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. 29, 2003
Filed:
Dec. 15, 1999
Applicant:
Inventor:
Paul John Seakins, Auckland, NZ;
Assignee:
Fisher & Paykel Limited, Auckland, NZ;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
A61M 1/500 ; H05B 3/02 ;
U.S. Cl.
CPC ...
A61M 1/500 ; H05B 3/02 ;
Abstract
A fault protection circuit for a respiratory conduit heater element in a respirator humidification system is disclosed. The circuit includes a spark detector as well as overcurrent detector. Several variations are included for the spark detector including a two winding transformer, a center tapped two winding transformer), and a high pass filtered inductor. A semiconductor switching configuration is also disclosed. Once the protection circuit detects a change in current over a certain level, or the average level raises above a threshold, then the current in the heater element is interrupted for a preset period.