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:
Sep. 30, 1986
Filed:
Aug. 23, 1985
Richard K Heiser, Wayzata, MN (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
Actuators typically include one or more coils which are driven by a current source to effect positioning of a movable member. However, faults can occur wherein a conductor connecting the coil to the current source is open circuited or short circuited to ground. This can lead to a loss of control over the actuator, in turn creating a potentially dangerous condition. In order to overcome this problem, an actuator driver circuit according to the present invention includes a first current source for generating a first current at an output terminal thereof, a second current source for generating a second current at an output terminal thereof and first and second actuator coils connected in parallel between the output terminals of the first and second current sources. The current sources are controlled so that at least one of the current sources is capable of generating current for the coils even in the event of an open or short circuit fault condition.