Abstract: A rectifier unit for supplying power to a D.C. load including a transformer having a primary, a secondary and a saturable core, the secondary defining an output section and a control section. A ferroresonance control circuit simulates saturation of the transformer core and includes an electronic switch for controlling the degree of simulated core saturation and thereby regulating the rectifier unit output. Rectifier failure alarm circuitry produces a failure alarm in response to a number of rectifier unit malfunctions. The rectifier failure alarm circuitry is coupled to the ferroresonance control circuitry and comprises a rectifier alarm element operable between the first condition wherein a rectifier failure alarm is produced and a second condition. The failure alarm element is operated from its first condition when the electronic switch minimizes the rectifier system output.

Abstract: A field of view display for presenting data in focus on a subject's far field of view is disclosed. The display comprises an optically transparent viewing medium interposed between a subject and the subject's far field of view. Display units are attached to or embedded in the medium for producing a visual signal to the subject which is small enough to allow substantially unobstructed viewing of the far field view. Focusing material connected to or comprising part of the medium between the subject and the display units brings the display units into focus on the subject's field of view.

Abstract: A digital signal phase shifting system which comprises a timing signal generator producing cyclic digitally coded timing signals; a first system output signal generator capable of decoding the timing signals and producing first system output signals in response to the occurrences of predetermined timing signals; a second system output signal generator capable of decoding digitally coded signals and producing a group of second system output signals in response to operation of the timing signal generator; and a setting device adjustable by the user to condition the second system output signal generator to shift the phase of the group of second system output signals.