Abstract: Aspects described herein relate to an electromagnetic seismic vibrator (EMSV) architecture that provide wide frequency range operation, ground force application with high fidelity, and low environmental impact. The EMSV architecture can include a base member that can support a force coil and mitigate electrical heating due, at least in part, to spurious currents. The EMSV architecture can include means for restricting movement of a reaction member included in the EMSV architecture relative to the base member. Such means can permit mitigation of damage of the EMSV architecture in scenarios in which control of the EMSV architecture may fail.

Abstract: Aspects described herein relate to an electromagnetic seismic vibrator (EMSV) architecture that provide wide frequency range operation, ground force application with high fidelity, and low environmental impact. The EMSV architecture can include a base member that can support a force coil and mitigate electrical heating due, at least in part, to spurious currents. The EMSV architecture can include means for restricting movement of a reaction member included in the EMSV architecture relative to the base member. Such means can permit mitigation of damage of the EMSV architecture in scenarios in which control of the EMSV architecture may fail.

Abstract: An apparatus and method are provided for controlling the switching characteristics of an explosively actuated switch. The switch comprises a conductor that is only partially severed by explosive forces. A bridge region, the conductive portion of the conductor remaining after the explosion, is then severed by thermal breakdown. Variations in the bridge region enable a user to vary the switching characteristics of the switch.

Abstract: A staged switch for conducting a large electrical current for an indefinite time period and then rapidly switching the current into a load circuit. The switch comprises a first stage which can conduct a large electrical current for an indefinite time period without damage to the stage and a second stage which is a fast-opening element. The first stage includes primary and secondary contacts wherein the primary contacts conduct a charging current and the secondary contacts divert the current into the fast-opening second stage. The secondary contacts "make" before the primary contacts "break", reducing the damage to the contacts which might otherwise be experienced. The second stage is a low-inductance element which reduces the level of energy absorbed by the first-stage contacts, minimizing damage to the contacts. The second-stage element may be constructed in a cartridge and may be loaded into the switch using an autoloader device.