Abstract: A method for the initial cutting of a workpiece by electrical discharge cutting by a wire electrode, in which the values for the specific cutting parameters are reduced along an introduction path in the workpiece at least in part as compared with the values of the cutting parameters for the actual cutting contour, and at least some of the reduced values of the cutting parameters are continuously changed until the values intended for the actual cutting contour are reached.

Abstract: A current supply device for movable electrodes of spark erosion machines comprises a plurality of individual contacts and includes in leads connecting the contacts with a current generator, electrical components in the form of pulse transformers for a pairwise negative feedback of partial currents or additional impedances stepped according to a mathematical series for uniform current distribution over the individual contacts. The current supply device is particularly suitable for the current transmission of high energy short pulses, such as are used for an erosive wire cutting. The current supply device operates in an almost wear-free manner and can also fulfill the function of guide for the electrode.