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:
May. 05, 1981
Filed:
Dec. 18, 1978
Kenneth Lipman, West Hartford, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
A magnetic amplifier sensor for measuring the magnitude and polarity of a DC current flowing in a line includes a pair of saturable cores, each having a primary and secondary winding mounted thereon. The primary coils are connected in series and a portion of the DC current component to be measured is diverted to a shunt circuit which includes the primary windings. The secondary coils are connected to a push/pull type of AC source so that the flux levels in the cores operate in a drive/reset mode. A DC current in the primary winding causes a variation in the absolute magnitude of the flux levels of the two cores as a function of the time constant of the shunt circuit so that during the drive interval one core saturates before the other. After rectifying, a differential signal is formed which when integrated provides an output signal whose magnitude is indicative of the magnitude DC component of current in the shunt circuit and where polarity is indicative of the polarity of the DC component of current in the shunt circuit. A second embodiment of a magnetic amplifier sensor includes an additional winding on each of the saturable cores. A portion of the output signal is fed back to the two additional windings, which are connected in series, to provide the negative feedback for improving overall input-to-output linearity, and also for enhancing the response time of the amplifier sensor.