Abstract: An emergency position indicating radio beacon ("EPIRB") includes a watertight housing with an ON-OFF switch on the outside of the housing which does not require holes through the housing wall. A floatation collar on the housing maintains the EPIRB in an upright position in the water and provides a storage cavity for a lanyard. Conductive grids on the interior of the housing either shield the EPIRB electronics from antenna radiation and form the lower half of the antenna, or couple the antenna to the water which acts as a ground plane, depending on whether the EPIRB is floating in the water or is surrounded by air.

Abstract: An emergency position indicating radio beacon is controlled by an annular switch ring which rotates to ON, OFF, SET, and TEST positions. In the SET position, the buoy transmitter automatically turns on in response to removal of the buoy from a mounting bracket. A light and an audible alarm on the buoy are activated during buoy transmission to alert an operator to the transmission in order to avoid false alarms. The mounting bracket automatically releases and ejects the buoy in an emergency situation in response to ambient water pressure, or the buoy may be manually removed from the bracket for deployment.

Abstract: A cant angle sensor comprises a conductive, nonmagnetic pendulum suspended from the shaft of a resolver for limited angular travel in the slot of a C-shaped magnet. When the angle of the sensor changes, the pendulum seeks a new vertical null, and the C-shaped magnet exerts a viscous hystersis damping force causing the pendulum to quickly come to rest without oscillation. The rotor magnet wire of the resolver is connected directly to output terminals to avoid friction due to brush contact on the rotor shaft.