Abstract: Disclosed is a toroidal core current transformer comprising a primary conductor which penetrates the toroidal core and a secondary winding that is wound around the toroidal core. A measuring shunt (RSh) or a load (Zb) is provided at the secondary end. In order to compensate the phase error (f) between the primary current (IP) and the secondary current (Is), a compensation circuit (K) whose capacity (C) is measured substantially according to equation (I) or (II) is provided at the secondary end. In equation (I) or (II), C represents the capacity of the compensation circuit, ? represents the radian frequency, ? represents the phase error between the primary current and the secondary current, Rsh represents the resistance of an optional measuring shunt, and Zb represents the impedance of an optional load.

Abstract: A pulsed-voltage generator circuit for producing a flash pulsed voltage for testing the capacitance of a unit under test has two stages (1, 2) which can be charged. Each stage (1, 2) comprises, connected in series, a surge capacitance (11, 21) and a switching spark gap (12, 22), a parallel resistor (13, 23) connected in parallel with the surge capacitance (11, 21) and the switching spark gap (12, 22), and, connected in series with them, a series resistor (14, 24). The two stages (1, 2) are connected to one another such that they can be charged connected in parallel and can be discharged connected in series. A load capacitance (4) is connected to the second stage (2), an additional circuit element (5) for reducing the overshoot of the pulse fronts of the flash pulsed voltage for the load capacitance (4) being arranged between the second stage (2) and the load capacitance (4). The additional circuit element (5) has a compensation capacitance (51) and, connected in parallel with it, a discharge resistor (52).