Abstract: A switching device, with a mechanism similar to that of a D'Arsonval galvanometer, acting responsive to current flow in a primary control circuit to close a switch in a secondary controlled circuit. The primary control circuit includes dual oppositely wound coils, and relative pivotal mounting is provided between the coils and permanent magnets. The pivotal movement therebetween, upon current flow, closes the switch.

Abstract: A marker buoy attached to an object such as a lobster or crab trap by a latch and released by a trigger struck by a falling weight. A sealed buoy compartment contains a first permanent magnet holding the weight in upper position by a supportive pole relationship to the poles of a second permanent magnet on the weight and releasing the weight when the first magnet is pivoted to a relative position of poles not sufficiently supportive of the weight. The first magnet is pivoted by an electric motor controlled by an electric clock. Setting of the clock and other operations are accomplished without disturbing compartment seals by an external hand-held magnet operating on internal magnetic reed switches. A line tethers the buoy to the object when the latch is released.