Patent GB-1123156-A (GB)
Title: Improvements in and relating to electric pulse generators
IPC: H02K39/00
Filed: 1967-01-30
Abstract: 1,123,156. Reciprocating generators. M. BAERMANN. 30 Jan., 1967 [5 Feb., 1966], No. 4474/67. Heading H2A. A generator for producing electric pulses by magnetic means comprises one or more high voltage windings, and a magnetic circuit having a movably arranged armature disposed therein and at least one permanent magnet, by means of which armature a sudden opening of the magnetic circuit can be effected to generate the pulse, an exterior pot- or shell-shaped ferromagnetic body being provided which has a permanent magnet adhering to a part of its interior wall, an interior ferromagnetic body adhering to the opposite side of the permanent magnet, a coil body being provided which carries the coil winding(s) and has a central ferromagnetic core in conductive connection with the exterior and interior magnetic bodies, the central core being disposed adjacent to a movable armature or being itself in the form of a movable armature. As shown, a cylinder 1, Fig. 1, of ferromagnetic material with an integral upper end has within it, and in contact with it, a permanent magnet 2, radially magnetized and preferably made of powdered magnet material and a plastics binder, and within that, again, a ferromagnetic body 3. A coil former 4, supported on a closure member 12 by projections 14, carries low and high voltage windings 5 and 6 respectively, and has a fixed core 7 with which an armature 8. is normally held in contact by a spring 11. The armature 8 has bores 13 to accommodate the projections 14. One end of the low-voltage winding is connected through a condenser 24 to one terminal of a normally-closed spring switch 21, 22, Fig. 2, and is also earthed. The other end of the low-voltage winding is connected to the other terminal of the switch 2J, 22 and is also connected to one end of the high-voltage winding. The other end of the high-voltage winding passes through an insulating bush 15 to one pole of a spark gap, (not shown), the other pole being earthed. In operation, a lever 10, pivoted at one end at 16, 17 on a plate 32, is moved so as to press a plunger 9 which thus separates armature 8 from core 7; this movement is suddenly increased by a U-shaped spring 18. A voltage is thus generated in the low-voltage winding 5. Almost immediately afterwards a member 19 on the plunger 9 presses the free end of terminal 22 to open the switch and thus cut off the current in winding 5. The resulting change of flux produces a high-voltage pulse in winding 6 and hence a spark at the spark gap. In a modification, (Fig. 4, not shown), the inner body (3) has an inturned. flange at the bottom, the armature is tubular and slides within the flange, and the region of contact between armature and core is located midway along the coil axis. Also the spring switch is below the armature, and is actuated by it after it has descended a certain distance. In the much simpler arrangement of Fig. 5 (not shown), a disc-shaped magnet, magnetized axially, is located between a cover of the outer cylinder and a circular ferromagnetic body spaced by an air gap from the cylindrical wall of the outer cylinder. The coil lies beyond the ferromagnetic body and has a movable core acting as the armature. The plunger extends through holes in the cover, the magnet, and the ferromagnetic body. Again, the spring switch is beyond the end of the armature for sequential operation.