摘要:
The disclosed is a reference frequency generating device (11), which includes a GPS receiver (21), a PLL circuit (31), a detector (28), a memory unit (29), and a controller (22). The PLL circuit (31) controls the digitally controlled oscillator (26) based on a synchronizing control signal acquired based on a reference signal from the GPS receiver (21). The memory unit (29) stores a correspondence relation between a control value of the synchronizing control signal, and a voltage value and a temperature at that time. When the reference signal is not acquired, the controller 22 determines a holdover control signal based on the correspondence relation, and the voltage and temperature detected by the detector 28, and controls the digitally controlled oscillator (26).
摘要:
A mass transit system. The system comprises a first platform for supporting a cargo compartment, a rotating platform having a center area, and a conveyor system for moving the cargo compartment from the first platform to the center area of the rotating platform, while the rotating platform is rotating. The system also includes apparatus for moving the cargo compartment from the center area of the rotating platform to a point relative to the rotating platform that is adjacent a perimeter of the rotating platform. Finally, the system may include apparatus for moving the cargo compartment from the center area to a point relative to the rotating platform that is adjacent a perimeter of the rotating platform.
摘要:
A seal backup ring assembly is provided that eliminates fluid differential pressure acting radially on the backup ring, preventing collapse of the backup ring against a shaft. The backup ring is assembled so that the initial clearance (extrusion gap) between the backup ring and relatively rotating member is not affected by the differential pressure acting across the assembly. This allows for an initially small extrusion gap to be present throughout the differential pressure range.