Abstract: A fan with a housing defining an interior and a flow path therein and a valve assembly including a valve element disposed in the flow path and configured to rotate between an opened position and a closed position, wherein the valve element closes the flow path and a linkage assembly and a method of operating.

Abstract: The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current.

Abstract: The system and method of this invention enhances the flow of electrical charges in selected micro-geologic regions by introducing a more conductive material into the geology of the selected region. In one simplistic embodiment, a circle of bare copper wire, bonded so as to create a single electrical entity of the lowest possible electrical resistance, is buried in the soil of the selected area in close physical contact with the soil and other components of the geology.

Abstract: In X-ray examining apparatus in which a compression counterweight is uncoupled in the vertical position, a problem exists in that, when the examining apparatus is turned over, the compression counterweight is coupled to the X-ray image section with a jolt. So as to avoid this jolt, pneumatic damping devices are known which, however, are very voluminous. According to the invention, a simple and efficient device for the damped coupling comprises a control circuit which brakes the counterweight when it exceeds a given speed.