Abstract: A sieve for use in a combine harvester includes a plurality of longitudinal parallel rails lying in a common plane of the sieve including two spaced side rails and at least one intermediate rail. Each rail has a row of holes supporting a plurality of parallel cross wires of square cross-section extending generally at right angles to the rails with each wire passing through a respective one of the holes. Each wire carries a plurality of separate louver sections thereon, each louver section spanning a distance between a respective pair of the rails. A common adjustment member for the wires causes common rotation of each of the wires about a longitudinal axis to cause rotation of the louver sections to adjust the louver openings. Each louver section has formed a square sleeve through which the wire passes without welding to the wire so that the wire can be pulled longitudinally relative to the louver sections for removal of individual louver sections for repair.

Abstract: A power factor correction circuit in which a divided-down version of a rectified input waveform is sampled approximately at its peak by a sample-and-hold circuit. The peak value is then processed to produce a correction signal which is subtracted from the original divided down rectified signal. This produces a reference signal which is then multiplied by the output of an error amplifier to produce a sinusoidal reference signal for the input current. The output of the error amplifier which is used is that which is sampled periodically when the divided-down rectified signal approaches zero volts. The sinusoidal reference is used by peak and valley comparators whose other inputs come from a current sense amplifier. The outputs of the comparators are used to switch a shunting transistor which controls the input current to achieve near unit y power factor.