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. 23, 1985
Filed:
Dec. 22, 1983
Applicant:
Inventor:
David P Giammarrusco, Bartlett, IL (US);
Assignee:
GTE Automatic Electric Incorporated, Northlake, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318565 ; 361 23 ; 236 89 ;
Abstract
A circuit which monitors air flow by comparing the speed of a fan to a predetermined frequency. A Hall effect device detects magnetic pulses representative of the fan speed and provides a corresponding electrical signal. This signal is compared with a predetermined threshold frequency by a retriggerable monostable multivibrator. A digital delay circuit isolates pace conditions and a relay circuit provides an indication of the fan speed status.