E.i. Dupont De Nemours and Company

Sorvall Products, L.p.

John A Fleming

William A Romanauskas

David Michael Carson

Lawrence R Barrett

Victor W Miranda, Jr

Edward A Kakos

Frank James Allen

An energy monitoring arrangement that is operatively associated with a centrifuge instrument monitors the magnitude of applied accelerating energy that is used to accelerate a rotor and to interrupt the continued application of accelerating energy if the magnitude of the applied accelerating energy exceeds a predetermined reference energy value. Preferably, the net applied accelerated energy to the rotor is monitored and used in the comparison with the energy reference. The invention may also be used in a predictive manner to provide, early in the centrifugation run, an indication of the energy of a rotor at an operator-ordered set velocity.

Energy monitor for a centrifuge instrument

A support substrate having an array of magnetically responsive sensors is mounted within the housing of a brushless DC motor in a plane perpendicular to the axis of the motor shaft having commutating magnets thereon. A ferromagnetic flux concentrating member in the form of a generally planar disc having an annular rim with radially inwardly directed spokes is mounted to the support substrate. Each spoke has a radial gap therein. A magnetically responsive sensor is received within each radial gap. The gap may divide the spoke into two discrete gap segments, or may alternatively form an enclosed recess with generally radially extending sidebars along each lateral edge of the spoke. The flux concentrating member conducts magnetic flux emanating from one magnetic pole to and through each of the magnetically responsive sensors and returns the flux to the other pole, such that, as the shaft is rotated, each of the magnetically responsive sensors is at substantially all times under the influence of magnetic flux emanating from one of the commutating magnets.

DC electric motor having a flux concentrating member thereon

The present invention is directed to a rotor identification system operable to identify each of a plurality of 2.sup.N rotors. Each rotor has at least two synchronizing detectable elements thereon and up to N additional identifying detectable elements. The identification system comprises a first and a second detector, each detector being operative to generate a synchronizing signal upon the passage of a synchronizing detectable element in proximity thereto; and means responsive to the substantially simultaneous generation of a synchronizing signal from each of the first and second detectors for generating an identification enabling signal. Rotor identification signal generating means responsive to the identification enabling signal is provided for generating a rotor identification signal in accordance with the number of identifying detectable elements provided on the rotor.

Centrifuge rotor identification system

The duty cycle of the alternating current waveform applied to an electric motor is varied by varying the firing point of an SCR circuit. This firing point is varied by logic circuitry which responds to the largest (or smallest) output of several integrators each of which provides an increasing or decreasing control voltage in response to different error signals. The error signals are related to different control criteria such as motor speed, motor current, etc. Thus the error signal indicating the greatest deviation from a set point controls the firing point. Since the output level of the integrators is slow to vary, a high degree of noise immunity is attained.

Motor control system

A locking ring having castellations is provided for a swinging bucket-type centrifuge. The locking ring is constructed such that the castellations can be angularly positioned relative to the rotor to either block or permit the buckets to swing outwardly during operation. The angular positioning of the castellations relative to the buckets is accomplished by relative angular acceleration and deceleration between the rotor and the locking ring.

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Newtown, CT, United States of America

John A Fleming