Abstract: Present invention relates to a device for reducing vibrations of a vibrating object as well as a method for reducing vibrations, wherein the perturbing vibrations are reduced drastically by induction of counter-forces. In general, vibrations of equal frequency (counter-vibration) as the perturbing vibration are generated. The force generated by the counter-vibration acts onto the vibrating object, whose amplitude of vibration is to be reduced. The phasing of the counter-vibration is antipodal to the vibration to be reduced, preferably the force of the generated counter-vibration is greater than the force being necessary for compensation of the perturbing vibration. The transfer of the force of the counter-vibration onto the vibrating object is affected by means of a magnetorheological or electrorheological material, whereby the absolute value of the transmitted force is adjusted by the magnitude of an applied magnetical or electric field.

Abstract: A microwave seed sensor produces an output signal in response to the passage of each seed through a seed planting tube or conduit forming a path of travel for seeds, as in a seed planting machine. The microwave seed sensor comprises a housing of predetermined dimensions defining a waveguide for supporting propagation of a standing wave pattern of predetermined order at a predetermined microwave frequency. The housing includes a tubular portion for receiving the seed conduit, so that the seed conduit and waveguide intersect to define a seed viewing area where the path of travel in the conduit is in registry with the waveguide. This seed viewing area is of predetermined dimension in the direction of the path of travel of seeds through the conduit for resolution of individual seeds by the microwave seed sensor so that seeds may be counted.