winding wound on a coil carrying body surrounding a transformer core, and an insulation housing encapsulating the secondary winding is provided to electrically insulate the secondary winding. Said insulation housing is walled by the coil carrying body carrying the secondary winding and by an enveloping body made of plastic and enveloping the secondary winding so that an annular gap is formed, wherein the annular gap between the secondary winding and the enveloping body is filled with an insulating fluid. The annular gap has a gap width of less than or equal to 20 mm viewed in the cross-section, and the enveloping body has a wall thickness of less than or equal to 20 mm, wherein the plastic is polypropylene, and a separate expansion volume is not provided for the insulating fluid.

Abstract: The invention relates to an arrangement comprising at least one electronic component and a cooling body associated therewith. A support physically interposed between the electronic component and the cooling body and the support has at least one layer with at least one material of an electric strength of at least 10 kV/mm and a thermal conductivity of at least 5 W/mK. At least one recess and/or at least one protruding element is arranged in and/or on the layer of the support, and is configured in such a manner that it extends, along the surface of the layer of the support, through preferably all electrically possible pathways between the electronic component and the cooling body as compared to the condition of the layer of the support without the recess and/or without the protruding element.

Abstract: A device for measuring the loss factor and/or measuring the phase angle between a voltage and a current and/or recording a voltage decay and/or current decay and/or recording partial discharge processes and/or measuring the propagation time on test objects that are to be tested, includes a housing in which at least one measuring circuit is arranged for measuring and/or recording purposes. A terminal adapter (12) is provided on the housing (9) to connect the test object that is to be tested directly to the housing (9).

Abstract: A portable high-voltage test instrument comprises an electronic unit having means for producing a test voltage located in the kV range, a control area cooperating with the electronic unit, at least one terminal for the component or cable to be tested and for an external voltage supply, a housing for permanently accommodating the electronic unit and a cooling system, disposed inside the housing, for cooling the electronic unit, the cooling system comprising an air-cooled assembly having an air inlet and an air outlet. This housing is provided with a lid part that can be moved between an open and a closed position, such that all terminals, the control area and the air inlet and air outlet are covered in closed position thereof, whereas all terminals, the control area and the air inlet and air outlet are unobstructed in open position thereof.