Repetitive High-Current Opening Switch for Railguns.
Patent, Filed 12 May 86, patented 19 Apr 88,
DEPARTMENT OF THE AIR FORCE WASHINGTON DC
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This patent discloses a very low inductance, high current, repetitive opening switch for railguns. A specific embodiment has a circular rotor positioned behind the rails with its rotational axis coaxial with the railgun projectile path defined by the rails. The face of the rotor facing the rails has at least one conducting and at least one insulating region, each symmetric about a diameter of the rotor. A pair of current collectors, or brushes are positioned against the rotor face so that the rotor, when rotating, will alternately conduct and insulate current between the current collectors as conducting or insulating rotor regions sweep past the brushes, thereby communicating current between the switch and the rails. A specific embodiment of the invention has the conducting region the shape of a diametric strip, or shorting bar, and each current collector substantially the shape of an annular segment. The current collectors are made as a plurality of conductive fingers. Stainless steel edges along the shorting bar increase the rate of rise of resistance as the switch commutates current to the rails. The rotor may be driven by a hollow shaft to allow breech loading of the projectiles through the rotor. Another embodiment forms the shorting bar as an undulating channel to allow maximum current while the switch is closed, but increasing the rate of rise of resistance as the switch begins to open.
- Electricity and Magnetism
- Electrical and Electronic Equipment