Abstract: A power monitor for indicating that a power outage has occurred is provided. The power monitor comprises an outer casing with a pair of electrical prongs extending from the outer casing. An AC relay is mounted within the outer casing and electrically connected to the prongs with the AC relay disconnecting when power is lost. A DC relay is mounted within the outer casing and electrically connected to the AC relay with the DC relay energized upon disconnection of the AC relay. A timer clock is mounted within the outer housing with the timer clock activated upon activation of the DC relay. A display screen is mounted on the outer casing for visually displaying the amount of time generated by the timer clock.

Abstract: A universal optical adapter assembly for use with a planar automatic grading system for an earth-moving vehicle having a grading implement that defines a graded surface. The automatic grading system includes an energy beam receiver mounted on the earth-moving vehicle and operable for detecting the height at which a datum energy beam strikes the receiver along a detection portion thereof. A control device is operably coupled to the energy beam receiver and the grading implement to control the elevation of the grading implement in response to the position at which the datum energy beam strikes the detection portion of energy beam receiver. The optical interface adapter assembly includes an optical interface apparatus having an energy source emitting one or more implement controlling energy beams strategically onto selected positions of the detection portion the energy beam receiver to control the elevation of the grading implement.

Abstract: A universal optical adapter assembly for use with a planar automatic grading system for an earth-moving vehicle having a grading implement that defines a graded surface. The automatic grading system includes an energy beam receiver mounted on the earth-moving vehicle and operable for detecting the height at which a datum energy beam strikes the receiver along a detection portion thereof. A control device is operably coupled to the energy beam receiver and the grading implement to control the elevation of the grading implement in response to the position at which the datum energy beam strikes the detection portion of energy beam receiver. The optical interface adapter assembly includes an optical interface apparatus having an energy source emitting one or more implement controlling energy beams strategically onto selected positions of the detection portion the energy beam receiver to control the elevation of the grading implement.

Abstract: A position sensing apparatus and method useful for surveying, marking, and grading implement sensing and control is disclosed. The position sensing apparatus includes two laser reference stations, each of which projects a laser beam that periodically sweeps in a plane across the area to be surveyed. Each time a laser beam strikes the opposite reference station, a radio timing signal is broadcast by that reference station. The position sensing apparatus also includes a portable sensing station that comprises a laser beam receiver, a radio reciever, and a programmed computer. The planar position of the portable sensing station relative to the reference stations is computed by a triangulation technique based on the relative timing of detection of the laser beams by the laser beam receiver and the reception of the radio timing signals by the radio receiver. Elevation is determined according to the height at which one of the laser beams strikes the laser beam receiver.

Abstract: A non-contacting range sensing and control device for controlling the position of a grading implement relative to a datum is disclosed. The device includes a non-contacting distance measuring device that periodically measures the separation distance between the distance measuring device and the datum. Also included is a reference circuit that defines consecutive first, second, and third intervals for comparison to the separation distance, and a comparison circuit that periodically compares the intervals to the separation distance, and generates a positive error signal if the separation distance is within the limits of the first interval, generates no error signal if the separation distance is within the limits of the second interval, and generates a negative error signal if the separation distance is within the limits of the third interval.