Abstract: Systems and methods of dispersion compensation in an optical device are disclosed. A holographic optical element may include a set of different holograms in a grating medium (704). Each hologram in the set may have a corresponding grating vector (708, 710, 712) with a grating frequency and direction. The directions of the grating vectors may vary as a function of the grating frequency. Different holograms in the set may diffract light in a particular direction so that the light emerges from a boundary of the grating medium in a single given direction regardless of wavelength. A prism (722) is used to couple light into the grating medium. The prism is formed using materials having dispersion properties that are similar to the dispersion properties of the grating material but not indentical. The prism may have an input face that receives perpendicular input light. The prism may include multiple portions having different refractive indices.

Abstract: A motor controller of the sort having both a transformation function for transforming three-phase feedback information into two components, and then changing an error signal for each of the two components back into three-phase correction numbers is provided with an ARCTAN correction function. The ARCTAN correction function takes in the time derivative of the changing angular position of the motor rotor, and creates a correction factor that is supplied back to the transformation function for changing the two error signals back into three. By supplying this correction ARCTAN function, the control eliminates a disturbance that may have occurred in the prior art at higher frequencies wherein both of the control loops for the two components needed to come into play to correct an error on either of the two loops.

Abstract: An electrical power controller controls the selection of power sources, backup generator and normal utility line, to an automatically controlled load and other loads during and at the end of a power failure in a system. As long as the automatic load needs to be on, the power controller will connect the automatic load directly to a backup generator bypassing the transfer switch and disable a stop generator signal. When utility power returns, the transfer switch switches all other loads to operate from utility power and the transfer switch sends the stop signal to the backup generator. However, only when the power controller determines that the automatic load is no longer turned on will it re-enable the stop signal and return the automatic load to normal utility power selected by the transfer switch.

Abstract: An electrical power controller controls the selection of power sources, backup generator and normal utility line, to an automatically controlled load and other loads during and at the end of a power failure in a system. As long as the automatic load needs to be on, the power controller will connect the automatic load directly to a backup generator bypassing the transfer switch and disable a stop generator signal. When utility power returns, the transfer switch switches all other loads to operate from utility power and the transfer switch sends the stop signal to the backup generator. However, only when the power controller determines that the automatic load is no longer turned on will it re-enable the stop signal and return the automatic load to normal utility power selected by the transfer switch.