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:
Jul. 04, 1989
Filed:
Jul. 05, 1988
Applicant:
Inventor:
Ronald W Carlsten, Tucson, AZ (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ; H03K / ;
U.S. Cl.
CPC ...
328120 ; 328146 ; 328149 ; 328140 ; 307362 ; 307354 ; 307518 ; 307519 ; 307494 ;
Abstract
A low-cost circuit capable of detecting the absence of a pulse train such as the pulse train generated by a fan cooling output circuit of open collector design. The detection circuit is capable of sensing that a pulse output has stopped in either a high or low state by converting the pulse train to a level that can be compared to a reference. The circuit design insures that the steady state voltage level decays to an under voltage value when the pulse train stops regardless of whether the fan output stops in a high or low state.