The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 18, 1981
Filed:
Mar. 14, 1979
Robert J Ehret, Los Altos, CA (US);
Beckman Instruments, Inc., Fullerton, CA (US);
Abstract
In an overspeed protection system for a centrifuge apparatus of the type including a rotor driven by a drive motor, a transducer for providing a signal whose frequency is a function of the rotational speed of the centrifuge rotor, an oscillator for generating a reference signal having a predetermined frequency, means for mixing the rotational speed signal with the reference signal to provide a difference frequency signal, a filter coupled to the output of the mixing means for passing signals having frequencies below a predetermined frequency, and means coupled to the filter for disconnecting power to the drive motor in response to an output signal from the filter, there is disclosed an improvement comprising a frequency comparator responsive to the rotational speed signal and the reference signal for generating an overspeed signal when the frequency of the rotational speed signal exceeds the frequency of the reference signal, and means for combining the outputs of the filter and the frequency comparator at the input to the power disconnecting means.