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:
Apr. 30, 1985
Filed:
Dec. 27, 1982
William A Gerard, Andover, MA (US);
Varian Associates, Inc., Palo Alto, CA (US);
Abstract
Apparatus for high resolution sensing of the position of a rapidly moving member. The apparatus includes at least two linear variable differential transformers (LVDT's) each having a magnetic core coupled to the movable member. A signal source and a phase shifter provide energizing signals to the primary coil of each LVDT. The energizing signals have the same frequency but are phase shifted relative to each other. The induced secondary voltages of the LVDT's are sampled by synchronous detectors, the outputs of which are combined by an adder into a high resolution output signal. When two LVDT's are utilized, the energizing signals have a relative phase shift of 90.degree. and the effective position sampling rate is doubled. The apparatus can be used to sense the operating frequency of a tunable magnetron.