Abstract: An electric motor, such as a limited-rotation-angle type, has two or more motor units, including spaced stators enclosing respective rotors on a common shaft. Circumferential, spaced permanent magnets are mounted on the rotors. Stator windings are recessed in slots that are angularly offset with respect to adjacent stator slots. This offset angle between spaced stators is equal to the slot pitch divided by the number of motor units. As a result, the cogging, or super-imposed varying torques of each motor section that occur as the magnets pass a stator slot, are out of phase, and thus substantially cancel out.

Abstract: A center pivot irrigation system includes an irrigation line supported by towers and rotatable about a central pivot. One tower thereof, for example the outermost tower, includes a drive motor energized in response to a signal from a pressure responsive control apparatus. The control apparatus is operable to sense the magnitude of the water pressure at a selected location in the line and therefore to sense decreases in such water pressure when the line travels uphill and increases in the pressure when the line travels downhill. The control apparatus produces a signal responsive to the sensed pressure which causes the drive motor to move the line at a rate inversely related to the average relative elevation of the line. That is, at faster rates of travel when the elevation of the line is below a reference elevation and at lower rates of travel when the elevation of the line is above the reference elevation to thereby prevent underwatering of uphill slopes and overwatering of downhill slopes.

Abstract: An apparatus for cooking eggs is described in which the control of cooking is based upon indirect measurement of viscosity of the contents of one of the eggs being cooked. Viscosity is measured by oscillating the egg in rotation at a frequency determined by the spring constant of the system and at a constant torque while measuring the amplitude of oscillation. When, due to cooking, the amplitude of oscillation, which is a function of the viscosity of the egg contents, increases to a preset threshold, cooking is automatically terminated.