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:
Oct. 24, 1978
Filed:
Jun. 16, 1977
George A Oberbeck, Belmont, MA (US);
The Charles Stark Draper Laboratory, Inc., Cambridge, MA (US);
Abstract
A current limiter to protect circuit elements from excessive current caused by transient load impedance or power supply surges. A multiple branch element magnetic circuit includes at least one saturable branch element inductively coupled by a coil connected in series with the load of an external electric circuit. The magnetic circuit further includes lower permeance bias branch element which biases the saturable branch element in a low permeance, saturated state when current through the coil is below a predetermined threshold value, and which biases at least one saturable branch element in its high permeance, non-saturated state when current through the coil is in a predetermined range above and extending from the threshold value. A relatively high permeance shunt branch element provides a shunt path for magnetic flux. The coil provides a relatively high inductive impedance in series with the external electrical circuit when at least one saturable element is in its non-saturated state and provides a relatively low impedance otherwise.