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:
Feb. 19, 1991
Filed:
Aug. 28, 1989
James R McColl, Concord, MA (US);
GTE Laboratories, Inc., Danvers, MA (US);
Abstract
An apparatus is featured for controlling remote devices. The status or one or more switches associated with remote devices may be transmitted along a single transmission line. One end of the transmission line contains a surface acoustical wave (SAW) delay line. The SAW delay line responds to an interrogation pulse of radio frequency electromagnetic energy with a series of delayed pulses, each of which transmits the status of a switch by means of the presence or absence of the pulse. The SAW delay line and switches are completely passive, requiring no power source. The transmission line may optionally be interrupted and coupled by means of a pair of inductive coils. This offers the potential for rotation, as within a steering column of an automobile, without wear or damage to the transmission line. The other end of the transmission line contains electronic circuitry to provide the interrogation pulse, to decode the return delayed pulses, and to drive other circuitry as required by the switch positions.