Electromagnetic generator for fast current and magnetic field pulses, for example, for use in magnetic metal working

An apparatus for shape changing electrically conducting objects with current and magnetic field pulses having a high rate of rise as expressed by dI/dt and dB/dt, comprising:

• a pulse transformer including a plurality of primary windings arranged in pairs and a secondary winding;
• said primary windings comprising a plurality of magnetic field coils subdivided into groups, each of which comprises a condenser and electrical current conductors;
• said primary windings positioned on said secondary winding for generating a single current pulse in said secondary winding in response to a plurality of primary current pulses applied simultaneously to different ones of said magnetic field coils;
• said secondary winding is an electrically conducting pipe with a longitudinal slit and said magnetic field coils are positioned on said electrically conducting pipe with an electrical insulating means therebetween;
• a plurality of current output connections on said electrically conducting pipe dividing said secondary winding into two sections for supporting said primary windings;
• a peak-current loop connected to said plurality of current output connections;
• a magnetic field concentrator arranged within said peak-current loop;
• said magnetic field concentrator comprises a conductive cylinder that is longitudinally slit for concentrating the magnetic field of said peak-current loop into a space with a surface area smaller than said peak-current loop;
• said magnetic field concentrator includes two parts that are separated by a longitudinal slit that can be varied in width;
• a reinforcing block surrounding said peak-current loop for absorbing radial mechanical forces created by said magnetic field pulses;
• a peak-current switch for each of said condenser and electrical current conductor groups;
• and
• said peak-current switches are switched simultaneously.

An electromagnetic generator for shape changing electrically conducting objects selected from a group consisting of lids of containers, connecting bushings, and fittings on pipes and hoses, with fast current pulses having a high rate of rise as expressed by dI/dt and magnetic field pulses having a high rate of rise as expressed by dB/dt, comprising:

• a pulse transformer including a plurality of primary windings arranged in pairs and a secondary winding;
• said primary windings comprising a plurality of magnetic field coils subdivided into groups, each of which comprises a condenser and electrical current conductors;
• said primary windings positioned on said secondary winding for generating a single current pulse in said secondary winding in response to a plurality of primary current pulses applied simultaneously to different ones of said magnetic field coils;
• said secondary winding is an electrically conducting pipe fabricated from a highly conductive material selected from a group including copper and aluminum with a longitudinal slit and said magnetic field coils are positioned on said electrically conducting pipe with an electrical insulating means therebetween;
• a plurality of current output connections in the middle of said electrically conducting pipe, dividing said electrically conducting pipe into two sections for supporting said primary windings;
• a peak-current loop connected to said plurality of current output connections;
• a magnetic field concentrator fabricated from a highly conductive material selected from a group including copper and aluminum arranged within said peak-current loop;
• said magnetic field concentrator comprises a conductive cylinder that is longitudinally slit for concentrating the magnetic field of said peak-current loop into a space with a surface area smaller than said peak-current loop;
• said magnetic field concentrator includes two parts that are separated by a longitudinal slit that can be varied in width;
• said peak-current loop is surrounded by a reinforcing block made of a material selected from a group comprising iron and non-metallic material for the absorption of radial mechanical forces created by said magnetic field pulses produced by said electromagnetic generator;
• a peak-current switch selected from a group including thyristors, transistors, and ignitrons for each of said condenser and electrical current conductor groups;
• and
• said peak-current switches are switched simultaneously.