Abstract: A process and apparatus for performing a ground fault test of a device is disclosed. A current level may be selected from a plurality of predetermined current levels. A ground fault current may be generated between a first power line and a ground at the selected current level until a ground fault interrupter within the device trips, or until expiration of an on-time period associated with the selected current level. The ground fault current may then be set to zero for an off-time period associated with the selected current level. The process may be repeated for each of the plurality of current levels. When the ground fault interrupter within the device trips, the current level and a time interval from an onset of the ground fault current at the selected level and a time when the ground fault interrupter tripped may be recorded.

Abstract: A process and apparatus for performing a ground fault test of a device is disclosed. A current level may be selected from a plurality of predetermined current levels. A ground fault current may be generated between a first power line and a ground at the selected current level until a ground fault interrupter within the device trips, or until expiration of an on-time period associated with the selected current level. The ground fault current may then be set to zero for an off-time period associated with the selected current level. The process may be repeated for each of the plurality of current levels. When the ground fault interrupter within the device trips, the current level and a time interval from an onset of the ground fault current at the selected level and a time when the ground fault interrupter tripped may be recorded.

Abstract: A wind turbine and braking system. A wind turbine may include a tower and a nacelle coupled to the tower, the nacelle rotatable with respect to the tower about a rotation axis. A collar may be centered on the rotation axis and rigidly connected to one of the nacelle and the tower. A first cable may be wrapped about the collar in a first direction. A first tensioning device may be anchored to a structure of the other of the nacelle and the tower, the first tensioning device configured to selectively apply tension to a first end of the first cable to apply a braking torque to the collar.

Abstract: A generic interface test adapter for connecting between a test station and a unit under test. The generic interface test adapter includes an interface frame and an interchangeable circuit card assembly that are configured to route the signals between test station and the unit under test. The interface frame includes an interface plane having a plurality of contact pins or spring-loaded probes, and the circuit card assembly has a plurality of contact pads, aligned to mated with the contact pins. The electrical connections between the test station and the unit under test can be reconfigured merely by changing the interchangeable circuit card assembly. A pressure frame is provided to securely hold the circuit card assembly against the interface plane to provide electrical connection. The pressure frame is pulled toward the interface frame by a cam and angled cam slot mechanism operated by a lever arm.

Abstract: A failsafe avionics interface unit serves as a protocol converter system for translating data for control purposes from a digital communication bus to an analog control channel as an upgrade or interface to an existing analog control system. The avionics interface unit includes digital interface bus logic, a digital data processor module, an analog interface, and a mode selection circuit. Data communicated over the digital interface bus is periodically translated into equivalent analog control signals. For safety purposes, the avionics interface unit ensures the integrity of the system by repetitively looping back or wrapping the digital equivalents of the analog output signals and comparing them to commanded digital control values. The protocol converter system additionally monitors communications over the digital data bus for data continuity.