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. 04, 1987
Filed:
May. 20, 1986
Applicant:
Inventors:
Ely S Zofan, Columbus, OH (US);
Marlin O Thurston, Columbus, OH (US);
Assignee:
Floyd Bell Associates, Inc., Columbus, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
3403 / ;
Abstract
A highly reliable annunciator circuit which is immune from spurious signals generated in an elevator environment is provided. The circuit employs an input condition verification network which performs in conjunction with low true logic two-bit inputs by carrying out switching only when those inputs fall below a preset control value, highly enhanced performance is achieved. Volume control over the piezoelectric output developing a chime or gong sound is achieved through a variable impedance control which is adjustable on site.