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:
Oct. 27, 2009
Filed:
Apr. 29, 2005
Applicant:
Steve Bennett, Portsmouth, GB;
Inventor:
Steve Bennett, Portsmouth, GB;
Assignee:
Thorn Security Limited, Walthamstow, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B 29/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method is disclosed for testing the functionality of a sensor () of a fire detector during operation thereof. The method comprises applying a current-limited test signal to the sensor (), the test signal being such that the impedance of the sensor is such as to absorb the current-limited test signal when the sensor is operating normally; and applying the output of the sensor to a test signal detector (). The arrangement is such that the test signal passes the output terminal of the sensor () only when the sensor is not operating normally.