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:
Aug. 08, 1978
Filed:
Jan. 26, 1976
Applicant:
Inventor:
Carl E Atkins, Montclair, NJ (US);
Assignee:
Wagner Electric Corporation, Parsippany, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04Q / ;
U.S. Cl.
CPC ...
340543 ; 3401 / ; 340552 ; 3401 / ; 3401 / ; 343 / ;
Abstract
A dual-frequency keyable control circuit is triggered into providing an electrical control output signal when two passive keying circuits, tuned to the correct radio frequencies are brought close enough to a sensing element of the keyable control circuit to cause mutual influence between the passive keying circuits and the sensing element. When the keyable control circuit detects that modulation is present at both ratio frequencies in sequence, it produces control signals which can unlock a door, actuate or defeat an alarm, or perform other functions for which it is desired to require key combinations to attain access.