Abstract: A passive filter device for a capacitor in series with a substantially inductive transmission line of an electric transmission system is disclosed. The passive filter device comprises a double-loop RCL filter in parallel with the series capacitor. At power frequency, the filter device allows the power frequency current to pass through the series capacitor with minimum power losses. At sub-synchronous resonance frequencies, the passive filter device provides bypassing of the series capacitor with maximum selectivity of the RCL filter.

Abstract: To improve the performance and life of a charging current-conducting commutating switch in an inductor storage-type electromagnetic launcher, the energy expended in propelling a mass through a breech rail gun section at a high velocity is utilized to generate a current in the breech section rails which flows through the commutating switch in opposition to the inductor charging current. The switch is opened in coordination with the movement of the mass through the launcher with little or no arcing when the current therethrough has been depressed to a minimal level to commutate inductor discharging current into the rails of a longitudinally aligned launch rail gun section of the launcher to accelerate the mass therethrough to a high exit velocity.